*** empty log message ***

From-SVN: r1442

diff --git a/gcc/combine.c b/gcc/combine.c
index 5e6a18300c7db3351b03acf500680fad8d874d94..5163f5c83f6c35b9a1b78410ba33b29f2db418b8 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -1520,6 +1520,19 @@ try_combine (i3, i2, i1)
          i2_code_number = recog_for_combine (&newi2pat, i2, &new_i2_notes);
          if (i2_code_number >= 0)
            insn_code_number = recog_for_combine (&newpat, i3, &new_i3_notes);
+
+         /* It is possible that both insns now set the destination of I3.
+            If so, we must show an extra use of it and update
+            reg_significant.  */
+
+         if (insn_code_number >= 0 && GET_CODE (SET_DEST (newpat)) == REG
+             && GET_CODE (SET_DEST (newi2pat)) == REG
+             && REGNO (SET_DEST (newpat)) == REGNO (SET_DEST (newi2pat)))
+           {
+             reg_n_sets[REGNO (SET_DEST (newpat))]++;
+             set_significant (SET_DEST (newi2pat), newi2pat);
+             set_significant (SET_DEST (newpat), newpat);
+           }
        }
 
       /* If we can split it and use I2DEST, go ahead and see if that