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Re: add h8sx support to h8300


Alexandre Oliva <aoliva@redhat.com> writes:
> gcc.c-torture/execute/builtin-setjmp.c.  It *still* fails at -O3
> -fomit-frame-pointer, but not at lower optimization levels, which it
> did before.

Are you sure it's still needed?  Is it possible that whatever was
causing the failure was fixed by another patch?

I tried the attached, both with and without the h8300.md bit,
and it didn't make any difference to the results for this testcase.
Like you say, -O3 -fomit-frame-pointer fails either way.

FWIW, the test pattern was h8300-sim{-msx}{,-mn}.

I just remember this making quite a big difference to quality of the
output, but it was over a year ago, so perhaps I'm misremembering,
or perhaps it doesn't make as much difference now.

Richard


Index: config/h8300/h8300.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/h8300/h8300.c,v
retrieving revision 1.290
diff -u -p -F^\([(a-zA-Z0-9_]\|#define\) -r1.290 h8300.c
--- config/h8300/h8300.c	8 Jul 2004 03:40:31 -0000	1.290
+++ config/h8300/h8300.c	8 Jul 2004 08:37:36 -0000
@@ -454,16 +454,12 @@ h8300_init_once (void)
        before reload so that register allocator will pick the second
        alternative.
 
-     - we would like 'D' to be be NO_REGS when the frame pointer isn't
-       live, but we the frame pointer may turn out to be needed after
-       we start reload, and then we may have already decided we don't
-       have a choice, so we can't do that.  Forcing the register
-       allocator to use er6 if possible might produce better code for
-       small functions: it's more efficient to save and restore er6 in
-       the prologue & epilogue than to do it in a define_split.
-       Hopefully disparaging 'D' will have a similar effect, without
-       forcing a reload failure if the frame pointer is found to be
-       needed too late.  */
+     - 'D' should be NO_REGS when the frame pointer isn't live.
+       The idea is to *make* it live by restricting the register allocator
+       to the first alternative.   This isn't needed for correctness
+       but it produces better code for small functions: it's more
+       efficient to save and restore er6 in the prologue & epilogue
+       than to do it in a define_split.  */
 
 enum reg_class
 h8300_reg_class_from_letter (int c)
@@ -484,8 +480,8 @@ h8300_reg_class_from_letter (int c)
       return DESTINATION_REGS;
 
     case 'D':
-      /* The meaning of a constraint shouldn't change dynamically, so
-	 we can't make this NO_REGS.  */
+      if (!regs_ever_live[FP_REG])
+	return NO_REGS;
       return GENERAL_REGS;
 
     case 'f':
@@ -3051,10 +3047,6 @@ h8300_swap_into_er6 (rtx addr)
 {
   push (HARD_FRAME_POINTER_REGNUM);
   emit_move_insn (hard_frame_pointer_rtx, addr);
-  if (REGNO (addr) == SP_REG)
-    emit_move_insn (hard_frame_pointer_rtx,
-		    plus_constant (hard_frame_pointer_rtx,
-				   GET_MODE_SIZE (word_mode)));
 }
 
 /* Move the current value of er6 into ADDR and pop its old value
@@ -3063,8 +3055,7 @@ h8300_swap_into_er6 (rtx addr)
 void
 h8300_swap_out_of_er6 (rtx addr)
 {
-  if (REGNO (addr) != SP_REG)
-    emit_move_insn (addr, hard_frame_pointer_rtx);
+  emit_move_insn (addr, hard_frame_pointer_rtx);
   pop (HARD_FRAME_POINTER_REGNUM);
 }
 
Index: config/h8300/h8300.md
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/h8300/h8300.md,v
retrieving revision 1.286
diff -u -p -F^\([(a-zA-Z0-9_]\|#define\) -r1.286 h8300.md
--- config/h8300/h8300.md	8 Jul 2004 03:40:33 -0000	1.286
+++ config/h8300/h8300.md	8 Jul 2004 08:37:37 -0000
@@ -574,7 +574,7 @@ (define_insn "movmd_internal_normal"
 	(mem:BLK (match_operand:HI 4 "register_operand" "1,1")))
    (unspec [(match_operand:HI 5 "register_operand" "2,2")
 	    (match_operand:HI 6 "const_int_operand" "n,n")] UNSPEC_MOVMD)
-   (clobber (match_operand:HI 0 "register_operand" "=d,??D"))
+   (clobber (match_operand:HI 0 "register_operand" "=d,!D"))
    (clobber (match_operand:HI 1 "register_operand" "=f,f"))
    (set (match_operand:HI 2 "register_operand" "=c,c")
 	(const_int 0))]
@@ -591,7 +591,7 @@ (define_insn "movmd_internal"
 	(mem:BLK (match_operand:SI 4 "register_operand" "1,1")))
    (unspec [(match_operand:HI 5 "register_operand" "2,2")
 	    (match_operand:HI 6 "const_int_operand" "n,n")] UNSPEC_MOVMD)
-   (clobber (match_operand:SI 0 "register_operand" "=d,??D"))
+   (clobber (match_operand:SI 0 "register_operand" "=d,!D"))
    (clobber (match_operand:SI 1 "register_operand" "=f,f"))
    (set (match_operand:HI 2 "register_operand" "=c,c")
 	(const_int 0))]
@@ -702,7 +702,7 @@ (define_insn "stpcpy_internal_normal"
   [(set (mem:BLK (match_operand:HI 3 "register_operand" "0,r"))
 	(unspec:BLK [(mem:BLK (match_operand:HI 4 "register_operand" "1,1"))]
 		UNSPEC_STPCPY))
-   (clobber (match_operand:HI 0 "register_operand" "=d,??D"))
+   (clobber (match_operand:HI 0 "register_operand" "=d,!D"))
    (clobber (match_operand:HI 1 "register_operand" "=f,f"))
    (clobber (match_operand:HI 2 "register_operand" "=c,c"))]
   "TARGET_H8300SX && TARGET_NORMAL_MODE"
@@ -716,7 +716,7 @@ (define_insn "stpcpy_internal"
   [(set (mem:BLK (match_operand:SI 3 "register_operand" "0,r"))
 	(unspec:BLK [(mem:BLK (match_operand:SI 4 "register_operand" "1,1"))]
 		UNSPEC_STPCPY))
-   (clobber (match_operand:SI 0 "register_operand" "=d,??D"))
+   (clobber (match_operand:SI 0 "register_operand" "=d,!D"))
    (clobber (match_operand:SI 1 "register_operand" "=f,f"))
    (clobber (match_operand:SI 2 "register_operand" "=c,c"))]
   "TARGET_H8300SX && !TARGET_NORMAL_MODE"


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