expmed.c (extract_bit_field): Reverse operands of && condition to prevent a…

expmed.c (extract_bit_field): Reverse operands of && condition to prevent a potential division by zero in the...

	* expmed.c (extract_bit_field): Reverse operands of && condition to
        prevent a potential division by zero in the previously first branch.
	* config/pa/pa.md (extv, extzv): FAIL if the bitfield length is zero.

From-SVN: r65907

gcc/ChangeLog

@@ -3,6 +3,10 @@
 	* calls.c (expand_call): Prevent sibcall optimization for calls to
 	nested subprograms.
 
+	* expmed.c (extract_bit_field): Reverse operands of && condition to
+        prevent a potential division by zero in the previously first branch.
+	* config/pa/pa.md (extv, extzv): FAIL if the bitfield length is zero.
+
 2003-04-21  Joel Brobecker  <brobecker@gnat.com>
 
 	* dwarf2out.c (is_ada, is_ada_subrange_type): New functions.

gcc/config/pa/pa.md

@@ -7153,6 +7153,10 @@
   ""
   "
 {
+  /* PA extraction insns don't support zero length bitfields.  */
+  if (INTVAL (operands[2]) == 0)
+    FAIL;
+
   if (TARGET_64BIT)
     emit_insn (gen_extzv_64 (operands[0], operands[1],
 			     operands[2], operands[3]));
@@ -7215,6 +7219,10 @@
   ""
   "
 {
+  /* PA extraction insns don't support zero length bitfields.  */
+  if (INTVAL (operands[2]) == 0)
+    FAIL;
+
   if (TARGET_64BIT)
     emit_insn (gen_extv_64 (operands[0], operands[1],
 			    operands[2], operands[3]));

gcc/expmed.c

@@ -1104,25 +1104,25 @@ extract_bit_field (str_rtx, bitsize, bitnum, unsignedp,
 	    ? mode
 	    : mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0));
 
-  if (((GET_CODE (op0) != MEM
-	&& TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
-				  GET_MODE_BITSIZE (GET_MODE (op0)))
-	&& GET_MODE_SIZE (mode1) != 0
-	&& byte_offset % GET_MODE_SIZE (mode1) == 0)
-       || (GET_CODE (op0) == MEM
-	   && (! SLOW_UNALIGNED_ACCESS (mode, MEM_ALIGN (op0))
-	       || (offset * BITS_PER_UNIT % bitsize == 0
-		   && MEM_ALIGN (op0) % bitsize == 0))))
-      && ((bitsize >= BITS_PER_WORD && bitsize == GET_MODE_BITSIZE (mode)
-	   && bitpos % BITS_PER_WORD == 0)
-	  || (mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0) != BLKmode
-	      /* ??? The big endian test here is wrong.  This is correct
-		 if the value is in a register, and if mode_for_size is not
-		 the same mode as op0.  This causes us to get unnecessarily
-		 inefficient code from the Thumb port when -mbig-endian.  */
-	      && (BYTES_BIG_ENDIAN
-		  ? bitpos + bitsize == BITS_PER_WORD
-		  : bitpos == 0))))
+  if (((bitsize >= BITS_PER_WORD && bitsize == GET_MODE_BITSIZE (mode)
+	&& bitpos % BITS_PER_WORD == 0)
+       || (mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0) != BLKmode
+	   /* ??? The big endian test here is wrong.  This is correct
+	      if the value is in a register, and if mode_for_size is not
+	      the same mode as op0.  This causes us to get unnecessarily
+	      inefficient code from the Thumb port when -mbig-endian.  */
+	   && (BYTES_BIG_ENDIAN
+	       ? bitpos + bitsize == BITS_PER_WORD
+	       : bitpos == 0)))
+      && ((GET_CODE (op0) != MEM
+	   && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
+				     GET_MODE_BITSIZE (GET_MODE (op0)))
+	   && GET_MODE_SIZE (mode1) != 0
+	   && byte_offset % GET_MODE_SIZE (mode1) == 0)
+	  || (GET_CODE (op0) == MEM
+	      && (! SLOW_UNALIGNED_ACCESS (mode, MEM_ALIGN (op0))
+		  || (offset * BITS_PER_UNIT % bitsize == 0
+		      && MEM_ALIGN (op0) % bitsize == 0)))))
     {
       if (mode1 != GET_MODE (op0))
 	{