@c Copyright (c) 2008, 2009, 2010 Free Software Foundation, Inc. @c Free Software Foundation, Inc. @c This is part of the GCC manual. @c For copying conditions, see the file gcc.texi. @node GIMPLE @chapter GIMPLE @cindex GIMPLE GIMPLE is a three-address representation derived from GENERIC by breaking down GENERIC expressions into tuples of no more than 3 operands (with some exceptions like function calls). GIMPLE was heavily influenced by the SIMPLE IL used by the McCAT compiler project at McGill University, though we have made some different choices. For one thing, SIMPLE doesn't support @code{goto}. Temporaries are introduced to hold intermediate values needed to compute complex expressions. Additionally, all the control structures used in GENERIC are lowered into conditional jumps, lexical scopes are removed and exception regions are converted into an on the side exception region tree. The compiler pass which converts GENERIC into GIMPLE is referred to as the @samp{gimplifier}. The gimplifier works recursively, generating GIMPLE tuples out of the original GENERIC expressions. One of the early implementation strategies used for the GIMPLE representation was to use the same internal data structures used by front ends to represent parse trees. This simplified implementation because we could leverage existing functionality and interfaces. However, GIMPLE is a much more restrictive representation than abstract syntax trees (AST), therefore it does not require the full structural complexity provided by the main tree data structure. The GENERIC representation of a function is stored in the @code{DECL_SAVED_TREE} field of the associated @code{FUNCTION_DECL} tree node. It is converted to GIMPLE by a call to @code{gimplify_function_tree}. If a front end wants to include language-specific tree codes in the tree representation which it provides to the back end, it must provide a definition of @code{LANG_HOOKS_GIMPLIFY_EXPR} which knows how to convert the front end trees to GIMPLE@. Usually such a hook will involve much of the same code for expanding front end trees to RTL@. This function can return fully lowered GIMPLE, or it can return GENERIC trees and let the main gimplifier lower them the rest of the way; this is often simpler. GIMPLE that is not fully lowered is known as ``High GIMPLE'' and consists of the IL before the pass @code{pass_lower_cf}. High GIMPLE contains some container statements like lexical scopes (represented by @code{GIMPLE_BIND}) and nested expressions (e.g., @code{GIMPLE_TRY}), while ``Low GIMPLE'' exposes all of the implicit jumps for control and exception expressions directly in the IL and EH region trees. The C and C++ front ends currently convert directly from front end trees to GIMPLE, and hand that off to the back end rather than first converting to GENERIC@. Their gimplifier hooks know about all the @code{_STMT} nodes and how to convert them to GENERIC forms. There was some work done on a genericization pass which would run first, but the existence of @code{STMT_EXPR} meant that in order to convert all of the C statements into GENERIC equivalents would involve walking the entire tree anyway, so it was simpler to lower all the way. This might change in the future if someone writes an optimization pass which would work better with higher-level trees, but currently the optimizers all expect GIMPLE@. You can request to dump a C-like representation of the GIMPLE form with the flag @option{-fdump-tree-gimple}. @menu * Tuple representation:: * GIMPLE instruction set:: * GIMPLE Exception Handling:: * Temporaries:: * Operands:: * Manipulating GIMPLE statements:: * Tuple specific accessors:: * GIMPLE sequences:: * Sequence iterators:: * Adding a new GIMPLE statement code:: * Statement and operand traversals:: @end menu @node Tuple representation @section Tuple representation @cindex tuples GIMPLE instructions are tuples of variable size divided in two groups: a header describing the instruction and its locations, and a variable length body with all the operands. Tuples are organized into a hierarchy with 3 main classes of tuples. @subsection @code{gimple_statement_base} (gsbase) @cindex gimple_statement_base This is the root of the hierarchy, it holds basic information needed by most GIMPLE statements. There are some fields that may not be relevant to every GIMPLE statement, but those were moved into the base structure to take advantage of holes left by other fields (thus making the structure more compact). The structure takes 4 words (32 bytes) on 64 bit hosts: @multitable {@code{references_memory_p}} {Size (bits)} @item Field @tab Size (bits) @item @code{code} @tab 8 @item @code{subcode} @tab 16 @item @code{no_warning} @tab 1 @item @code{visited} @tab 1 @item @code{nontemporal_move} @tab 1 @item @code{plf} @tab 2 @item @code{modified} @tab 1 @item @code{has_volatile_ops} @tab 1 @item @code{references_memory_p} @tab 1 @item @code{uid} @tab 32 @item @code{location} @tab 32 @item @code{num_ops} @tab 32 @item @code{bb} @tab 64 @item @code{block} @tab 63 @item Total size @tab 32 bytes @end multitable @itemize @bullet @item @code{code} Main identifier for a GIMPLE instruction. @item @code{subcode} Used to distinguish different variants of the same basic instruction or provide flags applicable to a given code. The @code{subcode} flags field has different uses depending on the code of the instruction, but mostly it distinguishes instructions of the same family. The most prominent use of this field is in assignments, where subcode indicates the operation done on the RHS of the assignment. For example, a = b + c is encoded as @code{GIMPLE_ASSIGN }. @item @code{no_warning} Bitflag to indicate whether a warning has already been issued on this statement. @item @code{visited} General purpose ``visited'' marker. Set and cleared by each pass when needed. @item @code{nontemporal_move} Bitflag used in assignments that represent non-temporal moves. Although this bitflag is only used in assignments, it was moved into the base to take advantage of the bit holes left by the previous fields. @item @code{plf} Pass Local Flags. This 2-bit mask can be used as general purpose markers by any pass. Passes are responsible for clearing and setting these two flags accordingly. @item @code{modified} Bitflag to indicate whether the statement has been modified. Used mainly by the operand scanner to determine when to re-scan a statement for operands. @item @code{has_volatile_ops} Bitflag to indicate whether this statement contains operands that have been marked volatile. @item @code{references_memory_p} Bitflag to indicate whether this statement contains memory references (i.e., its operands are either global variables, or pointer dereferences or anything that must reside in memory). @item @code{uid} This is an unsigned integer used by passes that want to assign IDs to every statement. These IDs must be assigned and used by each pass. @item @code{location} This is a @code{location_t} identifier to specify source code location for this statement. It is inherited from the front end. @item @code{num_ops} Number of operands that this statement has. This specifies the size of the operand vector embedded in the tuple. Only used in some tuples, but it is declared in the base tuple to take advantage of the 32-bit hole left by the previous fields. @item @code{bb} Basic block holding the instruction. @item @code{block} Lexical block holding this statement. Also used for debug information generation. @end itemize @subsection @code{gimple_statement_with_ops} @cindex gimple_statement_with_ops This tuple is actually split in two: @code{gimple_statement_with_ops_base} and @code{gimple_statement_with_ops}. This is needed to accommodate the way the operand vector is allocated. The operand vector is defined to be an array of 1 element. So, to allocate a dynamic number of operands, the memory allocator (@code{gimple_alloc}) simply allocates enough memory to hold the structure itself plus @code{N - 1} operands which run ``off the end'' of the structure. For example, to allocate space for a tuple with 3 operands, @code{gimple_alloc} reserves @code{sizeof (struct gimple_statement_with_ops) + 2 * sizeof (tree)} bytes. On the other hand, several fields in this tuple need to be shared with the @code{gimple_statement_with_memory_ops} tuple. So, these common fields are placed in @code{gimple_statement_with_ops_base} which is then inherited from the other two tuples. @multitable {@code{addresses_taken}} {56 + 8 * @code{num_ops} bytes} @item @code{gsbase} @tab 256 @item @code{addresses_taken} @tab 64 @item @code{def_ops} @tab 64 @item @code{use_ops} @tab 64 @item @code{op} @tab @code{num_ops} * 64 @item Total size @tab 56 + 8 * @code{num_ops} bytes @end multitable @itemize @bullet @item @code{gsbase} Inherited from @code{struct gimple_statement_base}. @item @code{addresses_taken} Bitmap holding the UIDs of all the @code{VAR_DECL}s whose addresses are taken by this statement. For example, a statement of the form @code{p = &b} will have the UID for symbol @code{b} in this set. @item @code{def_ops} Array of pointers into the operand array indicating all the slots that contain a variable written-to by the statement. This array is also used for immediate use chaining. Note that it would be possible to not rely on this array, but the changes required to implement this are pretty invasive. @item @code{use_ops} Similar to @code{def_ops} but for variables read by the statement. @item @code{op} Array of trees with @code{num_ops} slots. @end itemize @subsection @code{gimple_statement_with_memory_ops} This tuple is essentially identical to @code{gimple_statement_with_ops}, except that it contains 4 additional fields to hold vectors related memory stores and loads. Similar to the previous case, the structure is split in two to accommodate for the operand vector (@code{gimple_statement_with_memory_ops_base} and @code{gimple_statement_with_memory_ops}). @multitable {@code{addresses_taken}} {88 + 8 * @code{num_ops} bytes} @item Field @tab Size (bits) @item @code{gsbase} @tab 256 @item @code{addresses_taken} @tab 64 @item @code{def_ops} @tab 64 @item @code{use_ops} @tab 64 @item @code{vdef_ops} @tab 64 @item @code{vuse_ops} @tab 64 @item @code{stores} @tab 64 @item @code{loads} @tab 64 @item @code{op} @tab @code{num_ops} * 64 @item Total size @tab 88 + 8 * @code{num_ops} bytes @end multitable @itemize @bullet @item @code{vdef_ops} Similar to @code{def_ops} but for @code{VDEF} operators. There is one entry per memory symbol written by this statement. This is used to maintain the memory SSA use-def and def-def chains. @item @code{vuse_ops} Similar to @code{use_ops} but for @code{VUSE} operators. There is one entry per memory symbol loaded by this statement. This is used to maintain the memory SSA use-def chains. @item @code{stores} Bitset with all the UIDs for the symbols written-to by the statement. This is different than @code{vdef_ops} in that all the affected symbols are mentioned in this set. If memory partitioning is enabled, the @code{vdef_ops} vector will refer to memory partitions. Furthermore, no SSA information is stored in this set. @item @code{loads} Similar to @code{stores}, but for memory loads. (Note that there is some amount of redundancy here, it should be possible to reduce memory utilization further by removing