/* Perform optimizations on tree structure. Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. Written by Mark Michell (mark@codesourcery.com). This file is part of GNU CC. GNU CC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU CC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU CC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "config.h" #include "system.h" #include "tree.h" #include "cp-tree.h" #include "rtl.h" #include "insn-config.h" #include "input.h" #include "integrate.h" #include "toplev.h" #include "varray.h" #include "ggc.h" #include "params.h" #include "hashtab.h" #include "debug.h" /* To Do: o In order to make inlining-on-trees work, we pessimized function-local static constants. In particular, they are now always output, even when not addressed. Fix this by treating function-local static constants just like global static constants; the back-end already knows not to output them if they are not needed. o Provide heuristics to clamp inlining of recursive template calls? */ /* Data required for function inlining. */ typedef struct inline_data { /* A stack of the functions we are inlining. For example, if we are compiling `f', which calls `g', which calls `h', and we are inlining the body of `h', the stack will contain, `h', followed by `g', followed by `f'. The first few elements of the stack may contain other functions that we know we should not recurse into, even though they are not directly being inlined. */ varray_type fns; /* The index of the first element of FNS that really represents an inlined function. */ unsigned first_inlined_fn; /* The label to jump to when a return statement is encountered. If this value is NULL, then return statements will simply be remapped as return statements, rather than as jumps. */ tree ret_label; /* The map from local declarations in the inlined function to equivalents in the function into which it is being inlined. */ splay_tree decl_map; /* Nonzero if we are currently within the cleanup for a TARGET_EXPR. */ int in_target_cleanup_p; /* A stack of the TARGET_EXPRs that we are currently processing. */ varray_type target_exprs; /* A list of the functions current function has inlined. */ varray_type inlined_fns; /* The approximate number of statements we have inlined in the current call stack. */ int inlined_stmts; /* We use the same mechanism to build clones that we do to perform inlining. However, there are a few places where we need to distinguish between those two situations. This flag is true if we are cloning, rather than inlining. */ bool cloning_p; /* Hash table used to prevent walk_tree from visiting the same node umpteen million times. */ htab_t tree_pruner; } inline_data; /* Prototypes. */ static tree initialize_inlined_parameters PARAMS ((inline_data *, tree, tree)); static tree declare_return_variable PARAMS ((inline_data *, tree *)); static tree copy_body_r PARAMS ((tree *, int *, void *)); static tree copy_body PARAMS ((inline_data *)); static tree expand_call_inline PARAMS ((tree *, int *, void *)); static void expand_calls_inline PARAMS ((tree *, inline_data *)); static int inlinable_function_p PARAMS ((tree, inline_data *)); static tree remap_decl PARAMS ((tree, inline_data *)); static void remap_block PARAMS ((tree, tree, inline_data *)); static void copy_scope_stmt PARAMS ((tree *, int *, inline_data *)); static void optimize_inline_calls PARAMS ((tree)); static tree calls_setjmp_r PARAMS ((tree *, int *, void *)); static void update_cloned_parm PARAMS ((tree, tree)); static void dump_function PARAMS ((enum tree_dump_index, tree)); /* The approximate number of instructions per statement. This number need not be particularly accurate; it is used only to make decisions about when a function is too big to inline. */ #define INSNS_PER_STMT (10) /* Remap DECL during the copying of the BLOCK tree for the function. */ static tree remap_decl (decl, id) tree decl; inline_data *id; { splay_tree_node n; tree fn; /* We only remap local variables in the current function. */ fn = VARRAY_TOP_TREE (id->fns); if (!nonstatic_local_decl_p (decl) || DECL_CONTEXT (decl) != fn) return NULL_TREE; /* See if we have remapped this declaration. */ n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl); /* If we didn't already have an equivalent for this declaration, create one now. */ if (!n) { tree t; /* Make a copy of the variable or label. */ t = copy_decl_for_inlining (decl, fn, VARRAY_TREE (id->fns, 0)); /* The decl T could be a dynamic array or other variable size type, in which case some fields need to be remapped because they may contain SAVE_EXPRs. */ walk_tree (&DECL_SIZE (t), copy_body_r, id, NULL); walk_tree (&DECL_SIZE_UNIT (t), copy_body_r, id, NULL); if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE && TYPE_DOMAIN (TREE_TYPE (t))) { TREE_TYPE (t) = copy_node (TREE_TYPE (t)); TYPE_DOMAIN (TREE_TYPE (t)) = copy_node (TYPE_DOMAIN (TREE_TYPE (t))); walk_tree (&TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t))), copy_body_r, id, NULL); } if (!DECL_NAME (t) && TREE_TYPE (t) && ANON_AGGR_TYPE_P (TREE_TYPE ((t)))) { /* For a VAR_DECL of anonymous type, we must also copy the member VAR_DECLS here and rechain the DECL_ANON_UNION_ELEMS. */ tree members = NULL; tree src; for (src = DECL_ANON_UNION_ELEMS (t); src; src = TREE_CHAIN (src)) { tree member = remap_decl (TREE_VALUE (src), id); my_friendly_assert (!TREE_PURPOSE (src), 20010529); members = tree_cons (NULL, member, members); } DECL_ANON_UNION_ELEMS (t) = nreverse (members); } /* Remember it, so that if we encounter this local entity again we can reuse this copy. */ n = splay_tree_insert (id->decl_map, (splay_tree_key) decl, (splay_tree_value) t); } return (tree) n->value; } /* Copy the SCOPE_STMT_BLOCK associated with SCOPE_STMT to contain remapped versions of the variables therein. And hook the new block into the block-tree. If non-NULL, the DECLS are declarations to add to use instead of the BLOCK_VARS in the old block. */ static void remap_block (scope_stmt, decls, id) tree scope_stmt; tree decls; inline_data *id; { /* We cannot do this in the cleanup for a TARGET_EXPR since we do not know whether or not expand_expr will actually write out the code we put there. If it does not, then we'll have more BLOCKs than block-notes, and things will go awry. At some point, we should make the back-end handle BLOCK notes in a tidier way, without requiring a strict correspondence to the block-tree; then this check can go. */ if (id->in_target_cleanup_p) { SCOPE_STMT_BLOCK (scope_stmt) = NULL_TREE; return; } /* If this is the beginning of a scope, remap the associated BLOCK. */ if (SCOPE_BEGIN_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt)) { tree old_block; tree new_block; tree old_var; tree fn; /* Make the new block. */ old_block = SCOPE_STMT_BLOCK (scope_stmt); new_block = make_node (BLOCK); TREE_USED (new_block) = TREE_USED (old_block); BLOCK_ABSTRACT_ORIGIN (new_block) = old_block; SCOPE_STMT_BLOCK (scope_stmt) = new_block; /* Remap its variables. */ for (old_var = decls ? decls : BLOCK_VARS (old_block); old_var; old_var = TREE_CHAIN (old_var)) { tree new_var; /* Remap the variable. */ new_var = remap_decl (old_var, id); /* If we didn't remap this variable, so we can't mess with its TREE_CHAIN. If we remapped this variable to something other than a declaration (say, if we mapped it to a constant), then we must similarly omit any mention of it here. */ if (!new_var || !DECL_P (new_var)) ; else { TREE_CHAIN (new_var) = BLOCK_VARS (new_block); BLOCK_VARS (new_block) = new_var; } } /* We put the BLOCK_VARS in reverse order; fix that now. */ BLOCK_VARS (new_block) = nreverse (BLOCK_VARS (new_block)); fn = VARRAY_TREE (id->fns, 0); if (id->cloning_p) /* We're building a clone; DECL_INITIAL is still error_mark_node, and current_binding_level is the parm binding level. */ insert_block (new_block); else { /* Attach this new block after the DECL_INITIAL block for the function into which this block is being inlined. In rest_of_compilation we will straighten out the BLOCK tree. */ tree *first_block; if (DECL_INITIAL (fn)) first_block = &BLOCK_CHAIN (DECL_INITIAL (fn)); else first_block = &DECL_INITIAL (fn); BLOCK_CHAIN (new_block) = *first_block; *first_block = new_block; } /* Remember the remapped block. */ splay_tree_insert (id->decl_map, (splay_tree_key) old_block, (splay_tree_value) new_block); } /* If this is the end of a scope, set the SCOPE_STMT_BLOCK to be the remapped block. */ else if (SCOPE_END_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt)) { splay_tree_node n; /* Find this block in the table of remapped things. */ n = splay_tree_lookup (id->decl_map, (splay_tree_key) SCOPE_STMT_BLOCK (scope_stmt)); my_friendly_assert (n != NULL, 19991203); SCOPE_STMT_BLOCK (scope_stmt) = (tree) n->value; } } /* Copy the SCOPE_STMT pointed to by TP. */ static void copy_scope_stmt (tp, walk_subtrees, id) tree *tp; int *walk_subtrees; inline_data *id; { tree block; /* Remember whether or not this statement was nullified. When making a copy, copy_tree_r always sets SCOPE_NULLIFIED_P (and doesn't copy the SCOPE_STMT_BLOCK) to free callers from having to deal with copying BLOCKs if they do not wish to do so. */ block = SCOPE_STMT_BLOCK (*tp); /* Copy (and replace) the statement. */ copy_tree_r (tp, walk_subtrees, NULL); /* Restore the SCOPE_STMT_BLOCK. */ SCOPE_STMT_BLOCK (*tp) = block; /* Remap the associated block. */ remap_block (*tp, NULL_TREE, id); } /* Called