llvm-6502/test/DebugInfo/X86/nodebug_with_debug_loc.ll
Duncan P. N. Exon Smith 88e419d66e DebugInfo: Remove 'inlinedAt:' field from MDLocalVariable
Remove 'inlinedAt:' from MDLocalVariable.  Besides saving some memory
(variables with it seem to be single largest `Metadata` contributer to
memory usage right now in -g -flto builds), this stops optimization and
backend passes from having to change local variables.

The 'inlinedAt:' field was used by the backend in two ways:

 1. To tell the backend whether and into what a variable was inlined.
 2. To create a unique id for each inlined variable.

Instead, rely on the 'inlinedAt:' field of the intrinsic's `!dbg`
attachment, and change the DWARF backend to use a typedef called
`InlinedVariable` which is `std::pair<MDLocalVariable*, MDLocation*>`.
This `DebugLoc` is already passed reliably through the backend (as
verified by r234021).

This commit removes the check from r234021, but I added a new check
(that will survive) in r235048, and changed the `DIBuilder` API in
r235041 to require a `!dbg` attachment whose 'scope:` is in the same
`MDSubprogram` as the variable's.

If this breaks your out-of-tree testcases, perhaps the script I used
(mdlocalvariable-drop-inlinedat.sh) will help; I'll attach it to PR22778
in a moment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235050 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 22:29:27 +00:00

