[llvm] 5507f70 - [InstrProf][X86] Mark non-directly accessed globals as large (#74778)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 8 09:33:45 PST 2023
Author: Arthur Eubanks
Date: 2023-12-08T09:33:40-08:00
New Revision: 5507f70cc205a7ec21d264a64c703b3d314b998c
URL: https://github.com/llvm/llvm-project/commit/5507f70cc205a7ec21d264a64c703b3d314b998c
DIFF: https://github.com/llvm/llvm-project/commit/5507f70cc205a7ec21d264a64c703b3d314b998c.diff
LOG: [InstrProf][X86] Mark non-directly accessed globals as large (#74778)
We'd like to make various instrprof globals large to make them not
contribute to relocation pressure since there are no direct accesses
to them in the module.
Similar to what was done for asan_globals in #74514.
This affects the __llvm_prf_vals, __llvm_prf_vnds, and __llvm_prf_names
sections.
Added:
Modified:
llvm/include/llvm/Transforms/Instrumentation.h
llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
llvm/lib/Transforms/Instrumentation/Instrumentation.cpp
llvm/test/Instrumentation/InstrProfiling/icall-comdat.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/Transforms/Instrumentation.h b/llvm/include/llvm/Transforms/Instrumentation.h
index 3035cdeeacf68a..bb1a0d446aa2ab 100644
--- a/llvm/include/llvm/Transforms/Instrumentation.h
+++ b/llvm/include/llvm/Transforms/Instrumentation.h
@@ -49,6 +49,11 @@ GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str,
// Returns nullptr on failure.
Comdat *getOrCreateFunctionComdat(Function &F, Triple &T);
+// Place global in a large section for x86-64 ELF binaries to mitigate
+// relocation overflow pressure. This can be be used for metadata globals that
+// aren't directly accessed by code, which has no performance impact.
+void setGlobalVariableLargeSection(Triple &TargetTriple, GlobalVariable &GV);
+
// Insert GCOV profiling instrumentation
struct GCOVOptions {
static GCOVOptions getDefault();
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 3a3b41f5dc87d1..b175e6f93f3e8f 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -2146,9 +2146,7 @@ ModuleAddressSanitizer::CreateMetadataGlobal(Module &M, Constant *Initializer,
Metadata->setSection(getGlobalMetadataSection());
// Place metadata in a large section for x86-64 ELF binaries to mitigate
// relocation pressure.
- if (TargetTriple.getArch() == Triple::x86_64 &&
- TargetTriple.getObjectFormat() == Triple::ELF)
- Metadata->setCodeModel(CodeModel::Large);
+ setGlobalVariableLargeSection(TargetTriple, *Metadata);
return Metadata;
}
diff --git a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
index 10258e25467913..d3282779d9f5f3 100644
--- a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -49,6 +49,7 @@
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/TargetParser/Triple.h"
+#include "llvm/Transforms/Instrumentation.h"
#include "llvm/Transforms/Instrumentation/PGOInstrumentation.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
@@ -1294,6 +1295,7 @@ void InstrProfiling::createDataVariable(InstrProfCntrInstBase *Inc) {
*M, ValuesTy, false, Linkage, Constant::getNullValue(ValuesTy),
getVarName(Inc, getInstrProfValuesVarPrefix(), Renamed));
ValuesVar->setVisibility(Visibility);
+ setGlobalVariableLargeSection(TT, *ValuesVar);
ValuesVar->setSection(
getInstrProfSectionName(IPSK_vals, TT.getObjectFormat()));
ValuesVar->setAlignment(Align(8));
@@ -1422,6 +1424,7 @@ void InstrProfiling::emitVNodes() {
auto *VNodesVar = new GlobalVariable(
*M, VNodesTy, false, GlobalValue::PrivateLinkage,
Constant::getNullValue(VNodesTy), getInstrProfVNodesVarName());
+ setGlobalVariableLargeSection(TT, *VNodesVar);
VNodesVar->setSection(
getInstrProfSectionName(IPSK_vnodes, TT.getObjectFormat()));
VNodesVar->setAlignment(M->getDataLayout().getABITypeAlign(VNodesTy));
@@ -1449,6 +1452,7 @@ void InstrProfiling::emitNameData() {
GlobalValue::PrivateLinkage, NamesVal,
getInstrProfNamesVarName());
NamesSize = CompressedNameStr.size();
+ setGlobalVariableLargeSection(TT, *NamesVar);
NamesVar->setSection(
getInstrProfSectionName(IPSK_name, TT.getObjectFormat()));
