[IR] Add "large" global variable property #69638
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@llvm/pr-subscribers-backend-x86 @llvm/pr-subscribers-llvm-ir Author: Arthur Eubanks (aeubanks) ChangesThis means that when using a code model where there is a distinction between "small" and "large" data (e.g. the x86-64 medium code model), treat the global as "large" regardless of its size. The intention is to use this for globals that are accessed very infrequently but also take up a lot of space in the binary to mitigate relocation overflows. Prime examples are globals that go in "__llvm_prf_names" for coverage/PGO instrumented builds and "asan_globals" for ASan builds. Full diff: https://github.com/llvm/llvm-project/pull/69638.diff 13 Files Affected:
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index 64c61dd8c055868..e70e316644f0a11 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -700,6 +700,9 @@ target supports it, it will emit globals to the section specified.
Additionally, the global can placed in a comdat if the target has the necessary
support.
+For code models with a small/large data distinction, a global marked ``large``
+is considered large regardless of its size.
+
External declarations may have an explicit section specified. Section
information is retained in LLVM IR for targets that make use of this
information. Attaching section information to an external declaration is an
@@ -760,7 +763,7 @@ Syntax::
[(unnamed_addr|local_unnamed_addr)] [AddrSpace]
[ExternallyInitialized]
<global | constant> <Type> [<InitializerConstant>]
- [, section "name"] [, partition "name"]
+ [, section "name"] [, large] [, partition "name"]
[, comdat [($name)]] [, align <Alignment>]
[, no_sanitize_address] [, no_sanitize_hwaddress]
[, sanitize_address_dyninit] [, sanitize_memtag]
diff --git a/llvm/include/llvm/AsmParser/LLToken.h b/llvm/include/llvm/AsmParser/LLToken.h
index 2d6b8a19401d78d..4a233a1c90f8f13 100644
--- a/llvm/include/llvm/AsmParser/LLToken.h
+++ b/llvm/include/llvm/AsmParser/LLToken.h
@@ -114,6 +114,7 @@ enum Kind {
kw_addrspace,
kw_section,
kw_partition,
+ kw_large,
kw_alias,
kw_ifunc,
kw_module,
diff --git a/llvm/include/llvm/IR/GlobalVariable.h b/llvm/include/llvm/IR/GlobalVariable.h
index 5ddffd16acc68f2..89f1e722352c1e8 100644
--- a/llvm/include/llvm/IR/GlobalVariable.h
+++ b/llvm/include/llvm/IR/GlobalVariable.h
@@ -46,6 +46,9 @@ class GlobalVariable : public GlobalObject, public ilist_node<GlobalVariable> {
// Is this a global whose value can change from its initial value before
// global initializers are run?
bool isExternallyInitializedConstant : 1;
+ // Is this global unconditionally considered large in code models with a
+ // small/large data distinction?
+ bool isLargeGlobal : 1;
public:
/// GlobalVariable ctor - If a parent module is specified, the global is
@@ -53,7 +56,7 @@ class GlobalVariable : public GlobalObject, public ilist_node<GlobalVariable> {
GlobalVariable(Type *Ty, bool isConstant, LinkageTypes Linkage,
Constant *Initializer = nullptr, const Twine &Name = "",
ThreadLocalMode = NotThreadLocal, unsigned AddressSpace = 0,
- bool isExternallyInitialized = false);
+ bool isExternallyInitialized = false, bool isLarge = false);
/// GlobalVariable ctor - This creates a global and inserts it before the
/// specified other global.
GlobalVariable(Module &M, Type *Ty, bool isConstant, LinkageTypes Linkage,
@@ -61,7 +64,7 @@ class GlobalVariable : public GlobalObject, public ilist_node<GlobalVariable> {
GlobalVariable *InsertBefore = nullptr,
ThreadLocalMode = NotThreadLocal,
std::optional<unsigned> AddressSpace = std::nullopt,
- bool isExternallyInitialized = false);
+ bool isExternallyInitialized = false, bool isLarge = false);
GlobalVariable(const GlobalVariable &) = delete;
GlobalVariable &operator=(const GlobalVariable &) = delete;
@@ -159,6 +162,8 @@ class GlobalVariable : public GlobalObject, public ilist_node<GlobalVariable> {
void setExternallyInitialized(bool Val) {
isExternallyInitializedConstant = Val;
}
+ bool isLarge() const { return isLargeGlobal; }
+ void setLarge(bool Val) { isLargeGlobal = Val; }
/// copyAttributesFrom - copy all additional attributes (those not needed to
/// create a GlobalVariable) from the GlobalVariable Src to this one.