140 lines
6.0 KiB
LLVM

; REQUIRES: object-emission
; RUN: llc -mtriple=i386-linux-gnu -filetype=obj -relocation-model=pic %s -o /dev/null
; Derived from the test case in PR20367, there's nothing really positive to
; test here (hence no FileCheck, etc). All that was wrong is that the debug info
; intrinsics (introduced by inlining) in 'f1' were causing codegen to crash, but
; since 'f1' is a nodebug function, there's no positive outcome to confirm, just
; that debug info doesn't get in the way/cause a crash.
; The test case isn't particularly well reduced/tidy, but as simple as I could
; get the C++ source. I assume the complexity is mostly just about producing a
; certain amount of register pressure, so it might be able to be simplified/made
; more uniform.
; Generated from:
; $ clang-tot -cc1 -triple i386 -emit-obj -g -O3 repro.cpp
; void sink(const void *);
; int source();
; void f3(int);
;
; extern bool b;
;
; struct string {
; unsigned *mem;
; };
;
; extern string &str;
;
; inline __attribute__((always_inline)) void s2(string *lhs) { sink(lhs->mem); }
; inline __attribute__((always_inline)) void f() {
; string str2;
; s2(&str2);
; sink(&str2);
; }
; void __attribute__((nodebug)) f1() {
; for (int iter = 0; iter != 2; ++iter) {
; f();
; sink(str.mem);
; if (b) return;
; }
; }
%struct.string = type { i32* }
@str = external constant %struct.string*
@b = external global i8
; Function Attrs: nounwind
define void @_Z2f1v() #0 {
entry:
%str2.i = alloca %struct.string, align 4
%0 = bitcast %struct.string* %str2.i to i8*, !dbg !26
%1 = load %struct.string*, %struct.string** @str, align 4
%mem = getelementptr inbounds %struct.string, %struct.string* %1, i32 0, i32 0
br label %for.body
for.body: ; preds = %for.body, %entry
%iter.02 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
call void @llvm.lifetime.start(i64 4, i8* %0), !dbg !26
call void @llvm.dbg.value(metadata %struct.string* %str2.i, i64 0, metadata !16, metadata !MDExpression()) #3, !dbg !26
call void @llvm.dbg.value(metadata %struct.string* %str2.i, i64 0, metadata !27, metadata !MDExpression()) #3, !dbg !29
call void @_Z4sinkPKv(i8* undef) #3, !dbg !29
call void @_Z4sinkPKv(i8* %0) #3, !dbg !30
call void @llvm.lifetime.end(i64 4, i8* %0), !dbg !31
%2 = load i32*, i32** %mem, align 4, !tbaa !32
%3 = bitcast i32* %2 to i8*
call void @_Z4sinkPKv(i8* %3) #3
%4 = load i8, i8* @b, align 1, !tbaa !37, !range !39
%tobool = icmp ne i8 %4, 0
%inc = add nsw i32 %iter.02, 1
%cmp = icmp eq i32 %inc, 2
%or.cond = or i1 %tobool, %cmp
br i1 %or.cond, label %for.end, label %for.body
for.end: ; preds = %for.body
ret void
}
declare void @_Z4sinkPKv(i8*) #1
; Function Attrs: nounwind readnone
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #2
; Function Attrs: nounwind
declare void @llvm.lifetime.start(i64, i8* nocapture) #3
; Function Attrs: nounwind
declare void @llvm.lifetime.end(i64, i8* nocapture) #3
attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #2 = { nounwind readnone }
attributes #3 = { nounwind }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!23, !24}
!llvm.ident = !{!25}
!0 = !MDCompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: true, emissionKind: 1, file: !1, enums: !2, retainedTypes: !3, subprograms: !10, globals: !2, imports: !2)
!1 = !MDFile(filename: "<stdin>", directory: "/tmp/dbginfo")
!2 = !{}
!3 = !{!4}
!4 = !MDCompositeType(tag: DW_TAG_structure_type, name: "string", line: 7, size: 32, align: 32, file: !5, elements: !6, identifier: "_ZTS6string")
!5 = !MDFile(filename: "repro.cpp", directory: "/tmp/dbginfo")
!6 = !{!7}
!7 = !MDDerivedType(tag: DW_TAG_member, name: "mem", line: 8, size: 32, align: 32, file: !5, scope: !"_ZTS6string", baseType: !8)
!8 = !MDDerivedType(tag: DW_TAG_pointer_type, size: 32, align: 32, baseType: !9)
!9 = !MDBasicType(tag: DW_TAG_base_type, name: "unsigned int", size: 32, align: 32, encoding: DW_ATE_unsigned)
!10 = !{!11, !17}
!11 = !MDSubprogram(name: "f", linkageName: "_Z1fv", line: 14, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 14, file: !5, scope: !12, type: !13, variables: !15)
!12 = !MDFile(filename: "repro.cpp", directory: "/tmp/dbginfo")
!13 = !MDSubroutineType(types: !14)
!14 = !{null}
!15 = !{!16}
!16 = !MDLocalVariable(tag: DW_TAG_auto_variable, name: "str2", line: 15, scope: !11, file: !12, type: !"_ZTS6string")
!17 = !MDSubprogram(name: "s2", linkageName: "_Z2s2P6string", line: 13, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 13, file: !5, scope: !12, type: !18, variables: !21)
!18 = !MDSubroutineType(types: !19)
!19 = !{null, !20}
!20 = !MDDerivedType(tag: DW_TAG_pointer_type, size: 32, align: 32, baseType: !"_ZTS6string")
!21 = !{!22}
!22 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "lhs", line: 13, arg: 1, scope: !17, file: !12, type: !20)
!23 = !{i32 2, !"Dwarf Version", i32 4}
!24 = !{i32 2, !"Debug Info Version", i32 3}
!25 = !{!"clang version 3.5.0 "}
!26 = !MDLocation(line: 15, scope: !11)
!27 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "lhs", line: 13, arg: 1, scope: !17, file: !12, type: !20)
!28 = !MDLocation(line: 16, scope: !11)
!29 = !MDLocation(line: 13, scope: !17, inlinedAt: !28)
!30 = !MDLocation(line: 17, scope: !11)
!31 = !MDLocation(line: 18, scope: !11)
!32 = !{!33, !34, i64 0}
!33 = !{!"_ZTS6string", !34, i64 0}
!34 = !{!"any pointer", !35, i64 0}
!35 = !{!"omnipotent char", !36, i64 0}
!36 = !{!"Simple C/C++ TBAA"}
!37 = !{!38, !38, i64 0}
!38 = !{!"bool", !35, i64 0}
!39 = !{i8 0, i8 2}