- Only emit flag when GlobalMerge is disabled (per Akira and Duncan's reviews)
I added a target check to only emit the flags on ARM/AArch64. I'm fine with
emitting the flag no matter the target, if desired (less brittle), but I
personally don't like adding noise to every module ever, hence hiding it.
http://reviews.llvm.org/D7968
Files:
include/clang/Driver/Options.td
lib/CodeGen/BackendUtil.cpp
lib/CodeGen/CodeGenModule.cpp
lib/CodeGen/CodeGenModule.h
lib/Driver/Tools.cpp
lib/Frontend/CompilerInvocation.cpp
test/CodeGen/global-merge.c
test/Driver/mglobal-merge.c
test/Driver/mno-global-merge.c
EMAIL PREFERENCES
http://reviews.llvm.org/settings/panel/emailpreferences/
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -1126,7 +1126,7 @@
def mfpmath_EQ : Joined<["-"], "mfpmath=">, Group<m_Group>;
def mfpu_EQ : Joined<["-"], "mfpu=">, Group<m_Group>;
def mhwdiv_EQ : Joined<["-"], "mhwdiv=">, Group<m_Group>;
-def mglobal_merge : Flag<["-"], "mglobal-merge">, Group<m_Group>;
+def mglobal_merge : Flag<["-"], "mglobal-merge">, Group<m_Group>, Flags<[CC1Option]>;
def mhard_float : Flag<["-"], "mhard-float">, Group<m_Group>;
def miphoneos_version_min_EQ : Joined<["-"], "miphoneos-version-min=">, Group<m_Group>;
def mios_version_min_EQ : Joined<["-"], "mios-version-min=">,
Index: lib/CodeGen/BackendUtil.cpp
===================================================================
--- lib/CodeGen/BackendUtil.cpp
+++ lib/CodeGen/BackendUtil.cpp
@@ -433,8 +433,6 @@
BackendArgs.push_back("-time-passes");
for (unsigned i = 0, e = CodeGenOpts.BackendOptions.size(); i != e; ++i)
BackendArgs.push_back(CodeGenOpts.BackendOptions[i].c_str());
- if (CodeGenOpts.NoGlobalMerge)
- BackendArgs.push_back("-enable-global-merge=false");
BackendArgs.push_back(nullptr);
llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
BackendArgs.data());
Index: lib/CodeGen/CodeGenModule.cpp
===================================================================
--- lib/CodeGen/CodeGenModule.cpp
+++ lib/CodeGen/CodeGenModule.cpp
@@ -418,6 +418,8 @@
EmitVersionIdentMetadata();
EmitTargetMetadata();
+
+ EmitBackendOptionsMetadata();
}
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
@@ -3609,6 +3611,18 @@
}
}
+void CodeGenModule::EmitBackendOptionsMetadata() {
+ // Only emit the "Global Merge" flag when it disables it, and only on targets
+ // that support it (ARM/AArch64).
+ llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
+ if ((Arch == llvm::Triple::arm || Arch == llvm::Triple::armeb ||
+ Arch == llvm::Triple::thumb || Arch == llvm::Triple::thumbeb ||
+ Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_be) &&
+ getCodeGenOpts().NoGlobalMerge)
+ getModule().addModuleFlag(llvm::Module::Error, "Enable Global Merge",
+ llvm::MDString::get(VMContext, "false"));
+}
+
void CodeGenModule::EmitCoverageFile() {
if (!getCodeGenOpts().CoverageFile.empty()) {
if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) {
Index: lib/CodeGen/CodeGenModule.h
===================================================================
--- lib/CodeGen/CodeGenModule.h
+++ lib/CodeGen/CodeGenModule.h
@@ -1199,6 +1199,10 @@
/// Emits target specific Metadata for global declarations.
void EmitTargetMetadata();
+ /// Emit the module flag metadata used to pass options controlling the
+ /// the backend to LLVM.
+ void EmitBackendOptionsMetadata();
+
/// Emit the llvm.gcov metadata used to tell LLVM where to emit the .gcno and
/// .gcda files in a way that persists in .bc files.
void EmitCoverageFile();
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -860,12 +860,14 @@
}
}
- // Setting -mno-global-merge disables the codegen global merge pass. Setting
- // -mglobal-merge has no effect as the pass is enabled by default.
