diff options
author | Brian Booth <bbooth@redhat.com> | 2004-06-10 21:41:08 +0000 |
---|---|---|
committer | Brian Booth <bbooth@gcc.gnu.org> | 2004-06-10 21:41:08 +0000 |
commit | a32b97a20d6638f3cee28919f4e6bd7b1d9b39e8 (patch) | |
tree | 390a758454170e0dc2e6aea71342ec3d64fd2501 /gcc/doc | |
parent | d57f1617211f3309887c6ee18fca97ea7029ebc7 (diff) | |
download | gcc-a32b97a20d6638f3cee28919f4e6bd7b1d9b39e8.zip gcc-a32b97a20d6638f3cee28919f4e6bd7b1d9b39e8.tar.gz gcc-a32b97a20d6638f3cee28919f4e6bd7b1d9b39e8.tar.bz2 |
tree-ssa.texi: Remove references to VDEF and add descriptions of V_MAY_DEF and V_MUST_DEF.
* doc/tree-ssa.texi: Remove references to VDEF and add descriptions
of V_MAY_DEF and V_MUST_DEF.
* tree-dfa.c (dfa_stats_d): Add num_v_must_defs and rename
num_vdefs to num_v_may_defs.
(compute_immediate_uses_for_stmt): Rename occurences of vdef
to v_may_def.
(redirect_immediate_uses): Ditto.
(dump_dfa_stats): Ditto. Also added code to dump num_v_must_defs.
(collect_dfa_stats_r): Rename occurences of vdef to v_may_def.
Also add code to sum up the number of v_must_defs.
(vdefs_disappeared_p): Replace with...
(v_may_defs_disappeared_p): This.
(v_must_defs_disappeared_p): New function.
(mark_new_vars_to_rename): Rename occurences of vdef to v_may_def.
Also add code to mark new variables found in V_MUST_DEFs for
renameing.
* tree-flow.h (stmt_ann_d): Add v_must_def_ops and replace
vdef_ops to v_may_def_ops.
(get_vdef_ops): Replace with...
(get_v_may_def_ops): This.
* tree-flow-inline.h (get_vdef_ops): Replace with...
(get_v_may_def_ops): This.
(get_v_must_def_ops): New function.
(get_vdef_result_ptr): Replace with...
(get_v_may_def_result_ptr): This.
(get_vdef_op_ptr): Ditto with...
(get_v_may_def_op_ptr); This.
(get_v_must_def_op_ptr): New function.
* tree-into-ssa.c (mark_def_sites): Rename occurences of vdef
to v_may_def. Also add code to mark statements with
V_MUST_DEFs as definition sites.
(rewrite_stmt): Rename occurences of vdef to v_may_def. Also
add code to register new V_MUST_DEFs made by the statement.
* tree-outof-ssa.c (VIRTUAL_PARTITION): Update comments.
(check_replaceable): Rename occurences of vdef to v_may_def. Also
add check for V_MUST_DEFs.
(find_replaceable_in_bb): Ditto.
* tree-pretty-print.c (dump_vops): Rename occurences of vdef
to v_may_def. Also add code to dump V_MUST_DEFs.
* tree-sra.c (mark_all_vdefs): Replace with...
(mark_all_v_may_defs): This.
(mark_all_v_must_defs): New function.
(create_scalar_copies): Replace call to mark_all_vdefs with
calls to mark_all_v_may_defs and mark_all_v_must_defs.
(scalarize_structures): Rename occurences of vdef to v_may_def.
Also add a check for V_MUST_DEFs.
(scalarize_modify_expr): Rename occurences of vdef to v_may_def.
* tree-ssa-alias.c (global_var): Update comment.
(compute_may_aliases): Ditto.
(compute_points_to_and_addr_escape): Rename occurences of vdef
to v_may_def. Also add code to mark variables in V_MUST_DEF
operands as being written to.
(group_aliases): Update comment.
(maybe_create_global_var): Ditto.
* tree-ssa.c (verify_ssa): Rename occurences of vdef to v_may_def.
Also add a check for V_MUST_DEFs on GIMPLE registers.
(replace_immediate_uses): Rename occurences of vdef to v_may_def.
* tree-ssa-ccp.c (visit_stmt): Rename occurences of vdef
to v_may_def. Also add code to mark all V_MUST_DEF operands
VARYING.
(initialize): Ditto.
(set_rhs): Rename occurences of vdef to v_may_def. Also add
code to update SSA_NAMEs in V_MUST_DEFs.
* tree-ssa-copy.c (cprop_into_stmt): Rename occurences of vdef
to v_may_def.
* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Rename
occurences of vdef to v_may_def. Also add code to mark statements
with V_MUST_DEFs as necessary.
(propagate_necessity): Rename occurences of vdef to v_may_def.