from copy_body via walk_tree. DATA is really an `inline_data *'. */ static tree copy_body_r (tp, walk_subtrees, data) tree *tp; int *walk_subtrees; void *data; { inline_data* id; tree fn; /* Set up. */ id = (inline_data *) data; fn = VARRAY_TOP_TREE (id->fns); /* All automatic variables should have a DECL_CONTEXT indicating what function they come from. */ if ((TREE_CODE (*tp) == VAR_DECL || TREE_CODE (*tp) == LABEL_DECL) && DECL_NAMESPACE_SCOPE_P (*tp)) my_friendly_assert (DECL_EXTERNAL (*tp) || TREE_STATIC (*tp), 19991113); /* If this is a RETURN_STMT, change it into an EXPR_STMT and a GOTO_STMT with the RET_LABEL as its target. */ if (TREE_CODE (*tp) == RETURN_STMT && id->ret_label) { tree return_stmt = *tp; tree goto_stmt; /* Build the GOTO_STMT. */ goto_stmt = build_stmt (GOTO_STMT, id->ret_label); TREE_CHAIN (goto_stmt) = TREE_CHAIN (return_stmt); /* If we're returning something, just turn that into an assignment into the equivalent of the original RESULT_DECL. */ if (RETURN_EXPR (return_stmt)) { *tp = build_stmt (EXPR_STMT, RETURN_EXPR (return_stmt)); STMT_IS_FULL_EXPR_P (*tp) = 1; /* And then jump to the end of the function. */ TREE_CHAIN (*tp) = goto_stmt; } /* If we're not returning anything just do the jump. */ else *tp = goto_stmt; } /* Local variables and labels need to be replaced by equivalent variables. We don't want to copy static variables; there's only one of those, no matter how many times we inline the containing function. */ else if (nonstatic_local_decl_p (*tp) && DECL_CONTEXT (*tp) == fn) { tree new_decl; /* Remap the declaration. */ new_decl = remap_decl (*tp, id); my_friendly_assert (new_decl != NULL_TREE, 19991203); /* Replace this variable with the copy. */ STRIP_TYPE_NOPS (new_decl); *tp = new_decl; } else if (nonstatic_local_decl_p (*tp) && DECL_CONTEXT (*tp) != VARRAY_TREE (id->fns, 0)) my_friendly_abort (0); else if (TREE_CODE (*tp) == SAVE_EXPR) remap_save_expr (tp, id->decl_map, VARRAY_TREE (id->fns, 0), walk_subtrees); else if (TREE_CODE (*tp) == UNSAVE_EXPR) /* UNSAVE_EXPRs should not be generated until expansion time. */ my_friendly_abort (19991113); /* For a SCOPE_STMT, we must copy the associated block so that we can write out debugging information for the inlined variables. */ else if (TREE_CODE (*tp) == SCOPE_STMT && !id->in_target_cleanup_p) copy_scope_stmt (tp, walk_subtrees, id); /* Otherwise, just copy the node. Note that copy_tree_r already knows not to copy VAR_DECLs, etc., so this is safe. */ else { copy_tree_r (tp, walk_subtrees, NULL); /* The copied TARGET_EXPR has never been expanded, even if the original node was expanded already. */ if (TREE_CODE (*tp) == TARGET_EXPR && TREE_OPERAND (*tp, 3)) { TREE_OPERAND (*tp, 1) = TREE_OPERAND (*tp, 3); TREE_OPERAND (*tp, 3) = NULL_TREE; } else if (TREE_CODE (*tp) == MODIFY_EXPR && TREE_OPERAND (*tp, 0) == TREE_OPERAND (*tp, 1) && nonstatic_local_decl_p (TREE_OPERAND (*tp, 0)) && DECL_CONTEXT (TREE_OPERAND (*tp, 0)) == fn) { /* Some assignments VAR = VAR; don't generate any rtl code and thus don't count as variable modification. Avoid keeping bogosities like 0 = 0. */ tree decl = TREE_OPERAND (*tp, 0), value; splay_tree_node n; n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl); if (n) { value = (tree) n->value; STRIP_TYPE_NOPS (value); if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value)) *tp = value; } } } /* Keep iterating. */ return NULL_TREE; } /* Make a copy of the body of FN so that it can be inserted inline in another function. */ static tree copy_body (id) inline_data *id; { tree body; body = DECL_SAVED_TREE (VARRAY_TOP_TREE (id->fns)); walk_tree (&body, copy_body_r, id, NULL); return body; } /* Generate code to initialize the parameters of the function at the top of the stack in ID from the ARGS (presented as a TREE_LIST). */ static tree initialize_inlined_parameters (id, args, fn) inline_data *id; tree args; tree fn; { tree init_stmts; tree parms; tree a; tree p; /* Figure out what the parameters are. */ parms = DECL_ARGUMENTS (fn); /* Start with no initializations whatsoever. */ init_stmts = NULL_TREE; /* Loop through the parameter declarations, replacing each with an equivalent VAR_DECL, appropriately initialized. */ for (p = parms, a = args; p; a = TREE_CHAIN (a), p = TREE_CHAIN (p)) { tree init_stmt; tree var; tree value; /* Find the initializer. */ value = TREE_VALUE (a); /* If the parameter is never assigned to, we may not need to create a new variable here at all. Instead, we may be able to just use the argument value. */ if (TREE_READONLY (p) && !TREE_ADDRESSABLE (p) && !TREE_SIDE_EFFECTS (value)) { /* Simplify the value, if possible. */ value = fold (decl_constant_value (value)); /* We can't risk substituting