Revert r313400 "[DebugInfo] Insert DW_OP_deref when spilling indirect DBG_VALUEs"

This caused asserts in Chromium. See http://crbug.com/766261

> Summary:
> This comes up in optimized debug info for C++ programs that pass and
> return objects indirectly by address. In these programs,
> llvm.dbg.declare survives optimization, which causes us to emit indirect
> DBG_VALUE instructions. The fast register allocator knows to insert
> DW_OP_deref when spilling indirect DBG_VALUE instructions, but the
> LiveDebugVariables did not until this change.
>
> This fixes part of PR34513. I need to look into why this doesn't work at
> -O0 and I'll send follow up patches to handle that.
>
> Reviewers: aprantl, dblaikie, probinson
>
> Subscribers: qcolombet, hiraditya, llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D37911

llvm-svn: 313589

3 files changed, 3 insertions, 195 deletions

diff --git a/llvm/test/DebugInfo/X86/bbjoin.ll b/llvm/test/DebugInfo/X86/bbjoin.ll
index a41bde6d40b..4cb99410dd6 100644
--- a/llvm/test/DebugInfo/X86/bbjoin.ll
+++ b/llvm/test/DebugInfo/X86/bbjoin.ll
@@ -11,12 +11,12 @@
 ; }
 ; CHECK: ![[X:.*]] = !DILocalVariable(name: "x",
 ; CHECK: bb.0.entry:
-; CHECK:   DBG_VALUE 23, debug-use _, ![[X]],
+; CHECK:   DBG_VALUE 23, 0, ![[X]],
 ; CHECK:   DBG_VALUE %rsp, 0, ![[X]], !DIExpression(DW_OP_plus_uconst, 4, DW_OP_deref),
 ; CHECK: bb.1.if.then:
-; CHECK:   DBG_VALUE 43, debug-use _, ![[X]],
+; CHECK:   DBG_VALUE 43, 0, ![[X]],
 ; CHECK: bb.2.if.end:
-; CHECK-NOT:  DBG_VALUE 23, debug-use _, ![[X]],
+; CHECK-NOT:  DBG_VALUE 23, 0, ![[X]],
 ; CHECK:   RETQ %eax
 
