Index: lib/Transforms/Vectorize/LoopVectorize.cpp =================================================================== --- lib/Transforms/Vectorize/LoopVectorize.cpp +++ lib/Transforms/Vectorize/LoopVectorize.cpp @@ -7154,8 +7154,9 @@ Type *VectorTy; unsigned C = getInstructionCost(I, VF, VectorTy); - bool TypeNotScalarized = - VF > 1 && !VectorTy->isVoidTy() && TTI.getNumberOfParts(VectorTy) < VF; + bool TypeNotScalarized = VF > 1 && !VectorTy->isVoidTy() && + TTI.getNumberOfParts(VectorTy) < VF && + VectorTy->isVectorTy(); return VectorizationCostTy(C, TypeNotScalarized); } @@ -7238,7 +7239,7 @@ Type *RetTy = I->getType(); if (canTruncateToMinimalBitwidth(I, VF)) RetTy = IntegerType::get(RetTy->getContext(), MinBWs[I]); - VectorTy = ToVectorTy(RetTy, VF); + VectorTy = isScalarAfterVectorization(I, VF) ? RetTy : ToVectorTy(RetTy, VF); auto SE = PSE.getSE(); // TODO: We need to estimate the cost of intrinsic calls. @@ -7371,9 +7372,10 @@ } else if (Legal->isUniform(Op2)) { Op2VK = TargetTransformInfo::OK_UniformValue; } - SmallVector Operands(I->operand_values()); - return TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy, Op1VK, - Op2VK, Op1VP, Op2VP, Operands); + SmallVector Operands(I->operand_values()); + unsigned N = isScalarAfterVectorization(I, VF) ? VF : 1; + return N * TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy, Op1VK, + Op2VK, Op1VP, Op2VP, Operands); } case Instruction::Select: { SelectInst *SI = cast(I); @@ -7396,7 +7398,15 @@ } case Instruction::Store: case Instruction::Load: { - VectorTy = ToVectorTy(getMemInstValueType(I), VF); + unsigned Width = VF; + if (Width > 1) { + InstWidening Decision = getWideningDecision(I, Width); + assert(Decision != CM_Unknown && + "CM decision should be taken at this point"); + if (Decision == CM_Scalarize) + Width = 1; + } + VectorTy = ToVectorTy(getMemInstValueType(I), Width); return getMemoryInstructionCost(I, VF); } case Instruction::ZExt: Index: test/Transforms/LoopVectorize/AArch64/no_vector_instructions.ll =================================================================== --- /dev/null +++ test/Transforms/LoopVectorize/AArch64/no_vector_instructions.ll @@ -0,0 +1,25 @@ +; RUN: opt < %s -loop-vectorize -force-vector-interleave=1 -S --debug-only=loop-vectorize 2>&1 | FileCheck %s + +target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128" +target triple = "aarch64--linux-gnu" + +; CHECK-LABEL: all_scalar +; CHECK: LV: Found scalar instruction: %i.next = add nuw nsw i64 %i, 2 +; CHECK: LV: Found an estimated cost of 2 for VF 2 For instruction: %i.next = add nuw nsw i64 %i, 2 +; CHECK: LV: Not considering vector loop of width 2 because it will not generate any vector instructions +; +define void @all_scalar(i64* %a, i64 %n) { +entry: + br label %for.body + +for.body: + %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ] + %tmp0 = getelementptr i64, i64* %a, i64 %i + store i64 0, i64* %tmp0, align 1 + %i.next = add nuw nsw i64 %i, 2 + %cond = icmp eq i64 %i.next, %n + br i1 %cond, label %for.end, label %for.body + +for.end: + ret void +}