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author | Richard Sandiford <richard.sandiford@arm.com> | 2019-07-18 08:24:16 +0000 |
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committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2019-07-18 08:24:16 +0000 |
commit | f1f10541903b082d27114db38947fb31f5364bcc (patch) | |
tree | 81b40e730cc48482b0a65592b9ea5e4372ae654b /gcc/basic-block.h | |
parent | d119bf79862015d4ba3c7f8774835c216c9a26ed (diff) | |
download | gcc-f1f10541903b082d27114db38947fb31f5364bcc.zip gcc-f1f10541903b082d27114db38947fb31f5364bcc.tar.gz gcc-f1f10541903b082d27114db38947fb31f5364bcc.tar.bz2 |
Make ifcvt clean up dead comparisons
This change is needed to avoid a regression in gcc.dg/ifcvt-3.c
for a later patch. Without it, we enter CSE with a dead comparison left
by if-conversion and then eliminate the second (live) comparison in
favour of the dead one. That's functionally correct in itself, but it
meant that we'd combine the subtraction and comparison into a SUBS
before we have a chance to fold away the subtraction.
2019-07-18 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* basic-block.h (CLEANUP_FORCE_FAST_DCE): New macro.
* cfgcleanup.c (cleanup_cfg): Call run_fast_dce if
CLEANUP_FORCE_FAST_DCE is set.
* ifcvt.c (rest_of_handle_if_conversion): Pass
CLEANUP_FORCE_FAST_DCE to the final cleanup_cfg call if
if-conversion succeeded.
From-SVN: r273569
Diffstat (limited to 'gcc/basic-block.h')
-rw-r--r-- | gcc/basic-block.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/gcc/basic-block.h b/gcc/basic-block.h index 5e0fbc0..2a0e826 100644 --- a/gcc/basic-block.h +++ b/gcc/basic-block.h @@ -508,6 +508,8 @@ ei_cond (edge_iterator ei, edge *p) #define CLEANUP_CFGLAYOUT 32 /* Do cleanup in cfglayout mode. */ #define CLEANUP_CFG_CHANGED 64 /* The caller changed the CFG. */ #define CLEANUP_NO_PARTITIONING 128 /* Do not try to fix partitions. */ +#define CLEANUP_FORCE_FAST_DCE 0x100 /* Force run_fast_dce to be called + at least once. */ /* Return true if BB is in a transaction. */ |