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builtins.c
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/* Expand builtin functions.
Copyright (C) 1988-2017 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* Legacy warning! Please add no further builtin simplifications here
(apart from pure constant folding) - builtin simplifications should go
to match.pd or gimple-fold.c instead. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "target.h"
#include "rtl.h"
#include "tree.h"
#include "memmodel.h"
#include "gimple.h"
#include "predict.h"
#include "tm_p.h"
#include "stringpool.h"
#include "tree-vrp.h"
#include "tree-ssanames.h"
#include "expmed.h"
#include "optabs.h"
#include "emit-rtl.h"
#include "recog.h"
#include "diagnostic-core.h"
#include "alias.h"
#include "fold-const.h"
#include "fold-const-call.h"
#include "stor-layout.h"
#include "calls.h"
#include "varasm.h"
#include "tree-object-size.h"
#include "realmpfr.h"
#include "cfgrtl.h"
#include "except.h"
#include "dojump.h"
#include "explow.h"
#include "stmt.h"
#include "expr.h"
#include "libfuncs.h"
#include "output.h"
#include "typeclass.h"
#include "langhooks.h"
#include "value-prof.h"
#include "builtins.h"
#include "stringpool.h"
#include "attribs.h"
#include "asan.h"
#include "cilk.h"
#include "tree-chkp.h"
#include "rtl-chkp.h"
#include "internal-fn.h"
#include "case-cfn-macros.h"
#include "gimple-fold.h"
#include "intl.h"
struct target_builtins default_target_builtins;
#if SWITCHABLE_TARGET
struct target_builtins *this_target_builtins = &default_target_builtins;
#endif
/* Define the names of the builtin function types and codes. */
const char *const built_in_class_names[BUILT_IN_LAST]
= {"NOT_BUILT_IN", "BUILT_IN_FRONTEND", "BUILT_IN_MD", "BUILT_IN_NORMAL"};
#define DEF_BUILTIN(X, N, C, T, LT, B, F, NA, AT, IM, COND) #X,
const char * built_in_names[(int) END_BUILTINS] =
{
#include "builtins.def"
};
/* Setup an array of builtin_info_type, make sure each element decl is
initialized to NULL_TREE. */
builtin_info_type builtin_info[(int)END_BUILTINS];
/* Non-zero if __builtin_constant_p should be folded right away. */
bool force_folding_builtin_constant_p;
static rtx c_readstr (const char *, scalar_int_mode);
static int target_char_cast (tree, char *);
static rtx get_memory_rtx (tree, tree);
static int apply_args_size (void);
static int apply_result_size (void);
static rtx result_vector (int, rtx);
static void expand_builtin_prefetch (tree);
static rtx expand_builtin_apply_args (void);
static rtx expand_builtin_apply_args_1 (void);
static rtx expand_builtin_apply (rtx, rtx, rtx);
static void expand_builtin_return (rtx);
static enum type_class type_to_class (tree);
static rtx expand_builtin_classify_type (tree);
static rtx expand_builtin_mathfn_3 (tree, rtx, rtx);
static rtx expand_builtin_mathfn_ternary (tree, rtx, rtx);
static rtx expand_builtin_interclass_mathfn (tree, rtx);
static rtx expand_builtin_sincos (tree);
static rtx expand_builtin_cexpi (tree, rtx);
static rtx expand_builtin_int_roundingfn (tree, rtx);
static rtx expand_builtin_int_roundingfn_2 (tree, rtx);
static rtx expand_builtin_next_arg (void);
static rtx expand_builtin_va_start (tree);
static rtx expand_builtin_va_end (tree);
static rtx expand_builtin_va_copy (tree);
static rtx expand_builtin_strcmp (tree, rtx);
static rtx expand_builtin_strncmp (tree, rtx, machine_mode);
static rtx builtin_memcpy_read_str (void *, HOST_WIDE_INT, scalar_int_mode);
static rtx expand_builtin_memchr (tree, rtx);
static rtx expand_builtin_memcpy (tree, rtx);
static rtx expand_builtin_memcpy_with_bounds (tree, rtx);
static rtx expand_builtin_memory_copy_args (tree dest, tree src, tree len,
rtx target, tree exp, int endp);
static rtx expand_builtin_memmove (tree, rtx);
static rtx expand_builtin_mempcpy (tree, rtx);
static rtx expand_builtin_mempcpy_with_bounds (tree, rtx);
static rtx expand_builtin_mempcpy_args (tree, tree, tree, rtx, tree, int);
static rtx expand_builtin_strcat (tree, rtx);
static rtx expand_builtin_strcpy (tree, rtx);
static rtx expand_builtin_strcpy_args (tree, tree, rtx);
static rtx expand_builtin_stpcpy (tree, rtx, machine_mode);
static rtx expand_builtin_stpncpy (tree, rtx);
