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| author | David Majnemer <david.majnemer@gmail.com> | 2017-01-17 00:45:57 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2017-01-17 00:45:57 +0000 |
| commit | 36d382b773bd83daf7304e3a5d11a828e3316e2c (patch) | |
| tree | c2e98b8f5765991398253af319c619dcc643430e /llvm/test/Transforms/InstCombine/and.ll | |
| parent | c8cc2be9f847a8c81ae9f97009b4af1e71eb6e1f (diff) | |
| download | bcm5719-llvm-36d382b773bd83daf7304e3a5d11a828e3316e2c.tar.gz bcm5719-llvm-36d382b773bd83daf7304e3a5d11a828e3316e2c.zip | |
[InstCombine] Fold ((C1-zext(X)) & C2) -> zext((C1-X) & C2)
This is valid if C2 fits within the bitwidth of X thanks to two's
complement modulo arithmetic.
llvm-svn: 292179
Diffstat (limited to 'llvm/test/Transforms/InstCombine/and.ll')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/and.ll | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/and.ll b/llvm/test/Transforms/InstCombine/and.ll index e45012878ed..ee1dfbbe12e 100644 --- a/llvm/test/Transforms/InstCombine/and.ll +++ b/llvm/test/Transforms/InstCombine/and.ll @@ -425,3 +425,14 @@ define <2 x i32> @PR24942(<2 x i32> %x) { ret <2 x i32> %and } +define i64 @test35(i32 %X) { +; CHECK-LABEL: @test35( +; CHECK-NEXT: %[[sub:.*]] = sub i32 0, %X +; CHECK-NEXT: %[[and:.*]] = and i32 %[[sub]], 240 +; CHECK-NEXT: %[[cst:.*]] = zext i32 %[[and]] to i64 +; CHECK-NEXT: ret i64 %[[cst]] + %zext = zext i32 %X to i64 + %zsub = sub i64 0, %zext + %res = and i64 %zsub, 240 + ret i64 %res +} |
