[llvm] r324764 - [Utils] Salvage debug info from dead 'or' instructions
Vedant Kumar via llvm-commits
llvm-commits at lists.llvm.org
Fri Feb 9 11:19:55 PST 2018
Author: vedantk
Date: Fri Feb 9 11:19:55 2018
New Revision: 324764
URL: http://llvm.org/viewvc/llvm-project?rev=324764&view=rev
Log:
[Utils] Salvage debug info from dead 'or' instructions
Extend salvageDebugInfo to preserve the debug info from a dead 'or'
with a constant.
Patch by Ismail Badawi!
Differential Revision: https://reviews.llvm.org/D43129
Added:
llvm/trunk/test/Transforms/InstCombine/debuginfo-dce-or.ll
Modified:
llvm/trunk/include/llvm/IR/DebugInfoMetadata.h
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
llvm/trunk/lib/IR/DebugInfoMetadata.cpp
llvm/trunk/lib/Transforms/Utils/Local.cpp
Modified: llvm/trunk/include/llvm/IR/DebugInfoMetadata.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/DebugInfoMetadata.h?rev=324764&r1=324763&r2=324764&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/DebugInfoMetadata.h (original)
+++ llvm/trunk/include/llvm/IR/DebugInfoMetadata.h Fri Feb 9 11:19:55 2018
@@ -2340,6 +2340,12 @@ public:
int64_t Offset = 0, bool DerefAfter = false,
bool StackValue = false);
+ /// Prepend \p DIExpr with the given opcodes and optionally turn it into a
+ /// stack value.
+ static DIExpression *doPrepend(const DIExpression *DIExpr,
+ SmallVectorImpl<uint64_t> &Ops,
+ bool StackValue = false);
+
/// Create a DIExpression to describe one part of an aggregate variable that
/// is fragmented across multiple Values. The DW_OP_LLVM_fragment operation
/// will be appended to the elements of \c Expr. If \c Expr already contains
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp?rev=324764&r1=324763&r2=324764&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfExpression.cpp Fri Feb 9 11:19:55 2018
@@ -341,6 +341,7 @@ void DwarfExpression::addExpression(DIEx
case dwarf::DW_OP_plus:
case dwarf::DW_OP_minus:
case dwarf::DW_OP_mul:
+ case dwarf::DW_OP_or:
emitOp(Op->getOp());
break;
case dwarf::DW_OP_deref:
Modified: llvm/trunk/lib/IR/DebugInfoMetadata.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/DebugInfoMetadata.cpp?rev=324764&r1=324763&r2=324764&view=diff
==============================================================================
--- llvm/trunk/lib/IR/DebugInfoMetadata.cpp (original)
+++ llvm/trunk/lib/IR/DebugInfoMetadata.cpp Fri Feb 9 11:19:55 2018
@@ -706,6 +706,7 @@ bool DIExpression::isValid() const {
case dwarf::DW_OP_plus:
case dwarf::DW_OP_minus:
case dwarf::DW_OP_mul:
+ case dwarf::DW_OP_or:
case dwarf::DW_OP_deref:
case dwarf::DW_OP_xderef:
break;
@@ -772,6 +773,12 @@ DIExpression *DIExpression::prepend(cons
if (DerefAfter)
Ops.push_back(dwarf::DW_OP_deref);
+ return doPrepend(Expr, Ops, StackValue);
+}
+
+DIExpression *DIExpression::doPrepend(const DIExpression *Expr,
+ SmallVectorImpl<uint64_t> &Ops,
+ bool StackValue) {
if (Expr)
for (auto Op : Expr->expr_ops()) {
// A DW_OP_stack_value comes at the end, but before a DW_OP_LLVM_fragment.
Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=324764&r1=324763&r2=324764&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Fri Feb 9 11:19:55 2018
@@ -1497,16 +1497,27 @@ void llvm::salvageDebugInfo(Instruction
return MetadataAsValue::get(I.getContext(), ValueAsMetadata::get(V));
};
- auto applyOffset = [&](DbgInfoIntrinsic *DII, uint64_t Offset) {
+ auto doSalvage = [&](DbgInfoIntrinsic *DII, SmallVectorImpl<uint64_t> &Ops) {
auto *DIExpr = DII->getExpression();
- DIExpr = DIExpression::prepend(DIExpr, DIExpression::NoDeref, Offset,
- DIExpression::NoDeref,
- DIExpression::WithStackValue);
+ DIExpr = DIExpression::doPrepend(DIExpr, Ops,
+ DIExpression::WithStackValue);
DII->setOperand(0, wrapMD(I.getOperand(0)));
DII->setOperand(2, MetadataAsValue::get(I.getContext(), DIExpr));
DEBUG(dbgs() << "SALVAGE: " << *DII << '\n');
};
+ auto applyOffset = [&](DbgInfoIntrinsic *DII, uint64_t Offset) {
+ SmallVector<uint64_t, 8> Ops;
+ DIExpression::appendOffset(Ops, Offset);
+ doSalvage(DII, Ops);
+ };
+
+ auto applyOps = [&](DbgInfoIntrinsic *DII,
+ std::initializer_list<uint64_t> Opcodes) {
+ SmallVector<uint64_t, 8> Ops(Opcodes);
+ doSalvage(DII, Ops);
+ };
+
if (isa<BitCastInst>(&I) || isa<IntToPtrInst>(&I)) {
// Bitcasts are entirely irrelevant for debug info. Rewrite dbg.value,
// dbg.addr, and dbg.declare to use the cast's source.
