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| author | Eric Botcazou <ebotcazou@adacore.com> | 2012-06-15 09:22:00 +0000 |
|---|---|---|
| committer | Eric Botcazou <ebotcazou@gcc.gnu.org> | 2012-06-15 09:22:00 +0000 |
| commit | 2da02156af964dbd197f19cbd7fea003a73aacb3 (patch) | |
| tree | 25c62c51c178ea6a10880eb537b869fdb857970d /gcc/dce.c | |
| parent | 6724292e72a9bdbafb0d95587740378f36036707 (diff) | |
| download | gcc-2da02156af964dbd197f19cbd7fea003a73aacb3.tar.gz | |
re PR middle-end/53590 (compiler fails to generate SIMD instruction for FP division)
PR middle-end/53590
* common.opt (-fdelete-dead-exceptions): New switch.
* doc/invoke.texi (Code Gen Options): Document it.
* cse.c (count_reg_usage) <CALL_INSN>: Use !insn_nothrow_p in lieu of
insn_could_throw_p predicate. Do not skip an insn that could throw
if dead exceptions can be deleted.
(insn_live_p): Likewise, do not return true in that case.
* dce.c (can_alter_cfg): New flag.
(deletable_insn_p): Do not return false for an insn that can throw if
the CFG can be altered and dead exceptions can be deleted.
(init_dce): Set can_alter_cfg to false for fast DCE, true otherwise.
* dse.c (scan_insn): Use !insn_nothrow_p in lieu of insn_could_throw_
predicate. Do not preserve an insn that could throw if dead exceptions
can be deleted.
* function.h (struct function): Add can_delete_dead_exceptions flag.
* function.c (allocate_struct_function): Set it.
* lto-streamer-in.c (input_struct_function_base): Stream it.
* lto-streamer-out.c (input_struct_function_base): Likewise.
* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Do not mark a
statement that could throw as necessary if dead exceptions can be
deleted.
ada/
* gcc-interface/misc.c (gnat_init_options_struct): Set
opts->x_flag_delete_dead_exceptions to 1.
From-SVN: r188651
Diffstat (limited to 'gcc/dce.c')
| -rw-r--r-- | gcc/dce.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/gcc/dce.c b/gcc/dce.c index 86edea11c55..8954d5c0c01 100644 --- a/gcc/dce.c +++ b/gcc/dce.c @@ -47,6 +47,9 @@ along with GCC; see the file COPYING3. If not see we don't want to reenter it. */ static bool df_in_progress = false; +/* True if we are allowed to alter the CFG in this pass. */ +static bool can_alter_cfg = false; + /* Instructions that have been marked but whose dependencies have not yet been processed. */ static VEC(rtx,heap) *worklist; @@ -113,8 +116,9 @@ deletable_insn_p (rtx insn, bool fast, bitmap arg_stores) if (!NONJUMP_INSN_P (insn)) return false; - /* Don't delete insns that can throw. */ - if (!insn_nothrow_p (insn)) + /* Don't delete insns that may throw if we cannot do so. */ + if (!(cfun->can_delete_dead_exceptions && can_alter_cfg) + && !insn_nothrow_p (insn)) return false; body = PATTERN (insn); @@ -711,7 +715,10 @@ init_dce (bool fast) { bitmap_obstack_initialize (&dce_blocks_bitmap_obstack); bitmap_obstack_initialize (&dce_tmp_bitmap_obstack); + can_alter_cfg = false; } + else + can_alter_cfg = true; marked = sbitmap_alloc (get_max_uid () + 1); sbitmap_zero (marked); |