[llvm] r349214 - [Util] Refer to [s|z]exts of args when converting dbg.declares (fix PR35400)
Vedant Kumar via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 14 16:03:33 PST 2018
Author: vedantk
Date: Fri Dec 14 16:03:33 2018
New Revision: 349214
URL: http://llvm.org/viewvc/llvm-project?rev=349214&view=rev
Log:
[Util] Refer to [s|z]exts of args when converting dbg.declares (fix PR35400)
When converting dbg.declares, if the described value is a [s|z]ext,
refer to the ext directly instead of referring to its operand.
This fixes a narrowing bug (the debugger got the sign of a variable
wrong, see llvm.org/PR35400).
The main reason to refer to the ext's operand was that an optimization
may remove the ext itself, leading to a dropped variable. Now that
InstCombine has been taught to use replaceAllDbgUsesWith (r336451), this
is less of a concern. Other passes can/should adopt this API as needed
to fix dropped variable bugs.
Differential Revision: https://reviews.llvm.org/D51813
Added:
llvm/trunk/test/Transforms/Util/dbg-user-of-aext.ll
Removed:
llvm/trunk/test/Transforms/Util/split-bit-piece.ll
Modified:
llvm/trunk/lib/Transforms/Utils/Local.cpp
Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=349214&r1=349213&r2=349214&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Fri Dec 14 16:03:33 2018
@@ -1297,33 +1297,6 @@ void llvm::ConvertDebugDeclareToDebugVal
return;
}
- // If an argument is zero extended then use argument directly. The ZExt
- // may be zapped by an optimization pass in future.
- Argument *ExtendedArg = nullptr;
- if (ZExtInst *ZExt = dyn_cast<ZExtInst>(SI->getOperand(0)))
- ExtendedArg = dyn_cast<Argument>(ZExt->getOperand(0));
- if (SExtInst *SExt = dyn_cast<SExtInst>(SI->getOperand(0)))
- ExtendedArg = dyn_cast<Argument>(SExt->getOperand(0));
- if (ExtendedArg) {
- // If this DII was already describing only a fragment of a variable, ensure
- // that fragment is appropriately narrowed here.
- // But if a fragment wasn't used, describe the value as the original
- // argument (rather than the zext or sext) so that it remains described even
- // if the sext/zext is optimized away. This widens the variable description,
- // leaving it up to the consumer to know how the smaller value may be
- // represented in a larger register.
- if (auto Fragment = DIExpr->getFragmentInfo()) {
- unsigned FragmentOffset = Fragment->OffsetInBits;
- SmallVector<uint64_t, 3> Ops(DIExpr->elements_begin(),
- DIExpr->elements_end() - 3);
- Ops.push_back(dwarf::DW_OP_LLVM_fragment);
- Ops.push_back(FragmentOffset);
- const DataLayout &DL = DII->getModule()->getDataLayout();
- Ops.push_back(DL.getTypeSizeInBits(ExtendedArg->getType()));
- DIExpr = Builder.createExpression(Ops);
- }
- DV = ExtendedArg;
- }
if (!LdStHasDebugValue(DIVar, DIExpr, SI))
Builder.insertDbgValueIntrinsic(DV, DIVar, DIExpr, DII->getDebugLoc(),
SI);
Added: llvm/trunk/test/Transforms/Util/dbg-user-of-aext.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Util/dbg-user-of-aext.ll?rev=349214&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Util/dbg-user-of-aext.ll (added)
+++ llvm/trunk/test/Transforms/Util/dbg-user-of-aext.ll Fri Dec 14 16:03:33 2018
@@ -0,0 +1,87 @@
+; Checks that llvm.dbg.declare -> llvm.dbg.value conversion utility
+; (here exposed through the SROA) pass refers to [s|z]exts of values (as
+; opposed to the operand of a [s|z]ext).
+; RUN: opt -S -sroa %s | FileCheck %s
+
+; Built from:
+; struct foo { bool b; long i; };
+; void f(bool b, bool expr, foo g) {
+; }
+; And modifying the frag dbg.declare to use a fragmented DIExpression (with offset: 0, size: 4)
+; to test the dbg.declare+fragment case here.
