[llvm] 9482350 - [DebugInfo][SROA] Correct debug info for global variables in case of SROA
Alok Kumar Sharma via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 9 11:12:44 PST 2022
Author: Alok Kumar Sharma
Date: 2022-03-10T00:41:30+05:30
New Revision: 94823500a7288a61c6d68becf2cc82e853a80e52
URL: https://github.com/llvm/llvm-project/commit/94823500a7288a61c6d68becf2cc82e853a80e52
DIFF: https://github.com/llvm/llvm-project/commit/94823500a7288a61c6d68becf2cc82e853a80e52.diff
LOG: [DebugInfo][SROA] Correct debug info for global variables in case of SROA
The existing handling produced crash for test case (attached with patch).
Now the function transferSRADebugInfo is modified to
- Ignore the current variable if it starts after the current Fragment.
- Ignore the current variable if it ends before the current Fragment.
- Generate (!DIExpression()) if current variable completely fits the
current Fragment.
- Otherwise (as earlier), generate the DW_OP_LLVM_fragment in IR if current
Fragment partially defines current variable.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D121107
Added:
llvm/test/DebugInfo/X86/global-sra-struct-fit-segment.ll
Modified:
llvm/lib/Transforms/IPO/GlobalOpt.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
index a29d4f60a653e..6ff1a632baede 100644
--- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -405,9 +405,37 @@ static void transferSRADebugInfo(GlobalVariable *GV, GlobalVariable *NGV,
for (auto *GVE : GVs) {
DIVariable *Var = GVE->getVariable();
DIExpression *Expr = GVE->getExpression();
+ int64_t CurVarOffsetInBytes = 0;
+ uint64_t CurVarOffsetInBits = 0;
+
+ // Calculate the offset (Bytes), Continue if unknown.
+ if (!Expr->extractIfOffset(CurVarOffsetInBytes))
+ continue;
+
+ // Ignore negative offset.
+ if (CurVarOffsetInBytes < 0)
+ continue;
+
+ // Convert offset to bits.
+ CurVarOffsetInBits = CHAR_BIT * (uint64_t)CurVarOffsetInBytes;
+
+ // Current var starts after the fragment, ignore.
+ if (CurVarOffsetInBits >= (FragmentOffsetInBits + FragmentSizeInBits))
+ continue;
+
+ uint64_t CurVarSize = Var->getType()->getSizeInBits();
+ // Current variable ends before start of fragment, ignore.
+ if (CurVarSize != 0 &&
+ (CurVarOffsetInBits + CurVarSize) <= FragmentOffsetInBits)
+ continue;
+
+ // Current variable fits in the fragment.
+ if (CurVarOffsetInBits == FragmentOffsetInBits &&
+ CurVarSize == FragmentSizeInBits)
+ Expr = DIExpression::get(Expr->getContext(), {});
// If the FragmentSize is smaller than the variable,
// emit a fragment expression.
- if (FragmentSizeInBits < VarSize) {
+ else if (FragmentSizeInBits < VarSize) {
if (auto E = DIExpression::createFragmentExpression(
Expr, FragmentOffsetInBits, FragmentSizeInBits))
Expr = *E;
diff --git a/llvm/test/DebugInfo/X86/global-sra-struct-fit-segment.ll b/llvm/test/DebugInfo/X86/global-sra-struct-fit-segment.ll
new file mode 100644
index 0000000000000..d3c67c9c91653
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/global-sra-struct-fit-segment.ll
@@ -0,0 +1,133 @@
+; RUN: opt -S -globalopt < %s | FileCheck %s
+
+;; Generated at -g from:
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;subroutine sub(inode,node)
+;; implicit none
+;; integer nodea,nodeb,jmax,inode,node
+;; save nodea,nodeb,jmax
+;; if(inode.eq.1) then
+;; nodea=node
+;; nodeb=node
+;; jmax=0
+;; else
+;; jmax=node+1+nodea+nodeb+jmax
+;; return
+;; endif
+;;end
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+%struct.BSS1 = type <{ [12 x i8] }>
+
