--- a/aclocal.m4
+++ b/aclocal.m4
@@ -11,17 +11,16 @@ builtin(include, build/autoconf/pkg.m4)d
 builtin(include, build/autoconf/freetype2.m4)dnl
 builtin(include, build/autoconf/codeset.m4)dnl
 builtin(include, build/autoconf/altoptions.m4)dnl
 builtin(include, build/autoconf/mozprog.m4)dnl
 builtin(include, build/autoconf/mozheader.m4)dnl
 builtin(include, build/autoconf/acwinpaths.m4)dnl
 builtin(include, build/autoconf/lto.m4)dnl
 builtin(include, build/autoconf/gcc-pr49911.m4)dnl
-builtin(include, build/autoconf/frameptr.m4)dnl
 
 MOZ_PROG_CHECKMSYS()
 
 # Read the user's .mozconfig script.  We can't do this in
 # configure.in: autoconf puts the argument parsing code above anything
 # expanded from configure.in, and we need to get the configure options
 # from .mozconfig in place before that argument parsing code.
 MOZ_READ_MOZCONFIG(.)

--- a/config/autoconf.mk.in
+++ b/config/autoconf.mk.in
@@ -298,17 +298,16 @@ OS_COMPILE_CXXFLAGS = $(OS_CPPFLAGS) @CO
 
 OS_INCLUDES	= $(NSPR_CFLAGS) $(NSS_CFLAGS) $(JPEG_CFLAGS) $(PNG_CFLAGS) $(ZLIB_CFLAGS)
 OS_LIBS		= @LIBS@
 ACDEFINES	= @MOZ_DEFINES@
 
 WARNINGS_AS_ERRORS = @WARNINGS_AS_ERRORS@
 
 MOZ_OPTIMIZE	= @MOZ_OPTIMIZE@
-MOZ_FRAMEPTR_FLAGS = @MOZ_FRAMEPTR_FLAGS@
 MOZ_OPTIMIZE_FLAGS = @MOZ_OPTIMIZE_FLAGS@
 MOZ_PGO_OPTIMIZE_FLAGS = @MOZ_PGO_OPTIMIZE_FLAGS@
 MOZ_OPTIMIZE_LDFLAGS = @MOZ_OPTIMIZE_LDFLAGS@
 MOZ_OPTIMIZE_SIZE_TWEAK = @MOZ_OPTIMIZE_SIZE_TWEAK@
 
 MOZ_RTTI_FLAGS_ON = @_MOZ_RTTI_FLAGS_ON@
 MOZ_EXCEPTIONS_FLAGS_ON = @_MOZ_EXCEPTIONS_FLAGS_ON@
 

--- a/config/config.mk
+++ b/config/config.mk
@@ -458,19 +458,16 @@ else
 HOST_CFLAGS	+= $(MOZ_OPTIMIZE_FLAGS)
 endif # MODULE_OPTIMIZE_FLAGS
 else
 HOST_CFLAGS	+= $(MOZ_OPTIMIZE_FLAGS)
 endif # MOZ_OPTIMIZE == 1
 endif # MOZ_OPTIMIZE
 endif # CROSS_COMPILE
 
-CFLAGS += $(MOZ_FRAMEPTR_FLAGS)
-CXXFLAGS += $(MOZ_FRAMEPTR_FLAGS)
-
 # Check for FAIL_ON_WARNINGS & FAIL_ON_WARNINGS_DEBUG (Shorthand for Makefiles
 # to request that we use the 'warnings as errors' compile flags)
 
 # NOTE: First, we clear FAIL_ON_WARNINGS[_DEBUG] if we're doing a Windows PGO
 # build, since WARNINGS_AS_ERRORS has been suspected of causing isuses in that
 # situation. (See bug 437002.)
 ifeq (WINNT_1,$(OS_ARCH)_$(MOZ_PROFILE_GENERATE)$(MOZ_PROFILE_USE))
 FAIL_ON_WARNINGS_DEBUG=

