/* Subroutines for manipulating rtx's in semantically interesting ways.
Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GCC.
#include "system.h"
#include "coretypes.h"
#include "tm.h"
+#include "diagnostic-core.h"
#include "toplev.h"
#include "rtl.h"
#include "tree.h"
#include "function.h"
#include "expr.h"
#include "optabs.h"
+#include "libfuncs.h"
#include "hard-reg-set.h"
#include "insn-config.h"
#include "ggc.h"
#include "output.h"
static rtx break_out_memory_refs (rtx);
-static void emit_stack_probe (rtx);
/* Truncate and perhaps sign-extend C as appropriate for MODE. */
size = TREE_OPERAND (exp, 1);
else
{
- size = lang_hooks.expr_size (exp);
+ size = tree_expr_size (exp);
gcc_assert (size);
gcc_assert (size == SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, exp));
}
size = TREE_OPERAND (exp, 1);
else
{
- size = lang_hooks.expr_size (exp);
+ size = tree_expr_size (exp);
gcc_assert (size);
}
rtx op1 = break_out_memory_refs (XEXP (x, 1));
if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
- x = simplify_gen_binary (GET_CODE (x), Pmode, op0, op1);
+ x = simplify_gen_binary (GET_CODE (x), GET_MODE (x), op0, op1);
}
return x;
}
-/* Given X, a memory address in ptr_mode, convert it to an address
- in Pmode, or vice versa (TO_MODE says which way). We take advantage of
- the fact that pointers are not allowed to overflow by commuting arithmetic
- operations over conversions so that address arithmetic insns can be
- used. */
+/* Given X, a memory address in address space AS' pointer mode, convert it to
+ an address in the address space's address mode, or vice versa (TO_MODE says
+ which way). We take advantage of the fact that pointers are not allowed to
+ overflow by commuting arithmetic operations over conversions so that address
+ arithmetic insns can be used. */
rtx
-convert_memory_address (enum machine_mode to_mode ATTRIBUTE_UNUSED,
- rtx x)
+convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED,
+ rtx x, addr_space_t as ATTRIBUTE_UNUSED)
{
#ifndef POINTERS_EXTEND_UNSIGNED
gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode);
return x;
#else /* defined(POINTERS_EXTEND_UNSIGNED) */
- enum machine_mode from_mode;
+ enum machine_mode pointer_mode, address_mode, from_mode;
rtx temp;
enum rtx_code code;
if (GET_MODE (x) == to_mode)
return x;
- from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
+ pointer_mode = targetm.addr_space.pointer_mode (as);
+ address_mode = targetm.addr_space.address_mode (as);
+ from_mode = to_mode == pointer_mode ? address_mode : pointer_mode;
/* Here we handle some special cases. If none of them apply, fall through
to the default case. */
case CONST:
return gen_rtx_CONST (to_mode,
- convert_memory_address (to_mode, XEXP (x, 0)));
+ convert_memory_address_addr_space
+ (to_mode, XEXP (x, 0), as));
break;
case PLUS:
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
|| (GET_CODE (x) == PLUS
&& CONST_INT_P (XEXP (x, 1))
- && (XEXP (x, 1) == convert_memory_address (to_mode, XEXP (x, 1))
+ && (XEXP (x, 1) == convert_memory_address_addr_space
+ (to_mode, XEXP (x, 1), as)
|| POINTERS_EXTEND_UNSIGNED < 0)))
return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
- convert_memory_address (to_mode, XEXP (x, 0)),
+ convert_memory_address_addr_space
+ (to_mode, XEXP (x, 0), as),
XEXP (x, 1));
break;
#endif /* defined(POINTERS_EXTEND_UNSIGNED) */
}
\f
-/* Return something equivalent to X but valid as a memory address
- for something of mode MODE. When X is not itself valid, this
- works by copying X or subexpressions of it into registers. */
+/* Return something equivalent to X but valid as a memory address for something
+ of mode MODE in the named address space AS. When X is not itself valid,
+ this works by copying X or subexpressions of it into registers. */
rtx
-memory_address (enum machine_mode mode, rtx x)
+memory_address_addr_space (enum machine_mode mode, rtx x, addr_space_t as)
{
rtx oldx = x;
+ enum machine_mode address_mode = targetm.addr_space.address_mode (as);
- x = convert_memory_address (Pmode, x);
+ x = convert_memory_address_addr_space (address_mode, x, as);
/* By passing constant addresses through registers
we get a chance to cse them. */
if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
- x = force_reg (Pmode, x);
+ x = force_reg (address_mode, x);
/* We get better cse by rejecting indirect addressing at this stage.
