Turn on -fomit-frame-pointer by default for 32bit Linux/x86.

2010-08-12  H.J. Lu  <hongjiu.lu@intel.com>
	    Uros Bizjak  <ubizjak@gmail.com>

	* config.gcc: Handle --enable-frame-pointer.

	* configure.ac: Add --enable-frame-pointer.
	* configure: Regenerated.

	* config/i386/i386.c (USE_IX86_FRAME_POINTER): Default to 0.
	(override_options): If not configured with --enable-frame-pointer,
	enable -fomit-frame-pointer (but not for TARGET_MACHO or when
	optimizing for size), -fasynchronous-unwind-tables and
	-maccumulate-outgoing-args by default.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@163196 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 90 insertions, 29 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 31dd288030f..39b2e75ca82 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,17 @@
+2010-08-12  H.J. Lu  <hongjiu.lu@intel.com>
+	    Uros Bizjak  <ubizjak@gmail.com>
+
+	* config.gcc: Handle --enable-frame-pointer.
+
+	* configure.ac: Add --enable-frame-pointer.
+	* configure: Regenerated.
+
+	* config/i386/i386.c (USE_IX86_FRAME_POINTER): Default to 0.
+	(override_options): If not configured with --enable-frame-pointer,
+	enable -fomit-frame-pointer (but not for TARGET_MACHO or when
+	optimizing for size), -fasynchronous-unwind-tables and
+	-maccumulate-outgoing-args by default.
+
 2010-08-12  Jakub Jelinek  <jakub@redhat.com>
 
 	* builtins.c (fold_builtin_memory_op): Avoid -Wsign-compare
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 9170fc819c7..62dd9f65045 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -406,6 +406,9 @@ i[34567]86-*-*)
 	if test "x$enable_cld" = xyes; then
 		tm_defines="${tm_defines} USE_IX86_CLD=1"
 	fi
+	if test "x$enable_frame_pointer" = xyes; then
+		tm_defines="${tm_defines} USE_IX86_FRAME_POINTER=1"
+	fi
 	tm_file="vxworks-dummy.h ${tm_file}"
 	;;
 x86_64-*-*)
@@ -413,6 +416,9 @@ x86_64-*-*)
 	if test "x$enable_cld" = xyes; then
 		tm_defines="${tm_defines} USE_IX86_CLD=1"
 	fi
+	if test "x$enable_frame_pointer" = xyes; then
+		tm_defines="${tm_defines} USE_IX86_FRAME_POINTER=1"
+	fi
 	tm_file="vxworks-dummy.h ${tm_file}"
 	;;
 esac
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index c3863acb81f..a87175cf96d 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -2979,32 +2979,6 @@ override_options (bool main_args_p)
   if (TARGET_MACHO && TARGET_64BIT)
     flag_pic = 2;
 
-  /* Set the default values for switches whose default depends on TARGET_64BIT
-     in case they weren't overwritten by command line options.  */
-  if (TARGET_64BIT)
-    {
-      if (flag_zee == 2)
-        flag_zee = 1;
-      /* Mach-O doesn't support omitting the frame pointer for now.  */
-      if (flag_omit_frame_pointer == 2)
-	flag_omit_frame_pointer = (TARGET_MACHO ? 0 : 1);
-      if (flag_asynchronous_unwind_tables == 2)
-	flag_asynchronous_unwind_tables = 1;
-      if (flag_pcc_struct_return == 2)
-	flag_pcc_struct_return = 0;
-    }
-  else
-    {
-      if (flag_zee == 2)
-        flag_zee = 0;
-      if (flag_omit_frame_pointer == 2)
-	flag_omit_frame_pointer = 0;
-      if (flag_asynchronous_unwind_tables == 2)
-	flag_asynchronous_unwind_tables = 0;
-      if (flag_pcc_struct_return == 2)
-	flag_pcc_struct_return = DEFAULT_PCC_STRUCT_RETURN;
-    }
-
   /* Need to check -mtune=generic first.  */
   if (ix86_tune_string)
     {
@@ -3292,6 +3266,38 @@ override_options (bool main_args_p)
   for (i = 0; i < X86_TUNE_LAST; ++i)
     ix86_tune_features[i] = !!(initial_ix86_tune_features[i] & ix86_tune_mask);
 