--- a/configure.in
+++ b/configure.in
@@ -2066,17 +2066,22 @@ case "$target" in
 	    MKSHLIB_UNFORCE_ALL=''
 	;;
     esac
     ;;
 
 *-darwin*)
     MKSHLIB='$(CXX) $(CXXFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -o $@'
     MKCSHLIB='$(CC) $(CFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -o $@'
-    MOZ_OPTIMIZE_FLAGS="-O3"
+    # If we're building with --enable-profiling, we need a frame pointer.
+    if test -z "$MOZ_PROFILING"; then
+        MOZ_OPTIMIZE_FLAGS="-O3 -fomit-frame-pointer"
+    else
+        MOZ_OPTIMIZE_FLAGS="-O3 -fno-omit-frame-pointer"
+    fi
     _PEDANTIC=
     CFLAGS="$CFLAGS -fno-common"
     CXXFLAGS="$CXXFLAGS -fno-common"
     DLL_SUFFIX=".dylib"
     DSO_LDOPTS=''
     STRIP="$STRIP -x -S"
     # Check whether we're targeting OS X or iOS
     AC_CACHE_CHECK(for iOS target,
@@ -2178,17 +2183,22 @@ ia64*-hpux*)
 
 *-android*|*-linuxandroid*)
     AC_DEFINE(NO_PW_GECOS)
     no_x=yes
     _PLATFORM_DEFAULT_TOOLKIT=cairo-android
     TARGET_NSPR_MDCPUCFG='\"md/_linux.cfg\"'
 
     MOZ_GFX_OPTIMIZE_MOBILE=1
-    MOZ_OPTIMIZE_FLAGS="-Os -freorder-blocks -fno-reorder-functions"
+    # If we're building with --enable-profiling, we need a frame pointer.
+    if test -z "$MOZ_PROFILING"; then
+        MOZ_OPTIMIZE_FLAGS="-Os -freorder-blocks -fno-reorder-functions -fomit-frame-pointer"
+    else
+        MOZ_OPTIMIZE_FLAGS="-Os -freorder-blocks -fno-reorder-functions -fno-omit-frame-pointer"
+    fi
     ;;
 
 *-*linux*)
     # Note: both GNU_CC and INTEL_CC are set when using Intel's C compiler.
     # Similarly for GNU_CXX and INTEL_CXX.
     if test "$INTEL_CC" -o "$INTEL_CXX"; then
         # -Os has been broken on Intel's C/C++ compilers for quite a
         # while; Intel recommends against using it.
@@ -2196,18 +2206,24 @@ ia64*-hpux*)
         MOZ_DEBUG_FLAGS="-g"
     elif test "$GNU_CC" -o "$GNU_CXX"; then
         GCC_VERSION=`$CC -v 2>&1 | awk '/^gcc version/ { print $3 }'`
         case $GCC_VERSION in
         4.1.*|4.2.*|4.5.*)
             # -Os is broken on gcc 4.1.x 4.2.x, 4.5.x we need to tweak it to get good results.
             MOZ_OPTIMIZE_SIZE_TWEAK="-finline-limit=50"
         esac
-        MOZ_PGO_OPTIMIZE_FLAGS="-O3"
-        MOZ_OPTIMIZE_FLAGS="-Os -freorder-blocks $MOZ_OPTIMIZE_SIZE_TWEAK"
+        # If we're building with --enable-profiling, we need a frame pointer.
+        if test -z "$MOZ_PROFILING"; then
+            MOZ_FRAMEPTR_FLAGS="-fomit-frame-pointer"
+        else
+            MOZ_FRAMEPTR_FLAGS="-fno-omit-frame-pointer"
+        fi
+        MOZ_PGO_OPTIMIZE_FLAGS="-O3 $MOZ_FRAMEPTR_FLAGS"
+        MOZ_OPTIMIZE_FLAGS="-Os -freorder-blocks $MOZ_OPTIMIZE_SIZE_TWEAK $MOZ_FRAMEPTR_FLAGS"
         MOZ_DEBUG_FLAGS="-g"
     fi
 