Let the combiner create indirect addresses where appropriate.
x = break_out_memory_refs (x);
/* At this point, any valid address is accepted. */
- if (memory_address_p (mode, x))
+ if (memory_address_addr_space_p (mode, x, as))
goto done;
/* If it was valid before but breaking out memory refs invalidated it,
use it the old way. */
- if (memory_address_p (mode, oldx))
+ if (memory_address_addr_space_p (mode, oldx, as))
{
x = oldx;
goto done;
below can handle all possible cases, but machine-dependent
transformations can make better code. */
{
- rtx orig_x = x;
- x = targetm.legitimize_address (x, oldx, mode);
- if (orig_x != x && memory_address_p (mode, x))
+ rtx orig_x = x;
+ x = targetm.addr_space.legitimize_address (x, oldx, mode, as);
+ if (orig_x != x && memory_address_addr_space_p (mode, x, as))
goto done;
}
rtx constant_term = const0_rtx;
rtx y = eliminate_constant_term (x, &constant_term);
if (constant_term == const0_rtx
- || ! memory_address_p (mode, y))
+ || ! memory_address_addr_space_p (mode, y, as))
x = force_operand (x, NULL_RTX);
else
{
y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
- if (! memory_address_p (mode, y))
+ if (! memory_address_addr_space_p (mode, y, as))
x = force_operand (x, NULL_RTX);
else
x = y;
/* Last resort: copy the value to a register, since
the register is a valid address. */
else
- x = force_reg (Pmode, x);
+ x = force_reg (address_mode, x);
}
done:
- gcc_assert (memory_address_p (mode, x));
+ gcc_assert (memory_address_addr_space_p (mode, x, as));
/* If we didn't change the address, we are done. Otherwise, mark
a reg as a pointer if we have REG or REG + CONST_INT. */
if (oldx == x)
if (!MEM_P (ref))
return ref;
ref = use_anchored_address (ref);
- if (memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
+ if (memory_address_addr_space_p (GET_MODE (ref), XEXP (ref, 0),
+ MEM_ADDR_SPACE (ref)))
return ref;
/* Don't alter REF itself, since that is probably a stack slot. */
if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s)))
sa = DECL_ALIGN (SYMBOL_REF_DECL (s));
- ca = exact_log2 (INTVAL (c) & -INTVAL (c)) * BITS_PER_UNIT;
-
- align = MIN (sa, ca);
+ if (INTVAL (c) == 0)
+ align = sa;
+ else
+ {
+ ca = ctz_hwi (INTVAL (c)) * BITS_PER_UNIT;
+ align = MIN (sa, ca);
+ }
}
if (align || (MEM_P (x) && MEM_POINTER (x)))
case REFERENCE_TYPE:
case POINTER_TYPE:
*punsignedp = POINTERS_EXTEND_UNSIGNED;
- return Pmode;
+ return targetm.addr_space.address_mode
+ (TYPE_ADDR_SPACE (TREE_TYPE (type)));
break;
#endif
enum machine_mode mode = DECL_MODE (decl);
enum machine_mode pmode;
- if (TREE_CODE (decl) == RESULT_DECL)
- pmode = promote_function_mode (type, mode, &unsignedp,
- TREE_TYPE (current_function_decl), 1);
- else if (TREE_CODE (decl) == PARM_DECL)
+ if (TREE_CODE (decl) == RESULT_DECL
+ || TREE_CODE (decl) == PARM_DECL)
pmode = promote_function_mode (type, mode, &unsignedp,
- TREE_TYPE (current_function_decl), 0);
+ TREE_TYPE (current_function_decl), 2);
else
pmode = promote_mode (type, mode, &unsignedp);
static rtx
round_push (rtx size)
{
- int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
-
- if (align == 1)
- return size;
+ rtx align_rtx, alignm1_rtx;
- if (CONST_INT_P (size))
+ if (!SUPPORTS_STACK_ALIGNMENT
+ || crtl->preferred_stack_boundary == MAX_SUPPORTED_STACK_ALIGNMENT)
{
- HOST_WIDE_INT new_size = (INTVAL (size) + align - 1) / align * align;
+ int align = crtl->preferred_stack_boundary / BITS_PER_UNIT;
+
+ if (align == 1)
+ return size;
+
+ if (CONST_INT_P (size))
+ {
+ HOST_WIDE_INT new_size = (INTVAL (size) + align - 1) / align * align;
+
+ if (INTVAL (size) != new_size)
+ size = GEN_INT (new_size);
+ return size;
+ }
- if (INTVAL (size) != new_size)
- size = GEN_INT (new_size);
+ align_rtx = GEN_INT (align);
+ alignm1_rtx = GEN_INT (align - 1);
}
else
{
- /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
- but we know it can't. So add ourselves and then do
- TRUNC_DIV_EXPR. */
- size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1),
- NULL_RTX, 1, OPTAB_LIB_WIDEN);
- size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align),
- NULL_RTX, 1);
- size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1);
