i386.c (ix86_frame_pointer_required): New.

        * config/i386/i386.c (ix86_frame_pointer_required): New.
        (ix86_setup_frame_addresses): New.
        (struct machine_funciton): Add accesses_prev_frame.
        * config/i386/i386.h (FRAME_POINTER_REQUIRED): Call
        ix86_frame_pointer_required.
        (SUBTARGET_FRAME_POINTER_REQUIRED): New.
        (SETUP_FRAME_ADDRESSES): New.
        * config/i386/i386-protos.h: Update.
        * config/i386/sco5.h (SUBTARGET_FRAME_POINTER_REQUIRED): Rename
        from FRAME_POINTER_REQUIRED.
        * config/i386/svr3gas.h: Likewise.
        * config/i386/sysv3.h: Likewise.
        * config/i386/v3gas.h: Likewise.

From-SVN: r39545

gcc/ChangeLog

 2001-02-08  Richard Henderson  <rth@redhat.com>
 
+	* config/i386/i386.c (ix86_frame_pointer_required): New.
+	(ix86_setup_frame_addresses): New.
+	(struct machine_funciton): Add accesses_prev_frame.
+	* config/i386/i386.h (FRAME_POINTER_REQUIRED): Call
+	ix86_frame_pointer_required.
+	(SUBTARGET_FRAME_POINTER_REQUIRED): New.
+	(SETUP_FRAME_ADDRESSES): New.
+	* config/i386/i386-protos.h: Update.
+	* config/i386/sco5.h (SUBTARGET_FRAME_POINTER_REQUIRED): Rename
+	from FRAME_POINTER_REQUIRED.
+	* config/i386/svr3gas.h: Likewise.
+	* config/i386/sysv3.h: Likewise.
+	* config/i386/v3gas.h: Likewise.
+
+2001-02-08  Richard Henderson  <rth@redhat.com>
+
 	* config/sparc/sparc.c (function_arg_record_value_3): Fix
 	calculation of the number of integer registers required.
 	(function_arg_record_value): Likewise.

gcc/config/i386/i386-protos.h

@@ -25,6 +25,8 @@ extern void order_regs_for_local_alloc PARAMS ((void));
 extern void optimization_options PARAMS ((int, int));
 
 extern int ix86_can_use_return_insn_p PARAMS ((void));
+extern int ix86_frame_pointer_required PARAMS ((void));
+extern void ix86_setup_frame_addresses PARAMS ((void));
 
 extern void ix86_asm_file_end PARAMS ((FILE *));
 extern void load_pic_register PARAMS ((void));

gcc/config/i386/i386.c

@@ -331,6 +331,7 @@ struct rtx_def *ix86_compare_op1 = NULL_RTX;
 struct machine_function
 {
   rtx stack_locals[(int) MAX_MACHINE_MODE][MAX_386_STACK_LOCALS];
+  int accesses_prev_frame;
 };
 
 #define ix86_stack_locals (cfun->machine->stack_locals)
@@ -1701,6 +1702,40 @@ ix86_can_use_return_insn_p ()
   return tsize == 0 && nregs == 0;
 }
 
+/* Value should be nonzero if functions must have frame pointers.
+   Zero means the frame pointer need not be set up (and parms may
+   be accessed via the stack pointer) in functions that seem suitable.  */
+
+int
+ix86_frame_pointer_required ()
+{
+  /* If we accessed previous frames, then the generated code expects
+     to be able to access the saved ebp value in our frame.  */
+  if (cfun->machine->accesses_prev_frame)
+    return 1;
+  
+  /* Several x86 os'es need a frame pointer for other reasons,
+     usually pertaining to setjmp.  */
+  if (SUBTARGET_FRAME_POINTER_REQUIRED)
+    return 1;
+
+  /* In override_options, TARGET_OMIT_LEAF_FRAME_POINTER turns off
+     the frame pointer by default.  Turn it back on now if we've not
+     got a leaf function.  */
+  if (TARGET_OMIT_LEAF_FRAME_POINTER && ! leaf_function_p ())
+    return 1;
+
+  return 0;
+}
+
+/* Record that the current function accesses previous call frames.  */
+
+void
+ix86_setup_frame_addresses ()
+{
+  cfun->machine->accesses_prev_frame = 1;
+}
+
 static char pic_label_name[32];
 