static rtx expand_builtin_strncat (tree, rtx);
static rtx expand_builtin_strncpy (tree, rtx);
static rtx builtin_memset_gen_str (void *, HOST_WIDE_INT, scalar_int_mode);
static rtx expand_builtin_memset (tree, rtx, machine_mode);
static rtx expand_builtin_memset_with_bounds (tree, rtx, machine_mode);
static rtx expand_builtin_memset_args (tree, tree, tree, rtx, machine_mode, tree);
static rtx expand_builtin_bzero (tree);
static rtx expand_builtin_strlen (tree, rtx, machine_mode);
static rtx expand_builtin_alloca (tree);
static rtx expand_builtin_unop (machine_mode, tree, rtx, rtx, optab);
static rtx expand_builtin_frame_address (tree, tree);
static tree stabilize_va_list_loc (location_t, tree, int);
static rtx expand_builtin_expect (tree, rtx);
static tree fold_builtin_constant_p (tree);
static tree fold_builtin_classify_type (tree);
static tree fold_builtin_strlen (location_t, tree, tree);
static tree fold_builtin_inf (location_t, tree, int);
static tree rewrite_call_expr (location_t, tree, int, tree, int, ...);
static bool validate_arg (const_tree, enum tree_code code);
static rtx expand_builtin_fabs (tree, rtx, rtx);
static rtx expand_builtin_signbit (tree, rtx);
static tree fold_builtin_memcmp (location_t, tree, tree, tree);
static tree fold_builtin_isascii (location_t, tree);
static tree fold_builtin_toascii (location_t, tree);
static tree fold_builtin_isdigit (location_t, tree);
static tree fold_builtin_fabs (location_t, tree, tree);
static tree fold_builtin_abs (location_t, tree, tree);
static tree fold_builtin_unordered_cmp (location_t, tree, tree, tree, enum tree_code,
enum tree_code);
static tree fold_builtin_0 (location_t, tree);
static tree fold_builtin_1 (location_t, tree, tree);
static tree fold_builtin_2 (location_t, tree, tree, tree);
static tree fold_builtin_3 (location_t, tree, tree, tree, tree);
static tree fold_builtin_varargs (location_t, tree, tree*, int);
static tree fold_builtin_strpbrk (location_t, tree, tree, tree);
static tree fold_builtin_strspn (location_t, tree, tree);
static tree fold_builtin_strcspn (location_t, tree, tree);
static rtx expand_builtin_object_size (tree);
static rtx expand_builtin_memory_chk (tree, rtx, machine_mode,
enum built_in_function);
static void maybe_emit_chk_warning (tree, enum built_in_function);
static void maybe_emit_sprintf_chk_warning (tree, enum built_in_function);
static void maybe_emit_free_warning (tree);
static tree fold_builtin_object_size (tree, tree);
unsigned HOST_WIDE_INT target_newline;
unsigned HOST_WIDE_INT target_percent;
static unsigned HOST_WIDE_INT target_c;
static unsigned HOST_WIDE_INT target_s;
char target_percent_c[3];
char target_percent_s[3];
char target_percent_s_newline[4];
static tree do_mpfr_remquo (tree, tree, tree);
static tree do_mpfr_lgamma_r (tree, tree, tree);
static void expand_builtin_sync_synchronize (void);
/* Return true if NAME starts with __builtin_ or __sync_. */
static bool
is_builtin_name (const char *name)
{
if (strncmp (name, "__builtin_", 10) == 0)
return true;
if (strncmp (name, "__sync_", 7) == 0)
return true;
if (strncmp (name, "__atomic_", 9) == 0)
return true;
if (flag_cilkplus
&& (!strcmp (name, "__cilkrts_detach")
|| !strcmp (name, "__cilkrts_pop_frame")))
return true;
return false;
}
/* Return true if DECL is a function symbol representing a built-in. */
bool
is_builtin_fn (tree decl)
{
return TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl);
}
/* Return true if NODE should be considered for inline expansion regardless
of the optimization level. This means whenever a function is invoked with
its "internal" name, which normally contains the prefix "__builtin". */
bool
called_as_built_in (tree node)
{
/* Note that we must use DECL_NAME, not DECL_ASSEMBLER_NAME_SET_P since
we want the name used to call the function, not the name it
will have. */
const char *name = IDENTIFIER_POINTER (DECL_NAME (node));
return is_builtin_name (name);
}
/* Compute values M and N such that M divides (address of EXP - N) and such
that N < M. If these numbers can be determined, store M in alignp and N in
*BITPOSP and return true. Otherwise return false and store BITS_PER_UNIT to
*alignp and any bit-offset to *bitposp.
