/* Subroutines for manipulating rtx's in semantically interesting ways.
- Copyright (C) 1987-2013 Free Software Foundation, Inc.
+ Copyright (C) 1987-2021 Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
-#include "diagnostic-core.h"
+#include "target.h"
+#include "function.h"
#include "rtl.h"
#include "tree.h"
-#include "stor-layout.h"
+#include "memmodel.h"
#include "tm_p.h"
-#include "flags.h"
-#include "except.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 "expmed.h"
+#include "profile-count.h"
+#include "emit-rtl.h"
#include "recog.h"
-#include "langhooks.h"
-#include "target.h"
+#include "diagnostic-core.h"
+#include "stor-layout.h"
+#include "except.h"
+#include "dojump.h"
+#include "explow.h"
+#include "expr.h"
+#include "stringpool.h"
#include "common/common-target.h"
#include "output.h"
/* Truncate and perhaps sign-extend C as appropriate for MODE. */
HOST_WIDE_INT
-trunc_int_for_mode (HOST_WIDE_INT c, enum machine_mode mode)
+trunc_int_for_mode (HOST_WIDE_INT c, machine_mode mode)
{
- int width = GET_MODE_PRECISION (mode);
+ /* Not scalar_int_mode because we also allow pointer bound modes. */
+ scalar_mode smode = as_a <scalar_mode> (mode);
+ int width = GET_MODE_PRECISION (smode);
/* You want to truncate to a _what_? */
gcc_assert (SCALAR_INT_MODE_P (mode));
/* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
- if (mode == BImode)
+ if (smode == BImode)
return c & 1 ? STORE_FLAG_VALUE : 0;
/* Sign-extend for the requested mode. */
return c;
}
+/* Likewise for polynomial values, using the sign-extended representation
+ for each individual coefficient. */
+
+poly_int64
+trunc_int_for_mode (poly_int64 x, machine_mode mode)
+{
+ for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
+ x.coeffs[i] = trunc_int_for_mode (x.coeffs[i], mode);
+ return x;
+}
+
/* Return an rtx for the sum of X and the integer C, given that X has
- mode MODE. */
+ mode MODE. INPLACE is true if X can be modified inplace or false
+ if it must be treated as immutable. */
rtx
-plus_constant (enum machine_mode mode, rtx x, HOST_WIDE_INT c)
+plus_constant (machine_mode mode, rtx x, poly_int64 c, bool inplace)
{
RTX_CODE code;
rtx y;
gcc_assert (GET_MODE (x) == VOIDmode || GET_MODE (x) == mode);
- if (c == 0)
+ if (known_eq (c, 0))
return x;
restart:
switch (code)
{
- case CONST_INT:
- if (GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT)
- {
- double_int di_x = double_int::from_shwi (INTVAL (x));
- double_int di_c = double_int::from_shwi (c);
-
- bool overflow;
- double_int v = di_x.add_with_sign (di_c, false, &overflow);
- if (overflow)
- gcc_unreachable ();
-
- return immed_double_int_const (v, mode);
- }
-
- return gen_int_mode (INTVAL (x) + c, mode);
-
- case CONST_DOUBLE:
- {
- double_int di_x = double_int::from_pair (CONST_DOUBLE_HIGH (x),
- CONST_DOUBLE_LOW (x));
- double_int di_c = double_int::from_shwi (c);
-
- bool overflow;
- double_int v = di_x.add_with_sign (di_c, false, &overflow);
- if (overflow)
- /* Sorry, we have no way to represent overflows this wide.
- To fix, add constant support wider than CONST_DOUBLE. */
- gcc_assert (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_DOUBLE_INT);
-
- return immed_double_int_const (v, mode);
- }
-
+ CASE_CONST_SCALAR_INT:
+ return immed_wide_int_const (wi::add (rtx_mode_t (x, mode), c), mode);
case MEM:
/* If this is a reference to the constant pool, try replacing it with
a reference to a new constant. If the resulting address isn't
if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
&& CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
{
- tem = plus_constant (mode, get_pool_constant (XEXP (x, 0)), c);
- tem = force_const_mem (GET_MODE (x), tem);
- if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
- return tem;
+ rtx cst = get_pool_constant (XEXP (x, 0));
+
+ if (GET_CODE (cst) == CONST_VECTOR
+ && GET_MODE_INNER (GET_MODE (cst)) == mode)
+ {
+ cst = gen_lowpart (mode, cst);
+ gcc_assert (cst);
+ }
+ else if (GET_MODE (cst) == VOIDmode
+ && get_pool_mode (XEXP (x, 0)) != mode)
+ break;
+ if (GET_MODE (cst) == VOIDmode || GET_MODE (cst) == mode)
+ {
+ tem = plus_constant (mode, cst, c);
+ tem = force_const_mem (GET_MODE (x), tem);
+ /* Targets may disallow some constants in the constant pool, thus
+ force_const_mem may return NULL_RTX. */
+ if (tem && memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
+ return tem;
+ }
}
break;
case CONST:
/* If adding to something entirely constant, set a flag
so that we can add a CONST around the result. */
+ if (inplace && shared_const_p (x))
+ inplace = false;
x = XEXP (x, 0);
all_constant = 1;
goto restart;
if (CONSTANT_P (XEXP (x, 1)))
{
- x = gen_rtx_PLUS (mode, XEXP (x, 0),
- plus_constant (mode, XEXP (x, 1), c));
+ rtx term = plus_constant (mode, XEXP (x, 1), c, inplace);
+ if (term == const0_rtx)
+ x = XEXP (x, 0);
+ else if (inplace)
+ XEXP (x, 1) = term;
+ else
+ x = gen_rtx_PLUS (mode, XEXP (x, 0), term);
c = 0;
}
- else if (find_constant_term_loc (&y))
+ else if (rtx *const_loc = find_constant_term_loc (&y))
{
- /* We need to be careful since X may be shared and we can't
- modify it in place. */
- rtx copy = copy_rtx (x);
- rtx *const_loc = find_constant_term_loc (©);
-
- *const_loc = plus_constant (mode, *const_loc, c);
- x = copy;
+ if (!inplace)
+ {
+ /* We need to be careful since X may be shared and we can't
+ modify it in place. */
+ x = copy_rtx (x);
+ const_loc = find_constant_term_loc (&x);
+ }
+ *const_loc = plus_constant (mode, *const_loc, c, true);
c = 0;
}
break;
default:
+ if (CONST_POLY_INT_P (x))
+ return immed_wide_int_const (const_poly_int_value (x) + c, mode);
break;
}
- if (c != 0)
+ if (maybe_ne (c, 0))
x = gen_rtx_PLUS (mode, x, gen_int_mode (c, mode));
if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
/* First handle constants appearing at this level explicitly. */
if (CONST_INT_P (XEXP (x, 1))
- && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
- XEXP (x, 1)))
+ && (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
+ XEXP (x, 1))) != 0
&& CONST_INT_P (tem))
{
*constptr = tem;
x0 = eliminate_constant_term (XEXP (x, 0), &tem);
x1 = eliminate_constant_term (XEXP (x, 1), &tem);