     TARGET_NSPR_MDCPUCFG='\"md/_linux.cfg\"'
 
     MOZ_MEMORY=1
 
     case "${target_cpu}" in
@@ -2294,17 +2310,22 @@ ia64*-hpux*)
         CXXFLAGS="$CXXFLAGS -wd4800" # disable warning "forcing value to bool"
         # make 'foo == bar;' error out
         CFLAGS="$CFLAGS -we4553"
         CXXFLAGS="$CXXFLAGS -we4553"
         LIBS="$LIBS kernel32.lib user32.lib gdi32.lib winmm.lib wsock32.lib advapi32.lib"
         MOZ_DEBUG_FLAGS='-Zi'
         MOZ_DEBUG_LDFLAGS='-DEBUG -DEBUGTYPE:CV'
         WARNINGS_AS_ERRORS='-WX'
-        MOZ_OPTIMIZE_FLAGS='-O1'
+        # If we're building with --enable-profiling, we need -Oy-, which forces a frame pointer.
+        if test -z "$MOZ_PROFILING"; then
+            MOZ_OPTIMIZE_FLAGS='-O1'
+        else
+            MOZ_OPTIMIZE_FLAGS='-O1 -Oy-'
+        fi
         MOZ_FIX_LINK_PATHS=
         DYNAMIC_XPCOM_LIBS='$(LIBXUL_DIST)/lib/xpcom.lib $(LIBXUL_DIST)/lib/xpcom_core.lib $(LIBXUL_DIST)/lib/mozalloc.lib'
         XPCOM_FROZEN_LDOPTS='$(LIBXUL_DIST)/lib/xpcom.lib $(LIBXUL_DIST)/lib/mozalloc.lib'
         LIBXUL_LIBS='$(LIBXUL_DIST)/lib/xpcom.lib $(LIBXUL_DIST)/lib/xul.lib $(LIBXUL_DIST)/lib/mozalloc.lib'
         MOZ_COMPONENT_NSPR_LIBS='$(NSPR_LIBS)'
         if test $_MSC_VER -ge 1400; then
             LDFLAGS="$LDFLAGS -LARGEADDRESSAWARE -NXCOMPAT"
             dnl For profile-guided optimization
@@ -6871,18 +6892,16 @@ MOZ_ARG_ENABLE_STRING(optimize,
     if test -n "$enableval" -a "$enableval" != "yes"; then
         MOZ_OPTIMIZE_FLAGS=`echo "$enableval" | sed -e 's|\\\ | |g'`
         MOZ_OPTIMIZE=2
     fi
 else
     MOZ_OPTIMIZE=
 fi ], MOZ_OPTIMIZE=1)
 
-MOZ_SET_FRAMEPTR_FLAGS
-
 if test "$COMPILE_ENVIRONMENT"; then
 if test -n "$MOZ_OPTIMIZE"; then
     AC_MSG_CHECKING([for valid optimization flags])
     _SAVE_CFLAGS=$CFLAGS
     CFLAGS="$CFLAGS $MOZ_OPTIMIZE_FLAGS"
     AC_TRY_COMPILE([#include <stdio.h>],
         [printf("Hello World\n");],
         _results=yes,
@@ -6891,17 +6910,16 @@ if test -n "$MOZ_OPTIMIZE"; then
     if test "$_results" = "no"; then
         AC_MSG_ERROR([These compiler flags are invalid: $MOZ_OPTIMIZE_FLAGS])
     fi
     CFLAGS=$_SAVE_CFLAGS
 fi
 fi # COMPILE_ENVIRONMENT
 
