Index: lib/Transforms/Scalar/LoopUnrollPass.cpp =================================================================== --- lib/Transforms/Scalar/LoopUnrollPass.cpp +++ lib/Transforms/Scalar/LoopUnrollPass.cpp @@ -836,6 +836,8 @@ } else { UP.Count = TripCount; } + if (UP.Count > UP.MaxCount) + UP.Count = UP.MaxCount; if ((PragmaFullUnroll || PragmaEnableUnroll) && TripCount && UP.Count != TripCount) ORE->emit( Index: test/Transforms/LoopUnroll/unroll-maxcount.ll =================================================================== --- /dev/null +++ test/Transforms/LoopUnroll/unroll-maxcount.ll @@ -0,0 +1,31 @@ +; RUN: opt < %s -S -loop-unroll -unroll-allow-partial -unroll-max-count=1 | FileCheck %s +; Checks that unroll MaxCount is honored. +; +; CHECK-LABEL: @foo( +; CHECK-LABEL: for.body: +; CHECK-NEXT: phi +; CHECK-NEXT: getelementptr +; CHECK-NEXT: load +; CHECK-NEXT: add +; CHECK-NEXT: store +; CHECK-NEXT: add +; CHECK-NEXT: icmp +; CHECK-NEXT: br +define void @foo(i32* nocapture %a) { +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 i32, i32* %a, i64 %indvars.iv + %0 = load i32, i32* %arrayidx, align 4 + %inc = add nsw i32 %0, 1 + store i32 %inc, i32* %arrayidx, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv.next, 1024 + br i1 %exitcond, label %for.end, label %for.body + +for.end: ; preds = %for.body + ret void +} +