* tree-ssa-dom.c (redirect_edges_and_update_ssa_graph): Rename
occurences of vdef to v_may_def. Also add code to mark operands
in V_MUST_DEFs for renaming.
(eliminate_redundant_computations): Rename occurences of vdef
to v_may_def.
(record_equivalences_from_stmt): Rename occurences of vdef
to v_may_def. Also add code to record VUSEs for V_MUST_DEFs.
(optimize_stmt): Remove unnesessary variable vdefs. Update
comment.
(register_definitions_for_stmt): Rename occurences of vdef
to v_may_def. Also add code to register definitions made with
V_MUST_DEFs.
* tree-ssa-dse.c (fix_stmt_vdefs): Replace with...
(fix_stmt_v_may_defs): This.
(fix_phi_uses): Rename occurences of vdef to v_may_def.
(dse_optimize_stmt): Ditto.
* tree-ssa-live.c (create_ssa_var_map): Rename occurences of vdef
to v_may_def. Also add code to mark V_MUST_DEF operands as being
used in virtual operators.
* tree-ssa-loop.c (mark_defs_for_rewrite): Rename occurences of
vdef to v_may_def. Also add code to mark V_MUST_DEF operands for
renaming.
* tree-ssa-operands.c (opf_kill_def): New flag for killing
definitions.
(build_vdefs): Renamed to...
(build_v_may_defs): This.
(build_v_must_defs): New variable.
(voperands_d): Add v_must_def_ops and replace vdef_ops with
v_may_def_ops.
(append_vdef): Replace with...
(append_v_may_def): This.
(append_v_must_def): New function.
(NUM_FREE): Increment for V_MUST_DEF
(optype_freelist): Increment its size for V_MUST_DEF
(allocate_vdef_optype): Replace with...
(allocate_v_may_def_optype): This.
(allocate_v_must_def_optype): New function.
(free_vdefs): Replace with...
(free_v_may_defs): This.
(free_v_must_defs): New function.
(remove_vdefs): Replace with...
(remove_v_may_defs): This.
(remove_v_must_defs): New function.
(init_ssa_operands): Rename occurences of vdef to v_may_def. Also
add code to initialize build_v_must_defs.
(finalize_ssa_vdefs): Replace with...
(finalize_ssa_v_may_defs): This.
(finalize_ssa_vuses): Rename occurences of vdef to v_may_def.
(finalize_ssa_v_must_defs): New function.
(finalize_ssa_stmt_operands): Replace call to finalize_ssa_vdefs
with calls to finalize_ssa_v_may_defs and finalize_ssa_v_must_defs.
(verify_start_operands): Rename occurences of vdef to v_may_def.
Also add check for build_v_must_defs.
(get_stmt_operands): Rename occurences of vdef to v_may_def.
Also add code to handle V_MUST_DEFs and to use opf_kill_def for
killing definitions.
(get_expr_operands): Update comment and use opf_kill_def for
killing definitions.
(add_stmt_operand): Replace code that appends VDEFs with code
that appends V_MUST_DEFs when opf_kill_def is set and V_MAY_DEFs
otherwise.
(add_call_clobber_ops): Update comments.
* tree-ssa-operands.h (vdef_optype_d): Replace with...
(v_may_def_optype_d): This.
(v_must_def_optype_d): New structure.
(VDEF_OPS): Replace with...
(V_MAY_DEF_OPS): This.
(STMT_VDEF_OPS): Same with...
(STMT_V_MAY_DEF_OPS): This.
(NUM_VDEFS): And...
(NUM_V_MAY_DEFS): This.
(VDEF_RESULT_PTR): As well as...
(V_MAY_DEF_RESULT_PTR): This.
(VDEF_RESULT): Same goes for...
(V_MAY_DEF_RESULT): This.
(VDEF_OP_PTR): And...
(V_MAY_DEF_OP_PTR): This.
(VDEF_OP): And...
(V_MAY_DEF_OP): This.
(V_MUST_DEF_OPS): New macro.
(STMT_V_MUST_DEF_OPS): Ditto.
(NUM_V_MUST_DEFS): Ditto.
(V_MUST_DEF_OP_PTR): Ditto.
(V_MUST_DEF_OP): Ditto.
(remove_vdefs): Replace signature with...
(remove_v_may_defs): This.
(remove_v_must_defs): New function signature.
* tree-ssa-pre.c (subst_phis): Replace call to remove_vdefs
with calls to remove_v_may_defs and remove_v_must_defs.
(process_left_occs_and_kills): Rename occurences of vdef to v_may_def.
Also add code that marks left occurences of operands in V_MUST_DEFs.
* tree-tailcall.c (find_tail_calls): Rename occurences of vdef
to v_may_def. Also add check for V_MUST_DEFs.
(eliminate_tail_call):Rename occurences of vdef to v_may_def.
testsuite:
* gcc.dg/tree-ssa/20031015-1.c: Scan for
V_MAY_DEF instead of VDEF.
