diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LoopRotation.cpp | 5 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopRotate/convergent.ll | 31 |
2 files changed, 36 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopRotation.cpp b/llvm/lib/Transforms/Scalar/LoopRotation.cpp index 5e6c2da08cc..14621e51b60 100644 --- a/llvm/lib/Transforms/Scalar/LoopRotation.cpp +++ b/llvm/lib/Transforms/Scalar/LoopRotation.cpp @@ -165,6 +165,11 @@ static bool rotateLoop(Loop *L, unsigned MaxHeaderSize, LoopInfo *LI, << " instructions: "; L->dump()); return false; } + if (Metrics.convergent) { + DEBUG(dbgs() << "LoopRotation: NOT rotating - contains convergent " + "instructions: "; L->dump()); + return false; + } if (Metrics.NumInsts > MaxHeaderSize) return false; } diff --git a/llvm/test/Transforms/LoopRotate/convergent.ll b/llvm/test/Transforms/LoopRotate/convergent.ll new file mode 100644 index 00000000000..c8b34fd75f0 --- /dev/null +++ b/llvm/test/Transforms/LoopRotate/convergent.ll @@ -0,0 +1,31 @@ +; RUN: opt -S -loop-rotate < %s | FileCheck %s + +@e = global i32 10 + +declare void @f1(i32) convergent +declare void @f2(i32) + +; The call to f1 in the loop header shouldn't be duplicated (meaning, loop +; rotation shouldn't occur), because f1 is convergent. + +; CHECK: call void @f1 +; CHECK-NOT: call void @f1 + +define void @test(i32 %x) { +entry: + br label %loop + +loop: + %n.phi = phi i32 [ %n, %loop.fin ], [ 0, %entry ] + call void @f1(i32 %n.phi) + %cond = icmp eq i32 %n.phi, %x + br i1 %cond, label %exit, label %loop.fin + +loop.fin: + %n = add i32 %n.phi, 1 + call void @f2(i32 %n) + br label %loop + +exit: + ret void +} |