these sets). @end itemize All the other tuples are defined in terms of these three basic ones. Each tuple will add some fields. The main gimple type is defined to be the union of all these structures (@code{GTY} markers elided for clarity): @smallexample union gimple_statement_d @{ struct gimple_statement_base gsbase; struct gimple_statement_with_ops gsops; struct gimple_statement_with_memory_ops gsmem; struct gimple_statement_omp omp; struct gimple_statement_bind gimple_bind; struct gimple_statement_catch gimple_catch; struct gimple_statement_eh_filter gimple_eh_filter; struct gimple_statement_phi gimple_phi; struct gimple_statement_resx gimple_resx; struct gimple_statement_try gimple_try; struct gimple_statement_wce gimple_wce; struct gimple_statement_asm gimple_asm; struct gimple_statement_omp_critical gimple_omp_critical; struct gimple_statement_omp_for gimple_omp_for; struct gimple_statement_omp_parallel gimple_omp_parallel; struct gimple_statement_omp_task gimple_omp_task; struct gimple_statement_omp_sections gimple_omp_sections; struct gimple_statement_omp_single gimple_omp_single; struct gimple_statement_omp_continue gimple_omp_continue; struct gimple_statement_omp_atomic_load gimple_omp_atomic_load; struct gimple_statement_omp_atomic_store gimple_omp_atomic_store; @}; @end smallexample @node GIMPLE instruction set @section GIMPLE instruction set @cindex GIMPLE instruction set The following table briefly describes the GIMPLE instruction set. @multitable {@code{GIMPLE_OMP_SECTIONS_SWITCH}} {High GIMPLE} {Low GIMPLE} @item Instruction @tab High GIMPLE @tab Low GIMPLE @item @code{GIMPLE_ASM} @tab x @tab x @item @code{GIMPLE_ASSIGN} @tab x @tab x @item @code{GIMPLE_BIND} @tab x @tab @item @code{GIMPLE_CALL} @tab x @tab x @item @code{GIMPLE_CATCH} @tab x @tab @item @code{GIMPLE_COND} @tab x @tab x @item @code{GIMPLE_EH_FILTER} @tab x @tab @item @code{GIMPLE_GOTO} @tab x @tab x @item @code{GIMPLE_LABEL} @tab x @tab x @item @code{GIMPLE_NOP} @tab x @tab x @item @code{GIMPLE_OMP_ATOMIC_LOAD} @tab x @tab x @item @code{GIMPLE_OMP_ATOMIC_STORE} @tab x @tab x @item @code{GIMPLE_OMP_CONTINUE} @tab x @tab x @item @code{GIMPLE_OMP_CRITICAL} @tab x @tab x @item @code{GIMPLE_OMP_FOR} @tab x @tab x @item @code{GIMPLE_OMP_MASTER} @tab x @tab x @item @code{GIMPLE_OMP_ORDERED} @tab x @tab x @item @code{GIMPLE_OMP_PARALLEL} @tab x @tab x @item @code{GIMPLE_OMP_RETURN} @tab x @tab x @item @code{GIMPLE_OMP_SECTION} @tab x @tab x @item @code{GIMPLE_OMP_SECTIONS} @tab x @tab x @item @code{GIMPLE_OMP_SECTIONS_SWITCH} @tab x @tab x @item @code{GIMPLE_OMP_SINGLE} @tab x @tab x @item @code{GIMPLE_PHI} @tab @tab x @item @code{GIMPLE_RESX} @tab @tab x @item @code{GIMPLE_RETURN} @tab x @tab x @item @code{GIMPLE_SWITCH} @tab x @tab x @item @code{GIMPLE_TRY} @tab x @tab @end multitable @node GIMPLE Exception Handling @section Exception Handling @cindex GIMPLE Exception Handling Other exception handling constructs are represented using @code{GIMPLE_TRY_CATCH}. @code{GIMPLE_TRY_CATCH} has two operands. The first operand is a sequence of statements to execute. If executing these statements does not throw an exception, then the second operand is ignored. Otherwise, if an exception is thrown, then the second operand of the @code{GIMPLE_TRY_CATCH} is checked. The second operand may have the following forms: @enumerate @item A sequence of statements to execute. When an exception occurs, these statements are executed, and then the exception is rethrown. @item A sequence of @code{GIMPLE_CATCH} statements. Each @code{GIMPLE_CATCH} has a list of applicable exception types and handler code. If the thrown exception matches one of the caught types, the associated handler code is executed. If the handler code falls off the bottom, execution continues after the original @code{GIMPLE_TRY_CATCH}. @item A @code{GIMPLE_EH_FILTER} statement. This has a list of permitted exception types, and code to handle a match failure. If the thrown exception does not match one of the allowed types, the associated match failure code is executed. If the thrown exception does match, it continues unwinding the stack looking for the next handler. @end enumerate Currently throwing an exception is not directly represented in GIMPLE, since it is implemented by calling a function. At some point in the future we will want to add some way to express that the call will throw an exception of a known type. Just before running the optimizers, the compiler lowers the high-level EH constructs above into a set of @samp{goto}s, magic labels, and EH regions. Continuing to unwind at the end of a cleanup is represented with a @code{GIMPLE_RESX}. @node Temporaries @section Temporaries @cindex Temporaries When gimplification encounters a subexpression that is too complex, it creates a new temporary variable to hold the value of the subexpression, and adds a new statement to initialize it before the current statement. These special temporaries are known as @samp{expression temporaries}, and are allocated using @code{get_formal_tmp_var}. The compiler tries to always evaluate identical expressions into the same temporary, to simplify elimination of redundant calculations. We can only use expression temporaries when we know that it will not be reevaluated before its value is used, and that it will not be otherwise modified@footnote{These restrictions are derived from those in Morgan 4.8.}. Other temporaries can be allocated using @code{get_initialized_tmp_var} or @code{create_tmp_var}. Currently, an expression like @code{a = b + 5} is not reduced any further. We tried converting it to something like @smallexample T1 = b + 5; a = T1; @end smallexample but this bloated the representation for minimal benefit. However, a variable which must live in memory cannot appear in an expression; its value is explicitly loaded into a temporary first. Similarly, storing the value of an expression to a memory variable goes through a temporary. @node Operands @section Operands @cindex Operands In general, expressions in GIMPLE consist of an operation and the appropriate number of simple operands; these operands must either be a GIMPLE rvalue (@code{is_gimple_val}), i.e.@: a constant or a register variable. More complex operands are factored out into temporaries, so that @smallexample a = b + c + d @end smallexample becomes @smallexample T1 = b + c; a = T1 + d; @end smallexample The same rule holds for arguments to a @code{GIMPLE_CALL}. The target of an assignment is usually a variable, but can also be an @code{INDIRECT_REF} or a compound lvalue as described below. @menu * Compound Expressions:: * Compound Lvalues:: * Conditional Expressions:: * Logical Operators:: @end menu @node Compound Expressions @subsection Compound Expressions @cindex Compound Expressions The left-hand side of a C comma expression is simply moved into a separate statement. @node Compound Lvalues @subsection Compound Lvalues @cindex Compound Lvalues Currently compound lvalues involving array and structure field references are not broken down; an expression like @code{a.b[2] = 42} is not reduced any further (though complex array subscripts are). This restriction is a workaround for limitations in later optimizers; if we were to convert this to @smallexample T1 = &a.b; T1[2] = 42; @end smallexample alias analysis would not remember that the reference to @code{T1[2]} came by way of @code{a.b}, so it would think that the assignment could alias another member of @code{a}; this broke @code{struct-alias-1.c}. Future optimizer improvements may make this limitation unnecessary. @node Conditional Expressions @subsection Conditional Expressions @cindex Conditional Expressions A C @code{?:} expression is converted into an @code{if} statement with each branch assigning to the same temporary. So, @smallexample a = b ? c : d; @end smallexample becomes @smallexample if (b == 1) T1 = c; else T1 = d; a = T1; @end smallexample The GIMPLE level if-conversion pass re-introduces @code{?:} expression, if appropriate. It is used to vectorize loops with conditions using vector conditional operations. Note that in GIMPLE, @code{if} statements are represented using @code{GIMPLE_COND}, as described below. @node Logical Operators @subsection Logical Operators @cindex Logical Operators Except when they appear in the condition operand of a @code{GIMPLE_COND}, logical `and' and `or' operators are simplified as follows: @code{a = b && c} becomes @smallexample T1 = (bool)b; if (T1 == true) T1 = (bool)c; a = T1; @end smallexample Note that @code{T1} in this example cannot be an expression temporary, because it has two different assignments. @subsection Manipulating operands All gimple operands are of type @code{tree}. But only certain types of trees are allowed to be used as operand tuples. Basic validation is controlled by the function @code{get_gimple_rhs_class}, which given a tree code, returns an @code{enum} with the following values of type @code{enum gimple_rhs_class} @itemize @bullet @item @code{GIMPLE_INVALID_RHS} The tree cannot be used as a GIMPLE operand. @item @code{GIMPLE_BINARY_RHS} The tree is a valid GIMPLE binary operation. @item @code{GIMPLE_UNARY_RHS} The tree is a valid GIMPLE unary operation. @item @code{GIMPLE_SINGLE_RHS} The tree is a single object, that cannot be split into simpler operands (for instance, @code{SSA_NAME}, @code{VAR_DECL}, @code{COMPONENT_REF}, etc). This operand class also acts as an escape hatch for tree nodes that may be flattened out into the operand vector, but would need more than two slots on the RHS. For instance, a @code{COND_EXPR} expression of the form @code{(a op b) ? x : y} could be flattened out on the operand vector using 4 slots, but it would also require additional processing to distinguish @code{c = a op b} from @code{c = a op b ? x : y}. Something similar occurs with @code{ASSERT_EXPR}. In time, these special case tree expressions should be flattened into the operand vector. @end itemize For tree nodes in the categories @code{GIMPLE_BINARY_RHS} and @code{GIMPLE_UNARY_RHS}, they cannot be stored inside tuples directly. They first need to be flattened and separated into individual components. For instance, given the GENERIC expression @smallexample a = b + c @end smallexample its tree representation is: @smallexample MODIFY_EXPR , PLUS_EXPR , VAR_DECL >> @end smallexample In this case, the GIMPLE form for this statement is logically identical to its GENERIC form but in GIMPLE, the @code{PLUS_EXPR} on the RHS of the assignment is not represented as a tree, instead the two operands are taken out of the @code{PLUS_EXPR} sub-tree and flattened into the GIMPLE tuple as follows: @smallexample GIMPLE_ASSIGN , VAR_DECL , VAR_DECL > @end smallexample @subsection Operand vector allocation The operand vector is stored at the bottom of the three tuple structures that accept operands. This means, that depending on the code of a given statement, its operand vector will be at different offsets from the base of the structure. To access tuple operands use the following accessors @deftypefn {GIMPLE function} unsigned gimple_num_ops (gimple g) Returns the number of operands in statement G. @end deftypefn @deftypefn {GIMPLE function} tree gimple_op (gimple g, unsigned i) Returns operand @code{I} from statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_ops (gimple g) Returns a pointer into the operand vector for statement @code{G}. This is computed using an internal table called @code{gimple_ops_offset_}[]. This table is indexed by the gimple code of @code{G}. When the compiler is built, this table is filled-in using the sizes of the structures used by each statement code defined in gimple.def. Since the operand vector is at the bottom of the structure, for a gimple code @code{C} the offset is computed as sizeof (struct-of @code{C}) - sizeof (tree). This mechanism adds one memory indirection to every access when using @code{gimple_op}(), if this becomes a bottleneck, a pass can choose to memoize the result from @code{gimple_ops}() and use that to access the operands. @end deftypefn @subsection Operand validation When adding a new operand to a gimple statement, the operand will be validated according to what each tuple accepts in its operand vector. These predicates are called by the @code{gimple__set_...