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| author | Stuart Hastings <stuart@apple.com> | 2011-05-30 20:00:33 +0000 |
|---|---|---|
| committer | Stuart Hastings <stuart@apple.com> | 2011-05-30 20:00:33 +0000 |
| commit | acbf107d9b9ffeddbcc3d015107c6faff439ee9b (patch) | |
| tree | fa2416cfb76ac9b8fd8c0176472ad4ea198c237a /test | |
| parent | 67dc11352df491a6be79b615f0920ff377bcae5d (diff) | |
| download | llvm-acbf107d9b9ffeddbcc3d015107c6faff439ee9b.tar.gz llvm-acbf107d9b9ffeddbcc3d015107c6faff439ee9b.tar.bz2 llvm-acbf107d9b9ffeddbcc3d015107c6faff439ee9b.tar.xz | |
(1 - X) * (-2) -> (x - 1) * 2, for all positive nonzero powers of 2
rdar://problem/6501862
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132316 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/Transforms/InstCombine/2011-05-28-swapmulsub.ll | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/2011-05-28-swapmulsub.ll b/test/Transforms/InstCombine/2011-05-28-swapmulsub.ll new file mode 100644 index 0000000000..e4417ef96a --- /dev/null +++ b/test/Transforms/InstCombine/2011-05-28-swapmulsub.ll @@ -0,0 +1,24 @@ +; ModuleID = 'test1.c' +; RUN: opt -S -instcombine < %s | FileCheck %s +target triple = "x86_64-apple-macosx10.6.6" + +define zeroext i16 @foo(i32 %on_off, i16* %puls) nounwind uwtable ssp { +entry: + %on_off.addr = alloca i32, align 4 + %puls.addr = alloca i16*, align 8 + %a = alloca i32, align 4 + store i32 %on_off, i32* %on_off.addr, align 4 + store i16* %puls, i16** %puls.addr, align 8 + %tmp = load i32* %on_off.addr, align 4 +; CHECK-NOT: sub +; CHECK-NOT: mul +; (1 - %tmp) * (-2) -> (%tmp - 1) * 2 + %sub = sub i32 1, %tmp + %mul = mul i32 %sub, -2 +; CHECK: shl +; CHECK-NEXT: add + store i32 %mul, i32* %a, align 4 + %tmp1 = load i32* %a, align 4 + %conv = trunc i32 %tmp1 to i16 + ret i16 %conv +} |