jump.c (jump_optimize_1): The first operand in a relational can be a CONST_INT.

        * jump.c (jump_optimize_1): The first operand in a relational
        can be a CONST_INT.
        * optabs.c (emit_conditional_move): Handle relationals which
        have a known true/false result.

From-SVN: r31929

gcc/ChangeLog

+Feb 11 12:30:53 2000  Jeffrey A Law  (law@cygnus.com)
+
+	* jump.c (jump_optimize_1): The first operand in a relational
+	can be a CONST_INT.
+	* optabs.c (emit_conditional_move): Handle relationals which
+	have a known true/false result.
+
 2000-02-11  Geoff Keating  <geoffk@cygnus.com>
 
 	* function.c (thread_prologue_and_epilogue_insns): Don't insert

gcc/jump.c

@@ -1305,10 +1305,16 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
 		   insn?  After all, we're going to delete it.  We'd have
 		   to modify emit_conditional_move to take a comparison rtx
 		   instead or write a new function.  */
-		cond0 = gen_reg_rtx (GET_MODE (XEXP (temp4, 0)));
+
 		/* We want the target to be able to simplify comparisons with
 		   zero (and maybe other constants as well), so don't create
 		   pseudos for them.  There's no need to either.  */
+		if (GET_CODE (XEXP (temp4, 0)) == CONST_INT
+		    || GET_CODE (XEXP (temp4, 0)) == CONST_DOUBLE)
+		  cond0 = XEXP (temp4, 0);
+		else
+		  cond0 = gen_reg_rtx (GET_MODE (XEXP (temp4, 0)));
+
 		if (GET_CODE (XEXP (temp4, 1)) == CONST_INT
 		    || GET_CODE (XEXP (temp4, 1)) == CONST_DOUBLE)
 		  cond1 = XEXP (temp4, 1);

gcc/optabs.c

@@ -3593,9 +3593,11 @@ emit_conditional_move (target, code, op0, op1, cmode, op2, op3, mode,
     = compare_from_rtx (op0, op1, code, unsignedp, cmode, NULL_RTX, 0);
 
   /* ??? Watch for const0_rtx (nop) and const_true_rtx (unconditional)?  */
+  /* We can get const0_rtx or const_true_rtx in some circumstances.  Just
+     return NULL and let the caller figure out how best to deal with this
+     situation.  */
   if (GET_CODE (comparison) != code)
-    /* This shouldn't happen.  */
-    abort ();
+    return NULL_RTX;
   
   insn = GEN_FCN (icode) (subtarget, comparison, op2, op3);