()}. Each tuple will use one of the following predicates (Note, this list is not exhaustive): @deftypefn {GIMPLE function} is_gimple_operand (tree t) This is the most permissive of the predicates. It essentially checks whether t has a @code{gimple_rhs_class} of @code{GIMPLE_SINGLE_RHS}. @end deftypefn @deftypefn {GIMPLE function} is_gimple_val (tree t) Returns true if t is a "GIMPLE value", which are all the non-addressable stack variables (variables for which @code{is_gimple_reg} returns true) and constants (expressions for which @code{is_gimple_min_invariant} returns true). @end deftypefn @deftypefn {GIMPLE function} is_gimple_addressable (tree t) Returns true if t is a symbol or memory reference whose address can be taken. @end deftypefn @deftypefn {GIMPLE function} is_gimple_asm_val (tree t) Similar to @code{is_gimple_val} but it also accepts hard registers. @end deftypefn @deftypefn {GIMPLE function} is_gimple_call_addr (tree t) Return true if t is a valid expression to use as the function called by a @code{GIMPLE_CALL}. @end deftypefn @deftypefn {GIMPLE function} is_gimple_constant (tree t) Return true if t is a valid gimple constant. @end deftypefn @deftypefn {GIMPLE function} is_gimple_min_invariant (tree t) Return true if t is a valid minimal invariant. This is different from constants, in that the specific value of t may not be known at compile time, but it is known that it doesn't change (e.g., the address of a function local variable). @end deftypefn @deftypefn {GIMPLE function} is_gimple_min_invariant_address (tree t) Return true if t is an @code{ADDR_EXPR} that does not change once a function is running. @end deftypefn @deftypefn {GIMPLE function} is_gimple_ip_invariant (tree t) Return true if t is an interprocedural invariant. This means that t is a valid invariant in all functions (e.g. it can be an address of a global variable but not of a local one). @end deftypefn @deftypefn {GIMPLE function} is_gimple_ip_invariant_address (tree t) Return true if t is an @code{ADDR_EXPR} that does not change once the program is running (and which is valid in all functions). @end deftypefn @subsection Statement validation @deftypefn {GIMPLE function} is_gimple_assign (gimple g) Return true if the code of g is @code{GIMPLE_ASSIGN}. @end deftypefn @deftypefn {GIMPLE function} is_gimple_call (gimple g) Return true if the code of g is @code{GIMPLE_CALL}. @end deftypefn @deftypefn {GIMPLE function} is_gimple_debug (gimple g) Return true if the code of g is @code{GIMPLE_DEBUG}. @end deftypefn @deftypefn {GIMPLE function} gimple_assign_cast_p (gimple g) Return true if g is a @code{GIMPLE_ASSIGN} that performs a type cast operation. @end deftypefn @deftypefn {GIMPLE function} gimple_debug_bind_p (gimple g) Return true if g is a @code{GIMPLE_DEBUG} that binds the value of an expression to a variable. @end deftypefn @node Manipulating GIMPLE statements @section Manipulating GIMPLE statements @cindex Manipulating GIMPLE statements This section documents all the functions available to handle each of the GIMPLE instructions. @subsection Common accessors The following are common accessors for gimple statements. @deftypefn {GIMPLE function} enum gimple_code gimple_code (gimple g) Return the code for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} basic_block gimple_bb (gimple g) Return the basic block to which statement @code{G} belongs to. @end deftypefn @deftypefn {GIMPLE function} tree gimple_block (gimple g) Return the lexical scope block holding statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_expr_type (gimple stmt) Return the type of the main expression computed by @code{STMT}. Return @code{void_type_node} if @code{STMT} computes nothing. This will only return something meaningful for @code{GIMPLE_ASSIGN}, @code{GIMPLE_COND} and @code{GIMPLE_CALL}. For all other tuple codes, it will return @code{void_type_node}. @end deftypefn @deftypefn {GIMPLE function} enum tree_code gimple_expr_code (gimple stmt) Return the tree code for the expression computed by @code{STMT}. This is only meaningful for @code{GIMPLE_CALL}, @code{GIMPLE_ASSIGN} and @code{GIMPLE_COND}. If @code{STMT} is @code{GIMPLE_CALL}, it will return @code{CALL_EXPR}. For @code{GIMPLE_COND}, it returns the code of the comparison predicate. For @code{GIMPLE_ASSIGN} it returns the code of the operation performed by the @code{RHS} of the assignment. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_block (gimple g, tree block) Set the lexical scope block of @code{G} to @code{BLOCK}. @end deftypefn @deftypefn {GIMPLE function} location_t gimple_locus (gimple g) Return locus information for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_locus (gimple g, location_t locus) Set locus information for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_locus_empty_p (gimple g) Return true if @code{G} does not have locus information. @end deftypefn @deftypefn {GIMPLE function} bool gimple_no_warning_p (gimple stmt) Return true if no warnings should be emitted for statement @code{STMT}. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_visited (gimple stmt, bool visited_p) Set the visited status on statement @code{STMT} to @code{VISITED_P}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_visited_p (gimple stmt) Return the visited status on statement @code{STMT}. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_plf (gimple stmt, enum plf_mask plf, bool val_p) Set pass local flag @code{PLF} on statement @code{STMT} to @code{VAL_P}. @end deftypefn @deftypefn {GIMPLE function} unsigned int gimple_plf (gimple stmt, enum plf_mask plf) Return the value of pass local flag @code{PLF} on statement @code{STMT}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_has_ops (gimple g) Return true if statement @code{G} has register or memory operands. @end deftypefn @deftypefn {GIMPLE function} bool gimple_has_mem_ops (gimple g) Return true if statement @code{G} has memory operands. @end deftypefn @deftypefn {GIMPLE function} unsigned gimple_num_ops (gimple g) Return the number of operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_ops (gimple g) Return the array of operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_op (gimple g, unsigned i) Return operand @code{I} for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_op_ptr (gimple g, unsigned i) Return a pointer to operand @code{I} for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_op (gimple g, unsigned i, tree op) Set operand @code{I} of statement @code{G} to @code{OP}. @end deftypefn @deftypefn {GIMPLE function} bitmap gimple_addresses_taken (gimple stmt) Return the set of symbols that have had their address taken by @code{STMT}. @end deftypefn @deftypefn {GIMPLE function} struct def_optype_d *gimple_def_ops (gimple g) Return the set of @code{DEF} operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_def_ops (gimple g, struct def_optype_d *def) Set @code{DEF} to be the set of @code{DEF} operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} struct use_optype_d *gimple_use_ops (gimple g) Return the set of @code{USE} operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_use_ops (gimple g, struct use_optype_d *use) Set @code{USE} to be the set of @code{USE} operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} struct voptype_d *gimple_vuse_ops (gimple g) Return the set of @code{VUSE} operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_vuse_ops (gimple g, struct voptype_d *ops) Set @code{OPS} to be the set of @code{VUSE} operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} struct voptype_d *gimple_vdef_ops (gimple g) Return the set of @code{VDEF} operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_vdef_ops (gimple g, struct voptype_d *ops) Set @code{OPS} to be the set of @code{VDEF} operands for statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} bitmap gimple_loaded_syms (gimple g) Return the set of symbols loaded by statement @code{G}. Each element of the set is the @code{DECL_UID} of the corresponding symbol. @end deftypefn @deftypefn {GIMPLE function} bitmap gimple_stored_syms (gimple g) Return the set of symbols stored by statement @code{G}. Each element of the set is the @code{DECL_UID} of the corresponding symbol. @end deftypefn @deftypefn {GIMPLE function} bool gimple_modified_p (gimple g) Return true if statement @code{G} has operands and the modified field has been set. @end deftypefn @deftypefn {GIMPLE function} bool gimple_has_volatile_ops (gimple stmt) Return true if statement @code{STMT} contains volatile operands. @end deftypefn @deftypefn {GIMPLE function} void gimple_set_has_volatile_ops (gimple stmt, bool volatilep) Return true if statement @code{STMT} contains volatile operands. @end deftypefn @deftypefn {GIMPLE function} void update_stmt (gimple s) Mark statement @code{S} as modified, and update it. @end deftypefn @deftypefn {GIMPLE function} void update_stmt_if_modified (gimple s) Update statement @code{S} if it has been marked modified. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_copy (gimple stmt) Return a deep copy of statement @code{STMT}. @end deftypefn @node Tuple specific accessors @section Tuple specific accessors @cindex Tuple specific accessors @menu * @code{GIMPLE_ASM}:: * @code{GIMPLE_ASSIGN}:: * @code{GIMPLE_BIND}:: * @code{GIMPLE_CALL}:: * @code{GIMPLE_CATCH}:: * @code{GIMPLE_COND}:: * @code{GIMPLE_EH_FILTER}:: * @code{GIMPLE_LABEL}:: * @code{GIMPLE_NOP}:: * @code{GIMPLE_OMP_ATOMIC_LOAD}:: * @code{GIMPLE_OMP_ATOMIC_STORE}:: * @code{GIMPLE_OMP_CONTINUE}:: * @code{GIMPLE_OMP_CRITICAL}:: * @code{GIMPLE_OMP_FOR}:: * @code{GIMPLE_OMP_MASTER}:: * @code{GIMPLE_OMP_ORDERED}:: * @code{GIMPLE_OMP_PARALLEL}:: * @code{GIMPLE_OMP_RETURN}:: * @code{GIMPLE_OMP_SECTION}:: * @code{GIMPLE_OMP_SECTIONS}:: * @code{GIMPLE_OMP_SINGLE}:: * @code{GIMPLE_PHI}:: * @code{GIMPLE_RESX}:: * @code{GIMPLE_RETURN}:: * @code{GIMPLE_SWITCH}:: * @code{GIMPLE_TRY}:: * @code{GIMPLE_WITH_CLEANUP_EXPR}:: @end menu @node @code{GIMPLE_ASM} @subsection @code{GIMPLE_ASM} @cindex @code{GIMPLE_ASM} @deftypefn {GIMPLE function} gimple gimple_build_asm (const char *string, ninputs, noutputs, nclobbers, ...) Build a @code{GIMPLE_ASM} statement. This statement is used for building in-line assembly constructs. @code{STRING} is the assembly code. @code{NINPUT} is the number of register inputs. @code{NOUTPUT} is the number of register outputs. @code{NCLOBBERS} is the number of clobbered registers. The rest of the arguments trees for each input, output, and clobbered registers. