diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 1c4589ef14fe..1ed982d6baca 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -7042,18 +7042,23 @@ void SelectionDAG::transferDbgValues(SDValue From, SDValue To, auto *Expr = Dbg->getExpression(); // If a fragment is requested, update the expression. if (SizeInBits) { - auto Fragment = DIExpression::createFragmentExpression( - Dbg->getExpression(), OffsetInBits, SizeInBits); - if (Fragment) - Expr = *Fragment; - } - // Clone the SbgValue unless the fragment creation failed. - if (!SizeInBits || (SizeInBits && Expr)) { - SDDbgValue *Clone = - getDbgValue(Var, Expr, ToNode, To.getResNo(), Dbg->isIndirect(), - Dbg->getDebugLoc(), Dbg->getOrder()); - ClonedDVs.push_back(Clone); + // When splitting a larger (e.g., sign-extended) value whose + // lower bits are described with an SDDbgValue, do not attempt + // to transfer the SDDbgValue to the upper bits. + if (auto FI = Expr->getFragmentInfo()) + if (OffsetInBits + SizeInBits > FI->SizeInBits) + continue; + auto Fragment = DIExpression::createFragmentExpression(Expr, OffsetInBits, + SizeInBits); + if (!Fragment) + continue; + Expr = *Fragment; } + // Clone the SDDbgValue and move it to To. + SDDbgValue *Clone = + getDbgValue(Var, Expr, ToNode, To.getResNo(), Dbg->isIndirect(), + Dbg->getDebugLoc(), Dbg->getOrder()); + ClonedDVs.push_back(Clone); Dbg->setIsInvalidated(); } diff --git a/llvm/test/DebugInfo/ARM/sdag-split-arg1.ll b/llvm/test/DebugInfo/ARM/sdag-split-arg1.ll new file mode 100644 index 000000000000..c39083afd084 --- /dev/null +++ b/llvm/test/DebugInfo/ARM/sdag-split-arg1.ll @@ -0,0 +1,28 @@ +; RUN: llc -filetype=asm %s -o - -stop-after=livedebugvalues | FileCheck %s +; This tests that transferring debug info describing the lower bits of +; an extended SDNode works. +target triple = "thumbv6m-apple-unknown-macho" +define arm_aapcscc i64 @f(double %a) !dbg !5 { +entry: + %0 = bitcast double %a to i64 + %extract.t84 = trunc i64 %0 to i32 + tail call void @llvm.dbg.value(metadata i32 %extract.t84, metadata !8, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32)), !dbg !12 + ; CHECK: DBG_VALUE debug-use %r0, debug-use _, !6, !DIExpression(DW_OP_LLVM_fragment, 0, 32) + %r.sroa.0.0.insert.ext35 = zext i32 %extract.t84 to i64 + ret i64 %r.sroa.0.0.insert.ext35 +} + +declare void @llvm.dbg.value(metadata, metadata, metadata) + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "LLVM", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2) +!1 = !DIFile(filename: "f.c", directory: "/") +!2 = !{} +!3 = !{i32 2, !"Debug Info Version", i32 3} +!5 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 29, type: !7, isLocal: false, isDefinition: true, scopeLine: 30, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !2) +!7 = !DISubroutineType(types: !2) +!8 = !DILocalVariable(name: "r", scope: !5, file: !1, line: 37, type: !11) +!11 = distinct !DICompositeType(tag: DW_TAG_union_type, file: !1, line: 33, size: 64, elements: !2) +!12 = !DILocation(line: 37, column: 12, scope: !5)