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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2015-06-26 14:51:49 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2015-06-26 14:51:49 +0000 |
| commit | c2ae76737753a55f18a290f1e64f8bca60423449 (patch) | |
| tree | fdcb984129d8ef3720dfbdc54a2793c5510fe65a /llvm/test/CodeGen/X86/shift-combine.ll | |
| parent | 07e70b4fa4d6e2504fcd3d6c0b0415e378b937eb (diff) | |
| download | bcm5719-llvm-c2ae76737753a55f18a290f1e64f8bca60423449.tar.gz bcm5719-llvm-c2ae76737753a55f18a290f1e64f8bca60423449.zip | |
[DAGCombiner] Preserve the exact bit when simplifying SRA to SRL.
Allows more aggressive folding of ashr/shl pairs.
llvm-svn: 240788
Diffstat (limited to 'llvm/test/CodeGen/X86/shift-combine.ll')
| -rw-r--r-- | llvm/test/CodeGen/X86/shift-combine.ll | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/X86/shift-combine.ll b/llvm/test/CodeGen/X86/shift-combine.ll index 7fb19a6cad0..43301041a0b 100644 --- a/llvm/test/CodeGen/X86/shift-combine.ll +++ b/llvm/test/CodeGen/X86/shift-combine.ll @@ -37,6 +37,16 @@ define i32* @test_exact2(i32 %a, i32 %b, i32* %x) { ret i32* %gep } +define i32* @test_exact3(i32 %a, i32 %b, i32* %x) { +; CHECK-LABEL: test_exact3: +; CHECK-NOT: sarl + + %sub = sub i32 %b, %a + %shr = ashr exact i32 %sub, 2 + %gep = getelementptr inbounds i32, i32* %x, i32 %shr + ret i32* %gep +} + define i32* @test_exact4(i32 %a, i32 %b, i32* %x) { ; CHECK-LABEL: test_exact4: ; CHECK: shrl % |