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_build_asm_vec (const char *, VEC(tree,gc) *, VEC(tree,gc) *, VEC(tree,gc) *) Identical to gimple_build_asm, but the arguments are passed in VECs. @end deftypefn @deftypefn {GIMPLE function} gimple_asm_ninputs (gimple g) Return the number of input operands for @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_asm_noutputs (gimple g) Return the number of output operands for @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_asm_nclobbers (gimple g) Return the number of clobber operands for @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_asm_input_op (gimple g, unsigned index) Return input operand @code{INDEX} of @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_asm_set_input_op (gimple g, unsigned index, tree in_op) Set @code{IN_OP} to be input operand @code{INDEX} in @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_asm_output_op (gimple g, unsigned index) Return output operand @code{INDEX} of @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_asm_set_output_op (gimple g, @ unsigned index, tree out_op) Set @code{OUT_OP} to be output operand @code{INDEX} in @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_asm_clobber_op (gimple g, unsigned index) Return clobber operand @code{INDEX} of @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_asm_set_clobber_op (gimple g, unsigned index, tree clobber_op) Set @code{CLOBBER_OP} to be clobber operand @code{INDEX} in @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} const char *gimple_asm_string (gimple g) Return the string representing the assembly instruction in @code{GIMPLE_ASM} @code{G}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_asm_volatile_p (gimple g) Return true if @code{G} is an asm statement marked volatile. @end deftypefn @deftypefn {GIMPLE function} void gimple_asm_set_volatile (gimple g) Mark asm statement @code{G} as volatile. @end deftypefn @deftypefn {GIMPLE function} void gimple_asm_clear_volatile (gimple g) Remove volatile marker from asm statement @code{G}. @end deftypefn @node @code{GIMPLE_ASSIGN} @subsection @code{GIMPLE_ASSIGN} @cindex @code{GIMPLE_ASSIGN} @deftypefn {GIMPLE function} gimple gimple_build_assign (tree lhs, tree rhs) Build a @code{GIMPLE_ASSIGN} statement. The left-hand side is an lvalue passed in lhs. The right-hand side can be either a unary or binary tree expression. The expression tree rhs will be flattened and its operands assigned to the corresponding operand slots in the new statement. This function is useful when you already have a tree expression that you want to convert into a tuple. However, try to avoid building expression trees for the sole purpose of calling this function. If you already have the operands in separate trees, it is better to use @code{gimple_build_assign_with_ops}. @end deftypefn @deftypefn {GIMPLE function} gimple gimplify_assign (tree dst, tree src, gimple_seq *seq_p) Build a new @code{GIMPLE_ASSIGN} tuple and append it to the end of @code{*SEQ_P}. @end deftypefn @code{DST}/@code{SRC} are the destination and source respectively. You can pass ungimplified trees in @code{DST} or @code{SRC}, in which case they will be converted to a gimple operand if necessary. This function returns the newly created @code{GIMPLE_ASSIGN} tuple. @deftypefn {GIMPLE function} gimple gimple_build_assign_with_ops @ (enum tree_code subcode, tree lhs, tree op1, tree op2) This function is similar to @code{gimple_build_assign}, but is used to build a @code{GIMPLE_ASSIGN} statement when the operands of the right-hand side of the assignment are already split into different operands. The left-hand side is an lvalue passed in lhs. Subcode is the @code{tree_code} for the right-hand side of the assignment. Op1 and op2 are the operands. If op2 is null, subcode must be a @code{tree_code} for a unary expression. @end deftypefn @deftypefn {GIMPLE function} enum tree_code gimple_assign_rhs_code (gimple g) Return the code of the expression computed on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} enum gimple_rhs_class gimple_assign_rhs_class (gimple g) Return the gimple rhs class of the code for the expression computed on the rhs of assignment statement @code{G}. This will never return @code{GIMPLE_INVALID_RHS}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_assign_lhs (gimple g) Return the @code{LHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_assign_lhs_ptr (gimple g) Return a pointer to the @code{LHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_assign_rhs1 (gimple g) Return the first operand on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_assign_rhs1_ptr (gimple g) Return the address of the first operand on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_assign_rhs2 (gimple g) Return the second operand on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_assign_rhs2_ptr (gimple g) Return the address of the second operand on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_assign_set_lhs (gimple g, tree lhs) Set @code{LHS} to be the @code{LHS} operand of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_assign_set_rhs1 (gimple g, tree rhs) Set @code{RHS} to be the first operand on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_assign_rhs2 (gimple g) Return the second operand on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_assign_rhs2_ptr (gimple g) Return a pointer to the second operand on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_assign_set_rhs2 (gimple g, tree rhs) Set @code{RHS} to be the second operand on the @code{RHS} of assignment statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_assign_cast_p (gimple s) Return true if @code{S} is a type-cast assignment. @end deftypefn @node @code{GIMPLE_BIND} @subsection @code{GIMPLE_BIND} @cindex @code{GIMPLE_BIND} @deftypefn {GIMPLE function} gimple gimple_build_bind (tree vars, gimple_seq body) Build a @code{GIMPLE_BIND} statement with a list of variables in @code{VARS} and a body of statements in sequence @code{BODY}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_bind_vars (gimple g) Return the variables declared in the @code{GIMPLE_BIND} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_bind_set_vars (gimple g, tree vars) Set @code{VARS} to be the set of variables declared in the @code{GIMPLE_BIND} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_bind_append_vars (gimple g, tree vars) Append @code{VARS} to the set of variables declared in the @code{GIMPLE_BIND} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_bind_body (gimple g) Return the GIMPLE sequence contained in the @code{GIMPLE_BIND} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_bind_set_body (gimple g, gimple_seq seq) Set @code{SEQ} to be sequence contained in the @code{GIMPLE_BIND} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_bind_add_stmt (gimple gs, gimple stmt) Append a statement to the end of a @code{GIMPLE_BIND}'s body. @end deftypefn @deftypefn {GIMPLE function} void gimple_bind_add_seq (gimple gs, gimple_seq seq) Append a sequence of statements to the end of a @code{GIMPLE_BIND}'s body. @end deftypefn @deftypefn {GIMPLE function} tree gimple_bind_block (gimple g) Return the @code{TREE_BLOCK} node associated with @code{GIMPLE_BIND} statement @code{G}. This is analogous to the @code{BIND_EXPR_BLOCK} field in trees. @end deftypefn @deftypefn {GIMPLE function} void gimple_bind_set_block (gimple g, tree block) Set @code{BLOCK} to be the @code{TREE_BLOCK} node associated with @code{GIMPLE_BIND} statement @code{G}. @end deftypefn @node @code{GIMPLE_CALL} @subsection @code{GIMPLE_CALL} @cindex @code{GIMPLE_CALL} @deftypefn {GIMPLE function} gimple gimple_build_call (tree fn, unsigned nargs, ...) Build a @code{GIMPLE_CALL} statement to function @code{FN}. The argument @code{FN} must be either a @code{FUNCTION_DECL} or a gimple call address as determined by @code{is_gimple_call_addr}. @code{NARGS} are the number of arguments. The rest of the arguments follow the argument @code{NARGS}, and must be trees that are valid as rvalues in gimple (i.e., each operand is validated with @code{is_gimple_operand}). @end deftypefn @deftypefn {GIMPLE function} gimple gimple_build_call_from_tree (tree call_expr) Build a @code{GIMPLE_CALL} from a @code{CALL_EXPR} node. The arguments and the function are taken from the expression directly. This routine assumes that @code{call_expr} is already in GIMPLE form. That is, its operands are GIMPLE values and the function call needs no further simplification. All the call flags in @code{call_expr} are copied over to the new @code{GIMPLE_CALL}. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_build_call_vec (tree fn, @code{VEC}(tree, heap) *args) Identical to @code{gimple_build_call} but the arguments are stored in a @code{VEC}(). @end deftypefn @deftypefn {GIMPLE function} tree gimple_call_lhs (gimple g) Return the @code{LHS} of call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_call_lhs_ptr (gimple g) Return a pointer to the @code{LHS} of call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_call_set_lhs (gimple g, tree lhs) Set @code{LHS} to be the @code{LHS} operand of call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_call_fn (gimple g) Return the tree node representing the function called by call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_call_set_fn (gimple g, tree fn) Set @code{FN} to be the function called by call statement @code{G}. This has to be a gimple value specifying the address of the called function. @end deftypefn @deftypefn {GIMPLE function} tree gimple_call_fndecl (gimple g) If a given @code{GIMPLE_CALL}'s callee is a @code{FUNCTION_DECL}, return it. Otherwise return @code{NULL}. This function is analogous to @code{get_callee_fndecl} in @code{GENERIC}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_call_set_fndecl (gimple g, tree fndecl) Set the called function to @code{FNDECL}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_call_return_type (gimple g) Return the type returned by call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_call_chain (gimple g) Return the static chain for call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_call_set_chain (gimple g, tree chain) Set @code{CHAIN} to be the static chain for call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_call_num_args (gimple g) Return the number of arguments used by call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_call_arg (gimple g, unsigned index) Return the argument at position @code{INDEX} for call statement @code{G}. The first argument is 0. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_call_arg_ptr (gimple g, unsigned index) Return a pointer to the argument at position @code{INDEX} for call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_call_set_arg (gimple g, unsigned index, tree arg) Set @code{ARG} to be the argument at position @code{INDEX} for call statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_call_set_tail (gimple s) Mark call statement @code{S} as being a tail call (i.e., a call just before the exit of a function). These calls are candidate for tail call optimization. @end deftypefn @deftypefn {GIMPLE function} bool gimple_call_tail_p (gimple s) Return true if @code{GIMPLE_CALL} @code{S} is marked as a tail call. @end deftypefn @deftypefn {GIMPLE function} void gimple_call_mark_uninlinable (gimple s) Mark @code{GIMPLE_CALL} @code{S} as being uninlinable. @end deftypefn @deftypefn {GIMPLE function} bool gimple_call_cannot_inline_p (gimple s) Return true if @code{GIMPLE_CALL} @code{S} cannot be inlined. @end deftypefn @deftypefn {GIMPLE function} bool gimple_call_noreturn_p (gimple s) Return true if @code{S} is a noreturn call. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_call_copy_skip_args (gimple stmt, bitmap args_to_skip) Build a @code{GIMPLE_CALL} identical to @code{STMT} but skipping the arguments in the positions marked by the set @code{ARGS_TO_SKIP}. @end deftypefn @node @code{GIMPLE_CATCH} @subsection @code{GIMPLE_CATCH} @cindex @code{GIMPLE_CATCH} @deftypefn {GIMPLE function} gimple gimple_build_catch (tree types, gimple_seq handler) Build a @code{GIMPLE_CATCH} statement. @code{TYPES} are the tree types this catch handles. @code{HANDLER} is a sequence of statements with the code for the handler. @end deftypefn @deftypefn {GIMPLE function} tree gimple_catch_types (gimple g) Return the types handled by @code{GIMPLE_CATCH} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_catch_types_ptr (gimple g) Return a pointer to the types handled by @code{GIMPLE_CATCH} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_catch_handler (gimple g) Return the GIMPLE sequence representing the body of the handler of @code{GIMPLE_CATCH} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_catch_set_types (gimple g, tree t) Set @code{T} to be the set of types handled by @code{GIMPLE_CATCH} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_catch_set_handler (gimple g, gimple_seq handler) Set @code{HANDLER} to be the body of @code{GIMPLE_CATCH} @code{G}. @end deftypefn @node @code{GIMPLE_COND} @subsection @code{GIMPLE_COND} @cindex @code{GIMPLE_COND} @deftypefn {GIMPLE function} gimple gimple_build_cond (enum tree_code pred_code, tree lhs, tree rhs, tree t_label, tree f_label) Build a @code{GIMPLE_COND} statement. @code{A} @code{GIMPLE_COND} statement compares @code{LHS} and @code{RHS} and if the condition in @code{PRED_CODE} is true, jump to the label in @code{t_label}, otherwise jump to the label in @code{f_label}. @code{PRED_CODE} are relational operator tree codes like @code{EQ_EXPR}, @code{LT_EXPR}, @code{LE_EXPR}, @code{NE_EXPR}, etc. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_build_cond_from_tree (tree cond, tree t_label, tree f_label) Build a @code{GIMPLE_COND} statement from the conditional expression tree @code{COND}. @code{T_LABEL} and @code{F_LABEL} are as in @code{gimple_build_cond}. @end deftypefn @deftypefn {GIMPLE function} enum tree_code gimple_cond_code (gimple g) Return the code of the predicate computed by conditional statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_cond_set_code (gimple g, enum tree_code code) Set @code{CODE} to be the predicate code for the conditional statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_cond_lhs (gimple g) Return the @code{LHS} of the predicate computed by conditional statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_cond_set_lhs (gimple g, tree lhs) Set @code{LHS} to be the @code{LHS} operand of the predicate computed by conditional statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_cond_rhs (gimple g) Return the @code{RHS} operand of the predicate computed by conditional @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_cond_set_rhs (gimple g, tree rhs) Set @code{RHS} to be the @code{RHS} operand of the predicate computed by conditional statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_cond_true_label (gimple g) Return the label used by conditional statement @code{G} when its predicate evaluates to true. @end deftypefn @deftypefn {GIMPLE function} void gimple_cond_set_true_label (gimple g, tree label) Set @code{LABEL} to be the label used by conditional statement @code{G} when its predicate evaluates to true. @end deftypefn @deftypefn {GIMPLE function} void gimple_cond_set_false_label (gimple g, tree label) Set @code{LABEL} to be the label used by conditional statement @code{G} when its predicate evaluates to false. @end deftypefn @deftypefn {GIMPLE function} tree gimple_cond_false_label (gimple g) Return the label used by conditional statement @code{G} when its predicate evaluates to false. @end deftypefn @deftypefn {GIMPLE function} void gimple_cond_make_false (gimple g) Set the conditional @code{COND_STMT} to be of the form 'if (1 == 0)'. @end deftypefn @deftypefn {GIMPLE function} void gimple_cond_make_true (gimple g) Set the conditional @code{COND_STMT} to be of the form 'if (1 == 1)'. @end deftypefn @node @code{GIMPLE_EH_FILTER} @subsection @code{GIMPLE_EH_FILTER} @cindex @code{GIMPLE_EH_FILTER} @deftypefn {GIMPLE function} gimple gimple_build_eh_filter (tree types, gimple_seq failure) Build a @code{GIMPLE_EH_FILTER} statement. @code{TYPES} are the filter's types. @code{FAILURE} is a sequence with the filter's failure action. @end deftypefn @deftypefn {GIMPLE function} tree gimple_eh_filter_types (gimple g) Return the types handled by @code{GIMPLE_EH_FILTER} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_eh_filter_types_ptr (gimple g) Return a pointer to the types handled by @code{GIMPLE_EH_FILTER} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_eh_filter_failure (gimple g) Return the sequence of statement to execute when @code{GIMPLE_EH_FILTER} statement fails. @end deftypefn @deftypefn {GIMPLE function} void gimple_eh_filter_set_types (gimple g, tree types) Set @code{TYPES} to be the set of types handled by @code{GIMPLE_EH_FILTER} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_eh_filter_set_failure (gimple g, gimple_seq failure) Set @code{FAILURE} to be the sequence of statements to execute on failure for @code{GIMPLE_EH_FILTER} @code{G}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_eh_filter_must_not_throw (gimple g) Return the @code{EH_FILTER_MUST_NOT_THROW} flag. @end deftypefn @deftypefn {GIMPLE function} void gimple_eh_filter_set_must_not_throw (gimple g, bool mntp) Set the @code{EH_FILTER_MUST_NOT_THROW} flag. @end deftypefn @node @code{GIMPLE_LABEL} @subsection @code{GIMPLE_LABEL} @cindex @code{GIMPLE_LABEL} @deftypefn {GIMPLE function} gimple gimple_build_label (tree label) Build a @code{GIMPLE_LABEL} statement with corresponding to the tree label, @code{LABEL}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_label_label (gimple g) Return the @code{LABEL_DECL} node used by @code{GIMPLE_LABEL} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_label_set_label (gimple g, tree label) Set @code{LABEL} to be the @code{LABEL_DECL} node used by @code{GIMPLE_LABEL} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_build_goto (tree dest) Build a @code{GIMPLE_GOTO} statement to label @code{DEST}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_goto_dest (gimple g) Return the destination of the unconditional jump @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_goto_set_dest (gimple g, tree dest) Set @code{DEST} to be the destination of the unconditional jump @code{G}. @end deftypefn @node @code{GIMPLE_NOP} @subsection @code{GIMPLE_NOP} @cindex @code{GIMPLE_NOP} @deftypefn {GIMPLE function} gimple gimple_build_nop (void) Build a @code{GIMPLE_NOP} statement. @end deftypefn @deftypefn {GIMPLE function} bool gimple_nop_p (gimple g) Returns @code{TRUE} if statement @code{G} is a @code{GIMPLE_NOP}. @end deftypefn @node @code{GIMPLE_OMP_ATOMIC_LOAD} @subsection @code{GIMPLE_OMP_ATOMIC_LOAD} @cindex @code{GIMPLE_OMP_ATOMIC_LOAD} @deftypefn {GIMPLE function} gimple gimple_build_omp_atomic_load (tree lhs, tree rhs) Build a @code{GIMPLE_OMP_ATOMIC_LOAD} statement. @code{LHS} is the left-hand side of the assignment. @code{RHS} is the right-hand side of the assignment. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_atomic_load_set_lhs (gimple g, tree lhs) Set the @code{LHS} of an atomic load. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_atomic_load_lhs (gimple g) Get the @code{LHS} of an atomic load. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_atomic_load_set_rhs (gimple g, tree rhs) Set the @code{RHS} of an atomic set. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_atomic_load_rhs (gimple g) Get the @code{RHS} of an atomic set. @end deftypefn @node @code{GIMPLE_OMP_ATOMIC_STORE} @subsection @code{GIMPLE_OMP_ATOMIC_STORE} @cindex @code{GIMPLE_OMP_ATOMIC_STORE} @deftypefn {GIMPLE function} gimple gimple_build_omp_atomic_store (tree val) Build a @code{GIMPLE_OMP_ATOMIC_STORE} statement. @code{VAL} is the value to be stored. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_atomic_store_set_val (gimple g, tree val) Set the value being stored in an atomic store. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_atomic_store_val (gimple g) Return the value being stored in an atomic store. @end deftypefn @node @code{GIMPLE_OMP_CONTINUE} @subsection @code{GIMPLE_OMP_CONTINUE} @cindex @code{GIMPLE_OMP_CONTINUE} @deftypefn {GIMPLE function} gimple gimple_build_omp_continue (tree control_def, tree control_use) Build a @code{GIMPLE_OMP_CONTINUE} statement. @code{CONTROL_DEF} is the definition of the control variable. @code{CONTROL_USE} is the use of the control variable. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_continue_control_def (gimple s) Return the definition of the control variable on a @code{GIMPLE_OMP_CONTINUE} in @code{S}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_continue_control_def_ptr (gimple s) Same as above, but return the pointer. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_continue_set_control_def (gimple s) Set the control variable definition for a @code{GIMPLE_OMP_CONTINUE} statement in @code{S}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_continue_control_use (gimple s) Return the use of the control variable on a @code{GIMPLE_OMP_CONTINUE} in @code{S}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_continue_control_use_ptr (gimple s) Same as above, but return the pointer. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_continue_set_control_use (gimple s) Set the control variable use for a @code{GIMPLE_OMP_CONTINUE} statement in @code{S}. @end deftypefn @node @code{GIMPLE_OMP_CRITICAL} @subsection @code{GIMPLE_OMP_CRITICAL} @cindex @code{GIMPLE_OMP_CRITICAL} @deftypefn {GIMPLE function} gimple gimple_build_omp_critical (gimple_seq body, tree name) Build a @code{GIMPLE_OMP_CRITICAL} statement. @code{BODY} is the sequence of statements for which only one thread can execute. @code{NAME} is an optional identifier for this critical block. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_critical_name (gimple g) Return the name associated with @code{OMP_CRITICAL} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_critical_name_ptr (gimple g) Return a pointer to the name associated with @code{OMP} critical statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_critical_set_name (gimple g, tree name) Set @code{NAME} to be the name associated with @code{OMP} critical statement @code{G}. @end deftypefn @node @code{GIMPLE_OMP_FOR} @subsection @code{GIMPLE_OMP_FOR} @cindex @code{GIMPLE_OMP_FOR} @deftypefn {GIMPLE function} gimple gimple_build_omp_for (gimple_seq body, @ tree clauses, tree index, tree initial, tree final, tree incr, @ gimple_seq pre_body, enum tree_code omp_for_cond) Build a @code{GIMPLE_OMP_FOR} statement. @code{BODY} is sequence of statements inside the for loop. @code{CLAUSES}, are any of the @code{OMP} loop construct's clauses: private, firstprivate, lastprivate, reductions, ordered, schedule, and nowait. @code{PRE_BODY} is the sequence of statements that are loop invariant. @code{INDEX} is the index variable. @code{INITIAL} is the initial value of @code{INDEX}. @code{FINAL} is final value of @code{INDEX}. OMP_FOR_COND is the predicate used to compare @code{INDEX} and @code{FINAL}. @code{INCR} is the increment expression. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_for_clauses (gimple g) Return the clauses associated with @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_for_clauses_ptr (gimple g) Return a pointer to the @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_for_set_clauses (gimple g, tree clauses) Set @code{CLAUSES} to be the list of clauses associated with @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_for_index (gimple g) Return the index variable for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_for_index_ptr (gimple g) Return a pointer to the index variable for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_for_set_index (gimple g, tree index) Set @code{INDEX} to be the index variable for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_for_initial (gimple g) Return the initial value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_for_initial_ptr (gimple g) Return a pointer to the initial value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_for_set_initial (gimple g, tree initial) Set @code{INITIAL} to be the initial value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_for_final (gimple g) Return the final value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_for_final_ptr (gimple g) turn a pointer to the final value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_for_set_final (gimple g, tree final) Set @code{FINAL} to be the final value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_for_incr (gimple g) Return the increment value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_for_incr_ptr (gimple g) Return a pointer to the increment value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_for_set_incr (gimple g, tree incr) Set @code{INCR} to be the increment value for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_omp_for_pre_body (gimple g) Return the sequence of statements to execute before the @code{OMP_FOR} statement @code{G} starts. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_for_set_pre_body (gimple g, gimple_seq pre_body) Set @code{PRE_BODY} to be the sequence of statements to execute before the @code{OMP_FOR} statement @code{G} starts. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_for_set_cond (gimple g, enum tree_code cond) Set @code{COND} to be the condition code for @code{OMP_FOR} @code{G}. @end deftypefn @deftypefn {GIMPLE function} enum tree_code gimple_omp_for_cond (gimple g) Return the condition code associated with @code{OMP_FOR} @code{G}. @end deftypefn @node @code{GIMPLE_OMP_MASTER} @subsection @code{GIMPLE_OMP_MASTER} @cindex @code{GIMPLE_OMP_MASTER} @deftypefn {GIMPLE function} gimple gimple_build_omp_master (gimple_seq body) Build a @code{GIMPLE_OMP_MASTER} statement. @code{BODY} is the sequence of statements to be executed by just the master. @end deftypefn @node @code{GIMPLE_OMP_ORDERED} @subsection @code{GIMPLE_OMP_ORDERED} @cindex @code{GIMPLE_OMP_ORDERED} @deftypefn {GIMPLE function} gimple gimple_build_omp_ordered (gimple_seq body) Build a @code{GIMPLE_OMP_ORDERED} statement. @end deftypefn @code{BODY} is the sequence of statements inside a loop that will executed in sequence. @node @code{GIMPLE_OMP_PARALLEL} @subsection @code{GIMPLE_OMP_PARALLEL} @cindex @code{GIMPLE_OMP_PARALLEL} @deftypefn {GIMPLE function} gimple gimple_build_omp_parallel (gimple_seq body, tree clauses, tree child_fn, tree data_arg) Build a @code{GIMPLE_OMP_PARALLEL} statement. @end deftypefn @code{BODY} is sequence of statements which are executed in parallel. @code{CLAUSES}, are the @code{OMP} parallel construct's clauses. @code{CHILD_FN} is the function created for the parallel threads to execute. @code{DATA_ARG} are the shared data argument(s). @deftypefn {GIMPLE function} bool gimple_omp_parallel_combined_p (gimple g) Return true if @code{OMP} parallel statement @code{G} has the @code{GF_OMP_PARALLEL_COMBINED} flag set. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_parallel_set_combined_p (gimple g) Set the @code{GF_OMP_PARALLEL_COMBINED} field in @code{OMP} parallel statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_omp_body (gimple g) Return the body for the @code{OMP} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_set_body (gimple g, gimple_seq body) Set @code{BODY} to be the body for the @code{OMP} statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_parallel_clauses (gimple g) Return the clauses associated with @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_parallel_clauses_ptr (gimple g) Return a pointer to the clauses associated with @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_parallel_set_clauses (gimple g, tree clauses) Set @code{CLAUSES} to be the list of clauses associated with @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_parallel_child_fn (gimple g) Return the child function used to hold the body of @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_parallel_child_fn_ptr (gimple g) Return a pointer to the child function used to hold the body of @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_parallel_set_child_fn (gimple g, tree child_fn) Set @code{CHILD_FN} to be the child function for @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_parallel_data_arg (gimple g) Return the artificial argument used to send variables and values from the parent to the children threads in @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_parallel_data_arg_ptr (gimple g) Return a pointer to the data argument for @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_parallel_set_data_arg (gimple g, tree data_arg) Set @code{DATA_ARG} to be the data argument for @code{OMP_PARALLEL} @code{G}. @end deftypefn @deftypefn {GIMPLE function} bool is_gimple_omp (gimple stmt) Returns true when the gimple statement @code{STMT} is any of the OpenMP types. @end deftypefn @node @code{GIMPLE_OMP_RETURN} @subsection @code{GIMPLE_OMP_RETURN} @cindex @code{GIMPLE_OMP_RETURN} @deftypefn {GIMPLE function} gimple gimple_build_omp_return (bool wait_p) Build a @code{GIMPLE_OMP_RETURN} statement. @code{WAIT_P} is true if this is a non-waiting return. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_return_set_nowait (gimple s) Set the nowait flag on @code{GIMPLE_OMP_RETURN} statement @code{S}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_omp_return_nowait_p (gimple g) Return true if @code{OMP} return statement @code{G} has the @code{GF_OMP_RETURN_NOWAIT} flag set. @end deftypefn @node @code{GIMPLE_OMP_SECTION} @subsection @code{GIMPLE_OMP_SECTION} @cindex @code{GIMPLE_OMP_SECTION} @deftypefn {GIMPLE function} gimple gimple_build_omp_section (gimple_seq body) Build a @code{GIMPLE_OMP_SECTION} statement for a sections statement. @end deftypefn @code{BODY} is the sequence of statements in the section. @deftypefn {GIMPLE function} bool gimple_omp_section_last_p (gimple g) Return true if @code{OMP} section statement @code{G} has the @code{GF_OMP_SECTION_LAST} flag set. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_section_set_last (gimple g) Set the @code{GF_OMP_SECTION_LAST} flag on @code{G}. @end deftypefn @node @code{GIMPLE_OMP_SECTIONS} @subsection @code{GIMPLE_OMP_SECTIONS} @cindex @code{GIMPLE_OMP_SECTIONS} @deftypefn {GIMPLE function} gimple gimple_build_omp_sections (gimple_seq body, tree clauses) Build a @code{GIMPLE_OMP_SECTIONS} statement. @code{BODY} is a sequence of section statements. @code{CLAUSES} are any of the @code{OMP} sections construct's clauses: private, firstprivate, lastprivate, reduction, and nowait. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_build_omp_sections_switch (void) Build a @code{GIMPLE_OMP_SECTIONS_SWITCH} statement. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_sections_control (gimple g) Return the control variable associated with the @code{GIMPLE_OMP_SECTIONS} in @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_sections_control_ptr (gimple g) Return a pointer to the clauses associated with the @code{GIMPLE_OMP_SECTIONS} in @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_sections_set_control (gimple g, tree control) Set @code{CONTROL} to be the set of clauses associated with the @code{GIMPLE_OMP_SECTIONS} in @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_sections_clauses (gimple g) Return the clauses associated with @code{OMP_SECTIONS} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_sections_clauses_ptr (gimple g) Return a pointer to the clauses associated with @code{OMP_SECTIONS} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_sections_set_clauses (gimple g, tree clauses) Set @code{CLAUSES} to be the set of clauses associated with @code{OMP_SECTIONS} @code{G}. @end deftypefn @node @code{GIMPLE_OMP_SINGLE} @subsection @code{GIMPLE_OMP_SINGLE} @cindex @code{GIMPLE_OMP_SINGLE} @deftypefn {GIMPLE function} gimple gimple_build_omp_single (gimple_seq body, tree clauses) Build a @code{GIMPLE_OMP_SINGLE} statement. @code{BODY} is the sequence of statements that will be executed once. @code{CLAUSES} are any of the @code{OMP} single construct's clauses: private, firstprivate, copyprivate, nowait. @end deftypefn @deftypefn {GIMPLE function} tree gimple_omp_single_clauses (gimple g) Return the clauses associated with @code{OMP_SINGLE} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_omp_single_clauses_ptr (gimple g) Return a pointer to the clauses associated with @code{OMP_SINGLE} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_omp_single_set_clauses (gimple g, tree clauses) Set @code{CLAUSES} to be the clauses associated with @code{OMP_SINGLE} @code{G}. @end deftypefn @node @code{GIMPLE_PHI} @subsection @code{GIMPLE_PHI} @cindex @code{GIMPLE_PHI} @deftypefn {GIMPLE function} gimple make_phi_node (tree var, int len) Build a @code{PHI} node with len argument slots for variable var. @end deftypefn @deftypefn {GIMPLE function} unsigned gimple_phi_capacity (gimple g) Return the maximum number of arguments supported by @code{GIMPLE_PHI} @code{G}. @end deftypefn @deftypefn {GIMPLE function} unsigned gimple_phi_num_args (gimple g) Return the number of arguments in @code{GIMPLE_PHI} @code{G}. This must always be exactly the number of incoming edges for the basic block holding @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_phi_result (gimple g) Return the @code{SSA} name created by @code{GIMPLE_PHI} @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree *gimple_phi_result_ptr (gimple g) Return a pointer to the @code{SSA} name created by @code{GIMPLE_PHI} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_phi_set_result (gimple g, tree result) Set @code{RESULT} to be the @code{SSA} name created by @code{GIMPLE_PHI} @code{G}. @end deftypefn @deftypefn {GIMPLE function} struct