complex expressions. They might contain variables that will be assigned to later. Theoretically, we could check the expression to see if all of the variables that determine its value are read-only, but we don't bother. */ if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value)) { /* If this is a declaration, wrap it a NOP_EXPR so that we don't try to put the VALUE on the list of BLOCK_VARS. */ if (DECL_P (value)) value = build1 (NOP_EXPR, TREE_TYPE (value), value); splay_tree_insert (id->decl_map, (splay_tree_key) p, (splay_tree_value) value); continue; } } /* Make an equivalent VAR_DECL. */ var = copy_decl_for_inlining (p, fn, VARRAY_TREE (id->fns, 0)); /* Register the VAR_DECL as the equivalent for the PARM_DECL; that way, when the PARM_DECL is encountered, it will be automatically replaced by the VAR_DECL. */ splay_tree_insert (id->decl_map, (splay_tree_key) p, (splay_tree_value) var); /* Declare this new variable. */ init_stmt = build_stmt (DECL_STMT, var); TREE_CHAIN (init_stmt) = init_stmts; init_stmts = init_stmt; /* Initialize this VAR_DECL from the equivalent argument. If the argument is an object, created via a constructor or copy, this will not result in an extra copy: the TARGET_EXPR representing the argument will be bound to VAR, and the object will be constructed in VAR. */ if (! TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (p))) DECL_INITIAL (var) = value; else { /* Even if P was TREE_READONLY, the new VAR should not be. In the original code, we would have constructed a temporary, and then the function body would have never changed the value of P. However, now, we will be constructing VAR directly. The constructor body may change its value multiple times as it is being constructed. Therefore, it must not be TREE_READONLY; the back-end assumes that TREE_READONLY variable is assigned to only once. */ TREE_READONLY (var) = 0; /* Build a run-time initialization. */ init_stmt = build_stmt (EXPR_STMT, build (INIT_EXPR, TREE_TYPE (p), var, value)); /* Add this initialization to the list. Note that we want the declaration *after* the initialization because we are going to reverse all the initialization statements below. */ TREE_CHAIN (init_stmt) = init_stmts; init_stmts = init_stmt; } } /* The initialization statements have been built up in reverse order. Straighten them out now. */ return nreverse (init_stmts); } /* Declare a return variable to replace the RESULT_DECL for the function we are calling. An appropriate DECL_STMT is returned. The USE_STMT is filled in to contain a use of the declaration to indicate the return value of the function. */ static tree declare_return_variable (id, use_stmt) struct inline_data *id; tree *use_stmt; { tree fn = VARRAY_TOP_TREE (id->fns); tree result = DECL_RESULT (fn); tree var; int aggregate_return_p; /* We don't need to do anything for functions that don't return anything. */ if (!result || VOID_TYPE_P (TREE_TYPE (result))) { *use_stmt = NULL_TREE; return NULL_TREE; } /* Figure out whether or not FN returns an aggregate. */ aggregate_return_p = IS_AGGR_TYPE (TREE_TYPE (result)); /* If FN returns an aggregate then the caller will always create the temporary (using a TARGET_EXPR) and the call will be the initializing expression for the TARGET_EXPR. If we were just to create a new VAR_DECL here, then the result of this function would be copied (bitwise) into the variable initialized by the TARGET_EXPR. That's incorrect, so we must transform any references to the RESULT into references to the target. */ if (aggregate_return_p) { my_friendly_assert (VARRAY_ACTIVE_SIZE (id->target_exprs) != 0, 20000430); var = TREE_OPERAND (VARRAY_TOP_TREE (id->target_exprs), 0); my_friendly_assert (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (var), TREE_TYPE (result)), 20000430); } /* Otherwise, make an appropriate copy. */ else var = copy_decl_for_inlining (result, fn, VARRAY_TREE (id->fns, 0)); /* Register the VAR_DECL as the equivalent for the RESULT_DECL; that way, when the RESULT_DECL is encountered, it will be automatically replaced by the VAR_DECL. */ splay_tree_insert (id->decl_map, (splay_tree_key) result, (splay_tree_value) var); /* Build the USE_STMT. */ *use_stmt = build_stmt (EXPR_STMT, var); /* Build the declaration statement if FN does not return an aggregate. */ if (!aggregate_return_p) return build_stmt (DECL_STMT, var); /* If FN does return an aggregate, there's no need to declare the return variable; we're using a variable in our caller's frame. */ else return NULL_TREE; } /* Returns non-zero if FN is a function that can be inlined. */ static int inlinable_function_p (fn, id) tree fn; inline_data *id; { int inlinable; /* If we've already decided this function shouldn't