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| author | Wilco Dijkstra <wdijkstr@arm.com> | 2017-09-05 17:22:51 +0000 |
|---|---|---|
| committer | Wilco Dijkstra <wilco@gcc.gnu.org> | 2017-09-05 17:22:51 +0000 |
| commit | e5fc06a3d339c7db391f199c51354f61a033b555 (patch) | |
| tree | 1537c9c18f0dd49c1bc42405a1848868f550833f | |
| parent | f174328efedff73f53cad8848fe69f92e940309a (diff) | |
| download | gcc-e5fc06a3d339c7db391f199c51354f61a033b555.zip gcc-e5fc06a3d339c7db391f199c51354f61a033b555.tar.gz gcc-e5fc06a3d339c7db391f199c51354f61a033b555.tar.bz2 | |
Improve max_insns_skipped logic
Improve the logic when setting max_insns_skipped. Limit the maximum size of IT
to MAX_INSN_PER_IT_BLOCK as otherwise multiple IT instructions are needed,
increasing codesize. Given 4 works well for Thumb-2, use the same limit for ARM
for consistency.
gcc/
* config/arm/arm.c (arm_option_params_internal): Improve setting of
max_insns_skipped.
From-SVN: r251720
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/config/arm/arm.c | 18 |
2 files changed, 10 insertions, 13 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index fa34e13..99a3a76 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2017-09-05 Wilco Dijkstra <wdijkstr@arm.com> + + * config/arm/arm.c (arm_option_params_internal): Improve setting of + max_insns_skipped. + 2017-09-05 H.J. Lu <hongjiu.lu@intel.com> PR target/59501 diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 4870957..0094c0e 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -2873,20 +2873,12 @@ arm_option_params_internal (void) targetm.max_anchor_offset = TARGET_MAX_ANCHOR_OFFSET; } - if (optimize_size) - { - /* If optimizing for size, bump the number of instructions that we - are prepared to conditionally execute (even on a StrongARM). */ - max_insns_skipped = 6; + /* Increase the number of conditional instructions with -Os. */ + max_insns_skipped = optimize_size ? 4 : current_tune->max_insns_skipped; - /* For THUMB2, we limit the conditional sequence to one IT block. */ - if (TARGET_THUMB2) - max_insns_skipped = arm_restrict_it ? 1 : 4; - } - else - /* When -mrestrict-it is in use tone down the if-conversion. */ - max_insns_skipped = (TARGET_THUMB2 && arm_restrict_it) - ? 1 : current_tune->max_insns_skipped; + /* For THUMB2, we limit the conditional sequence to one IT block. */ + if (TARGET_THUMB2) + max_insns_skipped = MIN (max_insns_skipped, MAX_INSN_PER_IT_BLOCK); } /* True if -mflip-thumb should next add an attribute for the default |