phi_arg_d *gimple_phi_arg (gimple g, index) Return the @code{PHI} argument corresponding to incoming edge @code{INDEX} for @code{GIMPLE_PHI} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_phi_set_arg (gimple g, index, struct phi_arg_d * phiarg) Set @code{PHIARG} to be the argument corresponding to incoming edge @code{INDEX} for @code{GIMPLE_PHI} @code{G}. @end deftypefn @node @code{GIMPLE_RESX} @subsection @code{GIMPLE_RESX} @cindex @code{GIMPLE_RESX} @deftypefn {GIMPLE function} gimple gimple_build_resx (int region) Build a @code{GIMPLE_RESX} statement which is a statement. This statement is a placeholder for _Unwind_Resume before we know if a function call or a branch is needed. @code{REGION} is the exception region from which control is flowing. @end deftypefn @deftypefn {GIMPLE function} int gimple_resx_region (gimple g) Return the region number for @code{GIMPLE_RESX} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_resx_set_region (gimple g, int region) Set @code{REGION} to be the region number for @code{GIMPLE_RESX} @code{G}. @end deftypefn @node @code{GIMPLE_RETURN} @subsection @code{GIMPLE_RETURN} @cindex @code{GIMPLE_RETURN} @deftypefn {GIMPLE function} gimple gimple_build_return (tree retval) Build a @code{GIMPLE_RETURN} statement whose return value is retval. @end deftypefn @deftypefn {GIMPLE function} tree gimple_return_retval (gimple g) Return the return value for @code{GIMPLE_RETURN} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_return_set_retval (gimple g, tree retval) Set @code{RETVAL} to be the return value for @code{GIMPLE_RETURN} @code{G}. @end deftypefn @node @code{GIMPLE_SWITCH} @subsection @code{GIMPLE_SWITCH} @cindex @code{GIMPLE_SWITCH} @deftypefn {GIMPLE function} gimple gimple_build_switch ( nlabels, tree index, tree default_label, ...) Build a @code{GIMPLE_SWITCH} statement. @code{NLABELS} are the number of labels excluding the default label. The default label is passed in @code{DEFAULT_LABEL}. The rest of the arguments are trees representing the labels. Each label is a tree of code @code{CASE_LABEL_EXPR}. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_build_switch_vec (tree index, tree default_label, @code{VEC}(tree,heap) *args) This function is an alternate way of building @code{GIMPLE_SWITCH} statements. @code{INDEX} and @code{DEFAULT_LABEL} are as in gimple_build_switch. @code{ARGS} is a vector of @code{CASE_LABEL_EXPR} trees that contain the labels. @end deftypefn @deftypefn {GIMPLE function} unsigned gimple_switch_num_labels (gimple g) Return the number of labels associated with the switch statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_switch_set_num_labels (gimple g, unsigned nlabels) Set @code{NLABELS} to be the number of labels for the switch statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_switch_index (gimple g) Return the index variable used by the switch statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_switch_set_index (gimple g, tree index) Set @code{INDEX} to be the index variable for switch statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} tree gimple_switch_label (gimple g, unsigned index) Return the label numbered @code{INDEX}. The default label is 0, followed by any labels in a switch statement. @end deftypefn @deftypefn {GIMPLE function} void gimple_switch_set_label (gimple g, unsigned index, tree label) Set the label number @code{INDEX} to @code{LABEL}. 0 is always the default label. @end deftypefn @deftypefn {GIMPLE function} tree gimple_switch_default_label (gimple g) Return the default label for a switch statement. @end deftypefn @deftypefn {GIMPLE function} void gimple_switch_set_default_label (gimple g, tree label) Set the default label for a switch statement. @end deftypefn @node @code{GIMPLE_TRY} @subsection @code{GIMPLE_TRY} @cindex @code{GIMPLE_TRY} @deftypefn {GIMPLE function} gimple gimple_build_try (gimple_seq eval, gimple_seq cleanup, unsigned int kind) Build a @code{GIMPLE_TRY} statement. @code{EVAL} is a sequence with the expression to evaluate. @code{CLEANUP} is a sequence of statements to run at clean-up time. @code{KIND} is the enumeration value @code{GIMPLE_TRY_CATCH} if this statement denotes a try/catch construct or @code{GIMPLE_TRY_FINALLY} if this statement denotes a try/finally construct. @end deftypefn @deftypefn {GIMPLE function} enum gimple_try_flags gimple_try_kind (gimple g) Return the kind of try block represented by @code{GIMPLE_TRY} @code{G}. This is either @code{GIMPLE_TRY_CATCH} or @code{GIMPLE_TRY_FINALLY}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_try_catch_is_cleanup (gimple g) Return the @code{GIMPLE_TRY_CATCH_IS_CLEANUP} flag. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_try_eval (gimple g) Return the sequence of statements used as the body for @code{GIMPLE_TRY} @code{G}. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_try_cleanup (gimple g) Return the sequence of statements used as the cleanup body for @code{GIMPLE_TRY} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_try_set_catch_is_cleanup (gimple g, bool catch_is_cleanup) Set the @code{GIMPLE_TRY_CATCH_IS_CLEANUP} flag. @end deftypefn @deftypefn {GIMPLE function} void gimple_try_set_eval (gimple g, gimple_seq eval) Set @code{EVAL} to be the sequence of statements to use as the body for @code{GIMPLE_TRY} @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_try_set_cleanup (gimple g, gimple_seq cleanup) Set @code{CLEANUP} to be the sequence of statements to use as the cleanup body for @code{GIMPLE_TRY} @code{G}. @end deftypefn @node @code{GIMPLE_WITH_CLEANUP_EXPR} @subsection @code{GIMPLE_WITH_CLEANUP_EXPR} @cindex @code{GIMPLE_WITH_CLEANUP_EXPR} @deftypefn {GIMPLE function} gimple gimple_build_wce (gimple_seq cleanup) Build a @code{GIMPLE_WITH_CLEANUP_EXPR} statement. @code{CLEANUP} is the clean-up expression. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_wce_cleanup (gimple g) Return the cleanup sequence for cleanup statement @code{G}. @end deftypefn @deftypefn {GIMPLE function} void gimple_wce_set_cleanup (gimple g, gimple_seq cleanup) Set @code{CLEANUP} to be the cleanup sequence for @code{G}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_wce_cleanup_eh_only (gimple g) Return the @code{CLEANUP_EH_ONLY} flag for a @code{WCE} tuple. @end deftypefn @deftypefn {GIMPLE function} void gimple_wce_set_cleanup_eh_only (gimple g, bool eh_only_p) Set the @code{CLEANUP_EH_ONLY} flag for a @code{WCE} tuple. @end deftypefn @node GIMPLE sequences @section GIMPLE sequences @cindex GIMPLE sequences GIMPLE sequences are the tuple equivalent of @code{STATEMENT_LIST}'s used in @code{GENERIC}. They are used to chain statements together, and when used in conjunction with sequence iterators, provide a framework for iterating through statements. GIMPLE sequences are of type struct @code{gimple_sequence}, but are more commonly passed by reference to functions dealing with sequences. The type for a sequence pointer is @code{gimple_seq} which is the same as struct @code{gimple_sequence} *. When declaring a local sequence, you can define a local variable of type struct @code{gimple_sequence}. When declaring a sequence allocated on the garbage collected heap, use the function @code{gimple_seq_alloc} documented below. There are convenience functions for iterating through sequences in the section entitled Sequence Iterators. Below is a list of functions to manipulate and query sequences. @deftypefn {GIMPLE function} void gimple_seq_add_stmt (gimple_seq *seq, gimple g) Link a gimple statement to the end of the sequence *@code{SEQ} if @code{G} is not @code{NULL}. If *@code{SEQ} is @code{NULL}, allocate a sequence before linking. @end deftypefn @deftypefn {GIMPLE function} void gimple_seq_add_seq (gimple_seq *dest, gimple_seq src) Append sequence @code{SRC} to the end of sequence *@code{DEST} if @code{SRC} is not @code{NULL}. If *@code{DEST} is @code{NULL}, allocate a new sequence before appending. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_seq_deep_copy (gimple_seq src) Perform a deep copy of sequence @code{SRC} and return the result. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_seq_reverse (gimple_seq seq) Reverse the order of the statements in the sequence @code{SEQ}. Return @code{SEQ}. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_seq_first (gimple_seq s) Return the first statement in sequence @code{S}. @end deftypefn @deftypefn {GIMPLE function} gimple gimple_seq_last (gimple_seq s) Return the last statement in sequence @code{S}. @end deftypefn @deftypefn {GIMPLE function} void gimple_seq_set_last (gimple_seq s, gimple last) Set the last statement in sequence @code{S} to the statement in @code{LAST}. @end deftypefn @deftypefn {GIMPLE function} void gimple_seq_set_first (gimple_seq s, gimple first) Set the first statement in sequence @code{S} to the statement in @code{FIRST}. @end deftypefn @deftypefn {GIMPLE function} void gimple_seq_init (gimple_seq s) Initialize sequence @code{S} to an empty sequence. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gimple_seq_alloc (void) Allocate a new sequence in the garbage collected store and return it. @end deftypefn @deftypefn {GIMPLE function} void gimple_seq_copy (gimple_seq dest, gimple_seq src) Copy the sequence @code{SRC} into the sequence @code{DEST}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_seq_empty_p (gimple_seq s) Return true if the sequence @code{S} is empty. @end deftypefn @deftypefn {GIMPLE function} gimple_seq bb_seq (basic_block bb) Returns the sequence of statements in @code{BB}. @end deftypefn @deftypefn {GIMPLE function} void set_bb_seq (basic_block bb, gimple_seq seq) Sets the sequence of statements in @code{BB} to @code{SEQ}. @end deftypefn @deftypefn {GIMPLE function} bool gimple_seq_singleton_p (gimple_seq seq) Determine whether @code{SEQ} contains exactly one statement. @end deftypefn @node Sequence iterators @section Sequence iterators @cindex Sequence iterators Sequence iterators are convenience constructs for iterating through statements in a sequence. Given a sequence @code{SEQ}, here is a typical use of gimple sequence iterators: @smallexample gimple_stmt_iterator gsi; for (gsi = gsi_start (seq); !gsi_end_p (gsi); gsi_next (&gsi)) @{ gimple g = gsi_stmt (gsi); /* Do something with gimple statement @code{G}. */ @} @end smallexample Backward iterations are possible: @smallexample for (gsi = gsi_last (seq); !gsi_end_p (gsi); gsi_prev (&gsi)) @end smallexample Forward and backward iterations on basic blocks are possible with @code{gsi_start_bb} and @code{gsi_last_bb}. In the documentation below we sometimes refer to enum @code{gsi_iterator_update}. The valid options for this enumeration are: @itemize @bullet @item @code{GSI_NEW_STMT} Only valid when a single statement is added. Move the iterator to it. @item @code{GSI_SAME_STMT} Leave the iterator at the same statement. @item @code{GSI_CONTINUE_LINKING} Move iterator to whatever position is suitable for linking other statements in the same direction. @end itemize Below is a list of the functions used to manipulate and use statement iterators. @deftypefn {GIMPLE function} gimple_stmt_iterator gsi_start (gimple_seq seq) Return a new iterator pointing to the sequence @code{SEQ}'s first statement. If @code{SEQ} is empty, the iterator's basic block is @code{NULL}. Use @code{gsi_start_bb} instead