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
diff --git a/llvm/test/DebugInfo/X86/spill-indirect-nrvo.ll b/llvm/test/DebugInfo/X86/spill-indirect-nrvo.ll
deleted file mode 100644
index ec2959701e4..00000000000
--- a/llvm/test/DebugInfo/X86/spill-indirect-nrvo.ll
+++ /dev/null
@@ -1,103 +0,0 @@
-; RUN: llc < %s | FileCheck %s
-; RUN: llc -O0 < %s | FileCheck %s
-
-; Make sure we insert DW_OP_deref when spilling indirect DBG_VALUE instructions.
-
-; C++ source:
-; #define FORCE_SPILL() \
-;   __asm volatile("" : : : \
-;                    "rax", "rbx", "rcx", "rdx", "rsi", "rdi", "rbp", "r8", \
-;                    "r9", "r10", "r11", "r12", "r13", "r14", "r15")
-; struct string {
-;   string();
-;   string(int i);
-;   ~string();
-;   int i = 0;
-; };
-; string get_string() {
-;   string result = 3;
-;   FORCE_SPILL();
-;   return result;
-; }
-
-; CHECK-LABEL: _Z10get_stringv:
-; CHECK: #DEBUG_VALUE: get_string:result <- [%RDI+0]
-; CHECK: movq   %rdi, [[OFFS:[0-9]+]](%rsp)          # 8-byte Spill
-; CHECK: #DEBUG_VALUE: get_string:result <- [DW_OP_plus_uconst [[OFFS]], DW_OP_deref] [%RSP+0]
-; CHECK: callq  _ZN6stringC1Ei
-; CHECK: #APP
-; CHECK: #NO_APP
-
-; ModuleID = 't.cpp'
-source_filename = "t.cpp"
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64--linux"
-
-%struct.string = type { i32 }
-
-; Function Attrs: uwtable
-define void @_Z10get_stringv(%struct.string* noalias sret %agg.result) #0 !dbg !7 {
-entry:
-  %nrvo = alloca i1, align 1
-  store i1 false, i1* %nrvo, align 1, !dbg !24
-  call void @llvm.dbg.declare(metadata %struct.string* %agg.result, metadata !23, metadata !DIExpression()), !dbg !25
-  call void @_ZN6stringC1Ei(%struct.string* %agg.result, i32 3), !dbg !26
-  call void asm sideeffect "", "~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15},~{dirflag},~{fpsr},~{flags}"() #3, !dbg !27, !srcloc !28
-  store i1 true, i1* %nrvo, align 1, !dbg !29
-  %nrvo.val = load i1, i1* %nrvo, align 1, !dbg !30
-  br i1 %nrvo.val, label %nrvo.skipdtor, label %nrvo.unused, !dbg !30
-
-nrvo.unused:                                      ; preds = %entry
-  call void @_ZN6stringD1Ev(%struct.string* %agg.result), !dbg !30
-  br label %nrvo.skipdtor, !dbg !30
-
-nrvo.skipdtor:                                    ; preds = %nrvo.unused, %entry
-  ret void, !dbg !30
-}
-
-; Function Attrs: nounwind readnone speculatable
-declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
-
-declare void @_ZN6stringC1Ei(%struct.string*, i32) unnamed_addr
-
-declare void @_ZN6stringD1Ev(%struct.string*) unnamed_addr
-
-attributes #0 = { uwtable }
-attributes #1 = { nounwind readnone speculatable }
-attributes #3 = { nounwind }
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!3, !4, !5}
-!llvm.ident = !{!6}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 6.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
-!1 = !DIFile(filename: "t.cpp", directory: "C:\5Csrc\5Cllvm-project\5Cbuild")
-!2 = !{}
-!3 = !{i32 2, !"Dwarf Version", i32 4}
-!4 = !{i32 2, !"Debug Info Version", i32 3}
-!5 = !{i32 1, !"wchar_size", i32 4}
-!6 = !{!"clang version 6.0.0 "}
-!7 = distinct !DISubprogram(name: "get_string", linkageName: "_Z10get_stringv", scope: !1, file: !1, line: 13, type: !8, isLocal: false, isDefinition: true, scopeLine: 13, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !22)
-!8 = !DISubroutineType(types: !9)
-!9 = !{!10}
-!10 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "string", file: !1, line: 7, size: 32, elements: !11, identifier: "_ZTS6string")
-!11 = !{!12, !14, !18, !21}
-!12 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !10, file: !1, line: 11, baseType: !13, size: 32)
-!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-!14 = !DISubprogram(name: "string", scope: !10, file: !1, line: 8, type: !15, isLocal: false, isDefinition: false, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: true)
-!15 = !DISubroutineType(types: !16)
-!16 = !{null, !17}
-!17 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
-!18 = !DISubprogram(name: "string", scope: !10, file: !1, line: 9, type: !19, isLocal: false, isDefinition: false, scopeLine: 9, flags: DIFlagPrototyped, isOptimized: true)
-!19 = !DISubroutineType(types: !20)
-!20 = !{null, !17, !13}
-!21 = !DISubprogram(name: "~string", scope: !10, file: !1, line: 10, type: !15, isLocal: false, isDefinition: false, scopeLine: 10, flags: DIFlagPrototyped, isOptimized: true)
-!22 = !{!23}
-!23 = !DILocalVariable(name: "result", scope: !7, file: !1, line: 14, type: !10)
-!24 = !DILocation(line: 14, column: 3, scope: !7)
