* cse.c (fold_rtx): Use simplify_subreg.

	* simplify-rtx.c (simplify_replace_rtx): Use simplify_gen_subreg.
	(simplify_gen_subreg): New.
	(simplify_rtx): Use simplify_subreg.
	* rtl.h (simplify_gen_subreg): Declare.


git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@42221 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 65 insertions, 17 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 50551d9ea0f..b5be8d85fb1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+Thu May 17 20:43:36 CEST 2001  Jan Hubicka  <jh@suse.cz>
+
+	* cse.c (fold_rtx): Use simplify_subreg.
+
+	* simplify-rtx.c (simplify_replace_rtx): Use simplify_gen_subreg.
+	(simplify_gen_subreg): New.
+	(simplify_rtx): Use simplify_subreg.
+	* rtl.h (simplify_gen_subreg): Declare.
+
 2001-05-17  Mark Mitchell  <mark@codesourcery.com>
 
 	* doc/install.texi: Update Solaris information.
diff --git a/gcc/cse.c b/gcc/cse.c
index f3978e4b257..43cbf9ca020 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -3408,16 +3408,8 @@ fold_rtx (x, insn)
 
       if (folded_arg0 != SUBREG_REG (x))
 	{
-	  new = 0;
-
-	  if (GET_MODE_CLASS (mode) == MODE_INT
-	      && GET_MODE_SIZE (mode) == UNITS_PER_WORD
-	      && GET_MODE (SUBREG_REG (x)) != VOIDmode)
-	    new = operand_subword (folded_arg0,
-				   (SUBREG_BYTE (x) / UNITS_PER_WORD), 0,
-				   GET_MODE (SUBREG_REG (x)));
-	  if (new == 0 && subreg_lowpart_p (x))
-	    new = gen_lowpart_if_possible (mode, folded_arg0);
+	  new = simplify_subreg (mode, folded_arg0,
+				 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
 	  if (new)
 	    return new;
 	}
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 6aa86136b6f..7ba5440ef74 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -1331,6 +1331,10 @@ extern rtx simplify_subreg		PARAMS ((enum machine_mode,
 						 rtx,
 						 enum machine_mode,
 						 unsigned int));
+extern rtx simplify_gen_subreg		PARAMS ((enum machine_mode,
+						 rtx,
+						 enum machine_mode,
+						 unsigned int));
 extern rtx simplify_replace_rtx		PARAMS ((rtx, rtx, rtx));
 extern rtx simplify_rtx			PARAMS ((rtx));
 
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index fd1b6303768..a64b33e1836 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -259,13 +259,18 @@ simplify_replace_rtx (x, old, new)
 			      simplify_replace_rtx (XEXP (x, 2), old, new));
 
     case 'x':
-      /* The only case we try to handle is a lowpart SUBREG of a single-word
-	 CONST_INT.  */
-      if (code == SUBREG && subreg_lowpart_p (x) && old == SUBREG_REG (x)
-	  && GET_CODE (new) == CONST_INT
-	  && GET_MODE_SIZE (GET_MODE (old)) <= UNITS_PER_WORD)
-	return GEN_INT (INTVAL (new) & GET_MODE_MASK (mode));
-
+      /* The only case we try to handle is a SUBREG.  */
+      if (code == SUBREG)
+	{
+	  rtx exp;
+	  exp = simplify_gen_subreg (GET_MODE (x),
+				     simplify_replace_rtx (SUBREG_REG (x),
+				     			   old, new),
+				     GET_MODE (SUBREG_REG (x)),
+				     SUBREG_BYTE (x));
+	  if (exp)
+	   x = exp;
+	}
       return x;
 
     default:
@@ -2385,6 +2390,37 @@ simplify_subreg (outermode, op, innermode, byte)
     }
   return NULL_RTX;
 }
+/* Make a SUBREG operation or equivalent if it folds.  */
+
+rtx
+simplify_gen_subreg (outermode, op, innermode, byte)
+     rtx op;
+     unsigned int byte;
+     enum machine_mode outermode, innermode;
+{
+  rtx new;
+  /* Little bit of sanity checking.  */
+  if (innermode == VOIDmode || outermode == VOIDmode
+      || innermode == BLKmode || outermode == BLKmode)
+    abort ();
+
+  if (GET_MODE (op) != innermode
+      && GET_MODE (op) != VOIDmode)
+    abort ();
+
+  if (byte % GET_MODE_SIZE (outermode)
+      || byte >= GET_MODE_SIZE (innermode))
+    abort ();
+
+  new = simplify_subreg (outermode, op, innermode, byte);
+  if (new)
+    return new;
+
+  if (GET_CODE (op) == SUBREG || GET_MODE (op) == VOIDmode)
+    return NULL_RTX;
+
+  return gen_rtx_SUBREG (outermode, op, byte);
+}
 /* Simplify X, an rtx expression.
 
    Return the simplified expression or NULL if no simplifications
@@ -2454,6 +2490,13 @@ simplify_rtx (x)
 					     ? GET_MODE (XEXP (x, 0))
 					     : GET_MODE (XEXP (x, 1))),
 					    XEXP (x, 0), XEXP (x, 1));
+    case 'x':
+      /* The only case we try to handle is a SUBREG.  */
+      if (code == SUBREG)
+        return simplify_gen_subreg (mode, SUBREG_REG (x),
+				    GET_MODE (SUBREG_REG (x)),
+				    SUBREG_BYTE (x));
+      return NULL;
     default:
       return NULL;
     }