/* Combine stack adjustments.
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
- 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
- Free Software Foundation, Inc.
+ 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
+ 2010 Free Software Foundation, Inc.
This file is part of GCC.
#include "basic-block.h"
#include "df.h"
#include "except.h"
-#include "toplev.h"
#include "reload.h"
#include "timevar.h"
#include "tree-pass.h"
rtx set;
set = single_set_for_csa (insn);
- validate_change (insn, &XEXP (SET_SRC (set), 1), GEN_INT (new_adjust), 1);
+ if (MEM_P (SET_DEST (set)))
+ validate_change (insn, &SET_DEST (set),
+ replace_equiv_address (SET_DEST (set), stack_pointer_rtx),
+ 1);
+ else
+ validate_change (insn, &XEXP (SET_SRC (set), 1), GEN_INT (new_adjust), 1);
for (ml = reflist; ml ; ml = ml->next)
{
continue;
}
- /* Find a predecrement of exactly the previous adjustment and
- turn it into a direct store. Obviously we can't do this if
- there were any intervening uses of the stack pointer. */
- if (reflist == NULL
- && MEM_P (dest)
- && ((GET_CODE (XEXP (dest, 0)) == PRE_DEC
- && (last_sp_adjust
- == (HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (dest))))
- || (GET_CODE (XEXP (dest, 0)) == PRE_MODIFY
+ /* Find a store with pre-(dec|inc)rement or pre-modify of exactly
+ the previous adjustment and turn it into a simple store. This
+ is equivalent to anticipating the stack adjustment so this must
+ be an allocation. */
+ if (MEM_P (dest)
+ && ((STACK_GROWS_DOWNWARD
+ ? (GET_CODE (XEXP (dest, 0)) == PRE_DEC
+ && last_sp_adjust
+ == (HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (dest)))
+ : (GET_CODE (XEXP (dest, 0)) == PRE_INC
+ && last_sp_adjust
+ == -(HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (dest))))
+ || ((STACK_GROWS_DOWNWARD
+ ? last_sp_adjust >= 0 : last_sp_adjust <= 0)
+ && GET_CODE (XEXP (dest, 0)) == PRE_MODIFY
&& GET_CODE (XEXP (XEXP (dest, 0), 1)) == PLUS
- && XEXP (XEXP (XEXP (dest, 0), 1), 0) == stack_pointer_rtx
- && (GET_CODE (XEXP (XEXP (XEXP (dest, 0), 1), 1))
- == CONST_INT)
- && (INTVAL (XEXP (XEXP (XEXP (dest, 0), 1), 1))
- == -last_sp_adjust)))
+ && XEXP (XEXP (XEXP (dest, 0), 1), 0)
+ == stack_pointer_rtx
+ && GET_CODE (XEXP (XEXP (XEXP (dest, 0), 1), 1))
+ == CONST_INT
+ && INTVAL (XEXP (XEXP (XEXP (dest, 0), 1), 1))
+ == -last_sp_adjust))
&& XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx
- && ! reg_mentioned_p (stack_pointer_rtx, src)
+ && !reg_mentioned_p (stack_pointer_rtx, src)
&& memory_address_p (GET_MODE (dest), stack_pointer_rtx)
- && validate_change (insn, &SET_DEST (set),
- replace_equiv_address (dest,
- stack_pointer_rtx),
- 0))
+ && try_apply_stack_adjustment (insn, reflist, 0,
+ -last_sp_adjust))
{
delete_insn (last_sp_set);
free_csa_reflist (reflist);
static bool
gate_handle_stack_adjustments (void)
{
- return (optimize > 0);
+ return flag_combine_stack_adjustments;
}
static unsigned int
cleanup_cfg (flag_crossjumping ? CLEANUP_CROSSJUMP : 0);
/* This is kind of a heuristic. We need to run combine_stack_adjustments
- even for machines with possibly nonzero RETURN_POPS_ARGS
+ even for machines with possibly nonzero TARGET_RETURN_POPS_ARGS
and ACCUMULATE_OUTGOING_ARGS. We expect that only ports having
push instructions will have popping returns. */
#ifndef PUSH_ROUNDING