i386.md (neghi2): Do not output prefixed opcode when possible.

	* i386.md (neghi2): Do not output prefixed opcode when possible.
	(ashlhi3): Likewise.

From-SVN: r26433

gcc/ChangeLog

+Wed Apr 14 00:18:22 1999  Jan Hubicka <hubicka@freesoft.cz>
+
+	* i386.md (neghi2): Do not output prefixed opcode when possible.
+	(ashlhi3): Likewise.
+
 Wed Apr 14 00:08:46 1999  Richard Henderson  <rth@cygnus.com>
 
 	* i386.c (memory_address_length): New function.

gcc/config/i386/i386.md

@@ -4721,7 +4721,13 @@ byte_xor_operation:
   [(set (match_operand:HI 0 "nonimmediate_operand" "=rm")
 	(neg:HI (match_operand:HI 1 "nonimmediate_operand" "0")))]
   ""
-  "neg%W0 %0")
+  "*
+    if (REG_P (operands[0]) && i386_cc_probably_useless_p (insn))
+      {
+	CC_STATUS_INIT;
+	return AS1(neg%L0,%0);
+      }
+    return AS1(neg%W0,%0);")
 
 (define_insn "negqi2"
   [(set (match_operand:QI 0 "nonimmediate_operand" "=qm")
@@ -5053,11 +5059,30 @@ byte_xor_operation:
   "*
 {
   if (REG_P (operands[2]))
-    return AS2 (sal%W0,%b2,%0);
+    {
+      if (REG_P (operands[0]) && i386_cc_probably_useless_p (insn))
+        {
+          CC_STATUS_INIT;
+          return AS2 (sal%L0,%b2,%k0);
+        }
+      return AS2 (sal%W0,%b2,%0);
+    }
 
   if (REG_P (operands[0]) && operands[2] == const1_rtx)
-    return AS2 (add%W0,%0,%0);
+    {
+      if (i386_cc_probably_useless_p (insn))
+        {
+          CC_STATUS_INIT;
+          return AS2 (add%L0,%k0,%k0);
+        }
+      return AS2 (add%W0,%0,%0);
+    }
 
+  if (REG_P (operands[0]) && i386_cc_probably_useless_p (insn))
+    {
+      CC_STATUS_INIT;
+      return AS2 (sal%L0,%2,%k0);
+    }
   return AS2 (sal%W0,%2,%0);
 }")