be inlined, there's no need to check again. */ if (DECL_UNINLINABLE (fn)) return 0; /* Assume it is not inlinable. */ inlinable = 0; /* If we're not inlining things, then nothing is inlinable. */ if (!flag_inline_trees) ; /* If the function was not declared `inline', then we don't inline it. */ else if (!DECL_INLINE (fn)) ; /* We can't inline varargs functions. */ else if (varargs_function_p (fn)) ; /* We can't inline functions that are too big. */ else if (DECL_NUM_STMTS (fn) * INSNS_PER_STMT > MAX_INLINE_INSNS) ; /* All is well. We can inline this function. Traditionally, GCC has refused to inline functions using alloca, or functions whose values are returned in a PARALLEL, and a few other such obscure conditions. We are not equally constrained at the tree level. */ else inlinable = 1; /* Squirrel away the result so that we don't have to check again. */ DECL_UNINLINABLE (fn) = !inlinable; /* Even if this function is not itself too big to inline, it might be that we've done so much inlining already that we don't want to risk inlining any more. */ if ((DECL_NUM_STMTS (fn) + id->inlined_stmts) * INSNS_PER_STMT > MAX_INLINE_INSNS) inlinable = 0; /* We can inline a template instantiation only if it's fully instantiated. */ if (inlinable && DECL_TEMPLATE_INFO (fn) && TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (fn))) { fn = instantiate_decl (fn, /*defer_ok=*/0); inlinable = !TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (fn)); } /* If we don't have the function body available, we can't inline it. */ if (!DECL_SAVED_TREE (fn)) inlinable = 0; /* Don't do recursive inlining, either. We don't record this in DECL_UNINLINABLE; we may be able to inline this function later. */ if (inlinable) { size_t i; for (i = 0; i < VARRAY_ACTIVE_SIZE (id->fns); ++i) if (VARRAY_TREE (id->fns, i) == fn) return 0; if (inlinable && DECL_LANG_SPECIFIC (fn) && DECL_INLINED_FNS (fn)) { int j; tree inlined_fns = DECL_INLINED_FNS (fn); for (j = 0; j < TREE_VEC_LENGTH (inlined_fns); ++j) if (TREE_VEC_ELT (inlined_fns, j) == VARRAY_TREE (id->fns, 0)) return 0; } } /* Return the result. */ return inlinable; } /* If *TP is a CALL_EXPR, replace it with its inline expansion. */ static tree expand_call_inline (tp, walk_subtrees, data) tree *tp; int *walk_subtrees; void *data; { inline_data *id; tree t; tree expr; tree chain; tree fn; tree scope_stmt; tree use_stmt; tree arg_inits; tree *inlined_body; splay_tree st; /* See what we've got. */ id = (inline_data *) data; t = *tp; /* Recurse, but letting recursive invocations know that we are inside the body of a TARGET_EXPR. */ if (TREE_CODE (*tp) == TARGET_EXPR) { int i, len = first_rtl_op (TARGET_EXPR); /* We're walking our own subtrees. */ *walk_subtrees = 0; /* Push *TP on the stack of pending TARGET_EXPRs. */ VARRAY_PUSH_TREE (id->target_exprs, *tp); /* Actually walk over them. This loop is the body of walk_trees, omitting the case where the TARGET_EXPR itself is handled. */ for (i = 0; i < len; ++i) { if (i == 2) ++id->in_target_cleanup_p; walk_tree (&TREE_OPERAND (*tp, i), expand_call_inline, data, id->tree_pruner); if (i == 2) --id->in_target_cleanup_p; } /* We're done with this TARGET_EXPR now. */ VARRAY_POP (id->target_exprs); return NULL_TREE; } if (TYPE_P (t)) /* Because types were not copied in copy_body, CALL_EXPRs beneath them should not be expanded. This can happen if the type is a dynamic array type, for example. */ *walk_subtrees = 0; /* From here on, we're only interested in CALL_EXPRs. */ if (TREE_CODE (t) != CALL_EXPR) return NULL_TREE; /* First, see if we can figure out what function is being called. If we cannot, then there is no hope of inlining the function. */ fn = get_callee_fndecl (t); if (!fn) return NULL_TREE; /* Don't try to inline functions that are not well-suited to inlining. */ if (!inlinable_function_p (fn, id)) return NULL_TREE; /* Set the current filename and line number to the function we are inlining so that when we create new _STMT nodes here they get line numbers corresponding to the function we are calling. We wrap the whole inlined body in an EXPR_WITH_FILE_AND_LINE as well because individual statements don't record the filename. */ push_srcloc (fn->decl.filename, fn->decl.linenum); /* Build a statement-expression containing code to initialize the arguments, the actual inline expansion of the body, and a label for the return statements within the function to jump to. The type of the statement expression is the return type of the function call. */ expr = build_min (STMT_EXPR, TREE_TYPE (TREE_TYPE (fn)), NULL_TREE); /* Local declarations will be replaced by their equivalents in this map. */ st = id->decl_map; id->decl_map = splay_tree_new (splay_tree_compare_pointers, NULL, NULL); /* Initialize