[PATCH] D34336: [x86] transform vector inc/dec to use -1 constant (PR33483)
Sanjay Patel via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Mon Jun 19 08:09:04 PDT 2017
spatel added a comment.
Here's a test loop:
F3453503: inc_test.c <https://reviews.llvm.org/F3453503>
And asm (Linux x86 flavor):
F3453504: inc.s <https://reviews.llvm.org/F3453504>
compile with:
$ clang -O1 inc_test.c inc.s
I used this to benchmark this transform on Haswell and Jaguar, but I couldn't measure any difference. I also had expanded versions of the asm that repeated the padd/psub up to 128 times...but still no perf diff on either chip.
https://reviews.llvm.org/D34336
More information about the llvm-commits
mailing list