+ /* If crtl->preferred_stack_boundary might still grow, use
+ virtual_preferred_stack_boundary_rtx instead. This will be
+ substituted by the right value in vregs pass and optimized
+ during combine. */
+ align_rtx = virtual_preferred_stack_boundary_rtx;
+ alignm1_rtx = force_operand (plus_constant (align_rtx, -1), NULL_RTX);
}
+ /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
+ but we know it can't. So add ourselves and then do
+ TRUNC_DIV_EXPR. */
+ size = expand_binop (Pmode, add_optab, size, alignm1_rtx,
+ NULL_RTX, 1, OPTAB_LIB_WIDEN);
+ size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, align_rtx,
+ NULL_RTX, 1);
+ size = expand_mult (Pmode, size, align_rtx, NULL_RTX, 1);
+
return size;
}
\f
SIZE is an rtx representing the size of the area.
TARGET is a place in which the address can be placed.
- KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
+ KNOWN_ALIGN is the alignment (in bits) that we know SIZE has.
+
+ If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
+ stack space allocated by the generated code cannot be added with itself
+ in the course of the execution of the function. It is always safe to
+ pass FALSE here and the following criterion is sufficient in order to
+ pass TRUE: every path in the CFG that starts at the allocation point and
+ loops to it executes the associated deallocation code. */
rtx
-allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
+allocate_dynamic_stack_space (rtx size, rtx target, int known_align,
+ bool cannot_accumulate)
{
+ HOST_WIDE_INT stack_usage_size = -1;
+ bool known_align_valid = true;
+ rtx final_label, final_target;
+
/* If we're asking for zero bytes, it doesn't matter what we point
to since we can't dereference it. But return a reasonable
address anyway. */
/* Otherwise, show we're calling alloca or equivalent. */
cfun->calls_alloca = 1;
+ /* If stack usage info is requested, look into the size we are passed.
+ We need to do so this early to avoid the obfuscation that may be
+ introduced later by the various alignment operations. */
+ if (flag_stack_usage)
+ {
+ if (CONST_INT_P (size))
+ stack_usage_size = INTVAL (size);
+ else if (REG_P (size))
+ {
+ /* Look into the last emitted insn and see if we can deduce
+ something for the register. */
+ rtx insn, set, note;
+ insn = get_last_insn ();
+ if ((set = single_set (insn)) && rtx_equal_p (SET_DEST (set), size))
+ {
+ if (CONST_INT_P (SET_SRC (set)))
+ stack_usage_size = INTVAL (SET_SRC (set));
+ else if ((note = find_reg_equal_equiv_note (insn))
+ && CONST_INT_P (XEXP (note, 0)))
+ stack_usage_size = INTVAL (XEXP (note, 0));
+ }
+ }
+
+ /* If the size is not constant, we can't say anything. */
+ if (stack_usage_size == -1)
+ {
+ current_function_has_unbounded_dynamic_stack_size = 1;
+ stack_usage_size = 0;
+ }
+ }
+
/* Ensure the size is in the proper mode. */
if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
size = convert_to_mode (Pmode, size, 1);
/* We can't attempt to minimize alignment necessary, because we don't
know the final value of preferred_stack_boundary yet while executing
this code. */
- crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
+ if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
+ crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
/* We will need to ensure that the address we return is aligned to
BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
#if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
#define MUST_ALIGN 1
#else
-#define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
+#define MUST_ALIGN (crtl->preferred_stack_boundary < BIGGEST_ALIGNMENT)
#endif
if (MUST_ALIGN)
- size
- = force_operand (plus_constant (size,
- BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
- NULL_RTX);
+ {
+ size
+ = force_operand (plus_constant (size,
+ BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
+ NULL_RTX);
+
+ if (flag_stack_usage)
+ stack_usage_size += BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1;
+
+ known_align_valid = false;
+ }
#ifdef SETJMP_VIA_SAVE_AREA
/* If setjmp restores regs from a save area in the stack frame,
would use reg notes to store the "optimized" size and fix things
