mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2025-03-04 18:38:37 +00:00
[codeview] Optimize the size of defranges with gaps
For small, discontiguous local variable regions, CodeView can use a single defrange record with a gap, rather than having two defrange records. I expect that this optimization will only have a minor impact on debug info size. llvm-svn: 281664
This commit is contained in:
Reid Kleckner
parent
c6312b466a
commit
945118fc1c
@ -453,16 +453,41 @@ void CodeViewContext::encodeDefRange(MCAsmLayout &Layout,
|
||||
Fixups.clear();
|
||||
raw_svector_ostream OS(Contents);
|
||||
|
||||
// Write down each range where the variable is defined.
|
||||
// Compute all the sizes up front.
|
||||
SmallVector<std::pair<unsigned, unsigned>, 4> GapAndRangeSizes;
|
||||
const MCSymbol *LastLabel = nullptr;
|
||||
for (std::pair<const MCSymbol *, const MCSymbol *> Range : Frag.getRanges()) {
|
||||
unsigned GapSize =
|
||||
LastLabel ? computeLabelDiff(Layout, LastLabel, Range.first) : 0;
|
||||
unsigned RangeSize = computeLabelDiff(Layout, Range.first, Range.second);
|
||||
GapAndRangeSizes.push_back({GapSize, RangeSize});
|
||||
LastLabel = Range.second;
|
||||
}
|
||||
|
||||
// Write down each range where the variable is defined.
|
||||
for (size_t I = 0, E = Frag.getRanges().size(); I != E;) {
|
||||
// If the range size of multiple consecutive ranges is under the max,
|
||||
// combine the ranges and emit some gaps.
|
||||
const MCSymbol *RangeBegin = Frag.getRanges()[I].first;
|
||||
unsigned RangeSize = GapAndRangeSizes[I].second;
|
||||
size_t J = I + 1;
|
||||
for (; J != E; ++J) {
|
||||
unsigned GapAndRangeSize = GapAndRangeSizes[J].first + GapAndRangeSizes[J].second;
|
||||
if (RangeSize + GapAndRangeSize > MaxDefRange)
|
||||
break;
|
||||
RangeSize += GapAndRangeSize;
|
||||
}
|
||||
unsigned NumGaps = J - I - 1;
|
||||
|
||||
support::endian::Writer<support::little> LEWriter(OS);
|
||||
|
||||
unsigned Bias = 0;
|
||||
// We must split the range into chunks of MaxDefRange, this is a fundamental
|
||||
// limitation of the file format.
|
||||
do {
|
||||
uint16_t Chunk = std::min((uint32_t)MaxDefRange, RangeSize);
|
||||
|
||||
const MCSymbolRefExpr *SRE = MCSymbolRefExpr::create(Range.first, Ctx);
|
||||
const MCSymbolRefExpr *SRE = MCSymbolRefExpr::create(RangeBegin, Ctx);
|
||||
const MCBinaryExpr *BE =
|
||||
MCBinaryExpr::createAdd(SRE, MCConstantExpr::create(Bias, Ctx), Ctx);
|
||||
MCValue Res;
|
||||
@ -473,8 +498,8 @@ void CodeViewContext::encodeDefRange(MCAsmLayout &Layout,
|
||||
StringRef FixedSizePortion = Frag.getFixedSizePortion();
|
||||
// Our record is a fixed sized prefix and a LocalVariableAddrRange that we
|
||||
// are artificially constructing.
|
||||
size_t RecordSize =
|
||||
FixedSizePortion.size() + sizeof(LocalVariableAddrRange);
|
||||
size_t RecordSize = FixedSizePortion.size() +
|
||||
sizeof(LocalVariableAddrRange) + 4 * NumGaps;
|
||||
// Write out the recrod size.
|
||||
support::endian::Writer<support::little>(OS).write<uint16_t>(RecordSize);
|
||||
// Write out the fixed size prefix.
|
||||
@ -487,12 +512,25 @@ void CodeViewContext::encodeDefRange(MCAsmLayout &Layout,
|
||||
Fixups.push_back(MCFixup::create(Contents.size(), BE, FK_SecRel_2));
|
||||
Contents.resize(Contents.size() + 2); // Fixup for section index.
