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| author | Duncan Sands <baldrick@free.fr> | 2011-01-30 18:03:50 +0000 |
|---|---|---|
| committer | Duncan Sands <baldrick@free.fr> | 2011-01-30 18:03:50 +0000 |
| commit | 1895e98ef38afbe011575cc25f4889d96e37421b (patch) | |
| tree | 19f30e63e5aa7c09797f0d200d8e5935b9616bed /test/Transforms/InstSimplify | |
| parent | 9b108a338d544a6baf2ff087055326e301e6815d (diff) | |
| download | llvm-1895e98ef38afbe011575cc25f4889d96e37421b.tar.gz llvm-1895e98ef38afbe011575cc25f4889d96e37421b.tar.bz2 llvm-1895e98ef38afbe011575cc25f4889d96e37421b.tar.xz | |
Transform (X/Y)*Y into X if the division is exact. Instcombine already knows how
to do this and more, but would only do it if X/Y had only one use. Spotted as the
most common missed simplification in SPEC by my auto-simplifier, now that it knows
about nuw/nsw/exact flags. This removes a bunch of multiplications from 447.dealII
and 483.xalancbmk. It also removes a lot from tramp3d-v4, which results in much
more inlining.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124560 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/InstSimplify')
| -rw-r--r-- | test/Transforms/InstSimplify/2010-12-20-Reassociate.ll | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/test/Transforms/InstSimplify/2010-12-20-Reassociate.ll b/test/Transforms/InstSimplify/2010-12-20-Reassociate.ll index 13724669d7..928442ac56 100644 --- a/test/Transforms/InstSimplify/2010-12-20-Reassociate.ll +++ b/test/Transforms/InstSimplify/2010-12-20-Reassociate.ll @@ -119,6 +119,24 @@ define i32 @sdiv3(i32 %x, i32 %y) { ; CHECK: ret i32 0 } +define i32 @sdiv4(i32 %x, i32 %y) { +; CHECK: @sdiv4 +; (X / Y) * Y -> X if the division is exact + %div = sdiv exact i32 %x, %y + %mul = mul i32 %div, %y + ret i32 %mul +; CHECK: ret i32 %x +} + +define i32 @sdiv5(i32 %x, i32 %y) { +; CHECK: @sdiv5 +; Y * (X / Y) -> X if the division is exact + %div = sdiv exact i32 %x, %y + %mul = mul i32 %y, %div + ret i32 %mul +; CHECK: ret i32 %x +} + define i32 @udiv1(i32 %x, i32 %y) { ; CHECK: @udiv1 ; (no overflow X * Y) / Y -> X |