+;CHECK: @.BSS1.0 = internal unnamed_addr global i32 0, align 32, !dbg ![[GVE1:.*]]
+;CHECK: @.BSS1.1 = internal unnamed_addr global i32 0, align 32, !dbg ![[GVE2:.*]]
+;CHECK: @.BSS1.2 = internal unnamed_addr global i32 0, align 8, !dbg ![[GVE3:.*]]
+
+ at .BSS1 = internal global %struct.BSS1 zeroinitializer, align 32, !dbg !0, !dbg !7, !dbg !10, !dbg !27
+ at .C330_sub_ = internal constant i32 0
+ at .C332_sub_ = internal constant i32 1
+
+define void @sub_(i64* noalias %inode, i64* noalias %node) !dbg !2 {
+L.entry:
+ call void @llvm.dbg.declare(metadata i64* %inode, metadata !16, metadata !DIExpression()), !dbg !17
+ call void @llvm.dbg.declare(metadata i64* %node, metadata !18, metadata !DIExpression()), !dbg !17
+ br label %L.LB1_360
+
+L.LB1_360: ; preds = %L.entry
+ %0 = bitcast i64* %inode to i32*, !dbg !19
+ %1 = load i32, i32* %0, align 4, !dbg !19
+ %2 = icmp ne i32 %1, 1, !dbg !19
+ br i1 %2, label %L.LB1_356, label %L.LB1_370, !dbg !19
+
+L.LB1_370: ; preds = %L.LB1_360
+ %3 = bitcast i64* %node to i32*, !dbg !20
+ %4 = load i32, i32* %3, align 4, !dbg !20
+ %5 = bitcast %struct.BSS1* @.BSS1 to i32*, !dbg !20
+ store i32 %4, i32* %5, align 4, !dbg !20
+ %6 = bitcast i64* %node to i32*, !dbg !21
+ %7 = load i32, i32* %6, align 4, !dbg !21
+ %8 = bitcast %struct.BSS1* @.BSS1 to i8*, !dbg !21
+ %9 = getelementptr i8, i8* %8, i64 4, !dbg !21
+ %10 = bitcast i8* %9 to i32*, !dbg !21
+ store i32 %7, i32* %10, align 4, !dbg !21
+ %11 = bitcast %struct.BSS1* @.BSS1 to i8*, !dbg !22
+ %12 = getelementptr i8, i8* %11, i64 8, !dbg !22
+ %13 = bitcast i8* %12 to i32*, !dbg !22
+ store i32 0, i32* %13, align 4, !dbg !22
+ br label %L.LB1_357, !dbg !23
+
+L.LB1_356: ; preds = %L.LB1_360
+ %14 = bitcast i64* %node to i32*, !dbg !24
+ %15 = load i32, i32* %14, align 4, !dbg !24
+ %16 = add nsw i32 %15, 1, !dbg !24
+ %17 = bitcast %struct.BSS1* @.BSS1 to i32*, !dbg !24
+ %18 = load i32, i32* %17, align 4, !dbg !24
+ %19 = add nsw i32 %16, %18, !dbg !24
+ %20 = bitcast %struct.BSS1* @.BSS1 to i8*, !dbg !24
+ %21 = getelementptr i8, i8* %20, i64 4, !dbg !24
+ %22 = bitcast i8* %21 to i32*, !dbg !24
+ %23 = load i32, i32* %22, align 4, !dbg !24
+ %24 = add nsw i32 %19, %23, !dbg !24
+ %25 = bitcast %struct.BSS1* @.BSS1 to i8*, !dbg !24
+ %26 = getelementptr i8, i8* %25, i64 8, !dbg !24
+ %27 = bitcast i8* %26 to i32*, !dbg !24
+ %28 = load i32, i32* %27, align 4, !dbg !24
+ %29 = add nsw i32 %24, %28, !dbg !24
+ %30 = bitcast %struct.BSS1* @.BSS1 to i8*, !dbg !24
+ %31 = getelementptr i8, i8* %30, i64 8, !dbg !24
+ %32 = bitcast i8* %31 to i32*, !dbg !24
+ store i32 %29, i32* %32, align 4, !dbg !24
+ br label %L.LB1_354, !dbg !25
+
+L.LB1_357: ; preds = %L.LB1_370
+ br label %L.LB1_354
+
+L.LB1_354: ; preds = %L.LB1_357, %L.LB1_356
+ ret void, !dbg !26
+}
+
+; Function Attrs: nofree nosync nounwind readnone speculatable willreturn
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+
+!llvm.module.flags = !{!14, !15}
+!llvm.dbg.cu = !{!4}
+
+; CHECK-DAG: ![[GVE1]] = !DIGlobalVariableExpression(var: ![[GV1:.*]], expr: !DIExpression())
+; CHECK-DAG: ![[GV1]] = distinct !DIGlobalVariable(name: "nodea"
+; CHECK-DAG: ![[GVE2]] = !DIGlobalVariableExpression(var: ![[GV2:.*]], expr: !DIExpression())
+; CHECK-DAG: ![[GV2]] = distinct !DIGlobalVariable(name: "nodeb"
+; CHECK-DAG: ![[GVE3]] = !DIGlobalVariableExpression(var: ![[GV3:.*]], expr: !DIExpression())
+; CHECK-DAG: ![[GV3]] = distinct !DIGlobalVariable(name: "jmax"
+
+;; This does not make sense should be removed.