|
||||
// Write down the range's extent.
|
||||
support::endian::Writer<support::little>(OS).write<uint16_t>(Chunk);
|
||||
LEWriter.write<uint16_t>(Chunk);
|
||||
|
||||
// Move on to the next range.
|
||||
Bias += Chunk;
|
||||
RangeSize -= Chunk;
|
||||
} while (RangeSize > 0);
|
||||
|
||||
// Emit the gaps afterwards.
|
||||
assert((NumGaps == 0 || Bias < MaxDefRange) &&
|
||||
"large ranges should not have gaps");
|
||||
unsigned GapStartOffset = GapAndRangeSizes[I].second;
|
||||
for (++I; I != J; ++I) {
|
||||
unsigned GapSize, RangeSize;
|
||||
assert(I < GapAndRangeSizes.size());
|
||||
std::tie(GapSize, RangeSize) = GapAndRangeSizes[I];
|
||||
LEWriter.write<uint16_t>(GapStartOffset);
|
||||
LEWriter.write<uint16_t>(RangeSize);
|
||||
GapStartOffset += GapSize + RangeSize;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
174
test/DebugInfo/COFF/local-variable-gap.ll
Normal file
174
test/DebugInfo/COFF/local-variable-gap.ll
Normal file
@ -0,0 +1,174 @@
|
||||
; RUN: llc -mtriple=x86_64-windows-msvc < %s | FileCheck %s --check-prefix=ASM
|
||||
; RUN: llc -mtriple=x86_64-windows-msvc < %s -filetype=obj | llvm-readobj -codeview - | FileCheck %s --check-prefix=OBJ
|
||||
|
||||
; This test attempts to exercise gaps in local variables. The local variable 'p'
|
||||
; will end up in some CSR (ESI), which will be used in both the BB scheduled
|
||||
; discontiguously out of line and the normal return BB. The best way to encode
|
||||
; this is to use a LocalVariableAddrGap. If the gap is too large, multiple
|
||||
; ranges should be emitted.
|
||||
|
||||
; Source to regenerate:
|
||||
; int barrier();
|
||||
; int vardef();
|
||||
; void use(int);
|
||||
; void __declspec(noreturn) call_noreturn(int);
|
||||
; int f() {
|
||||
; if (barrier()) {
|
||||
; int p = vardef();
|
||||
; if (barrier()) // Unlikely, will be placed after return
|
||||
; call_noreturn(p);
|
||||
; use(p);
|
||||
; } else {
|
||||
; barrier();
|
||||
; }
|
||||
; return 0;
|
||||
; }
|
||||
|
||||
; ASM: f: # @f
|
||||
; ASM: pushq %rsi
|
||||
; ASM: subq $32, %rsp
|
||||
; ASM: callq barrier
|
||||
; ASM: testl %eax, %eax
|
||||
; ASM: je .LBB0_3
|
||||
; ASM: callq vardef
|
||||
; ASM: movl %eax, %esi
|
||||
; ASM: [[p_b1:\.Ltmp[0-9]+]]:
|
||||
; ASM: #DEBUG_VALUE: p <- %ESI
|
||||
; ASM: callq barrier
|
||||
; ASM: movl %esi, %ecx
|
||||
; ASM: testl %eax, %eax
|
||||
; ASM: jne .LBB0_5
|
||||
; ASM: # BB#2: # %if.end
|
||||
; ASM: #DEBUG_VALUE: p <- %ESI
|
||||
; ASM: callq use
|
||||
; ASM: jmp .LBB0_4
|
||||
; ASM: [[p_e1:\.Ltmp[0-9]+]]:
|
||||
; ASM: .LBB0_3: # %if.else
|
||||
; ASM: callq barrier
|
||||
; ASM: .LBB0_4: # %if.end6
|
||||
; ASM: xorl %eax, %eax
|
||||