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index ae46209b30ede03..7a79827aac603f5 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -569,6 +569,7 @@ lltok::Kind LLLexer::LexIdentifier() {
KEYWORD(addrspace);
KEYWORD(section);
KEYWORD(partition);
+ KEYWORD(large);
KEYWORD(alias);
KEYWORD(ifunc);
KEYWORD(module);
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index e104f8b3d1fdba5..28b79b15eb959a4 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -1286,6 +1286,9 @@ bool LLParser::parseGlobal(const std::string &Name, LocTy NameLoc,
return true;
if (Alignment)
GV->setAlignment(*Alignment);
+ } else if (Lex.getKind() == lltok::kw_large) {
+ GV->setLarge(true);
+ Lex.Lex();
} else if (Lex.getKind() == lltok::MetadataVar) {
if (parseGlobalObjectMetadataAttachment(*GV))
return true;
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 28addb9068b242b..52e6d8fe8b1f7f3 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -3910,6 +3910,9 @@ Error BitcodeReader::parseGlobalVarRecord(ArrayRef<uint64_t> Record) {
NewGV->setSanitizerMetadata(Meta);
}
+ if (Record.size() > 17 && Record[17])
+ NewGV->setLarge(Record[17]);
+
return Error::success();
}
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index c427459508ecfc8..1a43f003b3b343e 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1399,7 +1399,7 @@ void ModuleBitcodeWriter::writeModuleInfo() {
// GLOBALVAR: [strtab offset, strtab size, type, isconst, initid,
// linkage, alignment, section, visibility, threadlocal,
// unnamed_addr, externally_initialized, dllstorageclass,
- // comdat, attributes, DSO_Local, GlobalSanitizer]
+ // comdat, attributes, DSO_Local, GlobalSanitizer, large]
Vals.push_back(addToStrtab(GV.getName()));
Vals.push_back(GV.getName().size());
Vals.push_back(VE.getTypeID(GV.getValueType()));
@@ -1416,7 +1416,7 @@ void ModuleBitcodeWriter::writeModuleInfo() {
GV.isExternallyInitialized() ||
GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
GV.hasComdat() || GV.hasAttributes() || GV.isDSOLocal() ||
- GV.hasPartition() || GV.hasSanitizerMetadata()) {
+ GV.hasPartition() || GV.hasSanitizerMetadata() || GV.isLarge()) {
Vals.push_back(getEncodedVisibility(GV));
Vals.push_back(getEncodedThreadLocalMode(GV));
Vals.push_back(getEncodedUnnamedAddr(GV));
@@ -1434,6 +1434,7 @@ void ModuleBitcodeWriter::writeModuleInfo() {
Vals.push_back((GV.hasSanitizerMetadata() ? serializeSanitizerMetadata(
GV.getSanitizerMetadata())
: 0));
+ Vals.push_back(GV.isLarge());
} else {
AbbrevToUse = SimpleGVarAbbrev;
}
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index bd8b3e9ad52215e..1c1426619052202 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -3627,6 +3627,8 @@ void AssemblyWriter::printGlobal(const GlobalVariable *GV) {
printEscapedString(GV->getSection(), Out);
Out << '"';
}
+ if (GV->isLarge())
+ Out << ", large";
if (GV->hasPartition()) {
Out << ", partition \"";
printEscapedString(GV->getPartition(), Out);
diff --git a/llvm/lib/IR/Globals.cpp b/llvm/lib/IR/Globals.cpp
index 7bd4503a689e4ae..9d8decfad85b5ee 100644
--- a/llvm/lib/IR/Globals.cpp
+++ b/llvm/lib/IR/Globals.cpp
@@ -414,12 +414,13 @@ bool GlobalValue::canBeOmittedFromSymbolTable() const {
GlobalVariable::GlobalVariable(Type *Ty, bool constant, LinkageTypes Link,
Constant *InitVal, const Twine &Name,
ThreadLocalMode TLMode, unsigned AddressSpace,
- bool isExternallyInitialized)
+ bool isExternallyInitialized, bool isLarge)
: GlobalObject(Ty, Value::GlobalVariableVal,
OperandTraits<GlobalVariable>::op_begin(this),
InitVal != nullptr, Link, Name, AddressSpace),
isConstantGlobal(constant),
- isExternallyInitializedConstant(isExternallyInitialized) {
+ isExternallyInitializedConstant(isExternallyInitialized),
+ isLargeGlobal(isLarge) {