+; CHECK-NOT: !DIGlobalVariable(name: "doesnotexist"
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "nodea", scope: !2, file: !3, line: 3, type: !9, isLocal: true, isDefinition: true)
+!2 = distinct !DISubprogram(name: "sub", scope: !4, file: !3, line: 1, type: !12, scopeLine: 1, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition, unit: !4)
+!3 = !DIFile(filename: "global-sra-struct-fit-segment.f90", directory: "/tmp")
+!4 = distinct !DICompileUnit(language: DW_LANG_Fortran90, file: !3, producer: " F90 Flang - 1.5 2017-05-01", isOptimized: false, flags: "'+flang -g -O0 -S -emit-llvm'", runtimeVersion: 0, emissionKind: FullDebug, enums: !5, retainedTypes: !5, globals: !6, imports: !5, nameTableKind: None)
+!5 = !{}
+!6 = !{!0, !7, !10}
+!7 = !DIGlobalVariableExpression(var: !8, expr: !DIExpression(DW_OP_plus_uconst, 4))
+!8 = distinct !DIGlobalVariable(name: "nodeb", scope: !2, file: !3, line: 3, type: !9, isLocal: true, isDefinition: true)
+!9 = !DIBasicType(name: "integer", size: 32, align: 32, encoding: DW_ATE_signed)
+!10 = !DIGlobalVariableExpression(var: !11, expr: !DIExpression(DW_OP_plus_uconst, 8))
+!11 = distinct !DIGlobalVariable(name: "jmax", scope: !2, file: !3, line: 3, type: !9, isLocal: true, isDefinition: true)
+!12 = !DISubroutineType(types: !13)
+!13 = !{null, !9, !9}
+!14 = !{i32 2, !"Dwarf Version", i32 4}
+!15 = !{i32 2, !"Debug Info Version", i32 3}
+!16 = !DILocalVariable(name: "inode", arg: 1, scope: !2, file: !3, line: 1, type: !9)
+!17 = !DILocation(line: 0, scope: !2)
+!18 = !DILocalVariable(name: "node", arg: 2, scope: !2, file: !3, line: 1, type: !9)
+!19 = !DILocation(line: 5, column: 1, scope: !2)
+!20 = !DILocation(line: 6, column: 1, scope: !2)
+!21 = !DILocation(line: 7, column: 1, scope: !2)
+!22 = !DILocation(line: 8, column: 1, scope: !2)
+!23 = !DILocation(line: 9, column: 1, scope: !2)
+!24 = !DILocation(line: 10, column: 1, scope: !2)
+!25 = !DILocation(line: 11, column: 1, scope: !2)
+!26 = !DILocation(line: 13, column: 1, scope: !2)
+!27 = !DIGlobalVariableExpression(var: !28, expr: !DIExpression(DW_OP_constu, 4, DW_OP_minus))
+!28 = distinct !DIGlobalVariable(name: "doesnotexist", scope: !2, file: !3, line: 3, type: !9, isLocal: true, isDefinition: true)
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