PR debug/42897

[pf3gnuchains/gcc-fork.git] / gcc / combine.c

diff --git a/gcc/combine.c b/gcc/combine.c
index 2c60ae5..e5d4c5a 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -2663,10 +2663,16 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
          i2dest = SET_DEST (temp);
          i2dest_killed = dead_or_set_p (i2, i2dest);
 
+         /* Replace the source in I2 with the new constant and make the
+            resulting insn the new pattern for I3.  Then skip to where we
+            validate the pattern.  Everything was set up above.  */
          SUBST (SET_SRC (temp),
                 immed_double_const (olo, ohi, GET_MODE (SET_DEST (temp))));
 
          newpat = PATTERN (i2);
+
+          /* The dest of I3 has been replaced with the dest of I2.  */
+          changed_i3_dest = 1;
          goto validate_replacement;
        }
     }
@@ -3038,8 +3044,6 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p)
        }
     }
 
-  /* We come here when we are replacing a destination in I2 with the
-     destination of I3.  */
  validate_replacement:
 
   /* Note which hard regs this insn has as inputs.  */
@@ -7306,15 +7310,14 @@ make_compound_operation (rtx x, enum rtx_code in_code)
       tem = make_compound_operation (SUBREG_REG (x), in_code);
 
       {
-       rtx simplified;
-       simplified = simplify_subreg (GET_MODE (x), tem, GET_MODE (tem),
-                                     SUBREG_BYTE (x));
+       rtx simplified = simplify_subreg (mode, tem, GET_MODE (SUBREG_REG (x)),
+                                         SUBREG_BYTE (x));
 
        if (simplified)
          tem = simplified;
 
        if (GET_CODE (tem) != GET_CODE (SUBREG_REG (x))
-           && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (tem))
+           && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
            && subreg_lowpart_p (x))
          {
            rtx newer = force_to_mode (tem, mode, ~(HOST_WIDE_INT) 0,