This patch enables canonicalization of SPF_ABS and SPF_ABS
to the abs intrinsic.
This is a recommit, the original try was
05d4c4ebc2,
but it was reverted due to an apparent miscompile,
which since then has just been fixed by the previous commit.
Differential Revision: https://reviews.llvm.org/D87188
Enable canonicalization of SPF_ABS and SPF_NABS to the abs intrinsic.
To be conservative, the one-use check on the comparison is retained,
this may be relaxed if all goes well.
It's pretty likely that this will uncover places that missing
handling for the abs() intrinsic. Please report any seen performance
regressions.
Differential Revision: https://reviews.llvm.org/D87188
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
Also, produce the canonical IR abs (s<0) to be more efficient.
This is the libcall equivalent of the clang builtin change from:
rL333038
Pasting from that commit message:
The stdlib functions are defined in section 7.20.6.1 of the C standard with:
"If the result cannot be represented, the behavior is undefined."
That lets us mark the negation with 'nsw' because "sub i32 0, INT_MIN" would
be UB/poison.
llvm-svn: 333042
Roman Lebedev