recog.c (validate_replace_rtx_1): In ZERO_EXTEND / SIGN_EXTEND case...

	* recog.c (validate_replace_rtx_1): In ZERO_EXTEND / SIGN_EXTEND
	case, don't use operand_subword to calculate a SUBREG that is
	wider than a word.

	* rtl.texi: Comparisons yield 0 or STORE_FLAG_VALUE.

From-SVN: r39183

3 files changed, 50 insertions, 8 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 47d9e2e..de41674 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+Mon Jan 22 16:53:06 2001  J"orn Rennecke <amylaar@redhat.com>
+
+	* recog.c (validate_replace_rtx_1): In ZERO_EXTEND / SIGN_EXTEND
+	case, don't use operand_subword to calculate a SUBREG that is
+	wider than a word.
+
+	* rtl.texi: Comparisons yield 0 or STORE_FLAG_VALUE.
+
 2001-01-22 Herman A.J. ten Brugge <Haj.Ten.Brugge@net.HCC.nl>
 
 	* c4x.c (c4x_valid_rptb_p, c4x_label_ref_used_p): New functions.
diff --git a/gcc/recog.c b/gcc/recog.c
index 4257d7c..4dab907 100644
--- a/gcc/recog.c
+++ b/gcc/recog.c
@@ -491,8 +491,42 @@ validate_replace_rtx_1 (loc, from, to, object)
 	  /* If there is a subreg involved, crop to the portion of the
 	     constant that we are interested in.  */
 	  if (GET_CODE (XEXP (x, 0)) == SUBREG)
-	    to = operand_subword (to, SUBREG_WORD (XEXP (x, 0)),
-				  0, GET_MODE (from));
+	    {
+	      if (GET_MODE_SIZE (GET_MODE (XEXP (x, 0))) <= UNITS_PER_WORD)
+		to = operand_subword (to, SUBREG_WORD (XEXP (x, 0)),
+				      0, GET_MODE (from));
+	      else if (GET_MODE_CLASS (GET_MODE (from)) == MODE_INT
+		       && (GET_MODE_BITSIZE (GET_MODE (XEXP (x, 0)))
+			   <= HOST_BITS_PER_WIDE_INT))
+		{
+		  int i = SUBREG_WORD (XEXP (x, 0)) * BITS_PER_WORD;
+		  HOST_WIDE_INT valh;
+		  unsigned HOST_WIDE_INT vall;
+
+		  if (GET_CODE (to) == CONST_INT)
+		    {
+		      vall = INTVAL (to);
+		      valh = (HOST_WIDE_INT) vall < 0 ? ~0 : 0;
+		    }
+		  else
+		    {
+		      vall = CONST_DOUBLE_LOW (to);
+		      valh = CONST_DOUBLE_HIGH (to);
+		    }
+
+		  if (WORDS_BIG_ENDIAN)
+		    i = (GET_MODE_BITSIZE (GET_MODE (from))
+			 - GET_MODE_BITSIZE (GET_MODE (XEXP (x, 0))) - i);
+		  if (i > 0 && i < HOST_BITS_PER_WIDE_INT)
+		    vall = vall >> i | valh << (HOST_BITS_PER_WIDE_INT - i);
+		  else if (i >= HOST_BITS_PER_WIDE_INT)
+		    vall = valh >> (i - HOST_BITS_PER_WIDE_INT);
+		  to = GEN_INT (trunc_int_for_mode (vall,
+						    GET_MODE (XEXP (x, 0))));
+		}
+	      else
+		to = gen_rtx_CLOBBER (GET_MODE (x), const0_rtx);
+	    }
 
 	  /* If the above didn't fail, perform the extension from the
 	     mode of the operand (and not the mode of FROM).  */
diff --git a/gcc/rtl.texi b/gcc/rtl.texi
index 4cb0eb7..6ed90f8 100644
--- a/gcc/rtl.texi
+++ b/gcc/rtl.texi
@@ -1628,20 +1628,20 @@ point comparisons are distinguished by the machine modes of the operands.
 @findex eq
 @cindex equal
 @item (eq:@var{m} @var{x} @var{y})
-1 if the values represented by @var{x} and @var{y} are equal,
-otherwise 0.
+@code{STORE_FLAG_VALUE} if the values represented by @var{x} and @var{y}
+are equal, otherwise 0.
 
 @findex ne
 @cindex not equal
 @item (ne:@var{m} @var{x} @var{y})
-1 if the values represented by @var{x} and @var{y} are not equal,
-otherwise 0.
+@code{STORE_FLAG_VALUE} if the values represented by @var{x} and @var{y}
+are not equal, otherwise 0.
 
 @findex gt
 @cindex greater than
 @item (gt:@var{m} @var{x} @var{y})
-1 if the @var{x} is greater than @var{y}.  If they are fixed-point,
-the comparison is done in a signed sense.
+@code{STORE_FLAG_VALUE} if the @var{x} is greater than @var{y}.  If they
+are fixed-point, the comparison is done in a signed sense.
 
 @findex gtu
 @cindex greater than