diff --git a/llvm/lib/Transforms/Scalar/Scalarizer.cpp b/llvm/lib/Transforms/Scalar/Scalarizer.cpp --- a/llvm/lib/Transforms/Scalar/Scalarizer.cpp +++ b/llvm/lib/Transforms/Scalar/Scalarizer.cpp @@ -371,10 +371,12 @@ return Scatterer(Point->getParent(), Point->getIterator(), UndefValue::get(V->getType())); // Put the scattered form of an instruction directly after the - // instruction. + // instruction, unless it is a PHI node. BasicBlock *BB = VOp->getParent(); - return Scatterer(BB, std::next(BasicBlock::iterator(VOp)), - V, &Scattered[V]); + auto InsertionPoint = std::next(BasicBlock::iterator(VOp)); + if (isa(VOp)) + InsertionPoint = BB->getFirstInsertionPt(); + return Scatterer(BB, InsertionPoint, V, &Scattered[V]); } // In the fallback case, just put the scattered before Point and // keep the result local to Point. diff --git a/llvm/test/Transforms/Scalarizer/phi-order.ll b/llvm/test/Transforms/Scalarizer/phi-order.ll new file mode 100644 --- /dev/null +++ b/llvm/test/Transforms/Scalarizer/phi-order.ll @@ -0,0 +1,29 @@ +; RUN: opt %s -passes='function(scalarizer)' -S -o - | FileCheck %s + +; This input caused the scalarizer to insert non-PHI nodes +; in between PHI nodes (%1 and %2). + +define <3 x float> @func(i32 %inval) { +.entry: + br label %0 + +0: ; preds = %3, %.entry +; CHECK: %.i01 = phi float [ 0.000000e+00, %.entry ], [ %.i01, %3 ] +; CHECK-NEXT: %.i12 = phi float [ 0.000000e+00, %.entry ], [ %.i12, %3 ] +; CHECK-NEXT: %.i23 = phi float [ 0.000000e+00, %.entry ], [ %.i23, %3 ] +; CHECK-NEXT: %1 = phi float [ 1.000000e+00, %.entry ], [ 2.000000e+00, %3 ] +; CHECK-NEXT: %.upto0 = insertelement <3 x float> poison, float %.i01, i32 0 +; CHECK-NEXT: %.upto1 = insertelement <3 x float> %.upto0, float %.i12, i32 1 +; CHECK-NEXT: %2 = insertelement <3 x float> %.upto1, float %.i23, i32 2 + %1 = phi <3 x float> [ , %.entry], [ %1, %3 ] + %2 = phi float [ 1.0, %.entry], [ 2.0, %3 ] + br label %3 + +3: ; preds = %0 + %cond = icmp eq i32 %inval, 0 + br i1 %cond, label %0, label %exit + +exit: + ret <3 x float> %1 +} +