 AC_SUBST(MOZ_OPTIMIZE)
-AC_SUBST(MOZ_FRAMEPTR_FLAGS)
 AC_SUBST(MOZ_OPTIMIZE_FLAGS)
 AC_SUBST(MOZ_OPTIMIZE_LDFLAGS)
 AC_SUBST(MOZ_OPTIMIZE_SIZE_TWEAK)
 AC_SUBST(MOZ_PGO_OPTIMIZE_FLAGS)
 
 dnl ========================================================
 dnl = Enable generation of debug symbols
 dnl ========================================================

--- a/js/src/aclocal.m4
+++ b/js/src/aclocal.m4
@@ -6,11 +6,10 @@ dnl
 builtin(include, build/autoconf/pkg.m4)dnl
 builtin(include, build/autoconf/nspr.m4)dnl
 builtin(include, build/autoconf/altoptions.m4)dnl
 builtin(include, build/autoconf/moznbytetype.m4)dnl
 builtin(include, build/autoconf/mozprog.m4)dnl
 builtin(include, build/autoconf/acwinpaths.m4)dnl
 builtin(include, build/autoconf/lto.m4)dnl
 builtin(include, build/autoconf/gcc-pr49911.m4)dnl
-builtin(include, build/autoconf/frameptr.m4)dnl
 
 MOZ_PROG_CHECKMSYS()

deleted file mode 100644
--- a/js/src/build/autoconf/frameptr.m4
+++ /dev/null
@@ -1,25 +0,0 @@
-dnl Set MOZ_FRAMEPTR_FLAGS to the flags that should be used for enabling or
-dnl disabling frame pointers in this architecture based on the configure
-dnl options
-
-AC_DEFUN([MOZ_SET_FRAMEPTR_FLAGS], [
-  if test "$GNU_CC"; then
-    MOZ_ENABLE_FRAME_PTR="-fno-omit-frame-pointer"
-    MOZ_DISABLE_FRAME_PTR="-fomit-frame-pointer"
-  else
-    case "$target" in
-    *-mingw*)
-      MOZ_ENABLE_FRAME_PTR="-Oy-"
-      MOZ_DISABLE_FRAME_PTR="-Oy"
-    ;;
-    esac
-  fi
-
-  # if we are debugging or profiling, we want a frame pointer.
-  if test -z "$MOZ_OPTIMIZE" -o \
-          -n "$MOZ_PROFILING" -o -n "$MOZ_DEBUG"; then
-    MOZ_FRAMEPTR_FLAGS="$MOZ_ENABLE_FRAME_PTR"
-  else
-    MOZ_FRAMEPTR_FLAGS="$MOZ_DISABLE_FRAME_PTR"
-  fi
-])

--- a/js/src/config/autoconf.mk.in
+++ b/js/src/config/autoconf.mk.in
@@ -138,17 +138,16 @@ OS_COMPILE_CXXFLAGS = $(OS_CPPFLAGS) @CO
 OS_INCLUDES	= $(NSPR_CFLAGS)
 OS_LIBS		= @LIBS@
 ACDEFINES	= @MOZ_DEFINES@
 
 WARNINGS_AS_ERRORS = @WARNINGS_AS_ERRORS@
 FAIL_ON_WARNINGS = @FAIL_ON_WARNINGS@
 
 MOZ_OPTIMIZE	= @MOZ_OPTIMIZE@
-MOZ_FRAMEPTR_FLAGS = @MOZ_FRAMEPTR_FLAGS@
 MOZ_OPTIMIZE_FLAGS = @MOZ_OPTIMIZE_FLAGS@
 MOZ_PGO_OPTIMIZE_FLAGS = @MOZ_PGO_OPTIMIZE_FLAGS@
 MOZ_OPTIMIZE_LDFLAGS = @MOZ_OPTIMIZE_LDFLAGS@
 MOZ_OPTIMIZE_SIZE_TWEAK = @MOZ_OPTIMIZE_SIZE_TWEAK@
 
