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authorH.J. Lu <hjl.tools@gmail.com>2021-01-09 06:51:15 -0800
committerH.J. Lu <hjl.tools@gmail.com>2021-01-09 06:51:51 -0800
commitaf019bfde9b13d628202fe58054ec7ff08d92a0f (patch)
tree803e80c09c6e656ecd8b2939fee19e4961cff0b0 /configure.ac
parenta4966cd965cd7269426ea096113df862c1dcdf34 (diff)
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Support the PGO build for binutils+gdb
Add the --enable-pgo-build[=lto] configure option. When binutils+gdb is not built together with GCC, --enable-pgo-build enables the PGO build: 1. First build with -fprofile-generate. 2. Use "make maybe-check-*" to generate profiling data and pass -i to make to ignore errors when generating profiling data. 3. Use "make clean" to remove the previous build. 4. Rebuild with -fprofile-use. With --enable-pgo-build=lto, -flto=jobserver -ffat-lto-objects are used together with -fprofile-generate and -fprofile-use. Add '+' to the command line for recursive make to support -flto=jobserver -ffat-lto-objects. NB: --enable-pgo-build=lto enables the PGO build with LTO while --enable-lto enables LTO support in toolchain. PR binutils/26766 * Makefile.tpl (BUILD_CFLAGS): New. (CFLAGS): Append $(BUILD_CFLAGS). (CXXFLAGS): Likewise. (PGO_BUILD_GEN_FLAGS_TO_PASS): New. (PGO_BUILD_TRAINING_CFLAGS): Likewise. (PGO_BUILD_TRAINING_CXXFLAGS): Likewise. (PGO_BUILD_TRAINING_FLAGS_TO_PASS): Likewise. (PGO_BUILD_TRAINING_MFLAGS): Likewise. (PGO_BUILD_USE_FLAGS_TO_PASS): Likewise. (PGO-TRAINING-TARGETS): Likewise. (PGO_BUILD_TRAINING): Likewise. (all): Add '+' to the command line for recursive make. Support the PGO build. * configure.ac: Add --enable-pgo-build[=lto]. AC_SUBST PGO_BUILD_GEN_CFLAGS, PGO_BUILD_USE_CFLAGS and PGO_BUILD_LTO_CFLAGS. Enable the PGO build in Makefile. * Makefile.in: Regenerated. * configure: Likewise.
Diffstat (limited to 'configure.ac')
-rw-r--r--configure.ac65
1 files changed, 65 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac
index 7c4bdff..9dd51c3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1375,6 +1375,65 @@ if test "$enable_bootstrap:$GXX" = "yes:yes"; then
CXX="$CXX -std=gnu++98"
fi
+AC_ARG_ENABLE([pgo-build],
+[AS_HELP_STRING([--enable-pgo-build[[=lto]]],
+ [enable the PGO build])],
+[enable_pgo_build=$enableval],
+[enable_pgo_build=no])
+
+# Issue errors and warnings for invalid/strange PGO build combinations.
+case "$have_compiler:$host:$target:$enable_pgo_build" in
+ *:*:*:no) ;;
+
+ # Allow the PGO build only if we aren't building a compiler and
+ # we are in a native configuration.
+ no:$build:$build:yes | no:$build:$build:lto) ;;
+
+ # Disallow the PGO bootstrap if we are building a compiler.
+ yes:*:*:yes | yes:*:*:lto)
+ AC_MSG_ERROR([cannot perform the PGO bootstrap when building a compiler]) ;;
+
+ *)
+ AC_MSG_ERROR([invalid option for --enable-pgo-build])
+ ;;
+esac
+
+if test "$enable_pgo_build" != "no"; then
+ AC_MSG_CHECKING([whether the compiler supports -fprofile-generate])
+ old_CFLAGS="$CFLAGS"
+ PGO_BUILD_GEN_CFLAGS="-fprofile-generate"
+ CFLAGS="$CFLAGS $PGO_BUILD_CFLAGS"
+ AC_COMPILE_IFELSE([AC_LANG_SOURCE([int foo;])],,
+ [PGO_BUILD_GEN_CFLAGS=])
+ CFLAGS="$old_CFLAGS"
+ if test -n "$PGO_BUILD_GEN_CFLAGS"; then
+ AC_MSG_RESULT([yes])
+ PGO_BUILD_USE_CFLAGS="-fprofile-use"
+ else
+ AC_MSG_RESULT([no])
+ AC_MSG_ERROR([cannot perform the PGO build without -fprofile-generate])
+ fi
+
+ if test "$enable_pgo_build" = "lto"; then
+ AC_MSG_CHECKING([whether the compiler supports -flto=jobserver -ffat-lto-objects])
+ old_CFLAGS="$CFLAGS"
+ PGO_BUILD_LTO_CFLAGS="-flto=jobserver -ffat-lto-objects"
+ CFLAGS="$CFLAGS $PGO_BUILD_LTO_CFLAGS"
+ AC_COMPILE_IFELSE([AC_LANG_SOURCE([int foo;])],,
+ [PGO_BUILD_LTO_CFLAGS=])
+ CFLAGS="$old_CFLAGS"
+ if test -n "$PGO_BUILD_LTO_CFLAGS"; then
+ AC_MSG_RESULT([yes])
+ else
+ AC_MSG_RESULT([no])
+ AC_MSG_WARN([LTO is disabled for the PGO build])
+ fi
+ fi
+fi
+AC_SUBST(PGO_BUILD_GEN_CFLAGS)
+AC_SUBST(PGO_BUILD_USE_CFLAGS)
+AC_SUBST(PGO_BUILD_LTO_CFLAGS)
+
# Used for setting $lt_cv_objdir
_LT_CHECK_OBJDIR
@@ -2847,6 +2906,12 @@ extrasub_target="$extrasub_target
/^@unless /d
/^@endunless /d"
+if test "$enable_pgo_build" != "no"; then
+ extrasub_build="$extrasub_build
+/^@if pgo-build\$/d
+/^@endif pgo-build\$/d"
+fi
+
# Create the serialization dependencies. This uses a temporary file.
AC_ARG_ENABLE([serial-configure],