Note that the address (and thus the alignment) computed here is based
on the address to which a symbol resolves, whereas DECL_ALIGN is based
on the address at which an object is actually located. These two
addresses are not always the same. For example, on ARM targets,
the address &foo of a Thumb function foo() has the lowest bit set,
whereas foo() itself starts on an even address.
If ADDR_P is true we are taking the address of the memory reference EXP
and thus cannot rely on the access taking place. */
static bool
get_object_alignment_2 (tree exp, unsigned int *alignp,
unsigned HOST_WIDE_INT *bitposp, bool addr_p)
{
HOST_WIDE_INT bitsize, bitpos;
tree offset;
machine_mode mode;
int unsignedp, reversep, volatilep;
unsigned int align = BITS_PER_UNIT;
bool known_alignment = false;
/* Get the innermost object and the constant (bitpos) and possibly
variable (offset) offset of the access. */
exp = get_inner_reference (exp, &bitsize, &bitpos, &offset, &mode,
&unsignedp, &reversep, &volatilep);
/* Extract alignment information from the innermost object and
possibly adjust bitpos and offset. */
if (TREE_CODE (exp) == FUNCTION_DECL)
{
/* Function addresses can encode extra information besides their
alignment. However, if TARGET_PTRMEMFUNC_VBIT_LOCATION
allows the low bit to be used as a virtual bit, we know
that the address itself must be at least 2-byte aligned. */
if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_pfn)
align = 2 * BITS_PER_UNIT;
}
else if (TREE_CODE (exp) == LABEL_DECL)
;
else if (TREE_CODE (exp) == CONST_DECL)
{
/* The alignment of a CONST_DECL is determined by its initializer. */
exp = DECL_INITIAL (exp);
align = TYPE_ALIGN (TREE_TYPE (exp));
if (CONSTANT_CLASS_P (exp))
align = targetm.constant_alignment (exp, align);
known_alignment = true;
}
else if (DECL_P (exp))
{
align = DECL_ALIGN (exp);
known_alignment = true;
}
else if (TREE_CODE (exp) == INDIRECT_REF
|| TREE_CODE (exp) == MEM_REF
|| TREE_CODE (exp) == TARGET_MEM_REF)
{
tree addr = TREE_OPERAND (exp, 0);
unsigned ptr_align;
unsigned HOST_WIDE_INT ptr_bitpos;
unsigned HOST_WIDE_INT ptr_bitmask = ~0;
/* If the address is explicitely aligned, handle that. */
if (TREE_CODE (addr) == BIT_AND_EXPR
&& TREE_CODE (TREE_OPERAND (addr, 1)) == INTEGER_CST)
{
ptr_bitmask = TREE_INT_CST_LOW (TREE_OPERAND (addr, 1));
ptr_bitmask *= BITS_PER_UNIT;
align = least_bit_hwi (ptr_bitmask);
addr = TREE_OPERAND (addr, 0);
}
known_alignment
= get_pointer_alignment_1 (addr, &ptr_align, &ptr_bitpos);
align = MAX (ptr_align, align);
/* Re-apply explicit alignment to the bitpos. */
ptr_bitpos &= ptr_bitmask;
/* The alignment of the pointer operand in a TARGET_MEM_REF
has to take the variable offset parts into account. */
if (TREE_CODE (exp) == TARGET_MEM_REF)
{
if (TMR_INDEX (exp))
{
unsigned HOST_WIDE_INT step = 1;
if (TMR_STEP (exp))
step = TREE_INT_CST_LOW (TMR_STEP (exp));
align = MIN (align, least_bit_hwi (step) * BITS_PER_UNIT);
}
if (TMR_INDEX2 (exp))
align = BITS_PER_UNIT;
known_alignment = false;
}
/* When EXP is an actual memory reference then we can use
TYPE_ALIGN of a pointer indirection to derive alignment.
