Index: llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp =================================================================== --- llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp +++ llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp @@ -155,6 +155,10 @@ } unsigned AMDGPUTTIImpl::getMaxInterleaveFactor(unsigned VF) { + // Disable unrolling if the loop is not vectorized. + if (VF == 1) + return 1; + // Semi-arbitrary large amount. return 64; } Index: llvm/trunk/test/Transforms/LoopVectorize/AMDGPU/lit.local.cfg =================================================================== --- llvm/trunk/test/Transforms/LoopVectorize/AMDGPU/lit.local.cfg +++ llvm/trunk/test/Transforms/LoopVectorize/AMDGPU/lit.local.cfg @@ -0,0 +1,2 @@ +if not 'AMDGPU' in config.root.targets: + config.unsupported = True Index: llvm/trunk/test/Transforms/LoopVectorize/AMDGPU/unroll-in-loop-vectorizer.ll =================================================================== --- llvm/trunk/test/Transforms/LoopVectorize/AMDGPU/unroll-in-loop-vectorizer.ll +++ llvm/trunk/test/Transforms/LoopVectorize/AMDGPU/unroll-in-loop-vectorizer.ll @@ -0,0 +1,28 @@ +; RUN: opt -S -mtriple=amdgcn-unknown-amdhsa -mcpu=fiji -loop-vectorize < %s | FileCheck %s + + +; For AMDGPU, loop unroll in loop vectorizer is disabled when VF==1. +; +; CHECK-LABEL: @small_loop( +; CHECK: store i32 +; CHECK-NOT: store i32 +; CHECK: ret +define void @small_loop(i32* nocapture %inArray, i32 %size) nounwind { +entry: + %0 = icmp sgt i32 %size, 0 + br i1 %0, label %loop, label %exit + +loop: ; preds = %entry, %loop + %iv = phi i32 [ %iv1, %loop ], [ 0, %entry ] + %1 = getelementptr inbounds i32, i32* %inArray, i32 %iv + %2 = load i32, i32* %1, align 4 + %3 = add nsw i32 %2, 6 + store i32 %3, i32* %1, align 4 + %iv1 = add i32 %iv, 1 +; %lftr.wideiv = trunc i64 %indvars.iv.next to i32 + %cond = icmp eq i32 %iv1, %size + br i1 %cond, label %exit, label %loop + +exit: ; preds = %loop, %entry + ret void +}