assert(!Ty->isFunctionTy() && PointerType::isValidElementType(Ty) &&
"invalid type for global variable");
setThreadLocalMode(TLMode);
@@ -435,12 +436,12 @@ GlobalVariable::GlobalVariable(Module &M, Type *Ty, bool constant,
const Twine &Name, GlobalVariable *Before,
ThreadLocalMode TLMode,
std::optional<unsigned> AddressSpace,
- bool isExternallyInitialized)
+ bool isExternallyInitialized, bool isLarge)
: GlobalVariable(Ty, constant, Link, InitVal, Name, TLMode,
AddressSpace
? *AddressSpace
: M.getDataLayout().getDefaultGlobalsAddressSpace(),
- isExternallyInitialized) {
+ isExternallyInitialized, isLarge) {
if (Before)
Before->getParent()->insertGlobalVariable(Before->getIterator(), this);
else
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 6d7d4b758ad3f2f..a3c58adf5524d89 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -861,6 +861,9 @@ void Verifier::visitGlobalVariable(const GlobalVariable &GV) {
"Global @" + GV.getName() + " has illegal target extension type",
TTy);
+ Check(!(GV.isThreadLocal() && GV.isLarge()),
+ "Global cannot be thread-local and large", &GV);
+
if (!GV.hasInitializer()) {
visitGlobalValue(GV);
return;
diff --git a/llvm/lib/Target/TargetMachine.cpp b/llvm/lib/Target/TargetMachine.cpp
index 45fb612cb91da19..7b6f84f7c0c7408 100644
--- a/llvm/lib/Target/TargetMachine.cpp
+++ b/llvm/lib/Target/TargetMachine.cpp
@@ -42,6 +42,8 @@ TargetMachine::~TargetMachine() = default;
bool TargetMachine::isLargeData(const GlobalVariable *GV) const {
if (getTargetTriple().getArch() != Triple::x86_64 || GV->isThreadLocal())
return false;
+ if (GV->isLarge())
+ return true;
// Large data under the large code model still needs to be thought about, so
// restrict this to medium.
if (getCodeModel() != CodeModel::Medium)
diff --git a/llvm/test/Assembler/globalvariable-attributes.ll b/llvm/test/Assembler/globalvariable-attributes.ll
index 544f9bdb270e99a..06ec6d0d27c0652 100644
--- a/llvm/test/Assembler/globalvariable-attributes.ll
+++ b/llvm/test/Assembler/globalvariable-attributes.ll
@@ -9,6 +9,7 @@
@g7 = global i32 2, sanitize_address_dyninit, align 4
@g8 = global i32 2, sanitize_memtag, align 4
@g9 = global i32 2, no_sanitize_address, no_sanitize_hwaddress, sanitize_memtag, align 4
+@g10 = global i32 2, large
attributes #0 = { "string" = "value" nobuiltin norecurse }
@@ -21,6 +22,7 @@ attributes #0 = { "string" = "value" nobuiltin norecurse }
; CHECK: @g7 = global i32 2, sanitize_address_dyninit, align 4
; CHECK: @g8 = global i32 2, sanitize_memtag, align 4
; CHECK: @g9 = global i32 2, no_sanitize_address, no_sanitize_hwaddress, sanitize_memtag, align 4
+; CHECK: @g10 = global i32 2, large
; CHECK: attributes #0 = { "key"="value" "key2"="value2" }
; CHECK: attributes #1 = { "key3"="value3" }
diff --git a/llvm/test/CodeGen/X86/code-model-elf.ll b/llvm/test/CodeGen/X86/code-model-elf.ll
index 901a62d26f77e8a..9a4e9f66c2908d6 100644
--- a/llvm/test/CodeGen/X86/code-model-elf.ll
+++ b/llvm/test/CodeGen/X86/code-model-elf.ll
@@ -37,6 +37,7 @@ target triple = "x86_64--linux"
@global_data = dso_local global [10 x i32] [i32 1, i32 2, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0], align 16
@static_data = internal global [10 x i32] zeroinitializer, align 16
+@always_large_static_data = internal global [10 x i32] zeroinitializer, align 16, large
@extern_data = external global [10 x i32], align 16
@thread_data = external thread_local global i32, align 4
@unknown_size_data = dso_local global [0 x i32] zeroinitializer, align 16
@@ -87,6 +88,53 @@ define dso_local ptr @lea_static_data() #0 {
ret ptr @static_data
}
+define dso_local ptr @lea_always_large_static_data() #0 {
+; SMALL-STATIC-LABEL: lea_always_large_static_data:
+; SMALL-STATIC: # %bb.0:
+; SMALL-STATIC-NEXT: movl $always_large_static_data, %eax
+; SMALL-STATIC-NEXT: retq