if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
- && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
- *constptr, tem))
+ && (tem = simplify_binary_operation (PLUS, GET_MODE (x),
+ *constptr, tem)) != 0
&& CONST_INT_P (tem))
{
*constptr = tem;
return x;
}
-/* Returns a tree for the size of EXP in bytes. */
-
-static tree
-tree_expr_size (const_tree exp)
-{
- if (DECL_P (exp)
- && DECL_SIZE_UNIT (exp) != 0)
- return DECL_SIZE_UNIT (exp);
- else
- return size_in_bytes (TREE_TYPE (exp));
-}
-
-/* Return an rtx for the size in bytes of the value of EXP. */
-
-rtx
-expr_size (tree exp)
-{
- tree size;
-
- if (TREE_CODE (exp) == WITH_SIZE_EXPR)
- size = TREE_OPERAND (exp, 1);
- else
- {
- size = tree_expr_size (exp);
- gcc_assert (size);
- gcc_assert (size == SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, exp));
- }
-
- return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), EXPAND_NORMAL);
-}
-
-/* Return a wide integer for the size in bytes of the value of EXP, or -1
- if the size can vary or is larger than an integer. */
-
-HOST_WIDE_INT
-int_expr_size (tree exp)
-{
- tree size;
-
- if (TREE_CODE (exp) == WITH_SIZE_EXPR)
- size = TREE_OPERAND (exp, 1);
- else
- {
- size = tree_expr_size (exp);
- gcc_assert (size);
- }
-
- if (size == 0 || !tree_fits_shwi_p (size))
- return -1;
-
- return tree_to_shwi (size);
-}
\f
/* Return a copy of X in which all memory references
and all constants that involve symbol refs
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. */
+ arithmetic insns can be used. IN_CONST is true if this conversion is inside
+ a CONST. NO_EMIT is true if no insns should be emitted, and instead
+ it should return NULL if it can't be simplified without emitting insns. */
rtx
-convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED,
- rtx x, addr_space_t as ATTRIBUTE_UNUSED)
+convert_memory_address_addr_space_1 (scalar_int_mode to_mode ATTRIBUTE_UNUSED,
+ rtx x, addr_space_t as ATTRIBUTE_UNUSED,
+ bool in_const ATTRIBUTE_UNUSED,
+ bool no_emit 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 pointer_mode, address_mode, from_mode;
+ scalar_int_mode pointer_mode, address_mode, from_mode;
rtx temp;
enum rtx_code code;
break;
case LABEL_REF:
- temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
+ temp = gen_rtx_LABEL_REF (to_mode, label_ref_label (x));
LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
return temp;
- break;
case SYMBOL_REF:
temp = shallow_copy_rtx (x);
PUT_MODE (temp, to_mode);
return temp;
- break;
case CONST:
- return gen_rtx_CONST (to_mode,
- convert_memory_address_addr_space
- (to_mode, XEXP (x, 0), as));
- break;
+ temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), as,
+ true, no_emit);
+ return temp ? gen_rtx_CONST (to_mode, temp) : temp;
case PLUS:
case MULT:
- /* FIXME: For addition, we used to permute the conversion and
- addition operation only if one operand is a constant and
- converting the constant does not change it or if one operand
- is a constant and we are using a ptr_extend instruction
- (POINTERS_EXTEND_UNSIGNED < 0) even if the resulting address
- may overflow/underflow. We relax the condition to include
- zero-extend (POINTERS_EXTEND_UNSIGNED > 0) since the other
- parts of the compiler depend on it. See PR 49721.
-
+ /* For addition we can safely permute the conversion and addition
+ operation if one operand is a constant and converting the constant
+ does not change it or if one operand is a constant and we are
+ using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
We can always safely permute them if we are making the address
- narrower. */
+ narrower. Inside a CONST RTL, this is safe for both pointers
+ zero or sign extended as pointers cannot wrap. */
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
|| (GET_CODE (x) == PLUS
&& CONST_INT_P (XEXP (x, 1))
- && (POINTERS_EXTEND_UNSIGNED != 0
- || XEXP (x, 1) == convert_memory_address_addr_space
- (to_mode, XEXP (x, 1), as))))
- return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
- convert_memory_address_addr_space
- (to_mode, XEXP (x, 0), as),
- XEXP (x, 1));
+ && ((in_const && POINTERS_EXTEND_UNSIGNED != 0)
+ || XEXP (x, 1) == convert_memory_address_addr_space_1
+ (to_mode, XEXP (x, 1), as, in_const,
+ no_emit)
+ || POINTERS_EXTEND_UNSIGNED < 0)))
+ {
+ temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0),
+ as, in_const, no_emit);
+ return (temp ? gen_rtx_fmt_ee (GET_CODE (x), to_mode,
+ temp, XEXP (x, 1))
+ : temp);
+ }
+ break;
+
+ case UNSPEC:
+ /* Assume that all UNSPECs in a constant address can be converted
+ operand-by-operand. We could add a target hook if some targets
+ require different behavior. */
+ if (in_const && GET_MODE (x) == from_mode)
+ {
+ unsigned int n = XVECLEN (x, 0);
+ rtvec v = gen_rtvec (n);
+ for (unsigned int i = 0; i < n; ++i)
+ {
+ rtx op = XVECEXP (x, 0, i);
+ if (GET_MODE (op) == from_mode)
+ op = convert_memory_address_addr_space_1 (to_mode, op, as,
+ in_const, no_emit);
+ RTVEC_ELT (v, i) = op;
+ }
+ return gen_rtx_UNSPEC (to_mode, v, XINT (x, 1));
+ }
break;
default:
break;
}
+ if (no_emit)
+ return NULL_RTX;
+
return convert_modes (to_mode, from_mode,
x, POINTERS_EXTEND_UNSIGNED);
#endif /* defined(POINTERS_EXTEND_UNSIGNED) */
}
+
+/* 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_addr_space (scalar_int_mode to_mode, rtx x,
+ addr_space_t as)
+{
+ return convert_memory_address_addr_space_1 (to_mode, x, as, false, false);
+}
\f
+
/* 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_addr_space (enum machine_mode mode, rtx x, addr_space_t as)
+memory_address_addr_space (machine_mode mode, rtx x, addr_space_t as)
{
rtx oldx = x;
- enum machine_mode address_mode = targetm.addr_space.address_mode (as);
+ scalar_int_mode address_mode = targetm.addr_space.address_mode (as);
x = convert_memory_address_addr_space (address_mode, x, as);
{
rtx base;
HOST_WIDE_INT offset;
- enum machine_mode mode;
+ machine_mode mode;
if (!flag_section_anchors)
return x;
in case X is a constant. */
rtx
-copy_to_mode_reg (enum machine_mode mode, rtx x)
+copy_to_mode_reg (machine_mode mode, rtx x)
{
rtx temp = gen_reg_rtx (mode);
