Commit dfa8263f authored by Ruslan Baratov's avatar Ruslan Baratov Committed by Brad King
Browse files

Implement interprocedural optimization for GNU compilers

Honor the `INTERPROCEDURAL_OPTIMIZATION` target property for GNU
compilers by activating their link-time-optimization (LTO) flags.
parent 1588a577
GCC IPO
-------
* Interprocedural optimization (IPO) is now supported for GNU
compilers using link time optimization (LTO) flags. See the
:prop_tgt:`INTERPROCEDURAL_OPTIMIZATION` target property and
:module:`CheckIPOSupported` module.
......@@ -27,5 +27,13 @@ else()
set(CMAKE_${lang}_COMPILE_OPTIONS_TARGET "--target=")
set(CMAKE_${lang}_COMPILE_OPTIONS_EXTERNAL_TOOLCHAIN "--gcc-toolchain=")
endif()
set(_CMAKE_IPO_SUPPORTED_BY_CMAKE NO)
set(_CMAKE_IPO_MAY_BE_SUPPORTED_BY_COMPILER NO)
unset(CMAKE_${lang}_COMPILE_OPTIONS_IPO)
unset(CMAKE_${lang}_ARCHIVE_CREATE_IPO)
unset(CMAKE_${lang}_ARCHIVE_APPEND_IPO)
unset(CMAKE_${lang}_ARCHIVE_FINISH_IPO)
endmacro()
endif()
......@@ -45,4 +45,43 @@ macro(__compiler_gnu lang)
if(NOT APPLE OR NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 4) # work around #4462
set(CMAKE_INCLUDE_SYSTEM_FLAG_${lang} "-isystem ")
endif()
set(_CMAKE_IPO_SUPPORTED_BY_CMAKE YES)
set(_CMAKE_IPO_MAY_BE_SUPPORTED_BY_COMPILER NO)
# '-flto' introduced since GCC 4.5:
# * https://gcc.gnu.org/onlinedocs/gcc-4.4.7/gcc/Option-Summary.html (no)
# * https://gcc.gnu.org/onlinedocs/gcc-4.5.4/gcc/Option-Summary.html (yes)
if(NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 4.5)
set(_CMAKE_IPO_MAY_BE_SUPPORTED_BY_COMPILER YES)
set(__lto_flags -flto)
if(NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 4.7)
# '-ffat-lto-objects' introduced since GCC 4.7:
# * https://gcc.gnu.org/onlinedocs/gcc-4.6.4/gcc/Option-Summary.html (no)
# * https://gcc.gnu.org/onlinedocs/gcc-4.7.4/gcc/Option-Summary.html (yes)
list(APPEND __lto_flags -fno-fat-lto-objects)
endif()
set(CMAKE_${lang}_COMPILE_OPTIONS_IPO ${__lto_flags})
# Need to use version of 'ar'/'ranlib' with plugin support.
# Quote from [documentation][1]:
#
# To create static libraries suitable for LTO,
# use gcc-ar and gcc-ranlib instead of ar and ranlib
#
# [1]: https://gcc.gnu.org/onlinedocs/gcc-4.9.4/gcc/Optimize-Options.html
set(CMAKE_${lang}_ARCHIVE_CREATE_IPO
"${CMAKE_GCC_AR} cr <TARGET> <LINK_FLAGS> <OBJECTS>"
)
set(CMAKE_${lang}_ARCHIVE_APPEND_IPO
"${CMAKE_GCC_AR} r <TARGET> <LINK_FLAGS> <OBJECTS>"
)
set(CMAKE_${lang}_ARCHIVE_FINISH_IPO
"${CMAKE_GCC_RANLIB} <TARGET>"
)
endif()
endmacro()
......@@ -12,4 +12,12 @@ macro(__compiler_qcc lang)
set(CMAKE_INCLUDE_SYSTEM_FLAG_${lang} "-Wp,-isystem,")
set(CMAKE_DEPFILE_FLAGS_${lang} "-Wc,-MD,<DEPFILE>,-MT,<OBJECT>,-MF,<DEPFILE>")
set(_CMAKE_IPO_SUPPORTED_BY_CMAKE NO)
set(_CMAKE_IPO_MAY_BE_SUPPORTED_BY_COMPILER NO)
unset(CMAKE_${lang}_COMPILE_OPTIONS_IPO)
unset(CMAKE_${lang}_ARCHIVE_CREATE_IPO)
unset(CMAKE_${lang}_ARCHIVE_APPEND_IPO)
unset(CMAKE_${lang}_ARCHIVE_FINISH_IPO)
endmacro()
......@@ -2466,19 +2466,28 @@ void cmGeneratorTarget::GetAppleArchs(const std::string& config,
}
}
//----------------------------------------------------------------------------
std::string cmGeneratorTarget::GetFeatureSpecificLinkRuleVariable(
std::string const& var, std::string const& config) const
{
if (this->IsIPOEnabled(config)) {
std::string varIPO = var + "_IPO";
if (this->Makefile->IsDefinitionSet(varIPO)) {
return varIPO;
}
}
return var;
}
//----------------------------------------------------------------------------
std::string cmGeneratorTarget::GetCreateRuleVariable(
std::string const& lang, std::string const& config) const
{
switch (this->GetType()) {
case cmStateEnums::STATIC_LIBRARY: {
std::string var = "CMAKE_" + lang + "_CREATE_STATIC_LIBRARY";
if (this->IsIPOEnabled(config)) {
std::string varIPO = var + "_IPO";
if (this->Makefile->GetDefinition(varIPO)) {
return varIPO;
}
}
return var;
return this->GetFeatureSpecificLinkRuleVariable(var, config);
}
case cmStateEnums::SHARED_LIBRARY:
return "CMAKE_" + lang + "_CREATE_SHARED_LIBRARY";
......
