Commit Graph

7 Commits

Author SHA1 Message Date
Tim Northover 12c1f7675f InstCombine: move hasOneUse check to the top of foldICmpAddConstant
There were two combines not covered by the check before now, neither of which
actually differed from normal in the benefit analysis.

The most recent seems to be because it was just added at the top of the
function (naturally). The older is from way back in 2008 (r46687) when we just
didn't put those checks in so routinely, and has been diligently maintained
since.

llvm-svn: 341831
2018-09-10 14:26:44 +00:00
Nicola Zaghen 9588ad9611 [InstCombine] Fold icmp ugt/ult (add nuw X, C2), C --> icmp ugt/ult X, (C - C2)
Support for sgt/slt was added in rL294898, this adds the same cases also for unsigned compares.

This is the Alive proof: https://rise4fun.com/Alive/nyY

Differential Revision: https://reviews.llvm.org/D50972

llvm-svn: 341353
2018-09-04 10:29:48 +00:00
Max Kazantsev 20da7e467a Revert "[InstCombine] Delay foldICmpUsingKnownBits until simple transforms are done"
llvm-svn: 336410
2018-07-06 04:04:13 +00:00
Max Kazantsev 3097b76e8c [InstCombine] Delay foldICmpUsingKnownBits until simple transforms are done
This patch changes order of transform in InstCombineCompares to avoid
performing transforms based on ranges which produce complex bit arithmetics
before more simple things (like folding with constants) are done. See PR37636
for the motivating example.

Differential Revision: https://reviews.llvm.org/D48584
Reviewed By: spatel, lebedev.ri

llvm-svn: 336172
2018-07-03 06:23:57 +00:00
Nikolai Bozhenov 4d5e34b221 [ValueTracking] Adding missed lit-test for commit r316208
Reviewers: reames, hfinkel

Differential Revision: https://reviews.llvm.org/D34101

Patch by: Olga Chupina <olga.chupina@intel.com>

llvm-svn: 321792
2018-01-04 10:02:50 +00:00
Chandler Carruth 37c7b08710 [ValueTracking] Revert r310583 which enabled functionality that still is
causing compile time issues.

Moreover, the patch *deleted* the flag in addition to changing the
default, and links to a code review that doesn't even discuss the flag
and just has an update to a Clang test case.

I've followed up on the commit thread to ask for numbers on compile time
at this point, leaving the flag in place until things stabilize, and
pointing at specific code that seems to exhibit excessive compile time
with this patch.

Original commit message for r310583:
"""
[ValueTracking] Enabling ValueTracking patch by default (recommit). Part 2.

The original patch was an improvement to IR ValueTracking on
non-negative integers. It has been checked in to trunk (D18777,
r284022). But was disabled by default due to performance regressions.
Perf impact has improved. The patch would be enabled by default.
""""

llvm-svn: 310816
2017-08-14 07:03:24 +00:00
Nikolai Bozhenov d97136c182 [ValueTracking] Enabling ValueTracking patch by default (recommit). Part 2.
The original patch was an improvement to IR ValueTracking on non-negative
integers. It has been checked in to trunk (D18777, r284022). But was disabled by
default due to performance regressions.
Perf impact has improved. The patch would be enabled by default.
 
Reviewers: reames, hfinkel
 
Differential Revision: https://reviews.llvm.org/D34101
 
Patch by: Olga Chupina <olga.chupina@intel.com>

llvm-svn: 310583
2017-08-10 11:24:57 +00:00