up later. These days we know this information before we ever
start building RTL so the reg notes are unnecessary. */
- if (!cfun->calls_setjmp)
- {
- int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
-
- /* ??? Code below assumes that the save area needs maximal
- alignment. This constraint may be too strong. */
- gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
-
- if (CONST_INT_P (size))
- {
- HOST_WIDE_INT new_size = INTVAL (size) / align * align;
-
- if (INTVAL (size) != new_size)
- size = GEN_INT (new_size);
- }
- else
- {
- /* Since we know overflow is not possible, we avoid using
- CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
- size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
- GEN_INT (align), NULL_RTX, 1);
- size = expand_mult (Pmode, size,
- GEN_INT (align), NULL_RTX, 1);
- }
- }
- else
+ if (cfun->calls_setjmp)
{
rtx dynamic_offset
= expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
size = expand_binop (Pmode, add_optab, size, dynamic_offset,
NULL_RTX, 1, OPTAB_LIB_WIDEN);
+
+ /* The above dynamic offset cannot be computed statically at this
+ point, but it will be possible to do so after RTL expansion is
+ done. Record how many times we will need to add it. */
+ if (flag_stack_usage)
+ current_function_dynamic_alloc_count++;
+
+ known_align_valid = false;
}
#endif /* SETJMP_VIA_SAVE_AREA */
insns. Since this is an extremely rare event, we have no reliable
way of knowing which systems have this problem. So we avoid even
momentarily mis-aligning the stack. */
+ if (!known_align_valid || known_align % MAX_SUPPORTED_STACK_ALIGNMENT != 0)
+ {
+ size = round_push (size);
+
+ if (flag_stack_usage)
+ {
+ int align = crtl->preferred_stack_boundary / BITS_PER_UNIT;
+ stack_usage_size = (stack_usage_size + align - 1) / align * align;
+ }
+ }
+
+ /* Don't use a TARGET that isn't a pseudo or is the wrong mode. */
+ if (target == 0 || !REG_P (target)
+ || REGNO (target) < FIRST_PSEUDO_REGISTER
+ || GET_MODE (target) != Pmode)
+ target = gen_reg_rtx (Pmode);
+
+ mark_reg_pointer (target, known_align);
+
+ /* The size is supposed to be fully adjusted at this point so record it
+ if stack usage info is requested. */
+ if (flag_stack_usage)
+ {
+ current_function_dynamic_stack_size += stack_usage_size;
+
+ /* ??? This is gross but the only safe stance in the absence
+ of stack usage oriented flow analysis. */
+ if (!cannot_accumulate)
+ current_function_has_unbounded_dynamic_stack_size = 1;
+ }
+
+ final_label = NULL_RTX;
+ final_target = NULL_RTX;
+
+ /* If we are splitting the stack, we need to ask the backend whether
+ there is enough room on the current stack. If there isn't, or if
+ the backend doesn't know how to tell is, then we need to call a
+ function to allocate memory in some other way. This memory will
+ be released when we release the current stack segment. The
+ effect is that stack allocation becomes less efficient, but at
+ least it doesn't cause a stack overflow. */
+ if (flag_split_stack)
+ {
+ rtx available_label, space, func;
+
+ available_label = NULL_RTX;
+
+#ifdef HAVE_split_stack_space_check
+ if (HAVE_split_stack_space_check)
+ {
+ available_label = gen_label_rtx ();
- /* If we added a variable amount to SIZE,
- we can no longer assume it is aligned. */
-#if !defined (SETJMP_VIA_SAVE_AREA)
- if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0)
+ /* This instruction will branch to AVAILABLE_LABEL if there
+ are SIZE bytes available on the stack. */
+ emit_insn (gen_split_stack_space_check (size, available_label));
+ }
#endif
- size = round_push (size);
+
+ func = init_one_libfunc ("__morestack_allocate_stack_space");
+
+ space = emit_library_call_value (func, target, LCT_NORMAL, Pmode,
+ 1, size, Pmode);
+
+ if (available_label == NULL_RTX)
+ return space;
+
+ final_target = gen_reg_rtx (Pmode);
+ mark_reg_pointer (final_target, known_align);
+
+ emit_move_insn (final_target, space);
+
+ final_label = gen_label_rtx ();
+ emit_jump (final_label);
+
+ emit_label (available_label);
+ }
do_pending_stack_adjust ();
gcc_assert (!(stack_pointer_delta
% (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)));
- /* If needed, check that we have the required amount of stack.
