diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 7f48125a97a..2f82b7b4a91 100644 --- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -441,19 +441,23 @@ Instruction *InstCombiner::visitUDiv(BinaryOperator &I) { // Handle the integer div common cases if (Instruction *Common = commonIDivTransforms(I)) return Common; - - if (ConstantInt *C = dyn_cast(Op1)) { + + { // X udiv 2^C -> X >> C // Check to see if this is an unsigned division with an exact power of 2, // if so, convert to a right shift. - if (C->getValue().isPowerOf2()) { // 0 not included in isPowerOf2 + const APInt *C; + if (match(Op1, m_Power2(C))) { BinaryOperator *LShr = - BinaryOperator::CreateLShr(Op0, - ConstantInt::get(Op0->getType(), C->getValue().logBase2())); + BinaryOperator::CreateLShr(Op0, + ConstantInt::get(Op0->getType(), + C->logBase2())); if (I.isExact()) LShr->setIsExact(); return LShr; } + } + if (ConstantInt *C = dyn_cast(Op1)) { // X udiv C, where C >= signbit if (C->getValue().isNegative()) { Value *IC = Builder->CreateICmpULT(Op0, C); diff --git a/test/CodeGen/X86/vec_udiv_to_shift.ll b/test/CodeGen/X86/vec_udiv_to_shift.ll new file mode 100644 index 00000000000..e325f61c9f3 --- /dev/null +++ b/test/CodeGen/X86/vec_udiv_to_shift.ll @@ -0,0 +1,15 @@ +; RUN: opt < %s -instcombine -S | FileCheck %s + +define <8 x i16> @udiv_vec8x16(<8 x i16> %var) { +entry: +; CHECK: lshr <8 x i16> %var, +%0 = udiv <8 x i16> %var, +ret <8 x i16> %0 +} + +define <4 x i32> @udiv_vec4x32(<4 x i32> %var) { +entry: +; CHECK: lshr <4 x i32> %var, +%0 = udiv <4 x i32> %var, +ret <4 x i32> %0 +} \ No newline at end of file