V3 [PATCH 3/5] Support the PGO build for binutils+gdb

H.J. Lu via Gdb-patches
2020-12-19T18:11:10Z

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.
---
Makefile.in | 63 ++++++++++++++++++++++++++++++--
Makefile.tpl | 58 ++++++++++++++++++++++++++++--
configure | 100 +++++++++++++++++++++++++++++++++++++++++++++++++--
configure.ac | 65 +++++++++++++++++++++++++++++++++
4 files changed, 280 insertions(+), 6 deletions(-)

diff --git a/Makefile.in b/Makefile.in
index 978e777338..c73581d24e 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -412,6 +412,49 @@ CXXFLAGS = @CXXFLAGS@
LIBCXXFLAGS = $(CXXFLAGS) -fno-implicit-templates
GOCFLAGS = $(CFLAGS)

+# Pass additional PGO and LTO compiler options to the PGO build.
+BUILD_CFLAGS = $(PGO_BUILD_CFLAGS) $(PGO_BUILD_LTO_CFLAGS)
+override CFLAGS += $(BUILD_CFLAGS)
+override CXXFLAGS += $(BUILD_CFLAGS)
+
+# Additional PGO and LTO compiler options to generate profiling data
+# for the PGO build.
+PGO_BUILD_GEN_FLAGS_TO_PASS = \
+ PGO_BUILD_CFLAGS="@PGO_BUILD_GEN_CFLAGS@" \
+ PGO_BUILD_LTO_CFLAGS="@PGO_BUILD_LTO_CFLAGS@"
+
+# NB: Filter out any compiler options which may fail PGO training runs.
+PGO_BUILD_TRAINING_CFLAGS:= \
+ $(filter-out -Werror=%,$(CFLAGS))
+PGO_BUILD_TRAINING_CXXFLAGS:=\
+ $(filter-out -Werror=%,$(CXXFLAGS))
+PGO_BUILD_TRAINING_CFLAGS:= \
+ $(filter-out -Wall,$(PGO_BUILD_TRAINING_CFLAGS))
+PGO_BUILD_TRAINING_CXXFLAGS:= \
+ $(filter-out -Wall,$(PGO_BUILD_TRAINING_CXXFLAGS))
+PGO_BUILD_TRAINING_CFLAGS:= \
+ $(filter-out -specs=%,$(PGO_BUILD_TRAINING_CFLAGS))
+PGO_BUILD_TRAINING_CXXFLAGS:= \
+ $(filter-out -specs=%,$(PGO_BUILD_TRAINING_CXXFLAGS))
+PGO_BUILD_TRAINING_FLAGS_TO_PASS = \
+ PGO_BUILD_TRAINING=yes \
+ CFLAGS_FOR_TARGET="$(PGO_BUILD_TRAINING_CFLAGS)" \
+ CXXFLAGS_FOR_TARGET="$(PGO_BUILD_TRAINING_CXXFLAGS)"
+
+# Ignore "make check" errors in PGO training runs.
+PGO_BUILD_TRAINING_MFLAGS = -i
+
+# Additional PGO and LTO compiler options to use profiling data for the
+# PGO build.
+PGO_BUILD_USE_FLAGS_TO_PASS = \
+ PGO_BUILD_CFLAGS="@PGO_BUILD_USE_CFLAGS@" \
+ PGO_BUILD_LTO_CFLAGS="@PGO_BUILD_LTO_CFLAGS@"
+
+# PGO training targets for the PGO build. FIXME: Add gold tests to
+# training.
+PGO-TRAINING-TARGETS = binutils gas gdb ld sim
+PGO_BUILD_TRAINING = $(addprefix maybe-check-,$(PGO-TRAINING-TARGETS))
+
CREATE_GCOV = create_gcov

TFLAGS =
@@ -985,6 +1028,12 @@ configure-target: \

# The target built for a native non-bootstrap build.
.PHONY: all
+
+# --enable-pgo-build enables the PGO build.
+# 1. First build with -fprofile-generate.
+# 2. Use "make maybe-check-*" to generate profiling data.
+# 3. Use "make clean" to remove the previous build.
+# 4. Rebuild with -fprofile-use.
all:
@if gcc-bootstrap
[ -f stage_final ] || echo stage3 > stage_final
@@ -993,7 +1042,7 @@ all:
$(MAKE) $(RECURSE_FLAGS_TO_PASS) `cat stage_final`-bubble
@endif gcc-bootstrap
@: $(MAKE); $(unstage)
- @r=`${PWD_COMMAND}`; export r; \
+ +@r=`${PWD_COMMAND}`; export r; \
s=`cd $(srcdir); ${PWD_COMMAND}`; export s; \
@if gcc-bootstrap
if [ -f stage_last ]; then \
@@ -1001,7 +1050,17 @@ all:
$(MAKE) $(TARGET_FLAGS_TO_PASS) all-host all-target; \
else \
@endif gcc-bootstrap
- $(MAKE) $(RECURSE_FLAGS_TO_PASS) all-host all-target \
+ $(MAKE) $(RECURSE_FLAGS_TO_PASS) \
+ $(PGO_BUILD_GEN_FLAGS_TO_PASS) all-host all-target \
+@if pgo-build
+ && $(MAKE) $(RECURSE_FLAGS_TO_PASS) \
+ $(PGO_BUILD_TRAINING_MFLAGS) \
+ $(PGO_BUILD_TRAINING_FLAGS_TO_PASS) \
+ $(PGO_BUILD_TRAINING) \
+ && $(MAKE) $(RECURSE_FLAGS_TO_PASS) clean \
+ && $(MAKE) $(RECURSE_FLAGS_TO_PASS) \
+ $(PGO_BUILD_USE_FLAGS_TO_PASS) all-host all-target \
+@endif pgo-build
@if gcc-bootstrap
; \
fi \
diff --git a/Makefile.tpl b/Makefile.tpl
index a280a1498c..38f0b021f4 100644
--- a/Makefile.tpl
+++ b/Makefile.tpl
@@ -415,6 +415,45 @@ CXXFLAGS = @CXXFLAGS@
LIBCXXFLAGS = $(CXXFLAGS) -fno-implicit-templates
GOCFLAGS = $(CFLAGS)

