[codeview] Expose -gcodeview-ghash for global type hashing
Summary:
Experience has shown that the functionality is useful. It makes linking
optimized clang with debug info for me a lot faster, 20s to 13s. The
type merging phase of PDB writing goes from 10s to 3s.
This removes the LLVM cl::opt and replaces it with a metadata flag.
After this change, users can do the following to use ghash:
- add -gcodeview-ghash to compiler flags
- replace /DEBUG with /DEBUG:GHASH in linker flags
Reviewers: zturner, hans, thakis, takuto.ikuta
Subscribers: aprantl, hiraditya, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D54370
llvm-svn: 347072
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index 01d018f..3b1fd76 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -92,9 +92,6 @@
using namespace llvm;
using namespace llvm::codeview;
-static cl::opt<bool> EmitDebugGlobalHashes("emit-codeview-ghash-section",
- cl::ReallyHidden, cl::init(false));
-
static CPUType mapArchToCVCPUType(Triple::ArchType Type) {
switch (Type) {
case Triple::ArchType::x86:
@@ -125,6 +122,11 @@
TheCPU =
mapArchToCVCPUType(Triple(MMI->getModule()->getTargetTriple()).getArch());
+
+ // Check if we should emit type record hashes.
+ ConstantInt *GH = mdconst::extract_or_null<ConstantInt>(
+ MMI->getModule()->getModuleFlag("CodeViewGHash"));
+ EmitDebugGlobalHashes = GH && !GH->isZero();
}
StringRef CodeViewDebug::getFullFilepath(const DIFile *File) {
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
index ef0f0c3..e85de52 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
@@ -54,6 +54,9 @@
BumpPtrAllocator Allocator;
codeview::GlobalTypeTableBuilder TypeTable;
+ /// Whether to emit type record hashes into .debug$H.
+ bool EmitDebugGlobalHashes = false;
+
/// The codeview CPU type used by the translation unit.
codeview::CPUType TheCPU;
diff --git a/llvm/test/DebugInfo/COFF/global-type-hashes.ll b/llvm/test/DebugInfo/COFF/global-type-hashes.ll
index 2262a54..6790e9c 100644
--- a/llvm/test/DebugInfo/COFF/global-type-hashes.ll
+++ b/llvm/test/DebugInfo/COFF/global-type-hashes.ll
@@ -1,7 +1,6 @@
-; RUN: llc -filetype=obj -emit-codeview-ghash-section < %s > %t.obj
+; RUN: llc -filetype=obj < %s > %t.obj
; RUN: obj2yaml %t.obj | FileCheck %s --check-prefix=YAML
-; RUN: llc -filetype=asm -emit-codeview-ghash-section < %s \
-; RUN: | FileCheck %s --check-prefix=ASM
+; RUN: llc -filetype=asm < %s | FileCheck %s --check-prefix=ASM
; C++ source to regenerate:
; $ cat t.cpp
@@ -96,14 +95,16 @@
attributes #2 = { noinline nounwind optnone "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-features"="+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.module.flags = !{!3, !4, !5, !6, !100}
!llvm.ident = !{!7}
+
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 6.0.0 ", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "<stdin>", directory: "D:\5Csrc\5Cllvmbuild\5Cclang\5CDebug\5Cx86", checksumkind: CSK_MD5, checksum: "6279449503d9075c38e615e8387667c3")
!2 = !{}
!3 = !{i32 1, !"NumRegisterParameters", i32 0}
!4 = !{i32 2, !"CodeView", i32 1}
+!100 = !{i32 2, !"CodeViewGHash", i32 1}
!5 = !{i32 2, !"Debug Info Version", i32 3}
!6 = !{i32 1, !"wchar_size", i32 2}
!7 = !{!"clang version 6.0.0 "}