when the iterator needs to always have the correct basic block set. @end deftypefn @deftypefn {GIMPLE function} gimple_stmt_iterator gsi_start_bb (basic_block bb) Return a new iterator pointing to the first statement in basic block @code{BB}. @end deftypefn @deftypefn {GIMPLE function} gimple_stmt_iterator gsi_last (gimple_seq seq) Return a new iterator initially pointing to the last statement of sequence @code{SEQ}. If @code{SEQ} is empty, the iterator's basic block is @code{NULL}. Use @code{gsi_last_bb} instead when the iterator needs to always have the correct basic block set. @end deftypefn @deftypefn {GIMPLE function} gimple_stmt_iterator gsi_last_bb (basic_block bb) Return a new iterator pointing to the last statement in basic block @code{BB}. @end deftypefn @deftypefn {GIMPLE function} bool gsi_end_p (gimple_stmt_iterator i) Return @code{TRUE} if at the end of @code{I}. @end deftypefn @deftypefn {GIMPLE function} bool gsi_one_before_end_p (gimple_stmt_iterator i) Return @code{TRUE} if we're one statement before the end of @code{I}. @end deftypefn @deftypefn {GIMPLE function} void gsi_next (gimple_stmt_iterator *i) Advance the iterator to the next gimple statement. @end deftypefn @deftypefn {GIMPLE function} void gsi_prev (gimple_stmt_iterator *i) Advance the iterator to the previous gimple statement. @end deftypefn @deftypefn {GIMPLE function} gimple gsi_stmt (gimple_stmt_iterator i) Return the current stmt. @end deftypefn @deftypefn {GIMPLE function} gimple_stmt_iterator gsi_after_labels (basic_block bb) Return a block statement iterator that points to the first non-label statement in block @code{BB}. @end deftypefn @deftypefn {GIMPLE function} gimple *gsi_stmt_ptr (gimple_stmt_iterator *i) Return a pointer to the current stmt. @end deftypefn @deftypefn {GIMPLE function} basic_block gsi_bb (gimple_stmt_iterator i) Return the basic block associated with this iterator. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gsi_seq (gimple_stmt_iterator i) Return the sequence associated with this iterator. @end deftypefn @deftypefn {GIMPLE function} void gsi_remove (gimple_stmt_iterator *i, bool remove_eh_info) Remove the current stmt from the sequence. The iterator is updated to point to the next statement. When @code{REMOVE_EH_INFO} is true we remove the statement pointed to by iterator @code{I} from the @code{EH} tables. Otherwise we do not modify the @code{EH} tables. Generally, @code{REMOVE_EH_INFO} should be true when the statement is going to be removed from the @code{IL} and not reinserted elsewhere. @end deftypefn @deftypefn {GIMPLE function} void gsi_link_seq_before (gimple_stmt_iterator *i, gimple_seq seq, enum gsi_iterator_update mode) Links the sequence of statements @code{SEQ} before the statement pointed by iterator @code{I}. @code{MODE} indicates what to do with the iterator after insertion (see @code{enum gsi_iterator_update} above). @end deftypefn @deftypefn {GIMPLE function} void gsi_link_before (gimple_stmt_iterator *i, gimple g, enum gsi_iterator_update mode) Links statement @code{G} before the statement pointed-to by iterator @code{I}. Updates iterator @code{I} according to @code{MODE}. @end deftypefn @deftypefn {GIMPLE function} void gsi_link_seq_after (gimple_stmt_iterator *i, gimple_seq seq, enum gsi_iterator_update mode) Links sequence @code{SEQ} after the statement pointed-to by iterator @code{I}. @code{MODE} is as in @code{gsi_insert_after}. @end deftypefn @deftypefn {GIMPLE function} void gsi_link_after (gimple_stmt_iterator *i, gimple g, enum gsi_iterator_update mode) Links statement @code{G} after the statement pointed-to by iterator @code{I}. @code{MODE} is as in @code{gsi_insert_after}. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gsi_split_seq_after (gimple_stmt_iterator i) Move all statements in the sequence after @code{I} to a new sequence. Return this new sequence. @end deftypefn @deftypefn {GIMPLE function} gimple_seq gsi_split_seq_before (gimple_stmt_iterator *i) Move all statements in the sequence before @code{I} to a new sequence. Return this new sequence. @end deftypefn @deftypefn {GIMPLE function} void gsi_replace (gimple_stmt_iterator *i, gimple stmt, bool update_eh_info) Replace the statement pointed-to by @code{I} to @code{STMT}. If @code{UPDATE_EH_INFO} is true, the exception handling information of the original statement is moved to the new statement. @end deftypefn @deftypefn {GIMPLE function} void gsi_insert_before (gimple_stmt_iterator *i, gimple stmt, enum gsi_iterator_update mode) Insert statement @code{STMT} before the statement pointed-to by iterator @code{I}, update @code{STMT}'s basic block and scan it for new operands. @code{MODE} specifies how to update iterator @code{I} after insertion (see enum @code{gsi_iterator_update}). @end deftypefn @deftypefn {GIMPLE function} void gsi_insert_seq_before (gimple_stmt_iterator *i, gimple_seq seq, enum gsi_iterator_update mode) Like @code{gsi_insert_before}, but for all the statements in @code{SEQ}. @end deftypefn @deftypefn {GIMPLE function} void gsi_insert_after (gimple_stmt_iterator *i, gimple stmt, enum gsi_iterator_update mode) Insert statement @code{STMT} after the statement pointed-to by iterator @code{I}, update @code{STMT}'s basic block and scan it for new operands. @code{MODE} specifies how to update iterator @code{I} after insertion (see enum @code{gsi_iterator_update}). @end deftypefn @deftypefn {GIMPLE function} void gsi_insert_seq_after (gimple_stmt_iterator *i, gimple_seq seq, enum gsi_iterator_update mode) Like @code{gsi_insert_after}, but for all the statements in @code{SEQ}. @end deftypefn @deftypefn {GIMPLE function} gimple_stmt_iterator gsi_for_stmt (gimple stmt) Finds iterator for @code{STMT}. @end deftypefn @deftypefn {GIMPLE function} void gsi_move_after (gimple_stmt_iterator *from, gimple_stmt_iterator *to) Move the statement at @code{FROM} so it comes right after the statement at @code{TO}. @end deftypefn @deftypefn {GIMPLE function} void gsi_move_before (gimple_stmt_iterator *from, gimple_stmt_iterator *to) Move the statement at @code{FROM} so it comes right before the statement at @code{TO}. @end deftypefn @deftypefn {GIMPLE function} void gsi_move_to_bb_end (gimple_stmt_iterator *from, basic_block bb) Move the statement at @code{FROM} to the end of basic block @code{BB}. @end deftypefn @deftypefn {GIMPLE function} void gsi_insert_on_edge (edge e, gimple stmt) Add @code{STMT} to the pending list of edge @code{E}. No actual insertion is made until a call to @code{gsi_commit_edge_inserts}() is made. @end deftypefn @deftypefn {GIMPLE function} void gsi_insert_seq_on_edge (edge e, gimple_seq seq) Add the sequence of statements in @code{SEQ} to the pending list of edge @code{E}. No actual insertion is made until a call to @code{gsi_commit_edge_inserts}() is made. @end deftypefn @deftypefn {GIMPLE function} basic_block gsi_insert_on_edge_immediate (edge e, gimple stmt) Similar to @code{gsi_insert_on_edge}+@code{gsi_commit_edge_inserts}. If a new block has to be created, it is returned. @end deftypefn @deftypefn {GIMPLE function} void gsi_commit_one_edge_insert (edge e, basic_block *new_bb) Commit insertions pending at edge @code{E}. If a new block is created, set @code{NEW_BB} to this block, otherwise set it to @code{NULL}. @end deftypefn @deftypefn {GIMPLE function} void gsi_commit_edge_inserts (void) This routine will commit all pending edge insertions, creating any new basic blocks which are necessary. @end deftypefn @node Adding a new GIMPLE statement code @section Adding a new GIMPLE statement code @cindex Adding a new GIMPLE statement code The first step in adding a new GIMPLE statement code, is modifying the file @code{gimple.def}, which contains all the GIMPLE codes. Then you must add a corresponding structure, and an entry in @code{union gimple_statement_d}, both of which are located in @code{gimple.h}. This in turn, will require you to add a corresponding @code{GTY} tag in @code{gsstruct.def}, and code to handle this tag in @code{gss_for_code} which is located in @code{gimple.c}. In order for the garbage collector to know the size of the structure you created in @code{gimple.h}, you need to add a case to handle your new GIMPLE statement in @code{gimple_size} which is located in @code{gimple.c}. You will probably want to create a function to build the new gimple statement in @code{gimple.c}. The function should be called @code{gimple_build_<@code{NEW_TUPLE_NAME}>}, and should return the new tuple of type gimple. If your new statement requires accessors for any members or operands it may have, put simple inline accessors in @code{gimple.h} and any non-trivial accessors in @code{gimple.c} with a corresponding prototype in @code{gimple.h}. @node Statement and operand traversals @section Statement and operand traversals @cindex Statement and operand traversals There are two functions available for walking statements and sequences: @code{walk_gimple_stmt} and @code{walk_gimple_seq}, accordingly, and a third function for walking the operands in a statement: @code{walk_gimple_op}. @deftypefn {GIMPLE function} tree walk_gimple_stmt (gimple_stmt_iterator *gsi, walk_stmt_fn callback_stmt, walk_tree_fn callback_op, struct walk_stmt_info *wi) This function is used to walk the current statement in @code{GSI}, optionally using traversal state stored in @code{WI}. If @code{WI} is @code{NULL}, no state is kept during the traversal. The callback @code{CALLBACK_STMT} is called. If @code{CALLBACK_STMT} returns true, it means that the callback function has handled all the operands of the statement and it is not necessary to walk its operands. If @code{CALLBACK_STMT} is @code{NULL} or it returns false, @code{CALLBACK_OP} is called on each operand of the statement via @code{walk_gimple_op}. If @code{walk_gimple_op} returns non-@code{NULL} for any operand, the remaining operands are not scanned. The return value is that returned by the last call to @code{walk_gimple_op}, or @code{NULL_TREE} if no @code{CALLBACK_OP} is specified. @end deftypefn @deftypefn {GIMPLE function} tree walk_gimple_op (gimple stmt, walk_tree_fn callback_op, struct walk_stmt_info *wi) Use this function to walk the operands of statement @code{STMT}. Every operand is walked via @code{walk_tree} with optional state information in @code{WI}. @code{CALLBACK_OP} is called on each operand of @code{STMT} via @code{walk_tree}. Additional parameters to @code{walk_tree} must be stored in @code{WI}. For each operand @code{OP}, @code{walk_tree} is called as: @smallexample walk_tree (&@code{OP}, @code{CALLBACK_OP}, @code{WI}, @code{WI}- @code{PSET}) @end smallexample If @code{CALLBACK_OP} returns non-@code{NULL} for an operand, the remaining operands are not scanned. The return value is that returned by the last call to @code{walk_tree}, or @code{NULL_TREE} if no @code{CALLBACK_OP} is specified. @end deftypefn @deftypefn {GIMPLE function} tree walk_gimple_seq (gimple_seq seq, walk_stmt_fn callback_stmt, walk_tree_fn callback_op, struct walk_stmt_info *wi) This function walks all the statements in the sequence @code{SEQ} calling @code{walk_gimple_stmt} on each one. @code{WI} is as in @code{walk_gimple_stmt}. If @code{walk_gimple_stmt} returns non-@code{NULL}, the walk is stopped and the value returned. Otherwise, all the statements are walked and @code{NULL_TREE} returned. @end deftypefn