+# Pass additional PGO and LTO compiler options to the PGO build.
+BUILD_CFLAGS = $(PGO_BUILD_CFLAGS) $(PGO_BUILD_LTO_CFLAGS)
+override CFLAGS += $(BUILD_CFLAGS)
+override CXXFLAGS += $(BUILD_CFLAGS)
+
+# Additional PGO and LTO compiler options to generate profiling data
+# for the PGO build.
+PGO_BUILD_GEN_FLAGS_TO_PASS = \
+ PGO_BUILD_CFLAGS="@PGO_BUILD_GEN_CFLAGS@" \
+ PGO_BUILD_LTO_CFLAGS="@PGO_BUILD_LTO_CFLAGS@"
+
+# NB: Filter out any compiler options which may fail PGO training runs.
+PGO_BUILD_TRAINING_CFLAGS:= \
+ $(filter-out -Werror=%,$(CFLAGS))
+PGO_BUILD_TRAINING_CXXFLAGS:=\
+ $(filter-out -Werror=%,$(CXXFLAGS))
+PGO_BUILD_TRAINING_CFLAGS:= \
+ $(filter-out -Wall,$(PGO_BUILD_TRAINING_CFLAGS))
+PGO_BUILD_TRAINING_CXXFLAGS:= \
+ $(filter-out -Wall,$(PGO_BUILD_TRAINING_CXXFLAGS))
+PGO_BUILD_TRAINING_CFLAGS:= \
+ $(filter-out -specs=%,$(PGO_BUILD_TRAINING_CFLAGS))
+PGO_BUILD_TRAINING_CXXFLAGS:= \
+ $(filter-out -specs=%,$(PGO_BUILD_TRAINING_CXXFLAGS))
+PGO_BUILD_TRAINING_FLAGS_TO_PASS = \
+ CFLAGS_FOR_TARGET="$(PGO_BUILD_TRAINING_CFLAGS)" \
+ CXXFLAGS_FOR_TARGET="$(PGO_BUILD_TRAINING_CXXFLAGS)"
+
+# Additional PGO and LTO compiler options to use profiling data for the
+# PGO build.
+PGO_BUILD_USE_FLAGS_TO_PASS = \
+ PGO_BUILD_CFLAGS="@PGO_BUILD_USE_CFLAGS@" \
+ PGO_BUILD_LTO_CFLAGS="@PGO_BUILD_LTO_CFLAGS@"
+
+# PGO training targets for the PGO build. FIXME: Add gold tests to
+# training.
+PGO-TRAINING-TARGETS = binutils gas gdb ld sim
+PGO_BUILD_TRAINING = $(addprefix maybe-check-,$(PGO-TRAINING-TARGETS))
+
CREATE_GCOV = create_gcov