since we mark it as a "constant" register. */
rtx
-force_reg (enum machine_mode mode, rtx x)
+force_reg (machine_mode mode, rtx x)
{
- rtx temp, insn, set;
+ rtx temp, set;
+ rtx_insn *insn;
if (REG_P (x))
return x;
MODE is the mode to use for X in case it is a constant. */
rtx
-copy_to_suggested_reg (rtx x, rtx target, enum machine_mode mode)
+copy_to_suggested_reg (rtx x, rtx target, machine_mode mode)
{
rtx temp;
FOR_RETURN is nonzero if the caller is promoting the return value
of FNDECL, else it is for promoting args. */
-enum machine_mode
-promote_function_mode (const_tree type, enum machine_mode mode, int *punsignedp,
+machine_mode
+promote_function_mode (const_tree type, machine_mode mode, int *punsignedp,
const_tree funtype, int for_return)
{
/* Called without a type node for a libcall. */
PUNSIGNEDP points to the signedness of the type and may be adjusted
to show what signedness to use on extension operations. */
-enum machine_mode
-promote_mode (const_tree type ATTRIBUTE_UNUSED, enum machine_mode mode,
+machine_mode
+promote_mode (const_tree type ATTRIBUTE_UNUSED, machine_mode mode,
int *punsignedp ATTRIBUTE_UNUSED)
{
#ifdef PROMOTE_MODE
enum tree_code code;
int unsignedp;
+ scalar_mode smode;
#endif
/* For libcalls this is invoked without TYPE from the backends
{
case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE:
- PROMOTE_MODE (mode, unsignedp, type);
+ /* Values of these types always have scalar mode. */
+ smode = as_a <scalar_mode> (mode);
+ PROMOTE_MODE (smode, unsignedp, type);
*punsignedp = unsignedp;
- return mode;
- break;
+ return smode;
#ifdef POINTERS_EXTEND_UNSIGNED
case REFERENCE_TYPE:
*punsignedp = POINTERS_EXTEND_UNSIGNED;
return targetm.addr_space.address_mode
(TYPE_ADDR_SPACE (TREE_TYPE (type)));
- break;
#endif
default:
mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
of DECL after promotion. */
-enum machine_mode
+machine_mode
promote_decl_mode (const_tree decl, int *punsignedp)
{
tree type = TREE_TYPE (decl);
int unsignedp = TYPE_UNSIGNED (type);
- enum machine_mode mode = DECL_MODE (decl);
- enum machine_mode pmode;
+ machine_mode mode = DECL_MODE (decl);
+ machine_mode pmode;
- if (TREE_CODE (decl) == RESULT_DECL
- || TREE_CODE (decl) == PARM_DECL)
+ if (TREE_CODE (decl) == RESULT_DECL && !DECL_BY_REFERENCE (decl))
+ pmode = promote_function_mode (type, mode, &unsignedp,
+ TREE_TYPE (current_function_decl), 1);
+ else if (TREE_CODE (decl) == RESULT_DECL || TREE_CODE (decl) == PARM_DECL)
pmode = promote_function_mode (type, mode, &unsignedp,
TREE_TYPE (current_function_decl), 2);
else
return pmode;
}
+/* Return the promoted mode for name. If it is a named SSA_NAME, it
+ is the same as promote_decl_mode. Otherwise, it is the promoted
+ mode of a temp decl of same type as the SSA_NAME, if we had created
+ one. */
+
+machine_mode
+promote_ssa_mode (const_tree name, int *punsignedp)
+{
+ gcc_assert (TREE_CODE (name) == SSA_NAME);
+
+ /* Partitions holding parms and results must be promoted as expected
+ by function.c. */
+ if (SSA_NAME_VAR (name)
+ && (TREE_CODE (SSA_NAME_VAR (name)) == PARM_DECL
+ || TREE_CODE (SSA_NAME_VAR (name)) == RESULT_DECL))
+ {
+ machine_mode mode = promote_decl_mode (SSA_NAME_VAR (name), punsignedp);
+ if (mode != BLKmode)
+ return mode;
+ }
+
+ tree type = TREE_TYPE (name);
+ int unsignedp = TYPE_UNSIGNED (type);
+ machine_mode pmode = promote_mode (type, TYPE_MODE (type), &unsignedp);
+ if (punsignedp)
+ *punsignedp = unsignedp;
+
+ return pmode;
+}
+
+
\f
-/* Controls the behaviour of {anti_,}adjust_stack. */
+/* Controls the behavior of {anti_,}adjust_stack. */
static bool suppress_reg_args_size;
/* A helper for adjust_stack and anti_adjust_stack. */
static void
adjust_stack_1 (rtx adjust, bool anti_p)
{
- rtx temp, insn;
+ rtx temp;
+ rtx_insn *insn;
-#ifndef STACK_GROWS_DOWNWARD
/* Hereafter anti_p means subtract_p. */
- anti_p = !anti_p;
-#endif
+ if (!STACK_GROWS_DOWNWARD)
+ anti_p = !anti_p;
temp = expand_binop (Pmode,
anti_p ? sub_optab : add_optab,
}
if (!suppress_reg_args_size)
- add_reg_note (insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
+ add_args_size_note (insn, stack_pointer_delta);
}
/* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
/* We expect all variable sized adjustments to be multiple of
PREFERRED_STACK_BOUNDARY. */
- if (CONST_INT_P (adjust))
- stack_pointer_delta -= INTVAL (adjust);
+ poly_int64 const_adjust;
+ if (poly_int_rtx_p (adjust, &const_adjust))
+ stack_pointer_delta -= const_adjust;
adjust_stack_1 (adjust, false);
}
/* We expect all variable sized adjustments to be multiple of
PREFERRED_STACK_BOUNDARY. */
- if (CONST_INT_P (adjust))
- stack_pointer_delta += INTVAL (adjust);
+ poly_int64 const_adjust;
+ if (poly_int_rtx_p (adjust, &const_adjust))
+ stack_pointer_delta += const_adjust;
adjust_stack_1 (adjust, true);
}
{
rtx sa = *psave;
/* The default is that we use a move insn and save in a Pmode object. */
- rtx (*fcn) (rtx, rtx) = gen_move_insn;
- enum machine_mode mode = STACK_SAVEAREA_MODE (save_level);
+ rtx_insn *(*fcn) (rtx, rtx) = gen_move_insn;
+ machine_mode mode = STACK_SAVEAREA_MODE (save_level);
/* See if this machine has anything special to do for this kind of save. */
switch (save_level)
{
-#ifdef HAVE_save_stack_block
case SAVE_BLOCK:
- if (HAVE_save_stack_block)
- fcn = gen_save_stack_block;
+ if (targetm.have_save_stack_block ())
+ fcn = targetm.gen_save_stack_block;
break;
-#endif
-#ifdef HAVE_save_stack_function
case SAVE_FUNCTION:
- if (HAVE_save_stack_function)
- fcn = gen_save_stack_function;
+ if (targetm.have_save_stack_function ())
+ fcn = targetm.gen_save_stack_function;
break;
-#endif
-#ifdef HAVE_save_stack_nonlocal
case SAVE_NONLOCAL:
- if (HAVE_save_stack_nonlocal)
- fcn = gen_save_stack_nonlocal;
+ if (targetm.have_save_stack_nonlocal ())
+ fcn = targetm.gen_save_stack_nonlocal;
break;
-#endif
default:
break;
}
emit_stack_restore (enum save_level save_level, rtx sa)
{
/* The default is that we use a move insn. */
- rtx (*fcn) (rtx, rtx) = gen_move_insn;
+ rtx_insn *(*fcn) (rtx, rtx) = gen_move_insn;
/* If stack_realign_drap, the x86 backend emits a prologue that aligns both
STACK_POINTER and HARD_FRAME_POINTER.
