diff options
| author | Evan Cheng <evan.cheng@apple.com> | 2012-06-21 22:52:49 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2012-06-21 22:52:49 +0000 |
| commit | 2a5422b1a6955977d05af48222c86c77c7549484 (patch) | |
| tree | 8615d9db28212cc9b74bb852b0b2baeca27a471d | |
| parent | 5791df830dd8bc91f44aff98446d5f74a96ae185 (diff) | |
Look pass zext to strength reduce an udiv. Patch by David Majnemer. rdar://11721329
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158946 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 5 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/div-shift.ll | 23 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/sdiv-shift.ll | 9 |
3 files changed, 27 insertions, 10 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 5168e2a113..35a0bbb761 100644 --- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -464,9 +464,12 @@ Instruction *InstCombiner::visitUDiv(BinaryOperator &I) { // X udiv (C1 << N), where C1 is "1<<C2" --> X >> (N+C2) { const APInt *CI; Value *N; - if (match(Op1, m_Shl(m_Power2(CI), m_Value(N)))) { + if (match(Op1, m_Shl(m_Power2(CI), m_Value(N))) || + match(Op1, m_ZExt(m_Shl(m_Power2(CI), m_Value(N))))) { if (*CI != 1) N = Builder->CreateAdd(N, ConstantInt::get(I.getType(),CI->logBase2())); + if (ZExtInst *Z = dyn_cast<ZExtInst>(Op1)) + N = Builder->CreateZExt(N, Z->getDestTy()); if (I.isExact()) return BinaryOperator::CreateExactLShr(Op0, N); return BinaryOperator::CreateLShr(Op0, N); diff --git a/test/Transforms/InstCombine/div-shift.ll b/test/Transforms/InstCombine/div-shift.ll new file mode 100644 index 0000000000..a07f3ea949 --- /dev/null +++ b/test/Transforms/InstCombine/div-shift.ll @@ -0,0 +1,23 @@ +; RUN: opt < %s -instcombine -S | FileCheck %s + +define i32 @t1(i16 zeroext %x, i32 %y) nounwind { +entry: +; CHECK: t1 +; CHECK-NOT: sdiv +; CHECK: lshr i32 %conv + %conv = zext i16 %x to i32 + %s = shl i32 2, %y + %d = sdiv i32 %conv, %s + ret i32 %d +} + +; rdar://11721329 +define i64 @t2(i64 %x, i32 %y) nounwind { +; CHECK: t2 +; CHECK-NOT: udiv +; CHECK: lshr i64 %x + %1 = shl i32 1, %y + %2 = zext i32 %1 to i64 + %3 = udiv i64 %x, %2 + ret i64 %3 +} diff --git a/test/Transforms/InstCombine/sdiv-shift.ll b/test/Transforms/InstCombine/sdiv-shift.ll deleted file mode 100644 index f4d2b36cbb..0000000000 --- a/test/Transforms/InstCombine/sdiv-shift.ll +++ /dev/null @@ -1,9 +0,0 @@ -; RUN: opt < %s -instcombine -S | not grep div - -define i32 @a(i16 zeroext %x, i32 %y) nounwind { -entry: - %conv = zext i16 %x to i32 - %s = shl i32 2, %y - %d = sdiv i32 %conv, %s - ret i32 %d -} |