Do so only if get_pointer_alignment_1 did not reveal absolute
alignment knowledge and if using that alignment would
improve the situation. */
unsigned int talign;
if (!addr_p && !known_alignment
&& (talign = min_align_of_type (TREE_TYPE (exp)) * BITS_PER_UNIT)
&& talign > align)
align = talign;
else
{
/* Else adjust bitpos accordingly. */
bitpos += ptr_bitpos;
if (TREE_CODE (exp) == MEM_REF
|| TREE_CODE (exp) == TARGET_MEM_REF)
bitpos += mem_ref_offset (exp).to_short_addr () * BITS_PER_UNIT;
}
}
else if (TREE_CODE (exp) == STRING_CST)
{
/* STRING_CST are the only constant objects we allow to be not
wrapped inside a CONST_DECL. */
align = TYPE_ALIGN (TREE_TYPE (exp));
if (CONSTANT_CLASS_P (exp))
align = targetm.constant_alignment (exp, align);
known_alignment = true;
}
/* If there is a non-constant offset part extract the maximum
alignment that can prevail. */
if (offset)
{
unsigned int trailing_zeros = tree_ctz (offset);
if (trailing_zeros < HOST_BITS_PER_INT)
{
unsigned int inner = (1U << trailing_zeros) * BITS_PER_UNIT;
if (inner)
align = MIN (align, inner);
}
}
*alignp = align;
*bitposp = bitpos & (*alignp - 1);
return known_alignment;
}
/* For a memory reference expression EXP compute values M and N such that M
divides (&EXP - N) and such that N < M. If these numbers can be determined,
store M in alignp and N in *BITPOSP and return true. Otherwise return false
and store BITS_PER_UNIT to *alignp and any bit-offset to *bitposp. */
bool
get_object_alignment_1 (tree exp, unsigned int *alignp,
unsigned HOST_WIDE_INT *bitposp)
{
return get_object_alignment_2 (exp, alignp, bitposp, false);
}
/* Return the alignment in bits of EXP, an object. */
unsigned int
get_object_alignment (tree exp)
{
unsigned HOST_WIDE_INT bitpos = 0;
unsigned int align;
get_object_alignment_1 (exp, &align, &bitpos);
/* align and bitpos now specify known low bits of the pointer.
ptr & (align - 1) == bitpos. */
if (bitpos != 0)
align = least_bit_hwi (bitpos);
return align;
}
/* For a pointer valued expression EXP compute values M and N such that M
divides (EXP - N) and such that N < M. If these numbers can be determined,
store M in alignp and N in *BITPOSP and return true. Return false if
the results are just a conservative approximation.
If EXP is not a pointer, false is returned too. */
bool
get_pointer_alignment_1 (tree exp, unsigned int *alignp,
unsigned HOST_WIDE_INT *bitposp)
{
STRIP_NOPS (exp);
if (TREE_CODE (exp) == ADDR_EXPR)
return get_object_alignment_2 (TREE_OPERAND (exp, 0),
alignp, bitposp, true);
else if (TREE_CODE (exp) == POINTER_PLUS_EXPR)
{
unsigned int align;
unsigned HOST_WIDE_INT bitpos;
bool res = get_pointer_alignment_1 (TREE_OPERAND (exp, 0),
&align, &bitpos);
if (TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST)
bitpos += TREE_INT_CST_LOW (TREE_OPERAND (exp, 1)) * BITS_PER_UNIT;
else
{
unsigned int trailing_zeros = tree_ctz (TREE_OPERAND (exp, 1));
if (trailing_zeros < HOST_BITS_PER_INT)
{
unsigned int inner = (1U << trailing_zeros) * BITS_PER_UNIT;
if (inner)
align = MIN (align, inner);
}
}
*alignp = align;
*bitposp = bitpos & (align - 1);
return res;
}
else if (TREE_CODE (exp) == SSA_NAME
&& POINTER_TYPE_P (TREE_TYPE (exp)))
{
unsigned int ptr_align, ptr_misalign;
struct ptr_info_def *pi = SSA_NAME_PTR_INFO (exp);
if (pi && get_ptr_info_alignment (pi, &ptr_align, &ptr_misalign))
{
*bitposp = ptr_misalign * BITS_PER_UNIT;
*alignp = ptr_align * BITS_PER_UNIT;
/* Make sure to return a sensible alignment when the multiplication
by BITS_PER_UNIT overflowed. */
if (*alignp == 0)
*alignp = 1u << (HOST_BITS_PER_INT - 1);
/* We cannot really tell whether this result is an approximation. */
return false;
}
else
{
*bitposp = 0;
*alignp = BITS_PER_UNIT;
return false;
}
}
else if (TREE_CODE (exp) == INTEGER_CST)
{
*alignp = BIGGEST_ALIGNMENT;
*bitposp = ((TREE_INT_CST_LOW (exp) * BITS_PER_UNIT)
& (BIGGEST_ALIGNMENT - 1));
return true;
}
*bitposp = 0;
*alignp = BITS_PER_UNIT;
return false;
}
/* Return the alignment in bits of EXP, a pointer valued expression.
