From e5ca21a2df48e3b3246629b141ea27eb69d7b643 Mon Sep 17 00:00:00 2001 From: Adrian Prantl Date: Mon, 22 Dec 2014 22:26:00 +0000 Subject: [PATCH] Debug info: Teach SROA how to update debug info for fragmented variables. This allows us to generate debug info for extremely advanced code such as typedef struct { long int a; int b;} S; int foo(S s) { return s.b; } which at -O1 on x86_64 is codegen'd into define i32 @foo(i64 %s.coerce0, i32 %s.coerce1) #0 { ret i32 %s.coerce1, !dbg !24 } with this patch we emit the following debug info for this TAG_formal_parameter [3] AT_location( 0x00000000 0x0000000000000000 - 0x0000000000000006: rdi, piece 0x00000008, rsi, piece 0x00000004 0x0000000000000006 - 0x0000000000000008: rdi, piece 0x00000008, rax, piece 0x00000004 ) AT_name( "s" ) AT_decl_file( "/Volumes/Data/llvm/_build.ninja.release/test.c" ) Thanks to chandlerc, dblaikie, and echristo for their feedback on all previous iterations of this patch! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224739 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/SROA.cpp | 31 ++++++++- test/DebugInfo/X86/array2.ll | 8 +-- test/DebugInfo/X86/sroasplit-1.ll | 97 ++++++++++++++++++++++++++++ test/DebugInfo/X86/sroasplit-2.ll | 102 ++++++++++++++++++++++++++++++ 4 files changed, 233 insertions(+), 5 deletions(-) create mode 100644 test/DebugInfo/X86/sroasplit-1.ll create mode 100644 test/DebugInfo/X86/sroasplit-2.ll diff --git a/lib/Transforms/Scalar/SROA.cpp b/lib/Transforms/Scalar/SROA.cpp index 91818c8fc1..37772277b5 100644 --- a/lib/Transforms/Scalar/SROA.cpp +++ b/lib/Transforms/Scalar/SROA.cpp @@ -953,6 +953,10 @@ class SROA : public FunctionPass { /// currently in the promotable queue. SetVector> SpeculatableSelects; + /// Debug intrinsics do not show up as regular uses in the + /// IR. This side-table holds the missing use edges. + DenseMap DbgDeclares; + public: SROA(bool RequiresDomTree = true) : FunctionPass(ID), RequiresDomTree(RequiresDomTree), C(nullptr), @@ -3230,6 +3234,27 @@ bool SROA::rewritePartition(AllocaInst &AI, AllocaSlices &AS, new AllocaInst(SliceTy, nullptr, Alignment, AI.getName() + ".sroa." + Twine(B - AS.begin()), &AI); ++NumNewAllocas; + + // Migrate debug information from the old alloca to the new alloca + // and the individial slices. + if (DbgDeclareInst *DbgDecl = DbgDeclares.lookup(&AI)) { + DIVariable Var(DbgDecl->getVariable()); + DIExpression Piece; + DIBuilder DIB(*AI.getParent()->getParent()->getParent(), + /*AllowUnresolved*/ false); + // Create a piece expression describing the slice, if the new slize is + // smaller than the old alloca or the old alloca already was described + // with a piece. It would be even better to just compare against the size + // of the type described in the debug info, but then we would need to + // build an expensive DIRefMap. + if (SliceSize < DL->getTypeAllocSize(AI.getAllocatedType()) || + DIExpression(DbgDecl->getExpression()).isVariablePiece()) + Piece = DIB.createPieceExpression(BeginOffset, SliceSize); + Instruction *NewDDI = DIB.insertDeclare(NewAI, Var, Piece, &AI); + NewDDI->setDebugLoc(DbgDecl->getDebugLoc()); + DbgDeclares.insert(std::make_pair(NewAI, cast(NewDDI))); + DeadInsts.insert(DbgDecl); + } } DEBUG(dbgs() << "Rewriting alloca partition " @@ -3680,9 +3705,13 @@ bool SROA::runOnFunction(Function &F) { BasicBlock &EntryBB = F.getEntryBlock(); for (BasicBlock::iterator I = EntryBB.begin(), E = std::prev(EntryBB.end()); - I != E; ++I) + I != E; ++I) { if (AllocaInst *AI = dyn_cast(I)) Worklist.insert(AI); + else if (DbgDeclareInst *DDI = dyn_cast(I)) + if (auto AI = dyn_cast_or_null(DDI->getAddress())) + DbgDeclares.insert(std::make_pair(AI, DDI)); + } bool Changed = false; // A set of deleted alloca instruction pointers which should be removed from diff --git a/test/DebugInfo/X86/array2.ll b/test/DebugInfo/X86/array2.ll index 6dfa8d7178..74dd9303d7 100644 --- a/test/DebugInfo/X86/array2.ll +++ b/test/DebugInfo/X86/array2.ll @@ -13,12 +13,12 @@ ; } ; ; RUN: opt %s -O2 -S -o - | FileCheck %s -; Test that we do not lower dbg.declares for arrays. +; Test that we correctly lower dbg.declares for arrays. ; ; CHECK: define i32 @main -; CHECK: call void @llvm.dbg.value -; CHECK: call void @llvm.dbg.value -; CHECK: call void @llvm.dbg.declare +; CHECK: call void @llvm.dbg.value(metadata i32 42, i64 0, metadata ![[ARRAY:[0-9]+]], metadata ![[EXPR:[0-9]+]]) +; CHECK: ![[ARRAY]] = {{.*}}; [ DW_TAG_auto_variable ] [array] [line 6] +; CHECK: ![[EXPR]] = {{.*}}; [ DW_TAG_expression ] [DW_OP_piece offset=0, size=4] target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-apple-macosx10.9.0" diff --git a/test/DebugInfo/X86/sroasplit-1.ll b/test/DebugInfo/X86/sroasplit-1.ll new file mode 100644 index 0000000000..edb3f466f5 --- /dev/null +++ b/test/DebugInfo/X86/sroasplit-1.ll @@ -0,0 +1,97 @@ +; RUN: opt %s -sroa -verify -S -o - | FileCheck %s +; +; Test that we can partial emit debug info for aggregates repeatedly +; split up by SROA. +; +; // Compile with -O1 +; typedef struct { +; int a; +; long int b; +; } Inner; +; +; typedef struct { +; Inner inner[2]; +; } Outer; +; +; int foo(Outer outer) { +; Inner i1 = outer.inner[1]; +; return i1.a; +; } +; + +; Verify that SROA creates a variable piece when splitting i1. +; CHECK: %[[I1:.*]] = alloca [12 x i8], align 4 +; CHECK: call void @llvm.dbg.declare(metadata [12 x i8]* %[[I1]], metadata ![[VAR:[0-9]+]], metadata ![[PIECE1:[0-9]+]]) +; CHECK: call void @llvm.dbg.value(metadata i32 %[[A:.*]], i64 0, metadata ![[VAR]], metadata ![[PIECE2:[0-9]+]]) +; CHECK: ret i32 %[[A]] +; Read Var and Piece: +; CHECK: ![[VAR]] = {{.*}} ; [ DW_TAG_auto_variable ] [i1] [line 11] +; CHECK: ![[PIECE1]] = {{.*}} ; [ DW_TAG_expression ] [DW_OP_piece offset=4, size=12] +; CHECK: ![[PIECE2]] = {{.