re PR middle-end/30191 (GCC error: in eliminate_regs_in_insn, at reload1.c:3126)

        PR middle-end/30191
        Revert:
        * reload1.c (eliminate_regs_in_insn): Merge the plus_src "else" and
        the offset == 0 "then" clauses.
        * config/rs6000/predicates.md (gpc_reg_operand): Check for
        reload_in_progress.

From-SVN: r119844

gcc/ChangeLog

+2006-12-13  Peter Bergner  <bergner@vnet.ibm.com>
+
+	PR middle-end/30191
+	Revert:
+	* reload1.c (eliminate_regs_in_insn): Merge the plus_src "else" and
+	the offset == 0 "then" clauses.
+	* config/rs6000/predicates.md (gpc_reg_operand): Check for
+	reload_in_progress.
+
 2006-12-13  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386.h (FIRST_PSEUDO_REGISTER): Define to 53.

gcc/config/rs6000/predicates.md

@@ -81,13 +81,10 @@
   (and (match_code "const_int")
        (match_test "INTVAL (op) > 0 && exact_log2 (INTVAL (op)) >= 0")))
 
-;; Return 1 if op is a register that is not special.  We accept anything
-;; during reload_in_progress since eliminate_regs_in_insn() sometimes
-;; creates invalid insns which will be fixed up later in reload.
+;; Return 1 if op is a register that is not special.
 (define_predicate "gpc_reg_operand"
    (and (match_operand 0 "register_operand")
-	(match_test "(reload_in_progress
-		      || GET_CODE (op) != REG
+	(match_test "(GET_CODE (op) != REG
 		      || (REGNO (op) >= ARG_POINTER_REGNUM
 			  && !XER_REGNO_P (REGNO (op)))
 		      || REGNO (op) < MQ_REGNO)

gcc/reload1.c

@@ -3098,12 +3098,7 @@ eliminate_regs_in_insn (rtx insn, int replace)
 	    if (GET_CODE (XEXP (plus_cst_src, 0)) == SUBREG)
 	      to_rtx = gen_lowpart (GET_MODE (XEXP (plus_cst_src, 0)),
 				    to_rtx);
-	    /* If we have a nonzero offset, and the source is already
-	       a simple REG, the following transformation would
-	       increase the cost of the insn by replacing a simple REG
-	       with (plus (reg sp) CST).  So try only when we already
-	       had a PLUS before.  */
-	    if (offset == 0 || plus_src)
+	    if (offset == 0)
 	      {
 		int num_clobbers;
 		/* We assume here that if we need a PARALLEL with
@@ -3112,7 +3107,7 @@ eliminate_regs_in_insn (rtx insn, int replace)
 		   There's not much we can do if that doesn't work.  */
 		PATTERN (insn) = gen_rtx_SET (VOIDmode,
 					      SET_DEST (old_set),
-					      plus_constant (to_rtx, offset));
+					      to_rtx);
 		num_clobbers = 0;
 		INSN_CODE (insn) = recog (PATTERN (insn), insn, &num_clobbers);
 		if (num_clobbers)
@@ -3125,6 +3120,26 @@ eliminate_regs_in_insn (rtx insn, int replace)
 		  }
 		gcc_assert (INSN_CODE (insn) >= 0);
 	      }
+	    /* If we have a nonzero offset, and the source is already
+	       a simple REG, the following transformation would
+	       increase the cost of the insn by replacing a simple REG
+	       with (plus (reg sp) CST).  So try only when we already
+	       had a PLUS before.  */
+	    else if (plus_src)
+	      {
+		new_body = old_body;
+		if (! replace)
+		  {
+		    new_body = copy_insn (old_body);
+		    if (REG_NOTES (insn))
+		      REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
+		  }
+		PATTERN (insn) = new_body;
+		old_set = single_set (insn);
+
+		XEXP (SET_SRC (old_set), 0) = to_rtx;
+		XEXP (SET_SRC (old_set), 1) = GEN_INT (offset);
+	      }
 	    else
 	      break;