combine.c (try_combine): Don't set i3_subst_into_i2 for case of making new double...

	* combine.c (try_combine): Don't set i3_subst_into_i2 for
	case of making new double-word constant.
	Revert last change: instead just test i3_subst_into_i2.

From-SVN: r39094

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 37baa52a7ebeec6ee7a817833de7bb3bd7908eb9..3206f2ca6c536cac5fee2f1cd903ae6bd877e091 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+Wed Jan 17 13:26:34 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
+
+       * combine.c (try_combine): Don't set i3_subst_into_i2 for
+       case of making new double-word constant.
+       Revert last change: instead just test i3_subst_into_i2.
+
 2001-01-17  Jakub Jelinek  <jakub@redhat.com>
 
        * config/i386/i386.md (cmpqi_minus_1): Use {b} for QImode operation.

diff --git a/gcc/combine.c b/gcc/combine.c
index e684ba15654cacbfee9537b0084f965273408606..6028f6ae8d1fec5d67755460b7620a84c4d5ca47 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -1558,13 +1558,16 @@ try_combine (i3, i2, i1, new_direct_jump_p)
   added_links_insn = 0;
 
   /* First check for one important special-case that the code below will
-     not handle.  Namely, the case where I1 is zero, I2 has multiple sets,
+     not handle.  Namely, the case where I1 is zero, I2 is a PARALLEL
      and I3 is a SET whose SET_SRC is a SET_DEST in I2.  In that case,
      we may be able to replace that destination with the destination of I3.
      This occurs in the common code where we compute both a quotient and
      remainder into a structure, in which case we want to do the computation
      directly into the structure to avoid register-register copies.
 
+     Note that this case handles both multiple sets in I2 and also
+     cases where I2 has a number of CLOBBER or PARALLELs.
+
      We make very conservative checks below and only try to handle the
      most common cases of this.  For example, we only handle the case
      where I2 and I3 are adjacent to avoid making difficult register
@@ -1673,7 +1676,6 @@ try_combine (i3, i2, i1, new_direct_jump_p)
             immed_double_const (lo, hi, GET_MODE (SET_DEST (temp))));
 
       newpat = PATTERN (i2);
-      i3_subst_into_i2 = 1;
       goto validate_replacement;
     }
 
@@ -2524,7 +2526,7 @@ try_combine (i3, i2, i1, new_direct_jump_p)
        actually came from I3, so that REG_UNUSED notes from I2 will be
        properly handled.  */
 
-    if (i3_subst_into_i2 && single_set (i2) == 0)
+    if (i3_subst_into_i2)
       {
        for (i = 0; i < XVECLEN (PATTERN (i2), 0); i++)
          if (GET_CODE (XVECEXP (PATTERN (i2), 0, i)) != USE