re PR target/31701 (SH: wrong epilogue for sibling calls)

	PR target/31701
	* config/sh/sh.c (output_stack_adjust): Avoid using the frame
	register itself to hold the offset constant.  Tell flow the use
	of r4 and r5 when they are used.

From-SVN: r124248

gcc/ChangeLog

+2007-04-27  Kaz Kojima  <kkojima@gcc.gnu.org>
+
+	PR target/31701
+	* config/sh/sh.c (output_stack_adjust): Avoid using the frame
+	register itself to hold the offset constant.  Tell flow the use
+	of r4 and r5 when they are used.
+
 2007-04-27  Richard Guenther  <rguenther@suse.de>
 
 	* tree-ssa-forwprop.c (forward_propagate_into_cond): Keep track

gcc/config/sh/sh.c

@@ -5619,7 +5619,13 @@ output_stack_adjust (int size, rtx reg, int epilogue_p,
 	      temp = scavenge_reg (&temps);
 	    }
 	  if (temp < 0 && live_regs_mask)
-	    temp = scavenge_reg (live_regs_mask);
+	    {
+	      HARD_REG_SET temps;
+
+	      COPY_HARD_REG_SET (temps, *live_regs_mask);
+	      CLEAR_HARD_REG_BIT (temps, REGNO (reg));
+	      temp = scavenge_reg (&temps);
+	    }
 	  if (temp < 0)
 	    {
 	      rtx adj_reg, tmp_reg, mem;
@@ -5668,6 +5674,9 @@ output_stack_adjust (int size, rtx reg, int epilogue_p,
 	      emit_move_insn (adj_reg, mem);
 	      mem = gen_tmp_stack_mem (Pmode, gen_rtx_POST_INC (Pmode, reg));
 	      emit_move_insn (tmp_reg, mem);
+	      /* Tell flow the insns that pop r4/r5 aren't dead.  */
+	      emit_insn (gen_rtx_USE (VOIDmode, tmp_reg));
+	      emit_insn (gen_rtx_USE (VOIDmode, adj_reg));
 	      return;
 	    }
 	  const_reg = gen_rtx_REG (GET_MODE (reg), temp);