; ASM: addq $32, %rsp
|
||||
; ASM: popq %rsi
|
||||
; ASM: retq
|
||||
; ASM: .LBB0_5: # %if.then4
|
||||
; ASM: [[p_b2:\.Ltmp[0-9]+]]:
|
||||
; ASM: #DEBUG_VALUE: p <- %ESI
|
||||
; ASM: callq call_noreturn
|
||||
; ASM: ud2
|
||||
; ASM: .Lfunc_end0:
|
||||
|
||||
; ASM: .short {{.*}} # Record length
|
||||
; ASM: .short 4414 # Record kind: S_LOCAL
|
||||
; ASM: .long 116 # TypeIndex
|
||||
; ASM: .short 0 # Flags
|
||||
; ASM: .asciz "p"
|
||||
; ASM: .cv_def_range [[p_b1]] [[p_e1]] [[p_b2]] .Lfunc_end0, "A\021\027\000\000\000"
|
||||
; ASM: .short 2 # Record length
|
||||
; ASM: .short 4431 # Record kind: S_PROC_ID_END
|
||||
|
||||
; OBJ: Local {
|
||||
; OBJ: Type: int (0x74)
|
||||
; OBJ: VarName: p
|
||||
; OBJ: }
|
||||
; OBJ-NOT: Local {
|
||||
; OBJ: DefRangeRegister {
|
||||
; OBJ-NEXT: Register: 23
|
||||
; OBJ-NEXT: MayHaveNoName: 0
|
||||
; OBJ-NEXT: LocalVariableAddrRange {
|
||||
; OBJ-NEXT: OffsetStart: .text+0x{{.*}}
|
||||
; OBJ-NEXT: ISectStart: 0x0
|
||||
; OBJ-NEXT: Range: 0x{{.*}}
|
||||
; OBJ-NEXT: }
|
||||
; OBJ-NEXT: LocalVariableAddrGap [
|
||||
; OBJ-NEXT: GapStartOffset: 0x{{.*}}
|
||||
; OBJ-NEXT: Range: 0x{{.*}}
|
||||
; OBJ-NEXT: ]
|
||||
; OBJ-NEXT: }
|
||||
|
||||
; ModuleID = 't.cpp'
|
||||
source_filename = "t.cpp"
|
||||
target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
|
||||
target triple = "x86_64-pc-windows-msvc19.0.24210"
|
||||
|
||||
; Function Attrs: nounwind uwtable
|
||||
define i32 @f() local_unnamed_addr #0 !dbg !7 {
|
||||
entry:
|
||||
%call = tail call i32 bitcast (i32 (...)* @barrier to i32 ()*)() #4, !dbg !15
|
||||
%tobool = icmp eq i32 %call, 0, !dbg !15
|
||||
br i1 %tobool, label %if.else, label %if.then, !dbg !16
|
||||
|
||||
if.then: ; preds = %entry
|
||||
%call1 = tail call i32 bitcast (i32 (...)* @vardef to i32 ()*)() #4, !dbg !17
|
||||
tail call void @llvm.dbg.value(metadata i32 %call1, i64 0, metadata !12, metadata !18), !dbg !19
|
||||
%call2 = tail call i32 bitcast (i32 (...)* @barrier to i32 ()*)() #4, !dbg !20
|
||||
%tobool3 = icmp eq i32 %call2, 0, !dbg !20
|
||||
br i1 %tobool3, label %if.end, label %if.then4, !dbg !22
|
||||
|
||||
if.then4: ; preds = %if.then
|
||||
tail call void @call_noreturn(i32 %call1) #5, !dbg !23
|
||||
unreachable, !dbg !23
|
||||
|
||||
if.end: ; preds = %if.then
|
||||
tail call void @use(i32 %call1) #4, !dbg !24
|
||||
br label %if.end6, !dbg !25
|
||||
|
||||
if.else: ; preds = %entry
|
||||
%call5 = tail call i32 bitcast (i32 (...)* @barrier to i32 ()*)() #4, !dbg !26
|
||||
br label %if.end6
|
||||
|
||||
if.end6: ; preds = %if.else, %if.end
|
||||
ret i32 0, !dbg !28
|
||||
}
|
||||
|
||||
declare i32 @barrier(...) local_unnamed_addr #1
|