- Take into account what has already been checked. */
- if (flag_stack_check == GENERIC_STACK_CHECK)
+ /* If needed, check that we have the required amount of stack. Take into
+ account what has already been checked. */
+ if (STACK_CHECK_MOVING_SP)
+ ;
+ else if (flag_stack_check == GENERIC_STACK_CHECK)
probe_stack_range (STACK_OLD_CHECK_PROTECT + STACK_CHECK_MAX_FRAME_SIZE,
size);
else if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
probe_stack_range (STACK_CHECK_PROTECT, size);
- /* Don't use a TARGET that isn't a pseudo or is the wrong mode. */
- if (target == 0 || !REG_P (target)
- || REGNO (target) < FIRST_PSEUDO_REGISTER
- || GET_MODE (target) != Pmode)
- target = gen_reg_rtx (Pmode);
-
- mark_reg_pointer (target, known_align);
-
/* Perform the required allocation from the stack. Some systems do
this differently than simply incrementing/decrementing from the
stack pointer, such as acquiring the space by calling malloc(). */
else
#endif
{
+ int saved_stack_pointer_delta;
+
#ifndef STACK_GROWS_DOWNWARD
emit_move_insn (target, virtual_stack_dynamic_rtx);
#endif
emit_label (space_available);
}
- anti_adjust_stack (size);
+ saved_stack_pointer_delta = stack_pointer_delta;
+ if (flag_stack_check && STACK_CHECK_MOVING_SP)
+ anti_adjust_stack_and_probe (size, false);
+ else
+ anti_adjust_stack (size);
+ /* Even if size is constant, don't modify stack_pointer_delta.
+ The constant size alloca should preserve
+ crtl->preferred_stack_boundary alignment. */
+ stack_pointer_delta = saved_stack_pointer_delta;
#ifdef STACK_GROWS_DOWNWARD
emit_move_insn (target, virtual_stack_dynamic_rtx);
if (cfun->nonlocal_goto_save_area != 0)
update_nonlocal_goto_save_area ();
+ /* Finish up the split stack handling. */
+ if (final_label != NULL_RTX)
+ {
+ gcc_assert (flag_split_stack);
+ emit_move_insn (final_target, target);
+ emit_label (final_label);
+ target = final_target;
+ }
+
return target;
}
\f
static GTY(()) rtx stack_check_libfunc;
void
-set_stack_check_libfunc (rtx libfunc)
+set_stack_check_libfunc (const char *libfunc_name)
{
- stack_check_libfunc = libfunc;
+ gcc_assert (stack_check_libfunc == NULL_RTX);
+ stack_check_libfunc = gen_rtx_SYMBOL_REF (Pmode, libfunc_name);
}
\f
/* Emit one stack probe at ADDRESS, an address within the stack. */
-static void
+void
emit_stack_probe (rtx address)
{
rtx memref = gen_rtx_MEM (word_mode, address);
MEM_VOLATILE_P (memref) = 1;
- if (STACK_CHECK_PROBE_LOAD)
- emit_move_insn (gen_reg_rtx (word_mode), memref);
+ /* See if we have an insn to probe the stack. */
+#ifdef HAVE_probe_stack
+ if (HAVE_probe_stack)
+ emit_insn (gen_probe_stack (memref));
else
+#endif
emit_move_insn (memref, const0_rtx);
}
/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
- FIRST is a constant and size is a Pmode RTX. These are offsets from the
- current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
- subtract from the stack. If SIZE is constant, this is done
- with a fixed number of probes. Otherwise, we must make a loop. */
+ FIRST is a constant and size is a Pmode RTX. These are offsets from
+ the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
+ or subtract them from the stack pointer. */
+
+#define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
#ifdef STACK_GROWS_DOWNWARD
#define STACK_GROW_OP MINUS
+#define STACK_GROW_OPTAB sub_optab
+#define STACK_GROW_OFF(off) -(off)
#else
#define STACK_GROW_OP PLUS
+#define STACK_GROW_OPTAB add_optab
+#define STACK_GROW_OFF(off) (off)
#endif
void
if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
size = convert_to_mode (Pmode, size, 1);
- /* Next see if the front end has set up a function for us to call to
- check the stack. */
- if (stack_check_libfunc != 0)
