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| author | David Majnemer <david.majnemer@gmail.com> | 2013-06-29 23:44:53 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2013-06-29 23:44:53 +0000 |
| commit | 58b6dc032a668e637a9a9e63290652f32d372a5f (patch) | |
| tree | 85da3febc257d052ac3db7aaade17e71b867acd6 /test/Transforms | |
| parent | bebf6222f6b7cc871cfbc51f78cdb33d17fedb6c (diff) | |
ValueTracking: Teach isKnownToBeAPowerOfTwo about (ADD X, (XOR X, Y)) where X is a power of two
This allows us to simplify urem instructions involving the add+xor to
turn into simpler math.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185272 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms')
| -rw-r--r-- | test/Transforms/InstCombine/rem.ll | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/rem.ll b/test/Transforms/InstCombine/rem.ll index 808d51eba1d..2b49385b922 100644 --- a/test/Transforms/InstCombine/rem.ll +++ b/test/Transforms/InstCombine/rem.ll @@ -163,3 +163,18 @@ define i32 @test16(i32 %x, i32 %y) { %rem = urem i32 %x, %add ret i32 %rem } + +define i32 @test17(i16 %x, i32 %y) { +; CHECK: @test17 +; CHECK-NEXT: [[AND:%.*]] = and i16 %x, 4 +; CHECK-NEXT: [[EXT:%.*]] = zext i16 [[AND]] to i32 +; CHECK-NEXT: [[SHL:%.*]] = shl nuw nsw i32 [[EXT]], 3 +; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[SHL]], 63 +; CHECK-NEXT: [[REM:%.*]] = and i32 [[XOR]], %y +; CHECK-NEXT: ret i32 [[REM]] + %1 = and i16 %x, 4 + %2 = icmp ne i16 %1, 0 + %3 = select i1 %2, i32 32, i32 64 + %4 = urem i32 %y, %3 + ret i32 %4 +} |