TFLAGS =
@@ -719,6 +758,12 @@ configure-target: [+

# The target built for a native non-bootstrap build.
.PHONY: all
+
+# --enable-pgo-build enables the PGO build.
+# 1. First build with -fprofile-generate.
+# 2. Use "make maybe-check-*" to generate profiling data.
+# 3. Use "make clean" to remove the previous build.
+# 4. Rebuild with -fprofile-use.
all:
@if gcc-bootstrap
[ -f stage_final ] || echo stage3 > stage_final
@@ -727,7 +772,7 @@ all:
$(MAKE) $(RECURSE_FLAGS_TO_PASS) `cat stage_final`-bubble
@endif gcc-bootstrap
@: $(MAKE); $(unstage)
- @r=`${PWD_COMMAND}`; export r; \
+ +@r=`${PWD_COMMAND}`; export r; \
s=`cd $(srcdir); ${PWD_COMMAND}`; export s; \
@if gcc-bootstrap
if [ -f stage_last ]; then \
@@ -735,7 +780,16 @@ all:
$(MAKE) $(TARGET_FLAGS_TO_PASS) all-host all-target; \
else \
@endif gcc-bootstrap
- $(MAKE) $(RECURSE_FLAGS_TO_PASS) all-host all-target \
+ $(MAKE) $(RECURSE_FLAGS_TO_PASS) \
+ $(PGO_BUILD_GEN_FLAGS_TO_PASS) all-host all-target \
+@if pgo-build
+ && $(MAKE) $(RECURSE_FLAGS_TO_PASS) \
+ $(PGO_BUILD_TRAINING_FLAGS_TO_PASS) \
+ $(PGO_BUILD_TRAINING) \
+ && $(MAKE) $(RECURSE_FLAGS_TO_PASS) clean \
+ && $(MAKE) $(RECURSE_FLAGS_TO_PASS) \
+ $(PGO_BUILD_USE_FLAGS_TO_PASS) all-host all-target \
+@endif pgo-build
@if gcc-bootstrap
; \
fi \
diff --git a/configure b/configure
index 4c9297d378..a75bc26978 100755
--- a/configure
+++ b/configure
@@ -692,6 +692,9 @@ extra_mpc_gmp_configure_flags
extra_mpfr_configure_flags
gmpinc
gmplibs
+PGO_BUILD_LTO_CFLAGS
+PGO_BUILD_USE_CFLAGS
+PGO_BUILD_GEN_CFLAGS
do_compare
GNATMAKE
GNATBIND
@@ -792,6 +795,7 @@ enable_libssp
enable_libstdcxx
enable_liboffloadmic
enable_bootstrap
+enable_pgo_build
with_mpc
with_mpc_include
with_mpc_lib
@@ -1522,6 +1526,8 @@ Optional Features:
--enable-liboffloadmic=ARG
build liboffloadmic [ARG={no,host,target}]
--enable-bootstrap enable bootstrapping [yes if native build]
+ --enable-pgo-build[=lto]
+ enable the PGO build
--disable-isl-version-check
disable check for isl version
--enable-lto enable link time optimization support
@@ -5422,6 +5428,91 @@ if test "$enable_bootstrap:$GXX" = "yes:yes"; then
CXX="$CXX -std=gnu++98"
fi

+# Check whether --enable-pgo-build was given.
+if test "${enable_pgo_build+set}" = set; then :
+ enableval=$enable_pgo_build; enable_pgo_build=$enableval
+else
+ enable_pgo_build=no
+fi
+
+
+# Issue errors and warnings for invalid/strange PGO build combinations.
+case "$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)
+ as_fn_error $? "cannot perform the PGO bootstrap when building a compiler" "$LINENO" 5 ;;
+
+ *)
+ as_fn_error $? "invalid option for --enable-pgo-build" "$LINENO" 5
+ ;;
+esac
+
+if test "$enable_pgo_build" != "no"; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports -fprofile-generate" >&5
+$as_echo_n "checking whether the compiler supports -fprofile-generate... " >&6; }
+ old_CFLAGS="$CFLAGS"
+ PGO_BUILD_GEN_CFLAGS="-fprofile-generate"
+ CFLAGS="$CFLAGS $PGO_BUILD_CFLAGS"
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+int foo;
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+else
+ PGO_BUILD_GEN_CFLAGS=
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ CFLAGS="$old_CFLAGS"
+ if test -n "$PGO_BUILD_GEN_CFLAGS"; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+ PGO_BUILD_USE_CFLAGS="-fprofile-use"
+ else
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+ as_fn_error $? "cannot perform the PGO build without -fprofile-generate" "$LINENO" 5
+ fi
+
+ if test "$enable_pgo_build" = "lto"; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports -flto=jobserver -ffat-lto-objects" >&5
+$as_echo_n "checking whether the compiler supports -flto=jobserver -ffat-lto-objects... " >&6; }
+ old_CFLAGS="$CFLAGS"
+ PGO_BUILD_LTO_CFLAGS="-flto=jobserver -ffat-lto-objects"
+ CFLAGS="$CFLAGS $PGO_BUILD_LTO_CFLAGS"
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+int foo;
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+else
+ PGO_BUILD_LTO_CFLAGS=
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ CFLAGS="$old_CFLAGS"
+ if test -n "$PGO_BUILD_LTO_CFLAGS"; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+ else
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+ { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: LTO is disabled for the PGO build" >&5
+$as_echo "$as_me: WARNING: LTO is disabled for the PGO build" >&2;}
+ fi
+ fi
+fi
+
+
+
+
# Used for setting $lt_cv_objdir
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for objdir" >&5
$as_echo_n "checking for objdir... " >&6; }
@@ -5611,8 +5702,7 @@ if test -d ${srcdir}/gcc && test "x$have_gmp" = xno; then
# Check for the recommended and required versions of GMP.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for the correct version of gmp.h" >&5
$as_echo_n "checking for the correct version of gmp.h... " >&6; }
-
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
#include "gmp.h"
int
@@ -7331,6 +7421,12 @@ extrasub_target="$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.

# Check whether --enable-serial-configure was given.
diff --git a/configure.ac b/configure.ac
index 7c4bdff0fa..9dd51c36e5 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],
--
2.29.2