||||
|
||||
declare i32 @vardef(...) local_unnamed_addr #1
|
||||
|
||||
; Function Attrs: noreturn
|
||||
declare void @call_noreturn(i32) local_unnamed_addr #2
|
||||
|
||||
declare void @use(i32) local_unnamed_addr #1
|
||||
|
||||
; Function Attrs: nounwind readnone
|
||||
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #3
|
||||
|
||||
attributes #0 = { nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "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 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="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 #2 = { noreturn "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="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 #3 = { nounwind readnone }
|
||||
attributes #4 = { nounwind }
|
||||
attributes #5 = { noreturn nounwind }
|
||||
|
||||
!llvm.dbg.cu = !{!0}
|
||||
!llvm.module.flags = !{!3, !4, !5}
|
||||
!llvm.ident = !{!6}
|
||||
|
||||
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 4.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
|
||||
!1 = !DIFile(filename: "t.cpp", directory: "C:\5Csrc\5Cllvm\5Cbuild")
|
||||
!2 = !{}
|
||||
!3 = !{i32 2, !"CodeView", i32 1}
|
||||
!4 = !{i32 2, !"Debug Info Version", i32 3}
|
||||
!5 = !{i32 1, !"PIC Level", i32 2}
|
||||
!6 = !{!"clang version 4.0.0 "}
|
||||
!7 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 19, type: !8, isLocal: false, isDefinition: true, scopeLine: 19, isOptimized: true, unit: !0, variables: !11)
|
||||
!8 = !DISubroutineType(types: !9)
|
||||
!9 = !{!10}
|
||||
!10 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
|
||||
!11 = !{!12}
|
||||
!12 = !DILocalVariable(name: "p", scope: !13, file: !1, line: 21, type: !10)
|
||||
!13 = distinct !DILexicalBlock(scope: !14, file: !1, line: 20, column: 18)
|
||||
!14 = distinct !DILexicalBlock(scope: !7, file: !1, line: 20, column: 7)
|
||||
!15 = !DILocation(line: 20, column: 7, scope: !14)
|
||||
!16 = !DILocation(line: 20, column: 7, scope: !7)
|
||||
!17 = !DILocation(line: 21, column: 13, scope: !13)
|
||||
!18 = !DIExpression()
|
||||
!19 = !DILocation(line: 21, column: 9, scope: !13)
|
||||
!20 = !DILocation(line: 22, column: 9, scope: !21)
|
||||
!21 = distinct !DILexicalBlock(scope: !13, file: !1, line: 22, column: 9)
|
||||
!22 = !DILocation(line: 22, column: 9, scope: !13)
|
||||
!23 = !DILocation(line: 23, column: 7, scope: !21)
|
||||
!24 = !DILocation(line: 24, column: 5, scope: !13)
|
||||
!25 = !DILocation(line: 25, column: 3, scope: !13)
|
||||
!26 = !DILocation(line: 26, column: 5, scope: !27)
|
||||
!27 = distinct !DILexicalBlock(scope: !14, file: !1, line: 25, column: 10)
|
||||
!28 = !DILocation(line: 28, column: 3, scope: !7)