+;
+; MEDIUM-STATIC-LABEL: lea_always_large_static_data:
+; MEDIUM-STATIC: # %bb.0:
+; MEDIUM-STATIC-NEXT: movabsq $always_large_static_data, %rax
+; MEDIUM-STATIC-NEXT: retq
+;
+; LARGE-STATIC-LABEL: lea_always_large_static_data:
+; LARGE-STATIC: # %bb.0:
+; LARGE-STATIC-NEXT: movabsq $always_large_static_data, %rax
+; LARGE-STATIC-NEXT: retq
+;
+; SMALL-PIC-LABEL: lea_always_large_static_data:
+; SMALL-PIC: # %bb.0:
+; SMALL-PIC-NEXT: leaq always_large_static_data(%rip), %rax
+; SMALL-PIC-NEXT: retq
+;
+; MEDIUM-SMALL-DATA-PIC-LABEL: lea_always_large_static_data:
+; MEDIUM-SMALL-DATA-PIC: # %bb.0:
+; MEDIUM-SMALL-DATA-PIC-NEXT: leaq _GLOBAL_OFFSET_TABLE_(%rip), %rcx
+; MEDIUM-SMALL-DATA-PIC-NEXT: movabsq $always_large_static_data@GOTOFF, %rax
+; MEDIUM-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
+; MEDIUM-SMALL-DATA-PIC-NEXT: retq
+;
+; MEDIUM-PIC-LABEL: lea_always_large_static_data:
+; MEDIUM-PIC: # %bb.0:
+; MEDIUM-PIC-NEXT: leaq _GLOBAL_OFFSET_TABLE_(%rip), %rcx
+; MEDIUM-PIC-NEXT: movabsq $always_large_static_data@GOTOFF, %rax
+; MEDIUM-PIC-NEXT: addq %rcx, %rax
+; MEDIUM-PIC-NEXT: retq
+;
+; LARGE-PIC-LABEL: lea_always_large_static_data:
+; LARGE-PIC: # %bb.0:
+; LARGE-PIC-NEXT: .L1$pb:
+; LARGE-PIC-NEXT: leaq .L1$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L1$pb, %rcx
+; LARGE-PIC-NEXT: addq %rax, %rcx
+; LARGE-PIC-NEXT: movabsq $always_large_static_data@GOTOFF, %rax
+; LARGE-PIC-NEXT: addq %rcx, %rax
+; LARGE-PIC-NEXT: retq
+ ret ptr @always_large_static_data
+}
+
define dso_local ptr @lea_global_data() #0 {
; SMALL-STATIC-LABEL: lea_global_data:
; SMALL-STATIC: # %bb.0:
@@ -122,9 +170,9 @@ define dso_local ptr @lea_global_data() #0 {
;
; LARGE-PIC-LABEL: lea_global_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L1$pb:
-; LARGE-PIC-NEXT: leaq .L1$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L1$pb, %rcx
+; LARGE-PIC-NEXT: .L2$pb:
+; LARGE-PIC-NEXT: leaq .L2$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L2$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $global_data@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
@@ -165,9 +213,9 @@ define dso_local ptr @lea_extern_data() #0 {
;
; LARGE-PIC-LABEL: lea_extern_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L2$pb:
-; LARGE-PIC-NEXT: leaq .L2$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L2$pb, %rcx
+; LARGE-PIC-NEXT: .L3$pb:
+; LARGE-PIC-NEXT: leaq .L3$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L3$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $extern_data@GOT, %rax
; LARGE-PIC-NEXT: movq (%rcx,%rax), %rax
@@ -212,9 +260,9 @@ define dso_local ptr @lea_unknown_size_data() #0 {
;
; LARGE-PIC-LABEL: lea_unknown_size_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L3$pb:
-; LARGE-PIC-NEXT: leaq .L3$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L3$pb, %rcx
+; LARGE-PIC-NEXT: .L4$pb:
+; LARGE-PIC-NEXT: leaq .L4$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L4$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $unknown_size_data@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
@@ -260,9 +308,9 @@ define dso_local i32 @load_global_data() #0 {
;
; LARGE-PIC-LABEL: load_global_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L4$pb:
-; LARGE-PIC-NEXT: leaq .L4$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L4$pb, %rcx
+; LARGE-PIC-NEXT: .L5$pb:
+; LARGE-PIC-NEXT: leaq .L5$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L5$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $global_data@GOTOFF, %rax
; LARGE-PIC-NEXT: movl 8(%rcx,%rax), %eax
@@ -310,9 +358,9 @@ define dso_local i32 @load_extern_data() #0 {
;
; LARGE-PIC-LABEL: load_extern_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L5$pb:
-; LARGE-PIC-NEXT: leaq .L5$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L5$pb, %rcx
+; LARGE-PIC-NEXT: .L6$pb:
+; LARGE-PIC-NEXT: leaq .L6$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L6$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $extern_data@GOT, %rax
; LARGE-PIC-NEXT: movq (%rcx,%rax), %rax
@@ -361,9 +409,9 @@ define dso_local i32 @load_unknown_size_data() #0 {
;
; LARGE-PIC-LABEL: load_unknown_size_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L6$pb:
-; LARGE-PIC-NEXT: leaq .L6$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L6$pb, %rcx
+; LARGE-PIC-NEXT: .L7$pb:
+; LARGE-PIC-NEXT: leaq .L7$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L7$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $unknown_size_data@GOTOFF, %rax
; LARGE-PIC-NEXT: movl 8(%rcx,%rax), %eax
@@ -421,9 +469,9 @@ define dso_local ptr @lea_static_fn() #0 {
;
; LARGE-PIC-LABEL: lea_static_fn:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L9$pb:
-; LARGE-PIC-NEXT: leaq .L9$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L9$pb, %rcx
+; LARGE-PIC-NEXT: .L10$pb:
+; LARGE-PIC-NEXT: leaq .L10$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L10$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $static_fn@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
@@ -464,9 +512,9 @@ define dso_local ptr @lea_global_fn() #0 {
;
; LARGE-PIC-LABEL: lea_global_fn:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L10$pb:
-; LARGE-PIC-NEXT: leaq .L10$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L10$pb, %rcx
+; LARGE-PIC-NEXT: .L11$pb:
+; LARGE-PIC-NEXT: leaq .L11$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L11$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $global_fn@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
@@ -507,9 +555,9 @@ define dso_local ptr @lea_extern_fn() #0 {
;
; LARGE-PIC-LABEL: lea_extern_fn:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L11$pb:
-; LARGE-PIC-NEXT: leaq .L11$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L11$pb, %rcx
+; LARGE-PIC-NEXT: .L12$pb:
+; LARGE-PIC-NEXT: leaq .L12$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L12$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $extern_fn@GOT, %rax
; LARGE-PIC-NEXT: movq (%rcx,%rax), %rax
@@ -585,9 +633,9 @@ define dso_local float @load_constant_pool(float %x) #0 {
;
; LARGE-PIC-LABEL: load_constant_pool:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L13$pb:
-; LARGE-PIC-NEXT: leaq .L13$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L13$pb, %rcx
+; LARGE-PIC-NEXT: .L14$pb:
+; LARGE-PIC-NEXT: leaq .L14$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L14$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq ${{\.?LCPI[0-9]+_[0-9]+}}@GOTOFF, %rax
; LARGE-PIC-NEXT: addss (%rcx,%rax), %xmm0
|
This means that when using a code model where there is a distinction between "small" and "large" data (e.g. the x86-64 medium code model), treat the global as "large" regardless of its size. The intention is to use this for globals that are accessed very infrequently but also take up a lot of space in the binary to mitigate relocation overflows. Prime examples are globals that go in "__llvm_prf_names" for coverage/PGO instrumented builds and "asan_globals" for ASan builds.
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This means that when using a code model where there is a distinction between "small" and "large" data (e.g. the x86-64 medium code model), treat the global as "large" regardless of its size.
The intention is to use this for globals that are accessed very infrequently but also take up a lot of space in the binary to mitigate relocation overflows. Prime examples are globals that go in "__llvm_prf_names" for coverage/PGO instrumented builds and "asan_globals" for ASan builds.