*}} ; [ DW_TAG_expression ] [DW_OP_piece offset=0, size=4] + +target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.9.0" + +%struct.Outer = type { [2 x %struct.Inner] } +%struct.Inner = type { i32, i64 } + +; Function Attrs: nounwind ssp uwtable +define i32 @foo(%struct.Outer* byval align 8 %outer) #0 { +entry: + %i1 = alloca %struct.Inner, align 8 + call void @llvm.dbg.declare(metadata %struct.Outer* %outer, metadata !25, metadata !2), !dbg !26 + call void @llvm.dbg.declare(metadata %struct.Inner* %i1, metadata !27, metadata !2), !dbg !28 + %inner = getelementptr inbounds %struct.Outer* %outer, i32 0, i32 0, !dbg !28 + %arrayidx = getelementptr inbounds [2 x %struct.Inner]* %inner, i32 0, i64 1, !dbg !28 + %0 = bitcast %struct.Inner* %i1 to i8*, !dbg !28 + %1 = bitcast %struct.Inner* %arrayidx to i8*, !dbg !28 + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* %1, i64 16, i32 8, i1 false), !dbg !28 + %a = getelementptr inbounds %struct.Inner* %i1, i32 0, i32 0, !dbg !29 + %2 = load i32* %a, align 4, !dbg !29 + ret i32 %2, !dbg !29 +} + +; Function Attrs: nounwind readnone +declare void @llvm.dbg.declare(metadata, metadata, metadata) #1 + +; Function Attrs: nounwind +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) #2 + +attributes #0 = { nounwind ssp uwtable } +attributes #1 = { nounwind readnone } +attributes #2 = { nounwind } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!22, !23} +!llvm.ident = !{!24} + +!0 = !{!"0x11\0012\00clang version 3.5.0 \000\00\000\00\001", !1, !2, !2, !3, !2, !2} ; [ DW_TAG_compile_unit ] [ DW_TAG_compile_unit ] [sroasplit-1.c] [DW_LANG_C99] +!1 = !{!"sroasplit-1.c", !""} +!2 = !{} +!3 = !{!4} +!4 = !{!"0x2e\00foo\00foo\00\0010\000\001\000\006\00256\000\0010", !1, !5, !6, null, i32 (%struct.Outer*)* @foo, null, null, !2} ; [ DW_TAG_subprogram ] [ DW_TAG_subprogram ] [line 10] [def] [foo] +!5 = !{!"0x29", !1} ; [ DW_TAG_file_type ] [ DW_TAG_file_type ] [sroasplit-1.c] +!6 = !{!"0x15\00\000\000\000\000\000\000", i32 0, null, null, !7, null, null, null} ; [ DW_TAG_subroutine_type ] [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ] +!7 = !{!8, !9} +!8 = !{!"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed] +!9 = !{!"0x16\00Outer\008\000\000\000\000", !1, null, !10} ; [ DW_TAG_typedef ] [ DW_TAG_typedef ] [Outer] [line 8, size 0, align 0, offset 0] [from ] +!10 = !{!"0x13\00\006\00256\0064\000\000\000", !1, null, null, !11, null, null, null} ; [ DW_TAG_structure_type ] [line 6, size 256, align 64, offset 0] [def] [from ] +!11 = !{!12} +!12 = !{!"0xd\00inner\007\00256\0064\000\000", !1, !10, !13} ; [ DW_TAG_member ] [inner] [line 7, size 256, align 64, offset 0] [from ] +!13 = !{!"0x1\00\000\00256\0064\000\000", null, null, !14, !20, i32 0, null, null, null} ; [ DW_TAG_array_type ] [line 0, size 256, align 64, offset 0] [from Inner] +!14 = !{!"0x16\00Inner\004\000\000\000\000", !1, null, !15} ; [ DW_TAG_typedef ] [ DW_TAG_typedef ] [Inner] [line 4, size 0, align 0, offset 0] [from ] +!15 = !{!"0x13\00\001\00128\0064\000\000\000", !1, null, null, !16, null, null, null} ; [ DW_TAG_structure_type ] [line 1, size 128, align 64, offset 0] [def] [from ] +!16 = !{!17, !18} +!17 = !{!"0xd\00a\002\0032\0032\000\000", !1, !15, !8} ; [ DW_TAG_member ] [a] [line 2, size 32, align 32, offset 0] [from int] +!18 = !{!"0xd\00b\003\0064\0064\0064\000", !1, !15, !19} ; [ DW_TAG_member ] [b] [line 3, size 64, align 64, offset 64] [from long int] +!19 = !{!"0x24\00long int\000\0064\0064\000\000\005", null, null} ; [ DW_TAG_base_type ] [ DW_TAG_base_type ] [long int] [line 0, size 64, align 64, offset 0, enc DW_ATE_signed] +!20 = !