 MOZ_RTTI_FLAGS_ON = @_MOZ_RTTI_FLAGS_ON@
 MOZ_EXCEPTIONS_FLAGS_ON = @_MOZ_EXCEPTIONS_FLAGS_ON@
 

--- a/js/src/config/config.mk
+++ b/js/src/config/config.mk
@@ -458,19 +458,16 @@ else
 HOST_CFLAGS	+= $(MOZ_OPTIMIZE_FLAGS)
 endif # MODULE_OPTIMIZE_FLAGS
 else
 HOST_CFLAGS	+= $(MOZ_OPTIMIZE_FLAGS)
 endif # MOZ_OPTIMIZE == 1
 endif # MOZ_OPTIMIZE
 endif # CROSS_COMPILE
 
-CFLAGS += $(MOZ_FRAMEPTR_FLAGS)
-CXXFLAGS += $(MOZ_FRAMEPTR_FLAGS)
-
 # Check for FAIL_ON_WARNINGS & FAIL_ON_WARNINGS_DEBUG (Shorthand for Makefiles
 # to request that we use the 'warnings as errors' compile flags)
 
 # NOTE: First, we clear FAIL_ON_WARNINGS[_DEBUG] if we're doing a Windows PGO
 # build, since WARNINGS_AS_ERRORS has been suspected of causing isuses in that
 # situation. (See bug 437002.)
 ifeq (WINNT_1,$(OS_ARCH)_$(MOZ_PROFILE_GENERATE)$(MOZ_PROFILE_USE))
 FAIL_ON_WARNINGS_DEBUG=

--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -1967,17 +1967,23 @@ case "$target" in
 	    MKSHLIB_UNFORCE_ALL=''
 	;;
     esac
     ;;
 
 *-darwin*)
     MKSHLIB='$(CXX) $(CXXFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -o $@'
     MKCSHLIB='$(CC) $(CFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -o $@'
-    MOZ_OPTIMIZE_FLAGS="-O3 -fno-stack-protector"
+    # If we're building with --enable-profiling, we need a frame pointer.
+    if test -z "$MOZ_PROFILING"; then
+        MOZ_FRAMEPTR_FLAGS="-fomit-frame-pointer"
+    else
+        MOZ_FRAMEPTR_FLAGS="-fno-omit-frame-pointer"
+    fi
+    MOZ_OPTIMIZE_FLAGS="-O3 $MOZ_FRAMEPTR_FLAGS -fno-stack-protector"
     _PEDANTIC=
     CFLAGS="$CFLAGS -fpascal-strings -fno-common"
     CXXFLAGS="$CXXFLAGS -fpascal-strings -fno-common"
     DLL_SUFFIX=".dylib"
     DSO_LDOPTS=''
     STRIP="$STRIP -x -S"
     _PLATFORM_DEFAULT_TOOLKIT='cairo-cocoa'
     TARGET_NSPR_MDCPUCFG='\"md/_darwin.cfg\"'
@@ -2072,17 +2078,23 @@ ia64*-hpux*)
 
 *-android*|*-linuxandroid*)
     AC_DEFINE(NO_PW_GECOS)
     no_x=yes
     _PLATFORM_DEFAULT_TOOLKIT=cairo-android
     TARGET_NSPR_MDCPUCFG='\"md/_linux.cfg\"'
 
     MOZ_GFX_OPTIMIZE_MOBILE=1
-    MOZ_OPTIMIZE_FLAGS="-O3 -freorder-blocks -fno-reorder-functions"
+    # If we're building with --enable-profiling, we need a frame pointer.
+    if test -z "$MOZ_PROFILING"; then
+        MOZ_FRAMEPTR_FLAGS="-fomit-frame-pointer"
+    else
+        MOZ_FRAMEPTR_FLAGS="-fno-omit-frame-pointer"
+    fi
+    MOZ_OPTIMIZE_FLAGS="-O3 -freorder-blocks -fno-reorder-functions $MOZ_FRAMEPTR_FLAGS"
     # The Maemo builders don't know about this flag
     MOZ_ARM_VFP_FLAGS="-mfpu=vfp"
     ;;
 
