LTO tweaks

git-svn-id: https://svn.r-project.org/R/trunk@57807 00db46b3-68df-0310-9c12-caf00c1e9a41

Makeconf.in

@@ -59,7 +59,7 @@ LIBTOOL = @LIBTOOL@
 LN_S = @LN_S@
 MAIN_CFLAGS = @MAIN_CFLAGS@
 MAIN_FFLAGS = @MAIN_FFLAGS@
-MAIN_LD = @MAIN_LD@@BUILD_LTO_TRUE@ $(CFLAGS)
+MAIN_LD = @MAIN_LD@@BUILD_LTO_TRUE@ $(CFLAGS) -fwhole-program
 MAIN_LDFLAGS = @MAIN_LDFLAGS@ @WANT_R_SHLIB_FALSE@ @USE_EXPORTFILES_TRUE@ -Wl,-bE:$(top_builddir)/etc/R.exp
 MAIN_LINK = $(MAIN_LD) $(MAIN_LDFLAGS) $(LDFLAGS)
 ## need this for bootstrapping

configure

@@ -3998,7 +3998,7 @@ if test "x${want_lto}" == xyes; then
 fi
 
 
- if test "x${want_lto}" = xyes; then
+ if test "x${want_lto}" != xno; then
   BUILD_LTO_TRUE=
   BUILD_LTO_FALSE='#'
 else

configure.ac

@@ -336,7 +336,7 @@ if test "x${want_lto}" == xyes; then
 fi
 AC_SUBST(LTO)
 AC_SUBST(LTOALL)
-AM_CONDITIONAL(BUILD_LTO, [test "x${want_lto}" = xyes])
+AM_CONDITIONAL(BUILD_LTO, [test "x${want_lto}" != xno])
 
 
 ### ** Optional packages.

doc/manual/R-admin.texi

@@ -4648,7 +4648,8 @@ may need to be compiled without optimization.  Set the configure
 variable @env{SAFE_FFLAGS} to the flags to be used for this file.  If
 configure detects @acronym{GNU} FORTRAN it adds flag
 @option{-ffloat-store} to @env{FFLAGS}.  (Other settings are needed when
-using @command{icc} on @cputype{ix86} Linux, for example.)
+using @command{icc} on @cputype{ix86} Linux, for example.  Using
+@option{-mpc64} is preferable on more recent GCC compilers.)
 
 If you do manage to get @R{} running on a new platform please let us
 know about it so we can modify the configuration procedures to include