{!21} +!21 = !{!"0x21\000\002"} ; [ DW_TAG_subrange_type ] [0, 1] +!22 = !{i32 2, !"Dwarf Version", i32 2} +!23 = !{i32 1, !"Debug Info Version", i32 2} +!24 = !{!"clang version 3.5.0 "} +!25 = !{!"0x101\00outer\0016777226\000", !4, !5, !9} ; [ DW_TAG_arg_variable ] [ DW_TAG_arg_variable ] [outer] [line 10] +!26 = !{i32 10, i32 0, !4, null} +!27 = !{!"0x100\00i1\0011\000", !4, !5, !14} ; [ DW_TAG_auto_variable ] [ DW_TAG_auto_variable ] [i1] [line 11] +!28 = !{i32 11, i32 0, !4, null} +!29 = !{i32 12, i32 0, !4, null} diff --git a/test/DebugInfo/X86/sroasplit-2.ll b/test/DebugInfo/X86/sroasplit-2.ll new file mode 100644 index 0000000000..4e68d0c956 --- /dev/null +++ b/test/DebugInfo/X86/sroasplit-2.ll @@ -0,0 +1,102 @@ +; RUN: opt %s -sroa -verify -S -o - | FileCheck %s +; +; Test that we can partial emit debug info for aggregates repeatedly +; split up by SROA. +; +; // Compile with -O1 +; typedef struct { +; int a; +; int b; +; } Inner; +; +; typedef struct { +; Inner inner[2]; +; } Outer; +; +; int foo(Outer outer) { +; Inner i1 = outer.inner[1]; +; return i1.a; +; } +; + +; Verify that SROA creates a variable piece when splitting i1. +; CHECK: call void @llvm.dbg.value(metadata i64 %outer.coerce0, i64 0, metadata ![[O:[0-9]+]], metadata ![[PIECE1:[0-9]+]]), +; CHECK: call void @llvm.dbg.value(metadata i64 %outer.coerce1, i64 0, metadata ![[O]], metadata ![[PIECE2:[0-9]+]]), +; CHECK: call void @llvm.dbg.value({{.*}}, i64 0, metadata ![[I1:[0-9]+]], metadata ![[PIECE3:[0-9]+]]), +; CHECK-DAG: ![[O]] = {{.*}} [ DW_TAG_arg_variable ] [outer] [line 10] +; CHECK-DAG: ![[PIECE1]] = {{.*}} [ DW_TAG_expression ] [DW_OP_piece offset=0, size=8] +; CHECK-DAG: ![[PIECE2]] = {{.*}} [ DW_TAG_expression ] [DW_OP_piece offset=8, size=8] +; CHECK-DAG: ![[I1]] = {{.*}} [ DW_TAG_auto_variable ] [i1] [line 11] +; CHECK-DAG: ![[PIECE3]] = {{.*}} [ DW_TAG_expression ] [DW_OP_piece offset=0, size=4] + +; ModuleID = 'sroasplit-2.c' +target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.9.0" + +%struct.Outer = type { [2 x %struct.Inner] } +%struct.Inner = type { i32, i32 } + +; Function Attrs: nounwind ssp uwtable +define i32 @foo(i64 %outer.coerce0, i64 %outer.coerce1) #0 { + %outer = alloca %struct.Outer, align 8 + %i1 = alloca %struct.Inner, align 4 + %1 = bitcast %struct.Outer* %outer to { i64, i64 }* + %2 = getelementptr { i64, i64 }* %1, i32 0, i32 0 + store i64 %outer.coerce0, i64* %2 + %3 = getelementptr { i64, i64 }* %1, i32 0, i32 1 + store i64 %outer.coerce1, i64* %3 + call void @llvm.dbg.declare(metadata %struct.Outer* %outer, metadata !24, metadata !2), !dbg !25 + call void @llvm.dbg.declare(metadata %struct.Inner* %i1, metadata !26, metadata !2), !dbg !27 + %4 = getelementptr inbounds %struct.Outer* %outer, i32 0, i32 0, !dbg !27 + %5 = getelementptr inbounds [2 x %struct.Inner]* %4, i32 0, i64 1, !dbg !27 + %6 = bitcast %struct.Inner* %i1 to i8*, !dbg !27 + %7 = bitcast %struct.Inner* %5 to i8*, !dbg !27 + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %6, i8* %7, i64 