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| author | Sanjay Patel <spatel@rotateright.com> | 2018-05-30 23:55:12 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2018-05-30 23:55:12 +0000 |
| commit | ceb595b04e88f6d0da922a9631bb3edf715480fc (patch) | |
| tree | 5529c7d36094c2579f68edc40334e324696cad7e /llvm/test/Transforms | |
| parent | 61763b65af94107b75ec5be8797b7a845c626930 (diff) | |
| download | bcm5719-llvm-ceb595b04e88f6d0da922a9631bb3edf715480fc.tar.gz bcm5719-llvm-ceb595b04e88f6d0da922a9631bb3edf715480fc.zip | |
[InstCombine] don't negate constant expression with fsub (PR37605)
X + (-C) would be transformed back into X - C, so infinite loop:
https://bugs.llvm.org/show_bug.cgi?id=37605
llvm-svn: 333610
Diffstat (limited to 'llvm/test/Transforms')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/fsub.ll | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/fsub.ll b/llvm/test/Transforms/InstCombine/fsub.ll index 9ce73084f79..22295490cc6 100644 --- a/llvm/test/Transforms/InstCombine/fsub.ll +++ b/llvm/test/Transforms/InstCombine/fsub.ll @@ -242,3 +242,17 @@ define float @neg_trunc_op1_extra_uses(double %a, float %b) { ret float %t3 } +; Don't negate a constant expression to form fadd and induce infinite looping: +; https://bugs.llvm.org/show_bug.cgi?id=37605 + +@b = external global i16, align 1 + +define float @PR37605(float %conv) { +; CHECK-LABEL: @PR37605( +; CHECK-NEXT: [[SUB:%.*]] = fsub float [[CONV:%.*]], bitcast (i32 ptrtoint (i16* @b to i32) to float) +; CHECK-NEXT: ret float [[SUB]] +; + %sub = fsub float %conv, bitcast (i32 ptrtoint (i16* @b to i32) to float) + ret float %sub +} + |
