* Check in merge from gcc2. See ChangeLog.11 and ChangeLog.12

        for details.

        * haifa-sched.c: Mirror recent changes from gcc2.

From-SVN: r18988

gcc/haifa-sched.c

@@ -4443,12 +4443,7 @@ attach_deaths (x, insn, set_p)
 #endif
 		&& regno != STACK_POINTER_REGNUM)
 	      {
-		/* ??? It is perhaps a dead_or_set_p bug that it does
-		   not check for REG_UNUSED notes itself.  This is necessary
-		   for the case where the SET_DEST is a subreg of regno, as
-		   dead_or_set_p handles subregs specially.  */
-		if (! all_needed && ! dead_or_set_p (insn, x)
-		    && ! find_reg_note (insn, REG_UNUSED, x))
+		if (! all_needed && ! dead_or_set_p (insn, x))
 		  {
 		    /* Check for the case where the register dying partially
 		       overlaps the register set by this insn.  */
@@ -4511,17 +4506,20 @@ attach_deaths (x, insn, set_p)
       return;
 
     case SUBREG:
+      attach_deaths (SUBREG_REG (x), insn,
+		     set_p && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
+				<= UNITS_PER_WORD)
+			       || (GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
+				   == GET_MODE_SIZE (GET_MODE ((x))))));
+      return;
+
     case STRICT_LOW_PART:
-      /* These two cases preserve the value of SET_P, so handle them
-         separately.  */
-      attach_deaths (XEXP (x, 0), insn, set_p);
+      attach_deaths (XEXP (x, 0), insn, 0);
       return;
 
     case ZERO_EXTRACT:
     case SIGN_EXTRACT:
-      /* This case preserves the value of SET_P for the first operand, but
-         clears it for the other two.  */
-      attach_deaths (XEXP (x, 0), insn, set_p);
+      attach_deaths (XEXP (x, 0), insn, 0);
       attach_deaths (XEXP (x, 1), insn, 0);
       attach_deaths (XEXP (x, 2), insn, 0);
       return;