Commit Graph

7 Commits

Author SHA1 Message Date
Jim Grosbach
cbf676b3ba float comparison to double 'zero' constant can just be a float 'zero.'
InstCombine was incorrectly considering the conversion of the constant
zero to be unsafe.

We want to transform:
define float @bar(float %x) nounwind readnone optsize ssp {
  %conv = fpext float %x to double
  %cmp = fcmp olt double %conv, 0.000000e+00
  %conv1 = zext i1 %cmp to i32
  %conv2 = sitofp i32 %conv1 to float
  ret float %conv2
}

Into:
define float @bar(float %x) nounwind readnone optsize ssp {
  %cmp = fcmp olt float %x, 0.000000e+00   ; <---- This
  %conv1 = zext i1 %cmp to i32
  %conv2 = sitofp i32 %conv1 to float
  ret float %conv2
}


rdar://10215914


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140869 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-30 18:45:50 +00:00
Benjamin Kramer
7ebdc37d2b InstCombine: APFloat can't perform arithmetic on PPC double doubles, don't even try.
Thanks Eli!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128676 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 21:35:49 +00:00
Benjamin Kramer
00e00d693c InstCombine: Fix transform to use the swapped predicate.
Thanks Frits!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128628 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:46:03 +00:00
Benjamin Kramer
68b4bd0a63 InstCombine: fold fcmp (fneg x), (fneg y) -> fcmp x, y
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128627 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:12:22 +00:00
Benjamin Kramer
0db50189dc InstCombine: fold fcmp pred (fneg x), C -> fcmp swap(pred) x, -C
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128626 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:12:15 +00:00
Benjamin Kramer
b194bdc03b InstCombine: Shrink "fcmp (fpext x), C" to "fcmp x, C" if C can be losslessly converted to the type of x.
Fixes PR9592.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128625 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:12:07 +00:00
Benjamin Kramer
cd0274ca18 InstCombine: fold fcmp (fpext x), (fpext y) -> fcmp x, y.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128624 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:11:58 +00:00