// On COFF, it's important to reduce the alignment down to 1 to prevent the
diff --git a/llvm/lib/Transforms/Instrumentation/Instrumentation.cpp b/llvm/lib/Transforms/Instrumentation/Instrumentation.cpp
index 806afc8fcdf7cb..199afbe966dde4 100644
--- a/llvm/lib/Transforms/Instrumentation/Instrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/Instrumentation.cpp
@@ -85,3 +85,10 @@ Comdat *llvm::getOrCreateFunctionComdat(Function &F, Triple &T) {
return C;
}
+void llvm::setGlobalVariableLargeSection(Triple &TargetTriple,
+ GlobalVariable &GV) {
+ if (TargetTriple.getArch() == Triple::x86_64 &&
+ TargetTriple.getObjectFormat() == Triple::ELF) {
+ GV.setCodeModel(CodeModel::Large);
+ }
+}
diff --git a/llvm/test/Instrumentation/InstrProfiling/icall-comdat.ll b/llvm/test/Instrumentation/InstrProfiling/icall-comdat.ll
index c90f37c8208957..9fbff456ff50b5 100644
--- a/llvm/test/Instrumentation/InstrProfiling/icall-comdat.ll
+++ b/llvm/test/Instrumentation/InstrProfiling/icall-comdat.ll
@@ -1,5 +1,4 @@
;; Check that static counters are allocated for value profiler
-
; RUN: opt < %s -mtriple=x86_64-unknown-linux -passes=instrprof -vp-static-alloc=true -S | FileCheck %s --check-prefix=STATIC
; RUN: opt < %s -mtriple=powerpc-unknown-linux -passes=instrprof -vp-static-alloc=true -S | FileCheck %s --check-prefix=STATIC
; RUN: opt < %s -mtriple=sparc-unknown-linux -passes=instrprof -vp-static-alloc=true -S | FileCheck %s --check-prefix=STATIC
@@ -16,6 +15,10 @@
; RUN: opt %s -mtriple=powerpc64-ibm-aix -passes=instrprof -S | FileCheck %s --check-prefix=ALIGN
; RUN: opt %s -mtriple=x86_64-unknown-linux -passes=instrprof -S | FileCheck %s --check-prefix=ALIGN
+;; Check that globals have the proper code model.
+; RUN: opt %s -mtriple=x86_64-unknown-linux -passes=instrprof -S | FileCheck %s --check-prefixes=CODEMODEL,CODEMODEL-X8664
+; RUN: opt %s -mtriple=powerpc-unknown-linux -passes=instrprof -S | FileCheck %s --check-prefixes=CODEMODEL,CODEMODEL-PPC
+
@__profn_foo = private constant [3 x i8] c"foo"
@__profn_bar = private constant [3 x i8] c"bar"
@@ -46,8 +49,8 @@ declare void @llvm.instrprof.value.profile(ptr, i64, i64, i32, i32) #0
attributes #0 = { nounwind }
-; STATIC: @__profvp_foo = private global [1 x i64] zeroinitializer, section "{{[^"]+}}", comdat($__profc_foo)
-; STATIC: @__profvp_bar = private global [1 x i64] zeroinitializer, section "{{[^"]+}}", comdat($__profc_bar)
+; STATIC: @__profvp_foo = private global [1 x i64] zeroinitializer, section "{{[^"]+}}",{{.*}} comdat($__profc_foo)
+; STATIC: @__profvp_bar = private global [1 x i64] zeroinitializer, section "{{[^"]+}}",{{.*}} comdat($__profc_bar)
; STATIC: @__llvm_prf_vnodes
; DYN-NOT: @__profvp_foo
@@ -73,5 +76,26 @@ attributes #0 = { nounwind }
; ALIGN: @__profc_bar = private global {{.*}} section "__llvm_prf_cnts",{{.*}} align 8
; ALIGN: @__profvp_bar = private global {{.*}} section "__llvm_prf_vals",{{.*}} align 8
; ALIGN: @__profd_bar = private global {{.*}} section "__llvm_prf_data",{{.*}} align 8
-; ALIGN: @__llvm_prf_vnodes = private global {{.*}} section "__llvm_prf_vnds", align 8
-; ALIGN: @__llvm_prf_nm = private constant {{.*}} section "__llvm_prf_names", align 1
+; ALIGN: @__llvm_prf_vnodes = private global {{.*}} section "__llvm_prf_vnds",{{.*}} align 8
+; ALIGN: @__llvm_prf_nm = private constant {{.*}} section "__llvm_prf_names",{{.*}} align 1
+
+; CODEMODEL: @__profc_foo =
+; CODEMODEL-NOT: code_model "large"
+; CODEMODEL: @__profvp_foo =
+; CODEMODEL-X8664-SAME: code_model "large"
+; CODEMODEL-PPC-NOT: code_model
+; CODEMODEL: @__profd_foo =
+; CODEMODEL-NOT: code_model "large"
+; CODEMODEL: @__profc_bar =
+; CODEMODEL-NOT: code_model "large"
+; CODEMODEL: @__profvp_bar =
+; CODEMODEL-X8664-SAME: code_model "large"
+; CODEMODEL-PPC-NOT: code_model
+; CODEMODEL: @__profd_bar =
+; CODEMODEL-NOT: code_model "large"
+; CODEMODEL: @__llvm_prf_vnodes =
+; CODEMODEL-X8664-SAME: code_model "large"
+; CODEMODEL-PPC-NOT: code_model
+; CODEMODEL: @__llvm_prf_nm =
+; CODEMODEL-X8664-SAME: code_model "large"
+; CODEMODEL-PPC-NOT: code_model
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