the parameters. */ arg_inits = initialize_inlined_parameters (id, TREE_OPERAND (t, 1), fn); /* Expand any inlined calls in the initializers. Do this before we push FN on the stack of functions we are inlining; we want to inline calls to FN that appear in the initializers for the parameters. */ expand_calls_inline (&arg_inits, id); /* And add them to the tree. */ STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), arg_inits); /* Record the function we are about to inline so that we can avoid recursing into it. */ VARRAY_PUSH_TREE (id->fns, fn); /* Record the function we are about to inline if optimize_function has not been called on it yet and we don't have it in the list. */ if (DECL_LANG_SPECIFIC (fn) && !DECL_INLINED_FNS (fn)) { int i; for (i = VARRAY_ACTIVE_SIZE (id->inlined_fns) - 1; i >= 0; i--) if (VARRAY_TREE (id->inlined_fns, i) == fn) break; if (i < 0) VARRAY_PUSH_TREE (id->inlined_fns, fn); } /* Return statements in the function body will be replaced by jumps to the RET_LABEL. */ id->ret_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); DECL_CONTEXT (id->ret_label) = VARRAY_TREE (id->fns, 0); /* Create a block to put the parameters in. We have to do this after the parameters have been remapped because remapping parameters is different from remapping ordinary variables. */ scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn)); SCOPE_BEGIN_P (scope_stmt) = 1; SCOPE_NO_CLEANUPS_P (scope_stmt) = 1; remap_block (scope_stmt, DECL_ARGUMENTS (fn), id); TREE_CHAIN (scope_stmt) = STMT_EXPR_STMT (expr); STMT_EXPR_STMT (expr) = scope_stmt; /* Tell the debugging backends that this block represents the outermost scope of the inlined function. */ if (SCOPE_STMT_BLOCK (scope_stmt)) BLOCK_ABSTRACT_ORIGIN (SCOPE_STMT_BLOCK (scope_stmt)) = DECL_ORIGIN (fn); /* Declare the return variable for the function. */ STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), declare_return_variable (id, &use_stmt)); /* After we've initialized the parameters, we insert the body of the function itself. */ inlined_body = &STMT_EXPR_STMT (expr); while (*inlined_body) inlined_body = &TREE_CHAIN (*inlined_body); *inlined_body = copy_body (id); /* Close the block for the parameters. */ scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn)); SCOPE_NO_CLEANUPS_P (scope_stmt) = 1; my_friendly_assert (DECL_INITIAL (fn) && TREE_CODE (DECL_INITIAL (fn)) == BLOCK, 19991203); remap_block (scope_stmt, NULL_TREE, id); STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), scope_stmt); /* After the body of the function comes the RET_LABEL. This must come before we evaluate the returned value below, because that evalulation may cause RTL to be generated. */ STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), build_stmt (LABEL_STMT, id->ret_label)); /* Finally, mention the returned value so that the value of the statement-expression is the returned value of the function. */ STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), use_stmt); /* Clean up. */ splay_tree_delete (id->decl_map); id->decl_map = st; /* The new expression has side-effects if the old one did. */ TREE_SIDE_EFFECTS (expr) = TREE_SIDE_EFFECTS (t); /* Replace the call by the inlined body. Wrap it in an EXPR_WITH_FILE_LOCATION so that we'll get debugging line notes pointing to the right place. */ chain = TREE_CHAIN (*tp); *tp = build_expr_wfl (expr, DECL_SOURCE_FILE (fn), DECL_SOURCE_LINE (fn), /*col=*/0); EXPR_WFL_EMIT_LINE_NOTE (*tp) = 1; TREE_CHAIN (*tp) = chain; pop_srcloc (); /* If the value of the new expression is ignored, that's OK. We don't warn about this for CALL_EXPRs, so we shouldn't warn about the equivalent inlined version either. */ TREE_USED (*tp) = 1; /* Our function now has more statements than it did before. */ DECL_NUM_STMTS (VARRAY_TREE (id->fns, 0)) += DECL_NUM_STMTS (fn); id->inlined_stmts += DECL_NUM_STMTS (fn); /* Recurse into the body of the just inlined function. */ expand_calls_inline (inlined_body, id); VARRAY_POP (id->fns); /* If we've returned to the top level, clear out the record of how much inlining has been done. */ if (VARRAY_ACTIVE_SIZE (id->fns) == id->first_inlined_fn) id->inlined_stmts = 0; /* Don't walk into subtrees. We've already handled them above. */ *walk_subtrees = 0; /* Keep iterating. */ return NULL_TREE; } /* Walk over the entire tree *TP, replacing CALL_EXPRs with inline expansions as appropriate. */ static void expand_calls_inline (tp, id) tree *tp; inline_data *id; { /* Search through *TP, replacing all calls to inline functions by appropriate equivalents. Use walk_tree in no-duplicates mode to avoid exponential time complexity. (We can't just use walk_tree_without_duplicates, because of the special TARGET_EXPR