|
||||
101
test/MC/COFF/cv-def-range-gap.s
Normal file
101
test/MC/COFF/cv-def-range-gap.s
Normal file
@ -0,0 +1,101 @@
|
||||
# RUN: llvm-mc -triple=x86_64-pc-win32 -filetype=obj < %s | llvm-readobj -codeview | FileCheck %s
|
||||
|
||||
# This tries to test defrange gap edge cases.
|
||||
|
||||
# CHECK: Local {
|
||||
# CHECK: Type: int (0x74)
|
||||
# CHECK: VarName: p
|
||||
# CHECK: }
|
||||
# CHECK-NOT: Local {
|
||||
# CHECK: DefRangeRegister {
|
||||
# CHECK-NEXT: Register: 23
|
||||
# CHECK-NEXT: MayHaveNoName: 0
|
||||
# CHECK-NEXT: LocalVariableAddrRange {
|
||||
# CHECK-NEXT: OffsetStart: .text+0x5
|
||||
# CHECK-NEXT: ISectStart: 0x0
|
||||
# CHECK-NEXT: Range: 0x5
|
||||
# CHECK-NEXT: }
|
||||
# CHECK-NEXT: LocalVariableAddrGap [
|
||||
# CHECK-NEXT: GapStartOffset: 0x3
|
||||
# CHECK-NEXT: Range: 0x1
|
||||
# CHECK-NEXT: ]
|
||||
# CHECK-NEXT: }
|
||||
# CHECK-NEXT: DefRangeRegister {
|
||||
# CHECK-NEXT: Register: 23
|
||||
# CHECK-NEXT: MayHaveNoName: 0
|
||||
# CHECK-NEXT: LocalVariableAddrRange {
|
||||
# CHECK-NEXT: OffsetStart: .text+0x10015
|
||||
# CHECK-NEXT: ISectStart: 0x0
|
||||
# CHECK-NEXT: Range: 0x6
|
||||
# CHECK-NEXT: }
|
||||
# CHECK-NEXT: }
|
||||
# CHECK-NEXT: DefRangeRegister {
|
||||
# CHECK-NEXT: Register: 23
|
||||
# CHECK-NEXT: MayHaveNoName: 0
|
||||
# CHECK-NEXT: LocalVariableAddrRange {
|
||||
# CHECK-NEXT: OffsetStart: .text+0x2001B
|
||||
# CHECK-NEXT: ISectStart: 0x0
|
||||
# CHECK-NEXT: Range: 0x1
|
||||
# CHECK-NEXT: }
|
||||
# CHECK-NEXT: }
|
||||
|
||||
.text
|
||||
f: # @f
|
||||
mov $42, %esi
|
||||
.Lbegin0:
|
||||
nop
|
||||
jmp .Lbegin1
|
||||
.Lend0:
|
||||
nop
|
||||
.Lbegin1:
|
||||
nop
|
||||
.Lend1:
|
||||
.p2align 4
|
||||
.fill 0x10000, 1, 0x90
|
||||
|
||||
mov $42, %esi
|
||||
.Lbegin2:
|
||||
nop
|
||||
jmp .Lbegin3
|
||||
.Lend2:
|
||||
.fill 0x10000, 1, 0x90
|
||||
.Lbegin3:
|
||||
nop
|
||||
.Lend3:
|
||||
ret
|
||||
.Lfunc_end0:
|
||||
|
||||
.section .debug$S,"dr"
|
||||
.p2align 2
|
||||
.long 4 # Debug section magic
|
||||
.long 241 # Symbol subsection for f
|
||||
.long .Ltmp15-.Ltmp14 # Subsection size
|
||||
.Ltmp14:
|
||||
.short .Ltmp17-.Ltmp16 # Record length
|
||||
.Ltmp16:
|
||||
.short 4423 # Record kind: S_GPROC32_ID
|
||||
.long 0 # PtrParent
|
||||
.long 0 # PtrEnd
|
||||
.long 0 # PtrNext
|
||||
.long .Lfunc_end0-f # Code size
|
||||
.long 0 # Offset after prologue
|
||||
.long 0 # Offset before epilogue
|
||||
.long 4098 # Function type index
|
||||
.secrel32 f # Function section relative address
|
||||
.secidx f # Function section index
|
||||
.byte 0 # Flags
|
||||
.asciz "f" # Function name
|
||||
.Ltmp17:
|
||||
.short .Ltmp19-.Ltmp18 # Record length
|
||||
.Ltmp18:
|
||||
.short 4414 # Record kind: S_LOCAL
|
||||
.long 116 # TypeIndex
|
||||
.short 0 # Flags
|
||||
.asciz "p"
|
||||
.Ltmp19:
|
||||
.cv_def_range .Lbegin0 .Lend0 .Lbegin1 .Lend1 .Lbegin2 .Lend2 .Lbegin3 .Lend3, "A\021\027\000\000\000"
|
||||
.short 2 # Record length
|
||||
.short 4431 # Record kind: S_PROC_ID_END
|
||||
.Ltmp15:
|
||||
.cv_filechecksums # File index to string table offset subsection
|
||||
.cv_stringtable # String table
|
||||
Loading…
x
Reference in New Issue
Block a user