/* See if this machine has anything special to do for this kind of save. */
switch (save_level)
{
-#ifdef HAVE_restore_stack_block
case SAVE_BLOCK:
- if (HAVE_restore_stack_block)
- fcn = gen_restore_stack_block;
+ if (targetm.have_restore_stack_block ())
+ fcn = targetm.gen_restore_stack_block;
break;
-#endif
-#ifdef HAVE_restore_stack_function
case SAVE_FUNCTION:
- if (HAVE_restore_stack_function)
- fcn = gen_restore_stack_function;
+ if (targetm.have_restore_stack_function ())
+ fcn = targetm.gen_restore_stack_function;
break;
-#endif
-#ifdef HAVE_restore_stack_nonlocal
case SAVE_NONLOCAL:
- if (HAVE_restore_stack_nonlocal)
- fcn = gen_restore_stack_nonlocal;
+ if (targetm.have_restore_stack_nonlocal ())
+ fcn = targetm.gen_restore_stack_nonlocal;
break;
-#endif
default:
break;
}
}
/* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
- function. This function should be called whenever we allocate or
- deallocate dynamic stack space. */
+ function. This should be called whenever we allocate or deallocate
+ dynamic stack space. */
void
update_nonlocal_goto_save_area (void)
emit_stack_save (SAVE_NONLOCAL, &r_save);
}
-\f
-/* Return an rtx representing the address of an area of memory dynamically
- pushed on the stack.
- Any required stack pointer alignment is preserved.
-
- SIZE is an rtx representing the size of the area.
-
- SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
- parameter may be zero. If so, a proper value will be extracted
- from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
+/* Record a new stack level for the current function. This should be called
+ whenever we allocate or deallocate dynamic stack space. */
- REQUIRED_ALIGN is the alignment (in bits) required for the region
- of memory.
+void
+record_new_stack_level (void)
+{
+ /* Record the new stack level for nonlocal gotos. */
+ if (cfun->nonlocal_goto_save_area)
+ update_nonlocal_goto_save_area ();
+
+ /* Record the new stack level for SJLJ exceptions. */
+ if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
+ update_sjlj_context ();
+}
- 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. */
+/* Return an rtx doing runtime alignment to REQUIRED_ALIGN on TARGET. */
rtx
-allocate_dynamic_stack_space (rtx size, unsigned size_align,
- unsigned required_align, bool cannot_accumulate)
+align_dynamic_address (rtx target, unsigned required_align)
{
- HOST_WIDE_INT stack_usage_size = -1;
- rtx final_label, final_target, target;
- unsigned extra_align = 0;
- bool must_align;
+ /* 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. */
+ target = expand_binop (Pmode, add_optab, target,
+ gen_int_mode (required_align / BITS_PER_UNIT - 1,
+ Pmode),
+ NULL_RTX, 1, OPTAB_LIB_WIDEN);
+ target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
+ gen_int_mode (required_align / BITS_PER_UNIT,
+ Pmode),
+ NULL_RTX, 1);
+ target = expand_mult (Pmode, target,
+ gen_int_mode (required_align / BITS_PER_UNIT,
+ Pmode),
+ NULL_RTX, 1);
- /* 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. */
- if (size == const0_rtx)
- return virtual_stack_dynamic_rtx;
+ return target;
+}
- /* Otherwise, show we're calling alloca or equivalent. */
- cfun->calls_alloca = 1;
+/* Return an rtx through *PSIZE, representing the size of an area of memory to
+ be dynamically pushed on the stack.
- /* 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_info)
- {
- 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));
- }
- }
+ *PSIZE is an rtx representing the size of the area.
- /* 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;
- }
- }
+ SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
+ parameter may be zero. If so, a proper value will be extracted
+ from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
+
+ REQUIRED_ALIGN is the alignment (in bits) required for the region
+ of memory.
+
+ If PSTACK_USAGE_SIZE is not NULL it points to a value that is increased for
+ the additional size returned. */
+void
+get_dynamic_stack_size (rtx *psize, unsigned size_align,
+ unsigned required_align,
+ HOST_WIDE_INT *pstack_usage_size)
+{
+ rtx size = *psize;
/* Ensure the size is in the proper mode. */
if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
size = convert_to_mode (Pmode, size, 1);
- /* Adjust SIZE_ALIGN, if needed. */
if (CONST_INT_P (size))
{
unsigned HOST_WIDE_INT lsb;
crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
/* We will need to ensure that the address we return is aligned to
- REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
- always know its final value at this point in the compilation (it
- might depend on the size of the outgoing parameter lists, for
- example), so we must align the value to be returned in that case.
- (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
- STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
- We must also do an alignment operation on the returned value if
- the stack pointer alignment is less strict than REQUIRED_ALIGN.