......@@ -309,6 +309,9 @@ public:
void GetAppleArchs(const std::string& config,
std::vector<std::string>& archVec) const;
std::string GetFeatureSpecificLinkRuleVariable(
std::string const& var, std::string const& config) const;
/** Return the rule variable used to create this type of target. */
std::string GetCreateRuleVariable(std::string const& lang,
std::string const& config) const;
......
......@@ -129,14 +129,9 @@ void cmMakefileLibraryTargetGenerator::WriteStaticLibraryRules()
{
std::string linkLanguage =
this->GeneratorTarget->GetLinkerLanguage(this->ConfigName);
std::string linkRuleVar = "CMAKE_";
linkRuleVar += linkLanguage;
linkRuleVar += "_CREATE_STATIC_LIBRARY";
if (this->GeneratorTarget->IsIPOEnabled(this->ConfigName) &&
this->Makefile->GetDefinition(linkRuleVar + "_IPO")) {
linkRuleVar += "_IPO";
}
std::string linkRuleVar = this->GeneratorTarget->GetCreateRuleVariable(
linkLanguage, this->ConfigName);
std::string extraFlags;
this->LocalGenerator->GetStaticLibraryFlags(
......@@ -676,18 +671,30 @@ void cmMakefileLibraryTargetGenerator::WriteLibraryRules(
std::string arCreateVar = "CMAKE_";
arCreateVar += linkLanguage;
arCreateVar += "_ARCHIVE_CREATE";
arCreateVar = this->GeneratorTarget->GetFeatureSpecificLinkRuleVariable(
arCreateVar, this->ConfigName);
if (const char* rule = this->Makefile->GetDefinition(arCreateVar)) {
cmSystemTools::ExpandListArgument(rule, archiveCreateCommands);
}
std::string arAppendVar = "CMAKE_";
arAppendVar += linkLanguage;
arAppendVar += "_ARCHIVE_APPEND";
arAppendVar = this->GeneratorTarget->GetFeatureSpecificLinkRuleVariable(
arAppendVar, this->ConfigName);
if (const char* rule = this->Makefile->GetDefinition(arAppendVar)) {
cmSystemTools::ExpandListArgument(rule, archiveAppendCommands);
}
std::string arFinishVar = "CMAKE_";
arFinishVar += linkLanguage;
arFinishVar += "_ARCHIVE_FINISH";
arFinishVar = this->GeneratorTarget->GetFeatureSpecificLinkRuleVariable(
arFinishVar, this->ConfigName);
if (const char* rule = this->Makefile->GetDefinition(arFinishVar)) {
cmSystemTools::ExpandListArgument(rule, archiveFinishCommands);
}
......
......@@ -516,6 +516,10 @@ std::vector<std::string> cmNinjaNormalTargetGenerator::ComputeLinkCmd()
std::string linkCmdVar = "CMAKE_";
linkCmdVar += this->TargetLinkLanguage;
linkCmdVar += "_ARCHIVE_CREATE";
linkCmdVar = this->GeneratorTarget->GetFeatureSpecificLinkRuleVariable(
linkCmdVar, this->GetConfigName());
const char* linkCmd = mf->GetRequiredDefinition(linkCmdVar);
cmSystemTools::ExpandListArgument(linkCmd, linkCmds);
}
......@@ -523,6 +527,10 @@ std::vector<std::string> cmNinjaNormalTargetGenerator::ComputeLinkCmd()
std::string linkCmdVar = "CMAKE_";
linkCmdVar += this->TargetLinkLanguage;
linkCmdVar += "_ARCHIVE_FINISH";
linkCmdVar = this->GeneratorTarget->GetFeatureSpecificLinkRuleVariable(
linkCmdVar, this->GetConfigName());
const char* linkCmd = mf->GetRequiredDefinition(linkCmdVar);
cmSystemTools::ExpandListArgument(linkCmd, linkCmds);
}
......
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