Fix register elimination problem

From-SVN: r30134

gcc/ChangeLog

+Fri Oct 22 23:46:50 1999  Bernd Schmidt  <bernds@cygnus.co.uk>
+
+	* genoutput.c (struct operand_data): New elt eliminable.
+	(output_operand_data): Write it.
+	(scan_operands): Set it for MATCH_OPERAND, clear for other matchers.
+	(compare_operands): Take it into account.
+	* recog.h (struct insn_operand_data): New elt eliminable.
+	* reload1.c (check_eliminable_occurrences, elimination_effects): New
+	functions.
+	(old_asm_operands_vec, new_asm_operands_vec): Delete.
+	(eliminate_regs): Move code that detects changes to elimination
+	target regs into new function elimination_effects.
+	Delete one #if 0 block.
+	Abort for USE, CLOBBER, ASM_OPERANDS and SET. 
+	(eliminate_regs_in_insn): Return immediately for USEs, CLOBBERs,
+	ADDR_VECs, ADDR_DIFF_VECs and ASM_INPUTs.
+	Only call eliminate_regs for real operands of the insn, not for parts
+	of its structure or parts matched by things like match_operator.
+	Use elimination_effects and check_eliminable_occurrences.  Use
+	copy_insn to duplicate the pattern when not in the final pass.
+
 Fri Oct 22 09:03:44 1999  Mark Mitchell  <mark@codesourcery.com>
 
 	* i386.md: Add missing `y' modifiers to uses of fst, fstp, fld,

gcc/genoutput.c

@@ -65,6 +65,10 @@ Boston, MA 02111-1307, USA.  */
 
      e. `strict_low', is nonzero for operands contained in a STRICT_LOW_PART.
 
+     f. `eliminable', is nonzero for operands that are matched normally by
+     MATCH_OPERAND; it is zero for operands that should not be changed during
+     register elimination such as MATCH_OPERATORs.
+
   The code number of an insn is simply its position in the machine
   description; code numbers are assigned sequentially to entries in
   the description, starting with code number 0.
@@ -128,6 +132,7 @@ struct operand_data
   unsigned char n_alternatives;
   char address_p;
   char strict_low;
+  char eliminable;
   char seen;
 };
 
@@ -287,7 +292,9 @@ output_operand_data ()
 
       printf ("    %smode,\n", GET_MODE_NAME (d->mode));
 
-      printf ("    %d\n", d->strict_low);
+      printf ("    %d,\n", d->strict_low);
+
+      printf ("    %d\n", d->eliminable);
 
       printf("  },\n");
     }
@@ -436,6 +443,7 @@ scan_operands (d, part, this_address_p, this_strict_low)
 	d->operand[opno].n_alternatives
 	  = n_occurrences (',', XSTR (part, 2)) + 1;
       d->operand[opno].address_p = this_address_p;
+      d->operand[opno].eliminable = 1;
       return;
 
     case MATCH_SCRATCH:
@@ -460,6 +468,7 @@ scan_operands (d, part, this_address_p, this_strict_low)
 	d->operand[opno].n_alternatives
 	  = n_occurrences (',', XSTR (part, 1)) + 1;
       d->operand[opno].address_p = 0;
+      d->operand[opno].eliminable = 0;
       return;
 
     case MATCH_OPERATOR:
@@ -482,6 +491,7 @@ scan_operands (d, part, this_address_p, this_strict_low)
       d->operand[opno].predicate = XSTR (part, 1);
       d->operand[opno].constraint = 0;
       d->operand[opno].address_p = 0;
+      d->operand[opno].eliminable = 0;
       for (i = 0; i < XVECLEN (part, 2); i++)
 	scan_operands (d, XVECEXP (part, 2, i), 0, 0);
       return;
@@ -553,6 +563,9 @@ compare_operands (d0, d1)
   if (d0->strict_low != d1->strict_low)
     return 0;
 
+  if (d0->eliminable != d1->eliminable)
+    return 0;
+
   return 1;
 }
 

gcc/recog.h

@@ -209,6 +209,8 @@ struct insn_operand_data
   enum machine_mode mode;
 
   char strict_low;
+
+  char eliminable;
 };
 
 /* Legal values for insn_data.output_format.  Indicate what type of data