-
- If we have to align, we must leave space in SIZE for the hole
- that might result from the alignment operation. */
-
- must_align = (crtl->preferred_stack_boundary < required_align);
- if (must_align)
- {
- if (required_align > PREFERRED_STACK_BOUNDARY)
- extra_align = PREFERRED_STACK_BOUNDARY;
- else if (required_align > STACK_BOUNDARY)
- extra_align = STACK_BOUNDARY;
- else
- extra_align = BITS_PER_UNIT;
- }
-
- /* ??? STACK_POINTER_OFFSET is always defined now. */
-#if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
- must_align = true;
- extra_align = BITS_PER_UNIT;
-#endif
-
- if (must_align)
+ REQUIRED_ALIGN. At this point in the compilation, we don't always
+ know the final value of the STACK_DYNAMIC_OFFSET used in function.c
+ (it might depend on the size of the outgoing parameter lists, for
+ example), so we must preventively align the value. We leave space
+ in SIZE for the hole that might result from the alignment operation. */
+
+ unsigned known_align = REGNO_POINTER_ALIGN (VIRTUAL_STACK_DYNAMIC_REGNUM);
+ if (known_align == 0)
+ known_align = BITS_PER_UNIT;
+ if (required_align > known_align)
{
- unsigned extra = (required_align - extra_align) / BITS_PER_UNIT;
-
+ unsigned extra = (required_align - known_align) / BITS_PER_UNIT;
size = plus_constant (Pmode, size, extra);
size = force_operand (size, NULL_RTX);
+ if (size_align > known_align)
+ size_align = known_align;
- if (flag_stack_usage_info)
- stack_usage_size += extra;
-
- if (extra && size_align > extra_align)
- size_align = extra_align;
+ if (flag_stack_usage_info && pstack_usage_size)
+ *pstack_usage_size += extra;
}
/* Round the size to a multiple of the required stack alignment.
- Since the stack if presumed to be rounded before this allocation,
+ Since the stack is presumed to be rounded before this allocation,
this will maintain the required alignment.
If the stack grows downward, we could save an insn by subtracting
{
size = round_push (size);
- if (flag_stack_usage_info)
+ if (flag_stack_usage_info && pstack_usage_size)
{
int align = crtl->preferred_stack_boundary / BITS_PER_UNIT;
- stack_usage_size = (stack_usage_size + align - 1) / align * align;
+ *pstack_usage_size =
+ (*pstack_usage_size + align - 1) / align * align;
+ }
+ }
+
+ *psize = size;
+}
+
+/* Return the number of bytes to "protect" on the stack for -fstack-check.
+
+ "protect" in the context of -fstack-check means how many bytes we need
+ to always ensure are available on the stack; as a consequence, this is
+ also how many bytes are first skipped when probing the stack.
+
+ On some targets we want to reuse the -fstack-check prologue support
+ to give a degree of protection against stack clashing style attacks.
+
+ In that scenario we do not want to skip bytes before probing as that
+ would render the stack clash protections useless.
+
+ So we never use STACK_CHECK_PROTECT directly. Instead we indirectly
+ use it through this helper, which allows to provide different values
+ for -fstack-check and -fstack-clash-protection. */
+
+HOST_WIDE_INT
+get_stack_check_protect (void)
+{
+ if (flag_stack_clash_protection)
+ return 0;
+
+ return STACK_CHECK_PROTECT;
+}
+
+/* Return an rtx representing the address of an area of memory dynamically
+ pushed on the stack.
+
+ Any required stack pointer alignment is preserved.
+
+ SIZE is an rtx representing the size of the area.
+
+ SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
+ parameter may be zero. If so, a proper value will be extracted
+ from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
+
+ REQUIRED_ALIGN is the alignment (in bits) required for the region
+ of memory.
+
+ MAX_SIZE is an upper bound for SIZE, if SIZE is not constant, or -1 if
+ no such upper bound is known.
+
+ 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, unsigned size_align,
+ unsigned required_align,
+ HOST_WIDE_INT max_size,
+ bool cannot_accumulate)
+{
+ HOST_WIDE_INT stack_usage_size = -1;
+ rtx_code_label *final_label;
+ rtx final_target, 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. */
+ if (size == const0_rtx)
+ return virtual_stack_dynamic_rtx;
+
+ /* 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_info)
+ {
+ 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 *insn;
+ rtx 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, try the maximum size. */
+ if (stack_usage_size < 0)
+ stack_usage_size = max_size;
+
+ /* If the size is still not constant, we can't say anything. */
+ if (stack_usage_size < 0)
+ {
+ current_function_has_unbounded_dynamic_stack_size = 1;
+ stack_usage_size = 0;
}
}
+ get_dynamic_stack_size (&size, size_align, required_align, &stack_usage_size);
+
target = gen_reg_rtx (Pmode);
/* The size is supposed to be fully adjusted at this point so record it
current_function_has_unbounded_dynamic_stack_size = 1;
}
- final_label = NULL_RTX;
+ do_pending_stack_adjust ();
+
+ final_label = NULL;
final_target = NULL_RTX;
/* If we are splitting the stack, we need to ask the backend whether
least it doesn't cause a stack overflow. */
if (flag_split_stack)
{
- rtx available_label, ask, space, func;
+ rtx_code_label *available_label;
+ rtx ask, space, func;
- available_label = NULL_RTX;
+ available_label = NULL;
-#ifdef HAVE_split_stack_space_check
- if (HAVE_split_stack_space_check)
+ if (targetm.have_split_stack_space_check ())
{