handling in expand_calls. The hash table is set up in optimize_function. */ walk_tree (tp, expand_call_inline, id, id->tree_pruner); } /* Expand calls to inline functions in the body of FN. */ static void optimize_inline_calls (fn) tree fn; { inline_data id; tree prev_fn; struct saved_scope *s; /* Clear out ID. */ memset (&id, 0, sizeof (id)); /* Don't allow recursion into FN. */ VARRAY_TREE_INIT (id.fns, 32, "fns"); VARRAY_PUSH_TREE (id.fns, fn); /* Or any functions that aren't finished yet. */ prev_fn = NULL_TREE; if (current_function_decl) { VARRAY_PUSH_TREE (id.fns, current_function_decl); prev_fn = current_function_decl; } for (s = scope_chain; s; s = s->prev) if (s->function_decl && s->function_decl != prev_fn) { VARRAY_PUSH_TREE (id.fns, s->function_decl); prev_fn = s->function_decl; } /* Create the stack of TARGET_EXPRs. */ VARRAY_TREE_INIT (id.target_exprs, 32, "target_exprs"); /* Create the list of functions this call will inline. */ VARRAY_TREE_INIT (id.inlined_fns, 32, "inlined_fns"); /* Keep track of the low-water mark, i.e., the point where the first real inlining is represented in ID.FNS. */ id.first_inlined_fn = VARRAY_ACTIVE_SIZE (id.fns); /* Replace all calls to inline functions with the bodies of those functions. */ id.tree_pruner = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); expand_calls_inline (&DECL_SAVED_TREE (fn), &id); /* Clean up. */ htab_delete (id.tree_pruner); VARRAY_FREE (id.fns); VARRAY_FREE (id.target_exprs); if (DECL_LANG_SPECIFIC (fn)) { tree ifn = make_tree_vec (VARRAY_ACTIVE_SIZE (id.inlined_fns)); memcpy (&TREE_VEC_ELT (ifn, 0), &VARRAY_TREE (id.inlined_fns, 0), VARRAY_ACTIVE_SIZE (id.inlined_fns) * sizeof (tree)); DECL_INLINED_FNS (fn) = ifn; } VARRAY_FREE (id.inlined_fns); dump_function (TDI_inlined, fn); } /* Optimize the body of FN. */ void optimize_function (fn) tree fn; { dump_function (TDI_original, fn); /* While in this function, we may choose to go off and compile another function. For example, we might instantiate a function in the hopes of inlining it. Normally, that wouldn't trigger any actual RTL code-generation -- but it will if the template is actually needed. (For example, if it's address is taken, or if some other function already refers to the template.) If code-generation occurs, then garbage collection will occur, so we must protect ourselves, just as we do while building up the body of the function. */ ++function_depth; if (flag_inline_trees /* We do not inline thunks, as (a) the backend tries to optimize the call to the thunkee, (b) tree based inlining breaks that optimization, (c) virtual functions are rarely inlineable, and (d) ASM_OUTPUT_MI_THUNK is there to DTRT anyway. */ && !DECL_THUNK_P (fn)) optimize_inline_calls (fn); /* Undo the call to ggc_push_context above. */ --function_depth; dump_function (TDI_optimized, fn); } /* Called from calls_setjmp_p via walk_tree. */ static tree calls_setjmp_r (tp, walk_subtrees, data) tree *tp; int *walk_subtrees ATTRIBUTE_UNUSED; void *data ATTRIBUTE_UNUSED; { /* We're only interested in FUNCTION_DECLS. */ if (TREE_CODE (*tp) != FUNCTION_DECL) return NULL_TREE; return setjmp_call_p (*tp) ? *tp : NULL_TREE; } /* Returns non-zero if FN calls `setjmp' or some other function that can return more than once. This function is conservative; it may occasionally return a non-zero value even when FN does not actually call `setjmp'. */ int calls_setjmp_p (fn) tree fn; { return walk_tree_without_duplicates (&DECL_SAVED_TREE (fn), calls_setjmp_r, NULL) != NULL_TREE; } /* CLONED_PARM is a copy of CLONE, generated for a cloned constructor or destructor. Update it to ensure that the source-position for the cloned parameter matches that for the original, and that the debugging generation code will be able to find the original PARM. */ static void update_cloned_parm (parm, cloned_parm) tree parm; tree cloned_parm; { DECL_ABSTRACT_ORIGIN (cloned_parm) = parm; /* We may have taken its address. */ TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm); /* The definition might have different constness. */ TREE_READONLY (cloned_parm) = TREE_READONLY (parm); TREE_USED (cloned_parm) = TREE_USED (parm); /* The name may have changed from the declaration. */ DECL_NAME (cloned_parm) = DECL_NAME (parm); DECL_SOURCE_FILE (cloned_parm) = DECL_SOURCE_FILE (parm); DECL_SOURCE_LINE (cloned_parm) = DECL_SOURCE_LINE (parm); } /* FN is a function that has a complete body. Clone the body as necessary. Returns non-zero if there's no longer any need to process the main body. */ int maybe_clone_body (fn) tree fn; { inline_data id; tree clone; int first = 1; /* We only clone constructors and destructors. */ if (!DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)) return 