 *-*linux*)
     # Note: both GNU_CC and INTEL_CC are set when using Intel's C compiler.
     # Similarly for GNU_CXX and INTEL_CXX.
     if test "$INTEL_CC" -o "$INTEL_CXX"; then
@@ -2092,18 +2104,24 @@ ia64*-hpux*)
         MOZ_DEBUG_FLAGS="-g"
     elif test "$GNU_CC" -o "$GNU_CXX"; then
         GCC_VERSION=`$CC -v 2>&1 | awk '/^gcc version/ { print $3 }'`
         case $GCC_VERSION in
         4.1.*|4.2.*|4.5.*)
             # -Os is broken on gcc 4.1.x 4.2.x, 4.5.x we need to tweak it to get good results.
             MOZ_OPTIMIZE_SIZE_TWEAK="-finline-limit=50"
         esac
-        MOZ_PGO_OPTIMIZE_FLAGS="-O3"
-        MOZ_OPTIMIZE_FLAGS="-O3 -freorder-blocks $MOZ_OPTIMIZE_SIZE_TWEAK"
+        # If we're building with --enable-profiling, we need a frame pointer.
+        if test -z "$MOZ_PROFILING"; then
+            MOZ_FRAMEPTR_FLAGS="-fomit-frame-pointer"
+        else
+            MOZ_FRAMEPTR_FLAGS="-fno-omit-frame-pointer"
+        fi
+        MOZ_PGO_OPTIMIZE_FLAGS="-O3 $MOZ_FRAMEPTR_FLAGS"
+        MOZ_OPTIMIZE_FLAGS="-O3 -freorder-blocks $MOZ_OPTIMIZE_SIZE_TWEAK $MOZ_FRAMEPTR_FLAGS"
         MOZ_DEBUG_FLAGS="-g"
     fi
 
     TARGET_NSPR_MDCPUCFG='\"md/_linux.cfg\"'
 
     case "${target_cpu}" in
     alpha*)
     	CFLAGS="$CFLAGS -mieee"
@@ -2213,17 +2231,23 @@ ia64*-hpux*)
         CXXFLAGS="$CXXFLAGS -wd4244 -wd4800"
         # make 'foo == bar;' error out
         CFLAGS="$CFLAGS -we4553"
         CXXFLAGS="$CXXFLAGS -we4553"
         LIBS="$LIBS kernel32.lib user32.lib gdi32.lib winmm.lib wsock32.lib advapi32.lib"
         MOZ_DEBUG_FLAGS='-Zi'
         MOZ_DEBUG_LDFLAGS='-DEBUG -DEBUGTYPE:CV'
         WARNINGS_AS_ERRORS='-WX'
-        MOZ_OPTIMIZE_FLAGS="-O2"
+        # If we're building with --enable-profiling, we need -Oy-, which forces a frame pointer.
+        if test -z "$MOZ_PROFILING"; then
+            MOZ_FRAMEPTR_FLAGS=
+        else
+            MOZ_FRAMEPTR_FLAGS='-Oy-'
+        fi
+        MOZ_OPTIMIZE_FLAGS="-O2 $MOZ_FRAMEPTR_FLAGS"
         MOZ_JS_LIBS='$(libdir)/mozjs.lib'
         MOZ_FIX_LINK_PATHS=
         DYNAMIC_XPCOM_LIBS='$(LIBXUL_DIST)/lib/xpcom.lib $(LIBXUL_DIST)/lib/xpcom_core.lib $(LIBXUL_DIST)/lib/mozalloc.lib'
         XPCOM_FROZEN_LDOPTS='$(LIBXUL_DIST)/lib/xpcom.lib $(LIBXUL_DIST)/lib/mozalloc.lib'
         LIBXUL_LIBS='$(LIBXUL_DIST)/lib/xpcom.lib $(LIBXUL_DIST)/lib/xul.lib $(LIBXUL_DIST)/lib/mozalloc.lib'
         MOZ_COMPONENT_NSPR_LIBS='$(NSPR_LIBS)'
         if test $_MSC_VER -ge 1400; then
             LDFLAGS="$LDFLAGS -LARGEADDRESSAWARE -NXCOMPAT"
@@ -4364,18 +4388,16 @@ MOZ_ARG_ENABLE_STRING(optimize,
     if test -n "$enableval" -a "$enableval" != "yes"; then
         MOZ_OPTIMIZE_FLAGS=`echo "$enableval" | sed -e 's|\\\ | |g'`
         MOZ_OPTIMIZE=2
     fi
 else
     MOZ_OPTIMIZE=
 fi ], MOZ_OPTIMIZE=1)
 