available_label = gen_label_rtx ();
/* 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));
+ emit_insn (targetm.gen_split_stack_space_check
+ (size, available_label));
}
-#endif
/* The __morestack_allocate_stack_space function will allocate
memory using malloc. If the alignment of the memory returned
if (MALLOC_ABI_ALIGNMENT >= required_align)
ask = size;
else
- {
- ask = expand_binop (Pmode, add_optab, size,
- gen_int_mode (required_align / BITS_PER_UNIT - 1,
- Pmode),
- NULL_RTX, 1, OPTAB_LIB_WIDEN);
- must_align = true;
- }
+ ask = expand_binop (Pmode, add_optab, size,
+ gen_int_mode (required_align / BITS_PER_UNIT - 1,
+ Pmode),
+ NULL_RTX, 1, OPTAB_LIB_WIDEN);
func = init_one_libfunc ("__morestack_allocate_stack_space");
space = emit_library_call_value (func, target, LCT_NORMAL, Pmode,
- 1, ask, Pmode);
+ ask, Pmode);
if (available_label == NULL_RTX)
return space;
emit_label (available_label);
}
- do_pending_stack_adjust ();
-
/* We ought to be called always on the toplevel and stack ought to be aligned
properly. */
- gcc_assert (!(stack_pointer_delta
- % (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)));
+ gcc_assert (multiple_p (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. */
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);
+ probe_stack_range (get_stack_check_protect (), size);
/* Don't let anti_adjust_stack emit notes. */
suppress_reg_args_size = true;
/* 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(). */
-#ifdef HAVE_allocate_stack
- if (HAVE_allocate_stack)
+ if (targetm.have_allocate_stack ())
{
- struct expand_operand ops[2];
+ class expand_operand ops[2];
/* We don't have to check against the predicate for operand 0 since
TARGET is known to be a pseudo of the proper mode, which must
be valid for the operand. */
create_fixed_operand (&ops[0], target);
create_convert_operand_to (&ops[1], size, STACK_SIZE_MODE, true);
- expand_insn (CODE_FOR_allocate_stack, 2, ops);
+ expand_insn (targetm.code_for_allocate_stack, 2, ops);
}
else
-#endif
{
- int saved_stack_pointer_delta;
+ poly_int64 saved_stack_pointer_delta;
-#ifndef STACK_GROWS_DOWNWARD
- emit_move_insn (target, virtual_stack_dynamic_rtx);
-#endif
+ if (!STACK_GROWS_DOWNWARD)
+ emit_move_insn (target, virtual_stack_dynamic_rtx);
/* Check stack bounds if necessary. */
if (crtl->limit_stack)
{
rtx available;
- rtx space_available = gen_label_rtx ();
-#ifdef STACK_GROWS_DOWNWARD
- available = expand_binop (Pmode, sub_optab,
- stack_pointer_rtx, stack_limit_rtx,
- NULL_RTX, 1, OPTAB_WIDEN);
-#else
- available = expand_binop (Pmode, sub_optab,
- stack_limit_rtx, stack_pointer_rtx,
- NULL_RTX, 1, OPTAB_WIDEN);
-#endif
+ rtx_code_label *space_available = gen_label_rtx ();
+ if (STACK_GROWS_DOWNWARD)
+ available = expand_binop (Pmode, sub_optab,
+ stack_pointer_rtx, stack_limit_rtx,
+ NULL_RTX, 1, OPTAB_WIDEN);
+ else
+ available = expand_binop (Pmode, sub_optab,
+ stack_limit_rtx, stack_pointer_rtx,
+ NULL_RTX, 1, OPTAB_WIDEN);
+
emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1,
space_available);
-#ifdef HAVE_trap
- if (HAVE_trap)
- emit_insn (gen_trap ());
+ if (targetm.have_trap ())
+ emit_insn (targetm.gen_trap ());
else
-#endif
error ("stack limits not supported on this target");
emit_barrier ();
emit_label (space_available);
saved_stack_pointer_delta = stack_pointer_delta;
+ /* If stack checking or stack clash protection is requested,
+ then probe the stack while allocating space from it. */
if (flag_stack_check && STACK_CHECK_MOVING_SP)
anti_adjust_stack_and_probe (size, false);
+ else if (flag_stack_clash_protection)
+ anti_adjust_stack_and_probe_stack_clash (size);
else
anti_adjust_stack (size);
crtl->preferred_stack_boundary alignment. */
stack_pointer_delta = saved_stack_pointer_delta;
-#ifdef STACK_GROWS_DOWNWARD
- emit_move_insn (target, virtual_stack_dynamic_rtx);
-#endif
+ if (STACK_GROWS_DOWNWARD)
+ emit_move_insn (target, virtual_stack_dynamic_rtx);
}
suppress_reg_args_size = false;
target = final_target;
}
- if (must_align)
- {
- /* 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. */
- target = expand_binop (Pmode, add_optab, target,
- gen_int_mode (required_align / BITS_PER_UNIT - 1,
- Pmode),
- NULL_RTX, 1, OPTAB_LIB_WIDEN);
- target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
- gen_int_mode (required_align / BITS_PER_UNIT,
- Pmode),
- NULL_RTX, 1);
- target = expand_mult (Pmode, target,
- gen_int_mode (required_align / BITS_PER_UNIT,
- Pmode),
- NULL_RTX, 1);
- }
+ target = align_dynamic_address (target, required_align);
/* Now that we've committed to a return value, mark its alignment. */
mark_reg_pointer (target, required_align);
- /* Record the new stack level for nonlocal gotos. */
- if (cfun->nonlocal_goto_save_area != 0)
- update_nonlocal_goto_save_area ();
+ /* Record the new stack level. */
+ record_new_stack_level ();
+
+ return target;
+}
+
+/* Return an rtx representing the address of an area of memory already
+ statically pushed onto the stack in the virtual stack vars area. (It is
+ assumed that the area is allocated in the function prologue.)
+
+ Any required stack pointer alignment is preserved.
+
+ OFFSET is the offset of the area into the virtual stack vars area.
+
+ REQUIRED_ALIGN is the alignment (in bits) required for the region
+ of memory.
+
+ BASE is the rtx of the base of this virtual stack vars area.