+
+; Expect two fragments:
+; * first starting at bit 0, 8 bits (for the bool)
+; * second starting at bit 32, 32 bits (for the long)
+; (this happens to create/demonstrate a gap from bits [7, 32))
+
+; But also check that a complex expression is not used for a lone bool
+; parameter. It can reference the register it's in directly without masking off
+; high bits or anything
+
+; CHECK: call void @llvm.dbg.value(metadata i8 %g.coerce0, metadata ![[VAR_STRUCT:[0-9]+]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 8))
+; CHECK: call void @llvm.dbg.value(metadata i64 %g.coerce1, metadata ![[VAR_STRUCT]], metadata !DIExpression(DW_OP_LLVM_fragment, 32, 64))
+; CHECK: call void @llvm.dbg.value(metadata i8 %frombool, metadata ![[VAR_BOOL:[0-9]+]], metadata !DIExpression())
+; CHECK: call void @llvm.dbg.value(metadata i8 %frombool1, metadata ![[VAR_FRAG:[0-9]+]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 4))
+
+%struct.foo = type { i8, i64 }
+
+; Function Attrs: noinline nounwind uwtable
+define void @_Z1fbb3foo(i1 zeroext %b, i1 zeroext %frag, i8 %g.coerce0, i64 %g.coerce1) #0 !dbg !6 {
+entry:
+ %g = alloca %struct.foo, align 8
+ %b.addr = alloca i8, align 1
+ %frag.addr = alloca i8, align 1
+ %0 = bitcast %struct.foo* %g to { i8, i64 }*
+ %1 = getelementptr inbounds { i8, i64 }, { i8, i64 }* %0, i32 0, i32 0
+ store i8 %g.coerce0, i8* %1, align 8
+ %2 = getelementptr inbounds { i8, i64 }, { i8, i64 }* %0, i32 0, i32 1
+ store i64 %g.coerce1, i64* %2, align 8
+ %frombool = zext i1 %b to i8
+ store i8 %frombool, i8* %b.addr, align 1
+ call void @llvm.dbg.declare(metadata i8* %b.addr, metadata !15, metadata !16), !dbg !17
+ %frombool1 = sext i1 %frag to i8
+ store i8 %frombool1, i8* %frag.addr, align 1
+ call void @llvm.dbg.declare(metadata i8* %frag.addr, metadata !18, metadata !23), !dbg !19
+ call void @llvm.dbg.declare(metadata %struct.foo* %g, metadata !20, metadata !16), !dbg !21
+ ret void, !dbg !22
+}
+
+; CHECK: ![[VAR_STRUCT]] = !DILocalVariable(name: "g"
+; CHECK: ![[VAR_BOOL]] = !DILocalVariable(name: "b"
+; CHECK: ![[VAR_FRAG]] = !DILocalVariable(name: "frag"
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+attributes #0 = { noinline nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+!llvm.ident = !{!5}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 5.0.0 (trunk 303077) (llvm/trunk 303098)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "foo.cpp", directory: "/usr/local/google/home/blaikie/dev/scratch")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{!"clang version 5.0.0 (trunk 303077) (llvm/trunk 303098)"}
+!6 = distinct !DISubprogram(name: "f", linkageName: "_Z1fbb3foo", scope: !1, file: !1, line: 2, type: !7, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
+!7 = !DISubroutineType(types: !8)
+!8 = !{null, !9, !9, !10}
+!9 = !DIBasicType(name: "bool", size: 8, encoding: DW_ATE_boolean)
+!10 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "foo", file: !1, line: 1, size: 128, elements: !11, identifier: "_ZTS3foo")
+!11 = !{!12, !13}
+!12 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !10, file: !1, line: 1, baseType: !9, size: 8)
+!13 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !10, file: !1, line: 1, baseType: !14, size: 64, offset: 64)
+!14 = !DIBasicType(name: "long int", size: 64, encoding: DW_ATE_signed)
+!15 = !DILocalVariable(name: "b", arg: 1, scope: !6, file: !1, line: 2, type: !9)
+!16 = !DIExpression()
+!17 = !DILocation(line: 2, column: 13, scope: !6)
+!18 = !DILocalVariable(name: "frag", arg: 2, scope: !6, file: !1, line: 2, type: !9)
+!19 = !DILocation(line: 2, column: 21, scope: !6)
+!20 = !DILocalVariable(name: "g", arg: 3, scope: !6, file: !1, line: 2, type: !10)
+!21 = !DILocation(line: 2, column: 31, scope: !6)
+!22 = !DILocation(line: 3, column: 1, scope: !6)
+!23 = !DIExpression(DW_OP_LLVM_fragment, 0, 4)
Removed: llvm/trunk/test/Transforms/Util/split-bit-piece.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Util/split-bit-piece.ll?rev=349213&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Util/split-bit-piece.ll (original)
+++ llvm/trunk/test/Transforms/Util/split-bit-piece.ll (removed)
@@ -1,83 +0,0 @@
-; Checks that llvm.dbg.declare -> llvm.dbg.value conversion utility
-; (here exposed through the SROA) pass, properly inserts bit_piece expressions
-; if it only describes part of the variable.
-; RUN: opt -S -sroa %s | FileCheck %s
-
-; Built from:
-; struct foo { bool b; long i; };
-; void f(bool b, bool expr, foo g) {
-; }
-; And modifying the frag dbg.declare to use a fragmented DIExpression (with offset: 0, size: 4)
-; to test the dbg.declare+fragment case here.