+ /* Next see if we have a function to check the stack. */
+ if (stack_check_libfunc)
{
- rtx addr = memory_address (QImode,
+ rtx addr = memory_address (Pmode,
gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
stack_pointer_rtx,
plus_constant (size, first)));
-
- addr = convert_memory_address (ptr_mode, addr);
emit_library_call (stack_check_libfunc, LCT_NORMAL, VOIDmode, 1, addr,
- ptr_mode);
+ Pmode);
}
- /* Next see if we have an insn to check the stack. Use it if so. */
+ /* Next see if we have an insn to check the stack. */
#ifdef HAVE_check_stack
else if (HAVE_check_stack)
{
- insn_operand_predicate_fn pred;
- rtx last_addr
- = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
- stack_pointer_rtx,
- plus_constant (size, first)),
- NULL_RTX);
-
- pred = insn_data[(int) CODE_FOR_check_stack].operand[0].predicate;
- if (pred && ! ((*pred) (last_addr, Pmode)))
- last_addr = copy_to_mode_reg (Pmode, last_addr);
+ rtx addr = memory_address (Pmode,
+ gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
+ stack_pointer_rtx,
+ plus_constant (size, first)));
+ insn_operand_predicate_fn pred
+ = insn_data[(int) CODE_FOR_check_stack].operand[0].predicate;
+ if (pred && !((*pred) (addr, Pmode)))
+ addr = copy_to_mode_reg (Pmode, addr);
- emit_insn (gen_check_stack (last_addr));
+ emit_insn (gen_check_stack (addr));
}
#endif
- /* If we have to generate explicit probes, see if we have a constant
- small number of them to generate. If so, that's the easy case. */
- else if (CONST_INT_P (size)
- && INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL)
+ /* Otherwise we have to generate explicit probes. If we have a constant
+ small number of them to generate, that's the easy case. */
+ else if (CONST_INT_P (size) && INTVAL (size) < 7 * PROBE_INTERVAL)
{
- HOST_WIDE_INT offset;
-
- /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
- for values of N from 1 until it exceeds LAST. If only one
- probe is needed, this will not generate any code. Then probe
- at LAST. */
- for (offset = first + STACK_CHECK_PROBE_INTERVAL;
- offset < INTVAL (size);
- offset = offset + STACK_CHECK_PROBE_INTERVAL)
- emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
- stack_pointer_rtx,
- GEN_INT (offset)));
-
- emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
- stack_pointer_rtx,
- plus_constant (size, first)));
+ HOST_WIDE_INT isize = INTVAL (size), i;
+ rtx addr;
+
+ /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
+ it exceeds SIZE. If only one probe is needed, this will not
+ generate any code. Then probe at FIRST + SIZE. */
+ for (i = PROBE_INTERVAL; i < isize; i += PROBE_INTERVAL)
+ {
+ addr = memory_address (Pmode,
+ plus_constant (stack_pointer_rtx,
+ STACK_GROW_OFF (first + i)));
+ emit_stack_probe (addr);
+ }
+
+ addr = memory_address (Pmode,
+ plus_constant (stack_pointer_rtx,
+ STACK_GROW_OFF (first + isize)));
+ emit_stack_probe (addr);
}
- /* In the variable case, do the same as above, but in a loop. We emit loop
- notes so that loop optimization can be done. */
+ /* In the variable case, do the same as above, but in a loop. Note that we
+ must be extra careful with variables wrapping around because we might be
+ at the very top (or the very bottom) of the address space and we have to
+ be able to handle this case properly; in particular, we use an equality
+ test for the loop condition. */
else
{
- rtx test_addr
- = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
- stack_pointer_rtx,
- GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
- NULL_RTX);
- rtx last_addr
- = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
- stack_pointer_rtx,
- plus_constant (size, first)),
- NULL_RTX);
- rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