+#ifndef USE_IX86_FRAME_POINTER
+#define USE_IX86_FRAME_POINTER 0
+#endif
+
+  /* Set the default values for switches whose default depends on TARGET_64BIT
+     in case they weren't overwritten by command line options.  */
+  if (TARGET_64BIT)
+    {
+      if (flag_zee == 2)
+        flag_zee = 1;
+      /* Mach-O doesn't support omitting the frame pointer for now.  */
+      if (flag_omit_frame_pointer == 2)
+	flag_omit_frame_pointer = (TARGET_MACHO ? 0 : 1);
+      if (flag_asynchronous_unwind_tables == 2)
+	flag_asynchronous_unwind_tables = 1;
+      if (flag_pcc_struct_return == 2)
+	flag_pcc_struct_return = 0;
+    }
+  else
+    {
+      if (flag_zee == 2)
+        flag_zee = 0;
+      /* Mach-O doesn't support omitting the frame pointer for now.  */
+      if (flag_omit_frame_pointer == 2)
+	flag_omit_frame_pointer =
+	  (TARGET_MACHO ? 0 : !(USE_IX86_FRAME_POINTER || optimize_size));
+      if (flag_asynchronous_unwind_tables == 2)
+	flag_asynchronous_unwind_tables = !USE_IX86_FRAME_POINTER;
+      if (flag_pcc_struct_return == 2)
+	flag_pcc_struct_return = DEFAULT_PCC_STRUCT_RETURN;
+    }
+
   if (optimize_size)
     ix86_cost = &ix86_size_cost;
   else
@@ -3574,7 +3580,8 @@ override_options (bool main_args_p)
 	       prefix, suffix, sw);
     }
 
-  if ((x86_accumulate_outgoing_args & ix86_tune_mask)
+  if ((!USE_IX86_FRAME_POINTER
+       || (x86_accumulate_outgoing_args & ix86_tune_mask))
       && !(target_flags_explicit & MASK_ACCUMULATE_OUTGOING_ARGS)
       && !optimize_size)
     target_flags |= MASK_ACCUMULATE_OUTGOING_ARGS;
diff --git a/gcc/configure b/gcc/configure
index aa61cd6589c..ad548fc8c08 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -898,6 +898,7 @@ with_system_libunwind
 enable_secureplt
 enable_leading_mingw64_underscores
 enable_cld
+enable_frame_pointer
 enable_win32_registry
 enable_static
 with_pic
@@ -1597,6 +1598,7 @@ Optional Features:
   --enable-leading-mingw64-underscores
                           Enable leading underscores on 64 bit mingw targets
   --enable-cld            enable -mcld by default for 32bit x86
+  --enable-frame-pointer  enable -fno-omit-frame-pointer by default for 32bit x86
   --disable-win32-registry
                           disable lookup of installation paths in the
                           Registry on Windows hosts
@@ -10708,6 +10710,24 @@ else
 fi
 
 
+# Check whether --enable-frame-pointer was given.
+if test "${enable_frame_pointer+set}" = set; then :
+  enableval=$enable_frame_pointer;
+else
+
+case $target_os in
+linux*)
+  # Enable -fomit-frame-pointer by default for Linux.
+  enable_frame_pointer=no
+  ;;
+*)
+  enable_frame_pointer=yes
+  ;;
+esac
+
+fi
+
+
 # Windows32 Registry support for specifying GCC installation paths.
 # Check whether --enable-win32-registry was given.
 if test "${enable_win32_registry+set}" = set; then :
@@ -17109,7 +17129,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 17112 "configure"
+#line 17132 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -17215,7 +17235,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 17218 "configure"
+#line 17238 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 24d38aa73c3..dd0b1984c9f 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -1580,6 +1580,20 @@ AC_ARG_ENABLE(cld,
 [  --enable-cld            enable -mcld by default for 32bit x86], [],
 [enable_cld=no])
 
+AC_ARG_ENABLE(frame-pointer,
+[  --enable-frame-pointer  enable -fno-omit-frame-pointer by default for 32bit x86], [],
+[
+case $target_os in
+linux*)
+  # Enable -fomit-frame-pointer by default for Linux.
+  enable_frame_pointer=no
+  ;;
+*)
+  enable_frame_pointer=yes
+  ;;
+esac
+])
+
 # Windows32 Registry support for specifying GCC installation paths.
 AC_ARG_ENABLE(win32-registry,
 [  --disable-win32-registry