-MOZ_SET_FRAMEPTR_FLAGS
-
 if test "$COMPILE_ENVIRONMENT"; then
 if test -n "$MOZ_OPTIMIZE"; then
     AC_MSG_CHECKING([for valid optimization flags])
     _SAVE_CFLAGS=$CFLAGS
     CFLAGS="$CFLAGS $MOZ_OPTIMIZE_FLAGS"
     AC_TRY_COMPILE([#include <stdio.h>],
         [printf("Hello World\n");],
         _results=yes,
@@ -4384,17 +4406,16 @@ if test -n "$MOZ_OPTIMIZE"; then
     if test "$_results" = "no"; then
         AC_MSG_ERROR([These compiler flags are invalid: $MOZ_OPTIMIZE_FLAGS])
     fi
     CFLAGS=$_SAVE_CFLAGS
 fi
 fi # COMPILE_ENVIRONMENT
 
 AC_SUBST(MOZ_OPTIMIZE)
-AC_SUBST(MOZ_FRAMEPTR_FLAGS)
 AC_SUBST(MOZ_OPTIMIZE_FLAGS)
 AC_SUBST(MOZ_OPTIMIZE_LDFLAGS)
 AC_SUBST(MOZ_OPTIMIZE_SIZE_TWEAK)
 AC_SUBST(MOZ_PGO_OPTIMIZE_FLAGS)
 
 dnl ========================================================
 dnl = Enable generation of debug symbols
 dnl ========================================================

--- a/xpcom/reflect/xptcall/src/md/unix/Makefile.in
+++ b/xpcom/reflect/xptcall/src/md/unix/Makefile.in
@@ -64,24 +64,20 @@ ifneq (86,$(findstring 86,$(OS_TEST)))
 NO_PROFILE_GUIDED_OPTIMIZE = 1
 endif
 endif
 
 ifeq (Darwin,$(OS_ARCH))
 ifeq (86,$(findstring 86,$(OS_TEST)))
 ifneq (x86_64,$(OS_TEST))
 # If we compile xptcinvoke_unixish_x86.cpp with -fomit-frame-pointer
-# we end up crashing on startup. This is because
-# "movl  %5, %%eax\n\t"   /* function index */
-# becomes
-# mov    0x1c(%esp),%eax
-# but we have modified esp.
-# NOTE: MOZ_FRAMEPTR_FLAGS must be set before including config.mk
-# FIXME: change the file instead of using this hack.
-MOZ_FRAMEPTR_FLAGS=-fno-omit-frame-pointer
+# we end up crashing on startup, presumably because of the %esp munging we do
+# when KEEP_STACK_16_BYTE_ALIGNED.  So let's not use that flag here.
+# NOTE: MODULE_OPTIMIZE_FLAGS must be set before including config.mk
+MODULE_OPTIMIZE_FLAGS=-O3
 endif
 endif
 endif
 
 include $(topsrcdir)/config/config.mk
 
 ######################################################################
 # i386 and beyond