diff --git a/llvm/lib/Transforms/Scalar/Scalarizer.cpp b/llvm/lib/Transforms/Scalar/Scalarizer.cpp index 5f2e7bfe378b..6b7419abe1d1 100644 --- a/llvm/lib/Transforms/Scalar/Scalarizer.cpp +++ b/llvm/lib/Transforms/Scalar/Scalarizer.cpp @@ -66,6 +66,15 @@ static cl::opt namespace { +BasicBlock::iterator skipPastPhiNodesAndDbg(BasicBlock::iterator Itr) { + BasicBlock *BB = Itr->getParent(); + if (isa(Itr)) + Itr = BB->getFirstInsertionPt(); + if (Itr != BB->end()) + Itr = skipDebugIntrinsics(Itr); + return Itr; +} + // Used to store the scattered form of a vector. using ValueVector = SmallVector; @@ -371,10 +380,11 @@ Scatterer ScalarizerVisitor::scatter(Instruction *Point, Value *V) { return Scatterer(Point->getParent(), Point->getIterator(), UndefValue::get(V->getType())); // Put the scattered form of an instruction directly after the - // instruction. + // instruction, skipping over PHI nodes and debug intrinsics. BasicBlock *BB = VOp->getParent(); - return Scatterer(BB, std::next(BasicBlock::iterator(VOp)), - V, &Scattered[V]); + return Scatterer( + BB, skipPastPhiNodesAndDbg(std::next(BasicBlock::iterator(VOp))), 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/dbg-invariant.ll b/llvm/test/Transforms/Scalarizer/dbg-invariant.ll new file mode 100644 index 000000000000..ff334ebae395 --- /dev/null +++ b/llvm/test/Transforms/Scalarizer/dbg-invariant.ll @@ -0,0 +1,64 @@ +; RUN: opt -strip-debug -passes=scalarizer -S < %s | FileCheck %s +; RUN: opt -passes=scalarizer -S < %s | FileCheck %s + +; This input caused the scalarizer to violate a debug info +; invariance by using the wrong insertion point. + +; CHECK: %0 = load <8 x i16> + +; CHECK: %.i0 = extractelement <8 x i16> %0, i32 0 +; CHECK-NEXT: %.i01 = add i16 %.i0, 28690 +; CHECK: %.i1 = extractelement <8 x i16> %0, i32 1 +; CHECK-NEXT: %.i12 = add i16 %.i1, 28690 +; CHECK: %.i2 = extractelement <8 x i16> %0, i32 2 +; CHECK-NEXT: %.i23 = add i16 %.i2, 28690 +; CHECK: %.i3 = extractelement <8 x i16> %0, i32 3 +; CHECK-NEXT: %.i34 = add i16 %.i3, 28690 +; CHECK: %.i4 = extractelement <8 x i16> %0, i32 4 +; CHECK-NEXT: %.i45 = add i16 %.i4, 28690 +; CHECK: %.i5 = extractelement <8 x i16> %0, i32 5 +; CHECK-NEXT: %.i56 = add i16 %.i5, 28690 +; CHECK: %.i6 = extractelement <8 x i16> %0, i32 6 +; CHECK-NEXT: %.i67 = add i16 %.i6, 28690 +; CHECK: %.i7 = extractelement <8 x i16> %0, i32 7 +; CHECK-NEXT: = add i16 %.i7, 28690 + +@d = external global [8 x i16], align 1 +@e = external global i16, align 1 + +; Function Attrs: nofree norecurse nounwind +define dso_local void @foo() local_unnamed_addr #0 !dbg !7 { +entry: + %0 = load <8 x i16>, <8 x i16>* bitcast ([8 x i16]* @d to <8 x i16>*), align 1 + call void @llvm.dbg.value(metadata i16 0, metadata !11, metadata !DIExpression()), !dbg !13 + %1 = add <8 x i16> %0, , !dbg !13 + store <8 x i16> %1, <8 x i16>* bitcast ([8 x i16]* @d to <8 x i16>*), align 1, !dbg !13 + %2 = extractelement <8 x i16> %1, i32 7, !dbg !13 + store i16 %2, i16* @e, align 1, !dbg !13 + ret void +} + +; Function Attrs: nounwind readnone speculatable willreturn +declare void @llvm.dbg.value(metadata, metadata, metadata) #1 + +attributes #0 = { nofree norecurse nounwind } +attributes #1 = { nounwind readnone speculatable willreturn } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4, !5} +!llvm.ident = !{!6} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 11.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None) +!1 = !DIFile(filename: "foo.c", directory: "/") +!2 = !{} +!3 = !{i32 7, !"Dwarf Version", i32 4} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!5 = !{i32 1, !"wchar_size", i32 1} +!6 = !{!"clang version 11.0.0 "} +!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 4, type: !8, scopeLine: 4, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10) +!8 = !DISubroutineType(types: !9) +!9 = !{null} +!10 = !{!11} +!11 = !DILocalVariable(name: "i", scope: !7, file: !1, line: 5, type: !12) +!12 = !DIBasicType(name: "int", size: 16, encoding: DW_ATE_signed) +!13 = !DILocation(line: 0, scope: !7) diff --git a/llvm/test/Transforms/Scalarizer/phi-order.ll b/llvm/test/Transforms/Scalarizer/phi-order.ll new file mode 100644 index 000000000000..523daf3c900a --- /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 +} +