re PR c/2454 (Test Program A0376972.c fails with gcc-20010320, works with gcc-2.95.3)

	PR c/2454
	* combine.c (nonzero_bits): LOAD_EXTEND_OP should only apply
	to SUBREGs of MEMs.  (num_sign_bit_copies): Likewise.

From-SVN: r55386

gcc/ChangeLog

 2002-07-10  Roger Sayle  <roger@eyesopen.com>
+
+	PR c/2454
+	* combine.c (nonzero_bits): LOAD_EXTEND_OP should only apply
+	to SUBREGs of MEMs.  (num_sign_bit_copies): Likewise.
+
+2002-07-10  Roger Sayle  <roger@eyesopen.com>
 	    Zack Weinberg <zack@codesourcery.com>
 
 	* builtins.def: Make the argument types of abort and exit

gcc/combine.c

@@ -8344,12 +8344,13 @@ nonzero_bits (x, mode)
 #if defined (WORD_REGISTER_OPERATIONS) && defined (LOAD_EXTEND_OP)
 	  /* If this is a typical RISC machine, we only have to worry
 	     about the way loads are extended.  */
-	  if (LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (x))) == SIGN_EXTEND
-	      ? (((nonzero
-		   & (((unsigned HOST_WIDE_INT) 1
-		       << (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))) - 1))))
-		  != 0))
-	      : LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (x))) != ZERO_EXTEND)
+	  if ((LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (x))) == SIGN_EXTEND
+	       ? (((nonzero
+		    & (((unsigned HOST_WIDE_INT) 1
+			<< (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))) - 1))))
+		   != 0))
+	       : LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (x))) != ZERO_EXTEND)
+	      || GET_CODE (SUBREG_REG (x)) != MEM)
 #endif
 	    {
 	      /* On many CISC machines, accessing an object in a wider mode
@@ -8572,7 +8573,8 @@ num_sign_bit_copies (x, mode)
 
       if ((GET_MODE_SIZE (GET_MODE (x))
 	   > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
-	  && LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (x))) == SIGN_EXTEND)
+	  && LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (x))) == SIGN_EXTEND
+	  && GET_CODE (SUBREG_REG (x)) == MEM)
 	return num_sign_bit_copies (SUBREG_REG (x), mode);
 #endif
 #endif