-
-; Expect two fragments:
-; * first starting at bit 0, 8 bits (for the bool)
-; * second starting at bit 32, 32 bits (for the long)
-; (this happens to create/demonstrate a gap from bits [7, 32))
-
-; But also check that a complex expression is not used for a lone bool
-; parameter. It can reference the register it's in directly without masking off
-; high bits or anything
-
-; CHECK: call void @llvm.dbg.value(metadata i8 %g.coerce0, metadata ![[VAR_STRUCT:[0-9]+]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 8))
-; CHECK: call void @llvm.dbg.value(metadata i64 %g.coerce1, metadata ![[VAR_STRUCT]], metadata !DIExpression(DW_OP_LLVM_fragment, 32, 64))
-; CHECK: call void @llvm.dbg.value(metadata i1 %b, metadata ![[VAR_BOOL:[0-9]+]], metadata !DIExpression())
-; CHECK: call void @llvm.dbg.value(metadata i1 %frag, metadata ![[VAR_FRAG:[0-9]+]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 1))
-
-%struct.foo = type { i8, i64 }
-
-; Function Attrs: noinline nounwind uwtable
-define void @_Z1fbb3foo(i1 zeroext %b, i1 zeroext %frag, i8 %g.coerce0, i64 %g.coerce1) #0 !dbg !6 {
-entry:
- %g = alloca %struct.foo, align 8
- %b.addr = alloca i8, align 1
- %frag.addr = alloca i8, align 1
- %0 = bitcast %struct.foo* %g to { i8, i64 }*
- %1 = getelementptr inbounds { i8, i64 }, { i8, i64 }* %0, i32 0, i32 0
- store i8 %g.coerce0, i8* %1, align 8
- %2 = getelementptr inbounds { i8, i64 }, { i8, i64 }* %0, i32 0, i32 1
- store i64 %g.coerce1, i64* %2, align 8
- %frombool = zext i1 %b to i8
- store i8 %frombool, i8* %b.addr, align 1
- call void @llvm.dbg.declare(metadata i8* %b.addr, metadata !15, metadata !16), !dbg !17
- %frombool1 = zext i1 %frag to i8
- store i8 %frombool1, i8* %frag.addr, align 1
- call void @llvm.dbg.declare(metadata i8* %frag.addr, metadata !18, metadata !23), !dbg !19
- call void @llvm.dbg.declare(metadata %struct.foo* %g, metadata !20, metadata !16), !dbg !21
- ret void, !dbg !22
-}
-
-; Function Attrs: nounwind readnone speculatable
-declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
-
-attributes #0 = { noinline nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
-attributes #1 = { nounwind readnone speculatable }
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!3, !4}
-!llvm.ident = !{!5}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 5.0.0 (trunk 303077) (llvm/trunk 303098)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
-!1 = !DIFile(filename: "foo.cpp", directory: "/usr/local/google/home/blaikie/dev/scratch")
-!2 = !{}
-!3 = !{i32 2, !"Dwarf Version", i32 4}
-!4 = !{i32 2, !"Debug Info Version", i32 3}
-!5 = !{!"clang version 5.0.0 (trunk 303077) (llvm/trunk 303098)"}
-!6 = distinct !DISubprogram(name: "f", linkageName: "_Z1fbb3foo", scope: !1, file: !1, line: 2, type: !7, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
-!7 = !DISubroutineType(types: !8)
-!8 = !{null, !9, !9, !10}
-!9 = !DIBasicType(name: "bool", size: 8, encoding: DW_ATE_boolean)
-!10 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "foo", file: !1, line: 1, size: 128, elements: !11, identifier: "_ZTS3foo")
-!11 = !{!12, !13}
-!12 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !10, file: !1, line: 1, baseType: !9, size: 8)
-!13 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !10, file: !1, line: 1, baseType: !14, size: 64, offset: 64)
-!14 = !DIBasicType(name: "long int", size: 64, encoding: DW_ATE_signed)
-!15 = !DILocalVariable(name: "b", arg: 1, scope: !6, file: !1, line: 2, type: !9)
-!16 = !DIExpression()
-!17 = !DILocation(line: 2, column: 13, scope: !6)
-!18 = !DILocalVariable(name: "frag", arg: 2, scope: !6, file: !1, line: 2, type: !9)
-!19 = !DILocation(line: 2, column: 21, scope: !6)
-!20 = !DILocalVariable(name: "g", arg: 3, scope: !6, file: !1, line: 2, type: !10)
-!21 = !DILocation(line: 2, column: 31, scope: !6)
-!22 = !DILocation(line: 3, column: 1, scope: !6)
-!23 = !DIExpression(DW_OP_LLVM_fragment, 0, 4)
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