+ // Forward the -mglobal-merge option, for explicit control over the
+ // global-merge pass.
if (Arg *A = Args.getLastArg(options::OPT_mglobal_merge,
options::OPT_mno_global_merge)) {
if (A->getOption().matches(options::OPT_mno_global_merge))
CmdArgs.push_back("-mno-global-merge");
+ else
+ CmdArgs.push_back("-mglobal-merge");
}
if (!Args.hasFlag(options::OPT_mimplicit_float,
@@ -956,12 +958,14 @@
CmdArgs.push_back("-aarch64-fix-cortex-a53-835769=1");
}
- // Setting -mno-global-merge disables the codegen global merge pass. Setting
- // -mglobal-merge has no effect as the pass is enabled by default.
+ // Forward the -mglobal-merge option, for explicit control over the
+ // global-merge pass.
if (Arg *A = Args.getLastArg(options::OPT_mglobal_merge,
options::OPT_mno_global_merge)) {
if (A->getOption().matches(options::OPT_mno_global_merge))
CmdArgs.push_back("-mno-global-merge");
+ else
+ CmdArgs.push_back("-mglobal-merge");
}
if (Args.hasArg(options::OPT_ffixed_x18)) {
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -309,6 +309,16 @@
return "default";
}
+static bool shouldEnableGlobalMergeForTarget(const llvm::Triple &T,
+ const unsigned OptLevel) {
+ llvm::Triple::ArchType Arch = T.getArch();
+ return (OptLevel > 0 &&
+ (Arch == llvm::Triple::arm || Arch == llvm::Triple::armeb ||
+ Arch == llvm::Triple::thumb || Arch == llvm::Triple::thumbeb)) ||
+ (OptLevel > 2 &&
+ (Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_be));
+}
+
/// \brief Create a new Regex instance out of the string value in \p RpassArg.
/// It returns a pointer to the newly generated Regex instance.
static std::shared_ptr<llvm::Regex>
@@ -445,7 +455,12 @@
Opts.NoZeroInitializedInBSS = Args.hasArg(OPT_mno_zero_initialized_in_bss);
Opts.BackendOptions = Args.getAllArgValues(OPT_backend_option);
Opts.NumRegisterParameters = getLastArgIntValue(Args, OPT_mregparm, 0, Diags);
- Opts.NoGlobalMerge = Args.hasArg(OPT_mno_global_merge);
+
+ Opts.NoGlobalMerge = !Args.hasFlag(
+ OPT_mglobal_merge, OPT_mno_global_merge,
+ shouldEnableGlobalMergeForTarget(llvm::Triple(TargetOpts.Triple),
+ Opts.OptimizationLevel));
+
Opts.NoExecStack = Args.hasArg(OPT_mno_exec_stack);
Opts.FatalWarnings = Args.hasArg(OPT_massembler_fatal_warnings);
Opts.EnableSegmentedStacks = Args.hasArg(OPT_split_stacks);
Index: test/CodeGen/global-merge.c
===================================================================
--- /dev/null
+++ test/CodeGen/global-merge.c
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -emit-llvm -mglobal-merge %s -o - | FileCheck %s -check-prefix=CHECK-NONE
+// RUN: %clang_cc1 -emit-llvm -mno-global-merge %s -o - | FileCheck %s -check-prefix=CHECK-NONE
+
+// RUN: %clang_cc1 -emit-llvm -triple arm64-- -O1 %s -o - | FileCheck %s -check-prefix=CHECK-NGM
+// RUN: %clang_cc1 -emit-llvm -triple arm64-- -O3 %s -o - | FileCheck %s -check-prefix=CHECK-GM
+
+// RUN: %clang_cc1 -emit-llvm -triple arm-- -O1 %s -o - | FileCheck %s -check-prefix=CHECK-GM
+// RUN: %clang_cc1 -emit-llvm -triple arm-- -O3 %s -o - | FileCheck %s -check-prefix=CHECK-GM
+
+// CHECK-NONE-NOT: !"Enable Global Merge"
+
+// CHECK-GM-NOT: !"Enable Global Merge", !"false"
+
+// CHECK-NGM: !llvm.module.flags = !{{{.*}}}
+// CHECK-NGM: !{{[0-9]+}} = !{i32 1, !"Enable Global Merge", !"false"}
Index: test/Driver/mglobal-merge.c
===================================================================
--- test/Driver/mglobal-merge.c
+++ test/Driver/mglobal-merge.c
@@ -16,5 +16,5 @@
// RUN: -mglobal-merge -### -fsyntax-only %s 2> %t
// RUN: FileCheck --check-prefix=CHECK-GM < %t %s
-// CHECK-GM-NOT: "-mglobal-merge"
+// CHECK-GM: "-mglobal-merge"
_______________________________________________
cfe-commits mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