-!25 = !DILocation(line: 14, column: 10, scope: !7)
-!26 = !DILocation(line: 14, column: 19, scope: !7)
-!27 = !DILocation(line: 15, column: 3, scope: !7)
-!28 = !{i32 -2147471175}
-!29 = !DILocation(line: 16, column: 3, scope: !7)
-!30 = !DILocation(line: 17, column: 1, scope: !7)
diff --git a/llvm/test/DebugInfo/X86/spill-nontrivial-param.ll b/llvm/test/DebugInfo/X86/spill-nontrivial-param.ll
deleted file mode 100644
index 9ac82374a0e..00000000000
--- a/llvm/test/DebugInfo/X86/spill-nontrivial-param.ll
+++ /dev/null
@@ -1,89 +0,0 @@
-; RUN: llc < %s | FileCheck %s
-
-; Make sure we insert DW_OP_deref when spilling indirect DBG_VALUE instructions.
-; In this example, 'nt' is passed by address because it is not trivially
-; copyable. When we spill the physical argument register at the barrier, we need
-; to insert DW_OP_deref.
-
-; #define FORCE_SPILL() \
-;   __asm volatile("" : : : \
-;                    "rax", "rbx", "rcx", "rdx", "rsi", "rdi", "rbp", "r8", \
-;                    "r9", "r10", "r11", "r12", "r13", "r14", "r15")
-; struct NonTrivial {
-;   NonTrivial();
-;   ~NonTrivial();
-;   int i;
-; };
-; int foo(NonTrivial nt) {
-;   FORCE_SPILL();
-;   return nt.i;
-; }
-
-; CHECK-LABEL: _Z3foo10NonTrivial:
-; CHECK: #DEBUG_VALUE: foo:nt <- [%RDI+0]
-; CHECK: movq    %rdi, -8(%rsp)          # 8-byte Spill
-; CHECK: #DEBUG_VALUE: foo:nt <- [DW_OP_constu 8, DW_OP_minus, DW_OP_deref] [%RSP+0]
-; CHECK: #APP
-; CHECK: #NO_APP
-; CHECK: movq    -8(%rsp), %rax          # 8-byte Reload
-; CHECK: movl    (%rax), %eax
-
-; ModuleID = 't.cpp'
-source_filename = "t.cpp"
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64--linux"
-
-%struct.NonTrivial = type { i32 }
-
-; Function Attrs: nounwind uwtable
-define i32 @_Z3foo10NonTrivial(%struct.NonTrivial* nocapture readonly %nt) local_unnamed_addr #0 !dbg !7 {
-entry:
-  tail call void @llvm.dbg.declare(metadata %struct.NonTrivial* %nt, metadata !20, metadata !DIExpression()), !dbg !21
-  tail call void asm sideeffect "", "~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15},~{dirflag},~{fpsr},~{flags}"() #2, !dbg !22, !srcloc !23
-  %i = getelementptr inbounds %struct.NonTrivial, %struct.NonTrivial* %nt, i64 0, i32 0, !dbg !24
-  %0 = load i32, i32* %i, align 4, !dbg !24, !tbaa !25
-  ret i32 %0, !dbg !30
-}
-
-; Function Attrs: nounwind readnone speculatable
-declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
-
-attributes #0 = { nounwind uwtable }
-attributes #1 = { nounwind readnone speculatable }
-attributes #2 = { nounwind }
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!3, !4, !5}
-!llvm.ident = !{!6}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 6.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
-!1 = !DIFile(filename: "t.cpp", directory: "C:\5Csrc\5Cllvm-project\5Cbuild")
-!2 = !{}
-!3 = !{i32 2, !"Dwarf Version", i32 4}
-!4 = !{i32 2, !"Debug Info Version", i32 3}
-!5 = !{i32 1, !"wchar_size", i32 4}
-!6 = !{!"clang version 6.0.0 "}
-!7 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foo10NonTrivial", scope: !1, file: !1, line: 10, type: !8, isLocal: false, isDefinition: true, scopeLine: 10, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !19)
-!8 = !DISubroutineType(types: !9)
-!9 = !{!10, !11}
-!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-!11 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "NonTrivial", file: !1, line: 5, size: 32, elements: !12, identifier: "_ZTS10NonTrivial")
-!12 = !{!13, !14, !18}
-!13 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !11, file: !1, line: 8, baseType: !10, size: 32)
-!14 = !DISubprogram(name: "NonTrivial", scope: !11, file: !1, line: 6, type: !15, isLocal: false, isDefinition: false, scopeLine: 6, flags: DIFlagPrototyped, isOptimized: true)
-!15 = !DISubroutineType(types: !16)
-!16 = !{null, !17}
-!17 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
-!18 = !DISubprogram(name: "~NonTrivial", scope: !11, file: !1, line: 7, type: !15, isLocal: false, isDefinition: false, scopeLine: 7, flags: DIFlagPrototyped, isOptimized: true)
-!19 = !{!20}
-!20 = !DILocalVariable(name: "nt", arg: 1, scope: !7, file: !1, line: 10, type: !11)
-!21 = !DILocation(line: 10, column: 20, scope: !7)
-!22 = !DILocation(line: 11, column: 3, scope: !7)
-!23 = !{i32 -2147471481}
-!24 = !DILocation(line: 12, column: 13, scope: !7)
-!25 = !{!26, !27, i64 0}
-!26 = !{!"_ZTS10NonTrivial", !27, i64 0}
-!27 = !{!"int", !28, i64 0}
-!28 = !{!"omnipotent char", !29, i64 0}
-!29 = !{!"Simple C++ TBAA"}
-!30 = !DILocation(line: 12, column: 3, scope: !7)