The alignment returned is, by default, the alignment of the thing that
EXP points to. If it is not a POINTER_TYPE, 0 is returned.
Otherwise, look at the expression to see if we can do better, i.e., if the
expression is actually pointing at an object whose alignment is tighter. */
unsigned int
get_pointer_alignment (tree exp)
{
unsigned HOST_WIDE_INT bitpos = 0;
unsigned int align;
get_pointer_alignment_1 (exp, &align, &bitpos);
/* align and bitpos now specify known low bits of the pointer.
ptr & (align - 1) == bitpos. */
if (bitpos != 0)
align = least_bit_hwi (bitpos);
return align;
}
/* Return the number of non-zero elements in the sequence
[ PTR, PTR + MAXELTS ) where each element's size is ELTSIZE bytes.
ELTSIZE must be a power of 2 less than 8. Used by c_strlen. */
static unsigned
string_length (const void *ptr, unsigned eltsize, unsigned maxelts)
{
gcc_checking_assert (eltsize == 1 || eltsize == 2 || eltsize == 4);
unsigned n;
if (eltsize == 1)
{
/* Optimize the common case of plain char. */
for (n = 0; n < maxelts; n++)
{
const char *elt = (const char*) ptr + n;
if (!*elt)
break;
}
}
else
{
for (n = 0; n < maxelts; n++)
{
const char *elt = (const char*) ptr + n * eltsize;
if (!memcmp (elt, "\0\0\0\0", eltsize))
break;
}
}
return n;
}
/* Compute the length of a null-terminated character string or wide
character string handling character sizes of 1, 2, and 4 bytes.
TREE_STRING_LENGTH is not the right way because it evaluates to
the size of the character array in bytes (as opposed to characters)
and because it can contain a zero byte in the middle.
ONLY_VALUE should be nonzero if the result is not going to be emitted
into the instruction stream and zero if it is going to be expanded.
E.g. with i++ ? "foo" : "bar", if ONLY_VALUE is nonzero, constant 3
is returned, otherwise NULL, since
len = c_strlen (src, 1); if (len) expand_expr (len, ...); would not
evaluate the side-effects.
If ONLY_VALUE is two then we do not emit warnings about out-of-bound
accesses. Note that this implies the result is not going to be emitted
into the instruction stream.
The value returned is of type `ssizetype'.
Unfortunately, string_constant can't access the values of const char
arrays with initializers, so neither can we do so here. */
tree
c_strlen (tree src, int only_value)
{
STRIP_NOPS (src);
if (TREE_CODE (src) == COND_EXPR
&& (only_value || !TREE_SIDE_EFFECTS (TREE_OPERAND (src, 0))))
{
tree len1, len2;
len1 = c_strlen (TREE_OPERAND (src, 1), only_value);
len2 = c_strlen (TREE_OPERAND (src, 2), only_value);
if (tree_int_cst_equal (len1, len2))
return len1;
}
if (TREE_CODE (src) == COMPOUND_EXPR
&& (only_value || !TREE_SIDE_EFFECTS (TREE_OPERAND (src, 0))))
return c_strlen (TREE_OPERAND (src, 1), only_value);
location_t loc = EXPR_LOC_OR_LOC (src, input_location);
/* Offset from the beginning of the string in bytes. */
tree byteoff;
src = string_constant (src, &byteoff);
if (src == 0)
return NULL_TREE;
/* Determine the size of the string element. */
unsigned eltsize
= tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (src))));
/* Set MAXELTS to sizeof (SRC) / sizeof (*SRC) - 1, the maximum possible
length of SRC. */
unsigned maxelts = TREE_STRING_LENGTH (src) / eltsize - 1;
/* PTR can point to the byte representation of any string type, including
char* and wchar_t*. */
const char *ptr = TREE_STRING_POINTER (src);
if (byteoff && TREE_CODE (byteoff) != INTEGER_CST)
{
/* If the string has an internal zero byte (e.g., "foo\0bar"), we can't
compute the offset to the following null if we don't know where to
start searching for it. */
if (string_length (ptr, eltsize, maxelts) < maxelts)
{
/* Return when an embedded null character is found. */
return NULL_TREE;
}
/* We don't know the starting offset, but we do know that the string
has no internal zero bytes. We can assume that the offset falls
within the bounds of the string; otherwise, the programmer deserves
what he gets. Subtract the offset from the length of the string,
and return that. This would perhaps not be valid if we were dealing
