Index: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp =================================================================== --- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp +++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -4946,10 +4946,11 @@ void LoopVectorizationLegality::collectLoopUniforms() { // We now know that the loop is vectorizable! - // Collect variables that will remain uniform after vectorization. + // Collect instructions inside the loop that will remain uniform after + // vectorization. - // If V is not an instruction inside the current loop, it is a Value - // outside of the scope which we are interesting in. + // Global values, params and instructions outside of current loop are out of + // scope. auto isOutOfScope = [&](Value *V) -> bool { Instruction *I = dyn_cast(V); return (!I || !TheLoop->contains(I)); Index: llvm/trunk/test/Transforms/LoopVectorize/X86/uniform-phi.ll =================================================================== --- llvm/trunk/test/Transforms/LoopVectorize/X86/uniform-phi.ll +++ llvm/trunk/test/Transforms/LoopVectorize/X86/uniform-phi.ll @@ -48,3 +48,30 @@ for.end: ret void } + +; CHECK-LABEL: goo +; Check %indvars.iv and %indvars.iv.next are uniform instructions even if they are used outside of loop. +; CHECK-DAG: LV: Found uniform instruction: %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] +; CHECK-DAG: LV: Found uniform instruction: %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 +; CHECK-DAG: LV: Found uniform instruction: %exitcond = icmp eq i64 %indvars.iv, 1599 + +define i64 @goo(float* noalias nocapture %a, float* noalias nocapture readonly %b) #0 { +entry: + br label %for.body + +for.body: ; preds = %for.body, %entry + %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] + %arrayidx = getelementptr inbounds float, float* %b, i64 %indvars.iv + %tmp0 = load float, float* %arrayidx, align 4 + %add = fadd float %tmp0, 1.000000e+00 + %arrayidx5 = getelementptr inbounds float, float* %a, i64 %indvars.iv + store float %add, float* %arrayidx5, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv, 1599 + br i1 %exitcond, label %for.end, label %for.body + +for.end: ; preds = %for.body + %retval = add i64 %indvars.iv, %indvars.iv.next + ret i64 %retval +} +