+ rtx rounded_size, rounded_size_op, test_addr, last_addr, temp;
rtx loop_lab = gen_label_rtx ();
- rtx test_lab = gen_label_rtx ();
rtx end_lab = gen_label_rtx ();
- rtx temp;
- if (!REG_P (test_addr)
- || REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
- test_addr = force_reg (Pmode, test_addr);
- emit_jump (test_lab);
+ /* Step 1: round SIZE to the previous multiple of the interval. */
+
+ /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
+ rounded_size
+ = simplify_gen_binary (AND, Pmode, size, GEN_INT (-PROBE_INTERVAL));
+ rounded_size_op = force_operand (rounded_size, NULL_RTX);
+
+
+ /* Step 2: compute initial and final value of the loop counter. */
+
+ /* TEST_ADDR = SP + FIRST. */
+ test_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
+ stack_pointer_rtx,
+ GEN_INT (first)), NULL_RTX);
+
+ /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
+ last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
+ test_addr,
+ rounded_size_op), NULL_RTX);
+
+
+ /* Step 3: the loop
+
+ while (TEST_ADDR != LAST_ADDR)
+ {
+ TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
+ probe at TEST_ADDR
+ }
+
+ probes at FIRST + N * PROBE_INTERVAL for values of N from 1
+ until it is equal to ROUNDED_SIZE. */
emit_label (loop_lab);
- emit_stack_probe (test_addr);
-#ifdef STACK_GROWS_DOWNWARD
-#define CMP_OPCODE GTU
- temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
- 1, OPTAB_WIDEN);
-#else
-#define CMP_OPCODE LTU
- temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
+ /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
+ emit_cmp_and_jump_insns (test_addr, last_addr, EQ, NULL_RTX, Pmode, 1,
+ end_lab);
+
+ /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
+ temp = expand_binop (Pmode, STACK_GROW_OPTAB, test_addr,
+ GEN_INT (PROBE_INTERVAL), test_addr,
1, OPTAB_WIDEN);
-#endif
gcc_assert (temp == test_addr);
- emit_label (test_lab);
- emit_cmp_and_jump_insns (test_addr, last_addr, CMP_OPCODE,
- NULL_RTX, Pmode, 1, loop_lab);
- emit_jump (end_lab);
+ /* Probe at TEST_ADDR. */
+ emit_stack_probe (test_addr);
+
+ emit_jump (loop_lab);
+
emit_label (end_lab);
- emit_stack_probe (last_addr);
+
+ /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
+ that SIZE is equal to ROUNDED_SIZE. */
+
+ /* TEMP = SIZE - ROUNDED_SIZE. */
+ temp = simplify_gen_binary (MINUS, Pmode, size, rounded_size);
+ if (temp != const0_rtx)
+ {
+ rtx addr;
+
+ if (CONST_INT_P (temp))
+ {
+ /* Use [base + disp} addressing mode if supported. */
+ HOST_WIDE_INT offset = INTVAL (temp);
+ addr = memory_address (Pmode,
+ plus_constant (last_addr,
+ STACK_GROW_OFF (offset)));
+ }
+ else
+ {
+ /* Manual CSE if the difference is not known at compile-time. */
+ temp = gen_rtx_MINUS (Pmode, size, rounded_size_op);
+ addr = memory_address (Pmode,
+ gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
+ last_addr, temp));
+ }
+
+ emit_stack_probe (addr);
+ }
}
}
-\f
+
+/* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
+ while probing it. This pushes when SIZE is positive. SIZE need not
+ be constant. If ADJUST_BACK is true, adjust back the stack pointer
+ by plus SIZE at the end. */
+
+void
+anti_adjust_stack_and_probe (rtx size, bool adjust_back)
+{
+ /* We skip the probe for the first interval + a small dope of 4 words and
+ probe that many bytes past the specified size to maintain a protection
+ area at the botton of the stack. */
+ const int dope = 4 * UNITS_PER_WORD;
+
+ /* First ensure SIZE is Pmode. */
+ if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
+ size = convert_to_mode (Pmode, size, 1);
+
+ /* If we have a constant small number of probes to generate, that's the
+ easy case. */