with named arrays in addition to literal string constants. */
return size_diffop_loc (loc, size_int (maxelts * eltsize), byteoff);
}
/* Offset from the beginning of the string in elements. */
HOST_WIDE_INT eltoff;
/* We have a known offset into the string. Start searching there for
a null character if we can represent it as a single HOST_WIDE_INT. */
if (byteoff == 0)
eltoff = 0;
else if (! tree_fits_shwi_p (byteoff))
eltoff = -1;
else
eltoff = tree_to_shwi (byteoff) / eltsize;
/* If the offset is known to be out of bounds, warn, and call strlen at
runtime. */
if (eltoff < 0 || eltoff > maxelts)
{
/* Suppress multiple warnings for propagated constant strings. */
if (only_value != 2
&& !TREE_NO_WARNING (src))
{
warning_at (loc, 0, "offset %qwi outside bounds of constant string",
eltoff);
TREE_NO_WARNING (src) = 1;
}
return NULL_TREE;
}
/* Use strlen to search for the first zero byte. Since any strings
constructed with build_string will have nulls appended, we win even
if we get handed something like (char[4])"abcd".
Since ELTOFF is our starting index into the string, no further
calculation is needed. */
unsigned len = string_length (ptr + eltoff * eltsize, eltsize,
maxelts - eltoff);
return ssize_int (len);
}
/* Return a constant integer corresponding to target reading
GET_MODE_BITSIZE (MODE) bits from string constant STR. */
static rtx
c_readstr (const char *str, scalar_int_mode mode)
{
HOST_WIDE_INT ch;
unsigned int i, j;
HOST_WIDE_INT tmp[MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_WIDE_INT];
gcc_assert (GET_MODE_CLASS (mode) == MODE_INT);
unsigned int len = (GET_MODE_PRECISION (mode) + HOST_BITS_PER_WIDE_INT - 1)
/ HOST_BITS_PER_WIDE_INT;
gcc_assert (len <= MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_WIDE_INT);
for (i = 0; i < len; i++)
tmp[i] = 0;
ch = 1;
for (i = 0; i < GET_MODE_SIZE (mode); i++)
{
j = i;
if (WORDS_BIG_ENDIAN)
j = GET_MODE_SIZE (mode) - i - 1;
if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN
&& GET_MODE_SIZE (mode) >= UNITS_PER_WORD)
j = j + UNITS_PER_WORD - 2 * (j % UNITS_PER_WORD) - 1;
j *= BITS_PER_UNIT;
if (ch)
ch = (unsigned char) str[i];
tmp[j / HOST_BITS_PER_WIDE_INT] |= ch << (j % HOST_BITS_PER_WIDE_INT);
}
wide_int c = wide_int::from_array (tmp, len, GET_MODE_PRECISION (mode));
return immed_wide_int_const (c, mode);
}
/* Cast a target constant CST to target CHAR and if that value fits into
host char type, return zero and put that value into variable pointed to by
P. */
static int
target_char_cast (tree cst, char *p)
{
unsigned HOST_WIDE_INT val, hostval;
if (TREE_CODE (cst) != INTEGER_CST
|| CHAR_TYPE_SIZE > HOST_BITS_PER_WIDE_INT)
return 1;
/* Do not care if it fits or not right here. */
val = TREE_INT_CST_LOW (cst);
if (CHAR_TYPE_SIZE < HOST_BITS_PER_WIDE_INT)
val &= (HOST_WIDE_INT_1U << CHAR_TYPE_SIZE) - 1;
hostval = val;
if (HOST_BITS_PER_CHAR < HOST_BITS_PER_WIDE_INT)
hostval &= (HOST_WIDE_INT_1U << HOST_BITS_PER_CHAR) - 1;
if (val != hostval)
return 1;
*p = hostval;
return 0;
}
/* Similar to save_expr, but assumes that arbitrary code is not executed
in between the multiple evaluations. In particular, we assume that a
non-addressable local variable will not be modified. */
static tree
builtin_save_expr (tree exp)
{
if (TREE_CODE (exp) == SSA_NAME
|| (TREE_ADDRESSABLE (exp) == 0
&& (TREE_CODE (exp) == PARM_DECL
|| (VAR_P (exp) && !TREE_STATIC (exp)))))
return exp;
return save_expr (exp);
}
/* Given TEM, a pointer to a stack frame, follow the dynamic chain COUNT
times to get the address of either a higher stack frame, or a return
address located within it (depending on FNDECL_CODE). */
static rtx
expand_builtin_return_addr (enum built_in_function fndecl_code, int count)
{
int i;
rtx tem = INITIAL_FRAME_ADDRESS_RTX;
if (tem == NULL_RTX)
{
/* For a zero count with __builtin_return_address, we don't care what
frame address we return, because target-specific definitions will
override us. Therefore frame pointer elimination is OK, and using
the soft frame pointer is OK.