8, i32 4, i1 false), !dbg !27 + %8 = getelementptr inbounds %struct.Inner* %i1, i32 0, i32 0, !dbg !28 + %9 = load i32* %8, align 4, !dbg !28 + ret i32 %9, !dbg !28 +} + +; Function Attrs: nounwind readnone +declare void @llvm.dbg.declare(metadata, metadata, metadata) #1 + +; Function Attrs: nounwind +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) #2 + +attributes #0 = { nounwind ssp uwtable "no-frame-pointer-elim"="true" } +attributes #1 = { nounwind readnone } +attributes #2 = { nounwind } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!21, !22} +!llvm.ident = !{!23} + +!0 = !{!"0x11\0012\00clang version 3.5.0 \000\00\000\00\001", !1, !2, !2, !3, !2, !2} ; [ DW_TAG_compile_unit ] [ DW_TAG_compile_unit ] [sroasplit-2.c] [DW_LANG_C99] +!1 = !{!"sroasplit-2.c", !""} +!2 = !{} +!3 = !{!4} +!4 = !{!"0x2e\00foo\00foo\00\0010\000\001\000\006\00256\000\0010", !1, !5, !6, null, i32 (i64, i64)* @foo, null, null, !2} ; [ DW_TAG_subprogram ] [ DW_TAG_subprogram ] [line 10] [def] [foo] +!5 = !{!"0x29", !1} ; [ DW_TAG_file_type ] [ DW_TAG_file_type ] [sroasplit-2.c] +!6 = !{!"0x15\00\000\000\000\000\000\000", i32 0, null, null, !7, null, null, null} ; [ DW_TAG_subroutine_type ] [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ] +!7 = !{!8, !9} +!8 = !{!"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed] +!9 = !{!"0x16\00Outer\008\000\000\000\000", !1, null, !10} ; [ DW_TAG_typedef ] [ DW_TAG_typedef ] [Outer] [line 8, size 0, align 0, offset 0] [from ] +!10 = !{!"0x13\00\006\00128\0032\000\000\000", !1, null, null, !11, null, null, null} ; [ DW_TAG_structure_type ] [line 6, size 128, align 32, offset 0] [def] [from ] +!11 = !{!12} +!12 = !{!"0xd\00inner\007\00128\0032\000\000", !1, !10, !13} ; [ DW_TAG_member ] [inner] [line 7, size 128, align 32, offset 0] [from ] +!13 = !{!"0x1\00\000\00128\0032\000\000", null, null, !14, !19, i32 0, null, null, null} ; [ DW_TAG_array_type ] [line 0, size 128, align 32, offset 0] [from Inner] +!14 = !{!"0x16\00Inner\004\000\000\000\000", !1, null, !15} ; [ DW_TAG_typedef ] [ DW_TAG_typedef ] [Inner] [line 4, size 0, align 0, offset 0] [from ] +!15 = !{!"0x13\00\001\0064\0032\000\000\000", !1, null, null, !16, null, null, null} ; [ DW_TAG_structure_type ] [line 1, size 64, align 32, offset 0] [def] [from ] +!16 = !{!17, !18} +!17 = !{!"0xd\00a\002\0032\0032\000\000", !1, !15, !8} ; [ DW_TAG_member ] [a] [line 2, size 32, align 32, offset 0] [from int] +!18 = !{!"0xd\00b\003\0032\0032\0032\000", !1, !15, !8} ; [ DW_TAG_member ] [b] [line 3, size 32, align 32, offset 32] [from int] +!19 = !{!20} +!20 = !{!"0x21\000\002"} ; [ DW_TAG_subrange_type ] [0, 1] +!21 = !{i32 2, !"Dwarf Version", i32 2} +!22 = !{i32 1, !"Debug Info Version", i32 2} +!23 = !{!"clang version 3.5.0 "} +!24 = !{!"0x101\00outer\0016777226\000", !4, !5, !9} ; [ DW_TAG_arg_variable ] [ DW_TAG_arg_variable ] [outer] [line 10] +!25 = !{i32 10, i32 0, !4, null} +!26 = !{!"0x100\00i1\0011\000", !4, !5, !14} ; [ DW_TAG_auto_variable ] [ DW_TAG_auto_variable ] [i1] [line 11] +!27 = !{i32 11, i32 0, !4, null} +!28 = !{i32 12, i32 0, !4, null} -- 2.39.2