+ The only time this is not `virtual_stack_vars_rtx` is when tagging pointers
+ on the stack. */
+
+rtx
+get_dynamic_stack_base (poly_int64 offset, unsigned required_align, rtx base)
+{
+ rtx target;
+
+ if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
+ crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
+
+ target = gen_reg_rtx (Pmode);
+ emit_move_insn (target, base);
+ target = expand_binop (Pmode, add_optab, target,
+ gen_int_mode (offset, Pmode),
+ NULL_RTX, 1, OPTAB_LIB_WIDEN);
+ target = align_dynamic_address (target, required_align);
+
+ /* Now that we've committed to a return value, mark its alignment. */
+ mark_reg_pointer (target, required_align);
return target;
}
{
gcc_assert (stack_check_libfunc == NULL_RTX);
stack_check_libfunc = gen_rtx_SYMBOL_REF (Pmode, libfunc_name);
+ tree decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
+ get_identifier (libfunc_name), void_type_node);
+ DECL_EXTERNAL (decl) = 1;
+ SET_SYMBOL_REF_DECL (stack_check_libfunc, decl);
}
\f
/* Emit one stack probe at ADDRESS, an address within the stack. */
void
emit_stack_probe (rtx address)
{
-#ifdef HAVE_probe_stack_address
- if (HAVE_probe_stack_address)
- emit_insn (gen_probe_stack_address (address));
+ if (targetm.have_probe_stack_address ())
+ {
+ class expand_operand ops[1];
+ insn_code icode = targetm.code_for_probe_stack_address;
+ create_address_operand (ops, address);
+ maybe_legitimize_operands (icode, 0, 1, ops);
+ expand_insn (icode, 1, ops);
+ }
else
-#endif
{
rtx memref = gen_rtx_MEM (word_mode, address);
MEM_VOLATILE_P (memref) = 1;
+ memref = validize_mem (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));
+ if (targetm.have_probe_stack ())
+ emit_insn (targetm.gen_probe_stack (memref));
else
-#endif
- emit_move_insn (memref, const0_rtx);
+ emit_move_insn (memref, const0_rtx);
}
}
#define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
-#ifdef STACK_GROWS_DOWNWARD
+#if STACK_GROWS_DOWNWARD
#define STACK_GROW_OP MINUS
#define STACK_GROW_OPTAB sub_optab
#define STACK_GROW_OFF(off) -(off)
stack_pointer_rtx,
plus_constant (Pmode,
size, first)));
- emit_library_call (stack_check_libfunc, LCT_NORMAL, VOIDmode, 1, addr,
- Pmode);
+ emit_library_call (stack_check_libfunc, LCT_THROW, VOIDmode,
+ addr, Pmode);
}
/* Next see if we have an insn to check the stack. */
-#ifdef HAVE_check_stack
- else if (HAVE_check_stack)
+ else if (targetm.have_check_stack ())
{
- struct expand_operand ops[1];
+ class expand_operand ops[1];
rtx addr = memory_address (Pmode,
gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
stack_pointer_rtx,
size, first)));
bool success;
create_input_operand (&ops[0], addr, Pmode);
- success = maybe_expand_insn (CODE_FOR_check_stack, 1, ops);
+ success = maybe_expand_insn (targetm.code_for_check_stack, 1, ops);
gcc_assert (success);
}
-#endif
/* Otherwise we have to generate explicit probes. If we have a constant
small number of them to generate, that's the easy case. */
else
{
rtx rounded_size, rounded_size_op, test_addr, last_addr, temp;
- rtx loop_lab = gen_label_rtx ();
- rtx end_lab = gen_label_rtx ();
-
+ rtx_code_label *loop_lab = gen_label_rtx ();
+ rtx_code_label *end_lab = gen_label_rtx ();
/* Step 1: round SIZE to the previous multiple of the interval. */
emit_stack_probe (addr);
}
}
+
+ /* Make sure nothing is scheduled before we are done. */
+ emit_insn (gen_blockage ());
+}
+
+/* Compute parameters for stack clash probing a dynamic stack
+ allocation of SIZE bytes.
+
+ We compute ROUNDED_SIZE, LAST_ADDR, RESIDUAL and PROBE_INTERVAL.
+
+ Additionally we conditionally dump the type of probing that will
+ be needed given the values computed. */
+
+void
+compute_stack_clash_protection_loop_data (rtx *rounded_size, rtx *last_addr,
+ rtx *residual,
+ HOST_WIDE_INT *probe_interval,
+ rtx size)
+{
+ /* Round SIZE down to STACK_CLASH_PROTECTION_PROBE_INTERVAL */
+ *probe_interval
+ = 1 << param_stack_clash_protection_probe_interval;
+ *rounded_size = simplify_gen_binary (AND, Pmode, size,
+ GEN_INT (-*probe_interval));
+
+ /* Compute the value of the stack pointer for the last iteration.
+ It's just SP + ROUNDED_SIZE. */
+ rtx rounded_size_op = force_operand (*rounded_size, NULL_RTX);
+ *last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
+ stack_pointer_rtx,
+ rounded_size_op),
+ NULL_RTX);
+
+ /* Compute any residuals not allocated by the loop above. Residuals
+ are just the ROUNDED_SIZE - SIZE. */
+ *residual = simplify_gen_binary (MINUS, Pmode, size, *rounded_size);
+
+ /* Dump key information to make writing tests easy. */
+ if (dump_file)
+ {
+ if (*rounded_size == CONST0_RTX (Pmode))
+ fprintf (dump_file,
+ "Stack clash skipped dynamic allocation and probing loop.\n");
+ else if (CONST_INT_P (*rounded_size)
+ && INTVAL (*rounded_size) <= 4 * *probe_interval)
+ fprintf (dump_file,
+ "Stack clash dynamic allocation and probing inline.\n");
+ else if (CONST_INT_P (*rounded_size))
+ fprintf (dump_file,
+ "Stack clash dynamic allocation and probing in "
+ "rotated loop.\n");
+ else
+ fprintf (dump_file,
+ "Stack clash dynamic allocation and probing in loop.\n");
+
+ if (*residual != CONST0_RTX (Pmode))
+ fprintf (dump_file,
+ "Stack clash dynamic allocation and probing residuals.\n");
+ else
+ fprintf (dump_file,
+ "Stack clash skipped dynamic allocation and "
+ "probing residuals.\n");
+ }
+}
+
+/* Emit the start of an allocate/probe loop for stack
+ clash protection.
+
+ LOOP_LAB and END_LAB are returned for use when we emit the
+ end of the loop.
+
+ LAST addr is the value for SP which stops the loop. */
+void
+emit_stack_clash_protection_probe_loop_start (rtx *loop_lab,
+ rtx *end_lab,
+ rtx last_addr,
+ bool rotated)
+{
+ /* Essentially we want to emit any setup code, the top of loop
+ label and the comparison at the top of the loop. */
+ *loop_lab = gen_label_rtx ();
+ *end_lab = gen_label_rtx ();
+
+ emit_label (*loop_lab);
+ if (!rotated)
+ emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, EQ, NULL_RTX,
+ Pmode, 1, *end_lab);
+}
+
+/* Emit the end of a stack clash probing loop.
+
+ This consists of just the jump back to LOOP_LAB and
+ emitting END_LOOP after the loop. */
+
+void
+emit_stack_clash_protection_probe_loop_end (rtx loop_lab, rtx end_loop,
+ rtx last_addr, bool rotated)
+{
+ if (rotated)
+ emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, NE, NULL_RTX,
+ Pmode, 1, loop_lab);
+ else
+ emit_jump (loop_lab);
+
+ emit_label (end_loop);
+
+}
+
+/* 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.
+
+ This is subtly different than anti_adjust_stack_and_probe to try and
+ prevent stack-clash attacks
+
+ 1. It must assume no knowledge of the probing state, any allocation
+ must probe.
+
+ Consider the case of a 1 byte alloca in a loop. If the sum of the
+ allocations is large, then this could be used to jump the guard if
+ probes were not emitted.
+
+ 2. It never skips probes, whereas anti_adjust_stack_and_probe will
+ skip the probe on the first PROBE_INTERVAL on the assumption it
+ was already done in the prologue and in previous allocations.