For a nonzero count, or a zero count with __builtin_frame_address,
we require a stable offset from the current frame pointer to the
previous one, so we must use the hard frame pointer, and
we must disable frame pointer elimination. */
if (count == 0 && fndecl_code == BUILT_IN_RETURN_ADDRESS)
tem = frame_pointer_rtx;
else
{
tem = hard_frame_pointer_rtx;
/* Tell reload not to eliminate the frame pointer. */
crtl->accesses_prior_frames = 1;
}
}
if (count > 0)
SETUP_FRAME_ADDRESSES ();
/* On the SPARC, the return address is not in the frame, it is in a
register. There is no way to access it off of the current frame
pointer, but it can be accessed off the previous frame pointer by
reading the value from the register window save area. */
if (RETURN_ADDR_IN_PREVIOUS_FRAME && fndecl_code == BUILT_IN_RETURN_ADDRESS)
count--;
/* Scan back COUNT frames to the specified frame. */
for (i = 0; i < count; i++)
{
/* Assume the dynamic chain pointer is in the word that the
frame address points to, unless otherwise specified. */
tem = DYNAMIC_CHAIN_ADDRESS (tem);
tem = memory_address (Pmode, tem);
tem = gen_frame_mem (Pmode, tem);
tem = copy_to_reg (tem);
}
/* For __builtin_frame_address, return what we've got. But, on
the SPARC for example, we may have to add a bias. */
if (fndecl_code == BUILT_IN_FRAME_ADDRESS)
return FRAME_ADDR_RTX (tem);
/* For __builtin_return_address, get the return address from that frame. */
#ifdef RETURN_ADDR_RTX
tem = RETURN_ADDR_RTX (count, tem);
#else
tem = memory_address (Pmode,
plus_constant (Pmode, tem, GET_MODE_SIZE (Pmode)));
tem = gen_frame_mem (Pmode, tem);
#endif
return tem;
}
/* Alias set used for setjmp buffer. */
static alias_set_type setjmp_alias_set = -1;
/* Construct the leading half of a __builtin_setjmp call. Control will
return to RECEIVER_LABEL. This is also called directly by the SJLJ
exception handling code. */
void
expand_builtin_setjmp_setup (rtx buf_addr, rtx receiver_label)
{
machine_mode sa_mode = STACK_SAVEAREA_MODE (SAVE_NONLOCAL);
rtx stack_save;
rtx mem;
if (setjmp_alias_set == -1)
setjmp_alias_set = new_alias_set ();
buf_addr = convert_memory_address (Pmode, buf_addr);
buf_addr = force_reg (Pmode, force_operand (buf_addr, NULL_RTX));
/* We store the frame pointer and the address of receiver_label in
the buffer and use the rest of it for the stack save area, which
is machine-dependent. */
mem = gen_rtx_MEM (Pmode, buf_addr);
set_mem_alias_set (mem, setjmp_alias_set);
emit_move_insn (mem, targetm.builtin_setjmp_frame_value ());
mem = gen_rtx_MEM (Pmode, plus_constant (Pmode, buf_addr,
GET_MODE_SIZE (Pmode))),
set_mem_alias_set (mem, setjmp_alias_set);
emit_move_insn (validize_mem (mem),
force_reg (Pmode, gen_rtx_LABEL_REF (Pmode, receiver_label)));
stack_save = gen_rtx_MEM (sa_mode,
plus_constant (Pmode, buf_addr,
2 * GET_MODE_SIZE (Pmode)));
set_mem_alias_set (stack_save, setjmp_alias_set);
emit_stack_save (SAVE_NONLOCAL, &stack_save);
/* If there is further processing to do, do it. */
if (targetm.have_builtin_setjmp_setup ())
emit_insn (targetm.gen_builtin_setjmp_setup (buf_addr));
/* We have a nonlocal label. */
cfun->has_nonlocal_label = 1;
}
/* Construct the trailing part of a __builtin_setjmp call. This is
also called directly by the SJLJ exception handling code.