+ if (CONST_INT_P (size) && INTVAL (size) < 7 * PROBE_INTERVAL)
+ {
+ HOST_WIDE_INT isize = INTVAL (size), i;
+ bool first_probe = true;
+
+ /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
+ values of N from 1 until it exceeds SIZE. If only one probe is
+ needed, this will not generate any code. Then adjust and probe
+ to PROBE_INTERVAL + SIZE. */
+ for (i = PROBE_INTERVAL; i < isize; i += PROBE_INTERVAL)
+ {
+ if (first_probe)
+ {
+ anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL + dope));
+ first_probe = false;
+ }
+ else
+ anti_adjust_stack (GEN_INT (PROBE_INTERVAL));
+ emit_stack_probe (stack_pointer_rtx);
+ }
+
+ if (first_probe)
+ anti_adjust_stack (plus_constant (size, PROBE_INTERVAL + dope));
+ else
+ anti_adjust_stack (plus_constant (size, PROBE_INTERVAL - i));
+ emit_stack_probe (stack_pointer_rtx);
+ }
+
+ /* In the variable case, do the same as above, but in a loop. Note that we
+ must be extra careful with variables wrapping around because we might be
+ at the very top (or the very bottom) of the address space and we have to
+ be able to handle this case properly; in particular, we use an equality
+ test for the loop condition. */
+ else
+ {
+ rtx rounded_size, rounded_size_op, last_addr, temp;
+ rtx loop_lab = gen_label_rtx ();
+ rtx end_lab = gen_label_rtx ();
+
+
+ /* Step 1: round SIZE to the previous multiple of the interval. */
+
+ /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
+ rounded_size
+ = simplify_gen_binary (AND, Pmode, size, GEN_INT (-PROBE_INTERVAL));
+ rounded_size_op = force_operand (rounded_size, NULL_RTX);
+
+
+ /* Step 2: compute initial and final value of the loop counter. */
+
+ /* SP = SP_0 + PROBE_INTERVAL. */
+ anti_adjust_stack (GEN_INT (PROBE_INTERVAL + dope));
+
+ /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
+ last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
+ stack_pointer_rtx,
+ rounded_size_op), NULL_RTX);
+
+
+ /* Step 3: the loop
+
+ while (SP != LAST_ADDR)
+ {
+ SP = SP + PROBE_INTERVAL
+ probe at SP
+ }
+
+ adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
+ values of N from 1 until it is equal to ROUNDED_SIZE. */
+
+ emit_label (loop_lab);
+
+ /* Jump to END_LAB if SP == LAST_ADDR. */
+ emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, EQ, NULL_RTX,
+ Pmode, 1, end_lab);
+
+ /* SP = SP + PROBE_INTERVAL and probe at SP. */
+ anti_adjust_stack (GEN_INT (PROBE_INTERVAL));
+ emit_stack_probe (stack_pointer_rtx);
+
+ emit_jump (loop_lab);
+
+ emit_label (end_lab);
+
+
+ /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
+ assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
+
+ /* TEMP = SIZE - ROUNDED_SIZE. */
+ temp = simplify_gen_binary (MINUS, Pmode, size, rounded_size);
+ if (temp != const0_rtx)
+ {
+ /* Manual CSE if the difference is not known at compile-time. */
+ if (GET_CODE (temp) != CONST_INT)
+ temp = gen_rtx_MINUS (Pmode, size, rounded_size_op);
+ anti_adjust_stack (temp);
+ emit_stack_probe (stack_pointer_rtx);
+ }
+ }
+
+ /* Adjust back and account for the additional first interval. */
+ if (adjust_back)
+ adjust_stack (plus_constant (size, PROBE_INTERVAL + dope));
+ else
+ adjust_stack (GEN_INT (PROBE_INTERVAL + dope));
+}
+
/* Return an rtx representing the register or memory location
in which a scalar value of data type VALTYPE
was returned by a function call to function FUNC.
in which a scalar value of mode MODE was returned by a library call. */
rtx
-hard_libcall_value (enum machine_mode mode)
+hard_libcall_value (enum machine_mode mode, rtx fun)
{
- return LIBCALL_VALUE (mode);
+ return targetm.calls.libcall_value (mode, fun);
}
/* Look up the tree code for a given rtx code
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