+
+ 3. It only allocates and probes SIZE bytes, it does not need to
+ allocate/probe beyond that because this probing style does not
+ guarantee signal handling capability if the guard is hit. */
+
+void
+anti_adjust_stack_and_probe_stack_clash (rtx size)
+{
+ /* First ensure SIZE is Pmode. */
+ if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
+ size = convert_to_mode (Pmode, size, 1);
+
+ /* We can get here with a constant size on some targets. */
+ rtx rounded_size, last_addr, residual;
+ HOST_WIDE_INT probe_interval, probe_range;
+ bool target_probe_range_p = false;
+ compute_stack_clash_protection_loop_data (&rounded_size, &last_addr,
+ &residual, &probe_interval, size);
+
+ /* Get the back-end specific probe ranges. */
+ probe_range = targetm.stack_clash_protection_alloca_probe_range ();
+ target_probe_range_p = probe_range != 0;
+ gcc_assert (probe_range >= 0);
+
+ /* If no back-end specific range defined, default to the top of the newly
+ allocated range. */
+ if (probe_range == 0)
+ probe_range = probe_interval - GET_MODE_SIZE (word_mode);
+
+ if (rounded_size != CONST0_RTX (Pmode))
+ {
+ if (CONST_INT_P (rounded_size)
+ && INTVAL (rounded_size) <= 4 * probe_interval)
+ {
+ for (HOST_WIDE_INT i = 0;
+ i < INTVAL (rounded_size);
+ i += probe_interval)
+ {
+ anti_adjust_stack (GEN_INT (probe_interval));
+ /* The prologue does not probe residuals. Thus the offset
+ here to probe just beyond what the prologue had already
+ allocated. */
+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
+ probe_range));
+
+ emit_insn (gen_blockage ());
+ }
+ }
+ else
+ {
+ rtx loop_lab, end_loop;
+ bool rotate_loop = CONST_INT_P (rounded_size);
+ emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop,
+ last_addr, rotate_loop);
+
+ anti_adjust_stack (GEN_INT (probe_interval));
+
+ /* The prologue does not probe residuals. Thus the offset here
+ to probe just beyond what the prologue had already
+ allocated. */
+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
+ probe_range));
+
+ emit_stack_clash_protection_probe_loop_end (loop_lab, end_loop,
+ last_addr, rotate_loop);
+ emit_insn (gen_blockage ());
+ }
+ }
+
+ if (residual != CONST0_RTX (Pmode))
+ {
+ rtx label = NULL_RTX;
+ /* RESIDUAL could be zero at runtime and in that case *sp could
+ hold live data. Furthermore, we do not want to probe into the
+ red zone.
+
+ If TARGET_PROBE_RANGE_P then the target has promised it's safe to
+ probe at offset 0. In which case we no longer have to check for
+ RESIDUAL == 0. However we still need to probe at the right offset
+ when RESIDUAL > PROBE_RANGE, in which case we probe at PROBE_RANGE.
+
+ If !TARGET_PROBE_RANGE_P then go ahead and just guard the probe at *sp
+ on RESIDUAL != 0 at runtime if RESIDUAL is not a compile time constant.
+ */
+ anti_adjust_stack (residual);
+
+ if (!CONST_INT_P (residual))
+ {
+ label = gen_label_rtx ();
+ rtx_code op = target_probe_range_p ? LT : EQ;
+ rtx probe_cmp_value = target_probe_range_p
+ ? gen_rtx_CONST_INT (GET_MODE (residual), probe_range)
+ : CONST0_RTX (GET_MODE (residual));
+
+ if (target_probe_range_p)
+ emit_stack_probe (stack_pointer_rtx);
+
+ emit_cmp_and_jump_insns (residual, probe_cmp_value,
+ op, NULL_RTX, Pmode, 1, label);
+ }
+
+ rtx x = NULL_RTX;
+
+ /* If RESIDUAL isn't a constant and TARGET_PROBE_RANGE_P then we probe up
+ by the ABI defined safe value. */
+ if (!CONST_INT_P (residual) && target_probe_range_p)
+ x = GEN_INT (probe_range);
+ /* If RESIDUAL is a constant but smaller than the ABI defined safe value,
+ we still want to probe up, but the safest amount if a word. */
+ else if (target_probe_range_p)
+ {
+ if (INTVAL (residual) <= probe_range)
+ x = GEN_INT (GET_MODE_SIZE (word_mode));
+ else
+ x = GEN_INT (probe_range);
+ }
+ else
+ /* If nothing else, probe at the top of the new allocation. */
+ x = plus_constant (Pmode, residual, -GET_MODE_SIZE (word_mode));
+
+ emit_stack_probe (gen_rtx_PLUS (Pmode, stack_pointer_rtx, x));
+
+ emit_insn (gen_blockage ());
+ if (!CONST_INT_P (residual))
+ emit_label (label);
+ }
}
+
/* 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
else
{
rtx rounded_size, rounded_size_op, last_addr, temp;
- rtx loop_lab = gen_label_rtx ();
- rtx end_lab = gen_label_rtx ();
+ rtx_code_label *loop_lab = gen_label_rtx ();
+ rtx_code_label *end_lab = gen_label_rtx ();
/* Step 1: round SIZE to the previous multiple of the interval. */
if (REG_P (val)
&& GET_MODE (val) == BLKmode)
{
- unsigned HOST_WIDE_INT bytes = int_size_in_bytes (valtype);
- enum machine_mode tmpmode;
+ unsigned HOST_WIDE_INT bytes = arg_int_size_in_bytes (valtype);
+ opt_scalar_int_mode tmpmode;
/* int_size_in_bytes can return -1. We don't need a check here
since the value of bytes will then be large enough that no
mode will match anyway. */
- for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
- tmpmode != VOIDmode;
- tmpmode = GET_MODE_WIDER_MODE (tmpmode))
+ FOR_EACH_MODE_IN_CLASS (tmpmode, MODE_INT)
{
/* Have we found a large enough mode? */
- if (GET_MODE_SIZE (tmpmode) >= bytes)
+ if (GET_MODE_SIZE (tmpmode.require ()) >= bytes)
break;
}
- /* No suitable mode found. */
- gcc_assert (tmpmode != VOIDmode);
-
- PUT_MODE (val, tmpmode);
+ PUT_MODE (val, tmpmode.require ());
}
return val;
}
in which a scalar value of mode MODE was returned by a library call. */
rtx
-hard_libcall_value (enum machine_mode mode, rtx fun)
+hard_libcall_value (machine_mode mode, rtx fun)
{
return targetm.calls.libcall_value (mode, fun);
}
/* Look up the tree code for a given rtx code
- to provide the arithmetic operation for REAL_ARITHMETIC.
+ to provide the arithmetic operation for real_arithmetic.
The function returns an int because the caller may not know
what `enum tree_code' means. */
projects / gcc.git / blobdiff