i386.md (xorsi3): Do not output NOT instrctions on Pentium.

        * i386.md (xorsi3): Do not output NOT instrctions on Pentium.
        (xorqi3): Likewise.
        (xorhi3): Likewise.
        (notsi2): Likewise.
        (notqi2): Likewise.
        (nothi2): Likewise; do not output prefixed opcodes when possible.

From-SVN: r26434

gcc/ChangeLog

 Wed Apr 14 00:18:22 1999  Jan Hubicka <hubicka@freesoft.cz>
 
+	* i386.md (xorsi3): Do not output NOT instrctions on Pentium.
+	(xorqi3): Likewise.
+	(xorhi3): Likewise.
+	(notsi2): Likewise.
+	(notqi2): Likewise.
+	(nothi2): Likewise; do not output prefixed opcodes when possible.
+
 	* i386.md (neghi2): Do not output prefixed opcode when possible.
 	(ashlhi3): Likewise.
 

gcc/config/i386/i386.md

@@ -4525,7 +4525,10 @@ byte_or_operation:
 byte_xor_operation:
 	    CC_STATUS_INIT;
 	      
-	    if (intval == 0xff)
+	    if (intval == 0xff
+                && (!TARGET_PENTIUM || optimize_size
+                    || (GET_CODE (operands[0]) == MEM 
+                        && memory_address_length (XEXP (operands[0], 0)) != 0)))
 	      return AS1 (not%B0,%b0);
 
 	    if (intval != INTVAL (operands[2]))
@@ -4541,7 +4544,10 @@ byte_xor_operation:
 	  if (REG_P (operands[0]))
 	    {
 	      CC_STATUS_INIT;
-	      if (intval == 0xff)
+	      if (intval == 0xff 
+                  && (!TARGET_PENTIUM || optimize_size
+                      || (GET_CODE (operands[0]) == MEM 
+                          && memory_address_length (XEXP (operands[0], 0)) != 0)))
 		return AS1 (not%B0,%h0);
 
 	      operands[2] = GEN_INT (intval);
@@ -4598,7 +4604,10 @@ byte_xor_operation:
 	  if (INTVAL (operands[2]) & 0xffff0000)
 	    operands[2] = GEN_INT (INTVAL (operands[2]) & 0xffff);
 
-	  if (INTVAL (operands[2]) == 0xff)
+	  if (INTVAL (operands[2]) == 0xff 
+              && (!TARGET_PENTIUM || optimize_size
+                  || (GET_CODE (operands[0]) == MEM 
+                      && memory_address_length (XEXP (operands[0], 0)) != 0)))
 	    return AS1 (not%B0,%b0);
 
 	  return AS2 (xor%B0,%2,%b0);
@@ -4612,7 +4621,10 @@ byte_xor_operation:
 	  CC_STATUS_INIT;
 	  operands[2] = GEN_INT ((INTVAL (operands[2]) >> 8) & 0xff);
 
-	  if (INTVAL (operands[2]) == 0xff)
+	  if (INTVAL (operands[2]) == 0xff
+              && (!TARGET_PENTIUM || optimize_size
+                  || (GET_CODE (operands[0]) == MEM 
+                      && memory_address_length (XEXP (operands[0], 0)) != 0)))
 	    return AS1 (not%B0,%h0);
 
 	  return AS2 (xor%B0,%2,%h0);
@@ -4899,19 +4911,82 @@ byte_xor_operation:
   [(set (match_operand:SI 0 "nonimmediate_operand" "=rm")
 	(not:SI (match_operand:SI 1 "nonimmediate_operand" "0")))]
   ""
-  "not%L0 %0")
+  "*
+/* A Pentium NOT is not pariable.  Output it only in case of complex
+   memory address, because XOR will be inpariable anyway because
+   of immediate/displacement rule.  */
+
+if (TARGET_PENTIUM && !optimize_size
+    && (GET_CODE (operands[0]) != MEM 
+        || memory_address_length (XEXP (operands[0], 0)) == 0))
+  {
+    rtx xops[2];
+    xops[0] = operands[0];
+    xops[1] = GEN_INT (0xffffffff);
+    output_asm_insn (AS2 (xor%L0,%1,%0), xops);
+    RET;
+  }
+else
+  return AS1 (not%L0,%0);")
 
 (define_insn "one_cmplhi2"
   [(set (match_operand:HI 0 "nonimmediate_operand" "=rm")
 	(not:HI (match_operand:HI 1 "nonimmediate_operand" "0")))]
   ""
-  "not%W0 %0")
+  "*
+/* A Pentium NOT is not pariable.  Output it only in case of complex
+   memory address, because XOR will be inpariable anyway because
+   of immediate/displacement rule.  */
+
+if (TARGET_PENTIUM && !optimize_size
+    && (GET_CODE (operands[0]) != MEM 
+        || memory_address_length (XEXP (operands[0], 0)) == 0))
+  {
+    rtx xops[2];
+    xops[0] = operands[0];
+    xops[1] = GEN_INT (0xffff);
+    if (REG_P (operands[0])
+        && i386_cc_probably_useless_p (insn))
+     {
+        CC_STATUS_INIT;
+        output_asm_insn (AS2 (xor%L0,%1,%k0), xops);
+     }
+    else
+      output_asm_insn (AS2 (xor%W0,%1,%0), xops);
+    RET;
+  }
+else
+  {
+    if (REG_P (operands[0])
+        && i386_cc_probably_useless_p (insn))
+     {
+        CC_STATUS_INIT;
+        return AS1 (not%L0,%k0);
+     }
+    return AS1 (not%W0,%0);
+  }")
 
 (define_insn "one_cmplqi2"
   [(set (match_operand:QI 0 "nonimmediate_operand" "=qm")
 	(not:QI (match_operand:QI 1 "nonimmediate_operand" "0")))]
   ""
-  "not%B0 %0")
+  "*
+/* A Pentium NOT is not pariable.  Output it only in case of complex
+   memory address, because XOR will be inpariable anyway because
+   of immediate/displacement rule.  */
+
+if (TARGET_PENTIUM && !optimize_size
+    && (GET_CODE (operands[0]) != MEM 
+        || memory_address_length (XEXP (operands[0], 0)) == 0))
+  {
+    rtx xops[2];
+    xops[0] = operands[0];
+    xops[1] = GEN_INT (0xff);
+    output_asm_insn (AS2 (xor%B0,%1,%0), xops);
+    RET;
+  }
+else
+  return AS1 (not%B0,%0);")
 
 ;;- arithmetic shift instructions