0; /* Emit the DWARF1 abstract instance. */ (*debug_hooks->deferred_inline_function) (fn); /* We know that any clones immediately follow FN in the TYPE_METHODS list. */ for (clone = TREE_CHAIN (fn); clone && DECL_CLONED_FUNCTION_P (clone); clone = TREE_CHAIN (clone), first = 0) { tree parm; tree clone_parm; int parmno; /* Update CLONE's source position information to match FN's. */ DECL_SOURCE_FILE (clone) = DECL_SOURCE_FILE (fn); DECL_SOURCE_LINE (clone) = DECL_SOURCE_LINE (fn); DECL_INLINE (clone) = DECL_INLINE (fn); DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn); DECL_COMDAT (clone) = DECL_COMDAT (fn); DECL_WEAK (clone) = DECL_WEAK (fn); DECL_ONE_ONLY (clone) = DECL_ONE_ONLY (fn); DECL_SECTION_NAME (clone) = DECL_SECTION_NAME (fn); DECL_USE_TEMPLATE (clone) = DECL_USE_TEMPLATE (fn); DECL_EXTERNAL (clone) = DECL_EXTERNAL (fn); DECL_INTERFACE_KNOWN (clone) = DECL_INTERFACE_KNOWN (fn); DECL_NOT_REALLY_EXTERN (clone) = DECL_NOT_REALLY_EXTERN (fn); TREE_PUBLIC (clone) = TREE_PUBLIC (fn); /* Adjust the parameter names and locations. */ parm = DECL_ARGUMENTS (fn); clone_parm = DECL_ARGUMENTS (clone); /* Update the `this' parameter, which is always first. Sometimes, we end update the `this' parameter twice because we process it again in the loop below. That is harmless. */ update_cloned_parm (parm, clone_parm); if (DECL_HAS_IN_CHARGE_PARM_P (fn)) parm = TREE_CHAIN (parm); if (DECL_HAS_VTT_PARM_P (fn)) parm = TREE_CHAIN (parm); if (DECL_HAS_VTT_PARM_P (clone)) clone_parm = TREE_CHAIN (clone_parm); for (; parm; parm = TREE_CHAIN (parm), clone_parm = TREE_CHAIN (clone_parm)) { /* Update this paramter. */ update_cloned_parm (parm, clone_parm); /* We should only give unused information for one clone. */ if (!first) TREE_USED (clone_parm) = 1; } /* Start processing the function. */ push_to_top_level (); start_function (NULL_TREE, clone, NULL_TREE, SF_PRE_PARSED); /* Just clone the body, as if we were making an inline call. But, remap the parameters in the callee to the parameters of caller. If there's an in-charge parameter, map it to an appropriate constant. */ memset (&id, 0, sizeof (id)); VARRAY_TREE_INIT (id.fns, 2, "fns"); VARRAY_PUSH_TREE (id.fns, clone); VARRAY_PUSH_TREE (id.fns, fn); /* Cloning is treated slightly differently from inlining. Set CLONING_P so that its clear which operation we're performing. */ id.cloning_p = true; /* Remap the parameters. */ id.decl_map = splay_tree_new (splay_tree_compare_pointers, NULL, NULL); for (parmno = 0, parm = DECL_ARGUMENTS (fn), clone_parm = DECL_ARGUMENTS (clone); parm; ++parmno, parm = TREE_CHAIN (parm)) { /* Map the in-charge parameter to an appropriate constant. */ if (DECL_HAS_IN_CHARGE_PARM_P (fn) && parmno == 1) { tree in_charge; in_charge = in_charge_arg_for_name (DECL_NAME (clone)); splay_tree_insert (id.decl_map, (splay_tree_key) parm, (splay_tree_value) in_charge); } else if (DECL_ARTIFICIAL (parm) && DECL_NAME (parm) == vtt_parm_identifier) { /* For a subobject constructor or destructor, the next argument is the VTT parameter. Remap the VTT_PARM from the CLONE to this parameter. */ if (DECL_HAS_VTT_PARM_P (clone)) { DECL_ABSTRACT_ORIGIN (clone_parm) = parm; splay_tree_insert (id.decl_map, (splay_tree_key) parm, (splay_tree_value) clone_parm); clone_parm = TREE_CHAIN (clone_parm); } /* Otherwise, map the VTT parameter to `NULL'. */ else { splay_tree_insert (id.decl_map, (splay_tree_key) parm, (splay_tree_value) null_pointer_node); } } /* Map other parameters to their equivalents in the cloned function. */ else { splay_tree_insert (id.decl_map, (splay_tree_key) parm, (splay_tree_value) clone_parm); clone_parm = TREE_CHAIN (clone_parm); } } /* Actually copy the body. */ TREE_CHAIN (DECL_SAVED_TREE (clone)) = copy_body (&id); /* There are as many statements in the clone as in the original. */ DECL_NUM_STMTS (clone) = DECL_NUM_STMTS (fn); /* Clean up. */ splay_tree_delete (id.decl_map); VARRAY_FREE (id.fns); /* Now, expand this function into RTL, if appropriate. */ finish_function (0); BLOCK_ABSTRACT_ORIGIN (DECL_INITIAL (clone)) = DECL_INITIAL (fn); expand_body (clone); pop_from_top_level (); } /* We don't need to process the original function any further. */ return 1; } /* Dump FUNCTION_DECL FN as tree dump PHASE. */ static void dump_function (phase, fn) enum tree_dump_index phase; tree fn; { FILE *stream; int flags; stream = dump_begin (phase, &flags); if (stream) { fprintf (stream, "\n;; Function %s", decl_as_string (fn, TFF_DECL_SPECIFIERS)); fprintf (stream, " (%s)\n", decl_as_string (DECL_ASSEMBLER_NAME (fn), 0)); fprintf (stream, ";; enabled by -%s\n", dump_flag_name (phase)); fprintf (stream, "\n"); dump_node (fn, TDF_SLIM | flags, stream); dump_end (phase, stream); } }