 /* This function generates code for -fpic that loads %ebx with

gcc/config/i386/i386.h

@@ -852,7 +852,16 @@ extern int ix86_arch;
    Zero means the frame pointer need not be set up (and parms
    may be accessed via the stack pointer) in functions that seem suitable.
    This is computed in `reload', in reload1.c.  */
-#define FRAME_POINTER_REQUIRED (TARGET_OMIT_LEAF_FRAME_POINTER && !leaf_function_p ()) 	
+#define FRAME_POINTER_REQUIRED  ix86_frame_pointer_required ()
+
+/* Override this in other tm.h files to cope with various OS losage
+   requiring a frame pointer.  */
+#ifndef SUBTARGET_FRAME_POINTER_REQUIRED
+#define SUBTARGET_FRAME_POINTER_REQUIRED 0
+#endif
+
+/* Make sure we can access arbitrary call frames.  */
+#define SETUP_FRAME_ADDRESSES()  ix86_setup_frame_addresses ()
 
 /* Base register for access to arguments of the function.  */
 #define ARG_POINTER_REGNUM 16

gcc/config/i386/sco5.h

@@ -632,8 +632,8 @@ dtors_section ()							\
     }									\
 }
 
-#undef FRAME_POINTER_REQUIRED
-#define FRAME_POINTER_REQUIRED						\
+#undef SUBTARGET_FRAME_POINTER_REQUIRED
+#define SUBTARGET_FRAME_POINTER_REQUIRED				\
   ((TARGET_ELF) ? 0 : 							\
    (current_function_calls_setjmp || current_function_calls_longjmp))
 

gcc/config/i386/svr3gas.h

@@ -37,8 +37,8 @@ Boston, MA 02111-1307, USA.  */
    Since a frame pointer will be required in such a function, it is OK
    that the stack pointer is not restored.  */
 
-#undef FRAME_POINTER_REQUIRED
-#define FRAME_POINTER_REQUIRED \
+#undef SUBTARGET_FRAME_POINTER_REQUIRED
+#define SUBTARGET_FRAME_POINTER_REQUIRED \
   (current_function_calls_setjmp || current_function_calls_longjmp)
 
 /* Modify ASM_OUTPUT_LOCAL slightly to test -msvr3-shlib, adapted to gas  */

gcc/config/i386/sysv3.h

@@ -78,8 +78,8 @@ Boston, MA 02111-1307, USA.  */
    Since a frame pointer will be required in such a function, it is OK
    that the stack pointer is not restored.  */
 
-#undef FRAME_POINTER_REQUIRED
-#define FRAME_POINTER_REQUIRED \
+#undef SUBTARGET_FRAME_POINTER_REQUIRED
+#define SUBTARGET_FRAME_POINTER_REQUIRED \
   (current_function_calls_setjmp || current_function_calls_longjmp)
 
 /* Modify ASM_OUTPUT_LOCAL slightly to test -msvr3-shlib.  */

gcc/config/i386/v3gas.h

@@ -37,8 +37,8 @@ Boston, MA 02111-1307, USA.  */
    Since a frame pointer will be required in such a function, it is OK
    that the stack pointer is not restored.  */
 
-#undef FRAME_POINTER_REQUIRED
-#define FRAME_POINTER_REQUIRED \
+#undef SUBTARGET_FRAME_POINTER_REQUIRED
+#define SUBTARGET_FRAME_POINTER_REQUIRED \
   (current_function_calls_setjmp || current_function_calls_longjmp)
 
 /* Modify ASM_OUTPUT_LOCAL slightly to test -msvr3-shlib, adapted to gas  */