diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 5168e2a113ca..35a0bbb76146 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -464,9 +464,12 @@ Instruction *InstCombiner::visitUDiv(BinaryOperator &I) { // X udiv (C1 << N), where C1 is "1< 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(Op1)) + N = Builder->CreateZExt(N, Z->getDestTy()); if (I.isExact()) return BinaryOperator::CreateExactLShr(Op0, N); return BinaryOperator::CreateLShr(Op0, N); diff --git a/llvm/test/Transforms/InstCombine/div-shift.ll b/llvm/test/Transforms/InstCombine/div-shift.ll new file mode 100644 index 000000000000..a07f3ea94914 --- /dev/null +++ b/llvm/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/llvm/test/Transforms/InstCombine/sdiv-shift.ll b/llvm/test/Transforms/InstCombine/sdiv-shift.ll deleted file mode 100644 index f4d2b36cbbf8..000000000000 --- a/llvm/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 -}