* gcc.dg/tree-ssa/20040517-1.c: Ditto.
From-SVN: r82947
Diffstat (limited to 'gcc/doc')
-rw-r--r-- | gcc/doc/tree-ssa.texi | 48 |
1 files changed, 31 insertions, 17 deletions
diff --git a/gcc/doc/tree-ssa.texi b/gcc/doc/tree-ssa.texi index 56ccd61..a22b494 100644 --- a/gcc/doc/tree-ssa.texi +++ b/gcc/doc/tree-ssa.texi @@ -697,8 +697,17 @@ variable @code{b} is completely modified with the contents of variable @code{a}. Real definition are also known as @dfn{killing definitions}. Similarly, the use of @code{a} reads all its bits. -In contrast, virtual operands represent partial or ambiguous -references to a variable. For instance, given +In contrast, virtual operands are used with variables that can have +a partial or ambiguous reference. This includes structures, arrays, +globals, and aliased variables. In these cases, we have two types of +definitions. For globals, structures, and arrays, we can determine from +a statement whether a variable of these types has a killing definition. +If the variable does, then the statement is marked as having a +@dfn{must definition} of that variable. However, if a statement is only +defining a part of the variable (ie. a field in a structure), or if we +know that a statement might define the variable but we cannot say for sure, +then we mark that statement as having a @dfn{may definition}. For +instance, given @smallexample @{ @@ -730,8 +739,8 @@ operands, use the @option{-vops} option to @option{-fdump-tree}: p = &a; else p = &b; - # a = VDEF <a> - # b = VDEF <b> + # a = V_MAY_DEF <a> + # b = V_MAY_DEF <b> *p = 5; # VUSE <a> @@ -740,21 +749,21 @@ operands, use the @option{-vops} option to @option{-fdump-tree}: @} @end smallexample -Notice that @code{VDEF} operands have two copies of the referenced +Notice that @code{V_MAY_DEF} operands have two copies of the referenced variable. This indicates that this is not a killing definition of that variable. In this case we refer to it as a @dfn{may definition} or @dfn{aliased store}. The presence of the second copy of the -variable in the @code{VDEF} operand will become important when the +variable in the @code{V_MAY_DEF} operand will become important when the function is converted into SSA form. This will be used to link all the non-killing definitions to prevent optimizations from making incorrect assumptions about them. Operands are collected by @file{tree-ssa-operands.c}. They are stored inside each statement's annotation and can be accessed with -@code{DEF_OPS}, @code{USE_OPS}, @code{VDEF_OPS} and @code{VUSE_OPS}. -The following are all the accessor macros available to access USE -operands. To access all the other operand arrays, just change the -name accordingly: +@code{DEF_OPS}, @code{USE_OPS}, @code{V_MAY_DEF_OPS}, +@code{V_MUST_DEF_OPS} and @code{VUSE_OPS}. The following are all the +accessor macros available to access USE operands. To access all the +other operand arrays, just change the name accordingly: @defmac USE_OPS (@var{ann}) Returns the array of operands used by the statement with annotation @@ -786,7 +795,8 @@ void print_ops (tree stmt) @{ vuse_optype vuses; - vdef_optype vdefs; + v_may_def_optype v_may_defs; + v_must_def_optype v_must_defs; def_optype defs; use_optype uses; stmt_ann_t ann; @@ -803,9 +813,13 @@ print_ops (tree stmt) for (i = 0; i < NUM_USES (uses); i++) print_generic_expr (stderr, USE_OP (uses, i), 0); - vdefs = VDEF_OPS (ann); - for (i = 0; i < NUM_VDEFS (vdefs); i++) - print_generic_expr (stderr, VDEF_OP (vdefs, i), 0); + v_may_defs = V_MAY_DEF_OPS (ann); + for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++) + print_generic_expr (stderr, V_MAY_DEF_OP (v_may_defs, i), 0); + + v_must_defs = V_MUST_DEF_OPS (ann); + for (i = 0; i < NUM_V_MUST_DEFS (v_must_defs); i++) + print_generic_expr (stderr, V_MUST_DEF_OP (v_must_defs, i), 0); vuses = VUSE_OPS (ann); for (i = 0; i < NUM_VUSES (vuses); i++) @@ -1095,11 +1109,11 @@ foo (int i) p_6 = &b; # p_1 = PHI <p_4(1), p_6(2)>; - # a_7 = VDEF <a_3>; - # b_8 = VDEF <b_5>; + # a_7 = V_MAY_DEF <a_3>; + # b_8 = V_MAY_DEF <b_5>; *p_1 = 3; - # a_9 = VDEF <a_7> + # a_9 = V_MAY_DEF <a_7> # VUSE <b_8> a_9 = b_8 + 2; |