@@ -1525,11 +1536,17 @@ void llvm::salvageDebugInfo(Instruction
for (auto *DII : DbgUsers)
applyOffset(DII, Offset.getSExtValue());
} else if (auto *BI = dyn_cast<BinaryOperator>(&I)) {
- if (BI->getOpcode() == Instruction::Add)
+ if (BI->getOpcode() == Instruction::Add ||
+ BI->getOpcode() == Instruction::Or)
if (auto *ConstInt = dyn_cast<ConstantInt>(I.getOperand(1)))
- if (ConstInt->getBitWidth() <= 64)
+ if (ConstInt->getBitWidth() <= 64) {
+ uint64_t Val = ConstInt->getSExtValue();
for (auto *DII : DbgUsers)
- applyOffset(DII, ConstInt->getSExtValue());
+ if (BI->getOpcode() == Instruction::Add)
+ applyOffset(DII, Val);
+ else if (BI->getOpcode() == Instruction::Or)
+ applyOps(DII, {dwarf::DW_OP_constu, Val, dwarf::DW_OP_or});
+ }
} else if (isa<LoadInst>(&I)) {
MetadataAsValue *AddrMD = wrapMD(I.getOperand(0));
for (auto *DII : DbgUsers) {
Added: llvm/trunk/test/Transforms/InstCombine/debuginfo-dce-or.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/debuginfo-dce-or.ll?rev=324764&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/debuginfo-dce-or.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/debuginfo-dce-or.ll Fri Feb 9 11:19:55 2018
@@ -0,0 +1,44 @@
+; RUN: opt -instcombine %s -o - -S | FileCheck %s
+
+source_filename = "test.c"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-linux"
+
+define void @salvage_or(i64 %context) !dbg !9 {
+entry:
+ %0 = or i64 %context, 256, !dbg !18
+; CHECK: call void @llvm.dbg.value(metadata i64 %context,
+; CHECK-SAME: metadata !DIExpression(DW_OP_constu, 256, DW_OP_or, DW_OP_stack_value))
+ call void @llvm.dbg.value(metadata i64 %0, metadata !14, metadata !16), !dbg !19
+ ret void, !dbg !20
+}
+
+declare void @llvm.dbg.value(metadata, metadata, metadata) #0
+
+attributes #0 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!5, !6, !7}
+!llvm.ident = !{!8}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 7.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3)
+!1 = !DIFile(filename: "test.c", directory: "/")
+!2 = !{}
+!3 = !{}
+!4 = !DIBasicType(name: "long long int", size: 64, encoding: DW_ATE_signed)
+!5 = !{i32 2, !"Dwarf Version", i32 4}
+!6 = !{i32 2, !"Debug Info Version", i32 3}
+!7 = !{i32 1, !"PIC Level", i32 2}
+!8 = !{!"clang version 7.0.0"}
+!9 = distinct !DISubprogram(name: "salvage_or", scope: !1, file: !1, line: 91, type: !10, isLocal: false, isDefinition: true, scopeLine: 93, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !12)
+!10 = !DISubroutineType(types: !11)
+!11 = !{!4}
+!12 = !{!13, !14}
+!13 = !DILocalVariable(name: "context", arg: 2, scope: !9, file: !1, line: 92, type: !4)
+!14 = !DILocalVariable(name: "master", scope: !9, file: !1, line: 94, type: !4)
+!15 = !{}
+!16 = !DIExpression()
+!17 = !DILexicalBlockFile(scope: !9, file: !1, discriminator: 2)
+!18 = !DILocation(line: 94, column: 18, scope: !17)
+!19 = !DILocation(line: 94, column: 18, scope: !9)
+!20 = !DILocation(line: 126, column: 1, scope: !9)
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