If RECEIVER_LABEL is NULL, instead contruct a nonlocal goto handler. */
void
expand_builtin_setjmp_receiver (rtx receiver_label)
{
rtx chain;
/* Mark the FP as used when we get here, so we have to make sure it's
marked as used by this function. */
emit_use (hard_frame_pointer_rtx);
/* Mark the static chain as clobbered here so life information
doesn't get messed up for it. */
chain = targetm.calls.static_chain (current_function_decl, true);
if (chain && REG_P (chain))
emit_clobber (chain);
/* Now put in the code to restore the frame pointer, and argument
pointer, if needed. */
if (! targetm.have_nonlocal_goto ())
{
/* First adjust our frame pointer to its actual value. It was
previously set to the start of the virtual area corresponding to
the stacked variables when we branched here and now needs to be
adjusted to the actual hardware fp value.
Assignments to virtual registers are converted by
instantiate_virtual_regs into the corresponding assignment
to the underlying register (fp in this case) that makes
the original assignment true.
So the following insn will actually be decrementing fp by
TARGET_STARTING_FRAME_OFFSET. */
emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
/* Restoring the frame pointer also modifies the hard frame pointer.
Mark it used (so that the previous assignment remains live once
the frame pointer is eliminated) and clobbered (to represent the
implicit update from the assignment). */
emit_use (hard_frame_pointer_rtx);
emit_clobber (hard_frame_pointer_rtx);
}
if (!HARD_FRAME_POINTER_IS_ARG_POINTER && fixed_regs[ARG_POINTER_REGNUM])
{
/* If the argument pointer can be eliminated in favor of the
frame pointer, we don't need to restore it. We assume here
that if such an elimination is present, it can always be used.
This is the case on all known machines; if we don't make this
assumption, we do unnecessary saving on many machines. */
size_t i;
static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
if (elim_regs[i].from == ARG_POINTER_REGNUM
&& elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
break;
if (i == ARRAY_SIZE (elim_regs))
{
/* Now restore our arg pointer from the address at which it
was saved in our stack frame. */
emit_move_insn (crtl->args.internal_arg_pointer,
copy_to_reg (get_arg_pointer_save_area ()));
}
}
if (receiver_label != NULL && targetm.have_builtin_setjmp_receiver ())
emit_insn (targetm.gen_builtin_setjmp_receiver (receiver_label));
else if (targetm.have_nonlocal_goto_receiver ())
emit_insn (targetm.gen_nonlocal_goto_receiver ());
else
{ /* Nothing */ }
/* We must not allow the code we just generated to be reordered by
scheduling. Specifically, the update of the frame pointer must
happen immediately, not later. */
emit_insn (gen_blockage ());
}
/* __builtin_longjmp is passed a pointer to an array of five words (not
all will be used on all machines). It operates similarly to the C
library function of the same name, but is more efficient. Much of
the code below is copied from the handling of non-local gotos. */
static void
expand_builtin_longjmp (rtx buf_addr, rtx value)
{
rtx fp, lab, stack;
rtx_insn *insn, *last;
machine_mode sa_mode = STACK_SAVEAREA_MODE (SAVE_NONLOCAL);
/* DRAP is needed for stack realign if longjmp is expanded to current
function */
if (SUPPORTS_STACK_ALIGNMENT)
crtl->need_drap = true;
if (setjmp_alias_set == -1)
setjmp_alias_set = new_alias_set ();
buf_addr = convert_memory_address (Pmode, buf_addr);
buf_addr = force_reg (Pmode, buf_addr);
/* We require that the user must pass a second argument of 1, because
that is what builtin_setjmp will return. */
gcc_assert (value == const1_rtx);
last = get_last_insn ();
if (targetm.have_builtin_longjmp ())
emit_insn (targetm.gen_builtin_longjmp (buf_addr));
else
{
fp = gen_rtx_MEM (Pmode, buf_addr);
lab = gen_rtx_MEM (Pmode, plus_constant (Pmode, buf_addr,
GET_MODE_SIZE (Pmode)));
stack = gen_rtx_MEM (sa_mode, plus_constant (Pmode, buf_addr,
2 * GET_MODE_SIZE (Pmode)));
set_mem_alias_set (fp, setjmp_alias_set);
set_mem_alias_set (lab, setjmp_alias_set);
set_mem_alias_set (stack, setjmp_alias_set);
/* Pick up FP, label, and SP from the block and jump. This code is
from expand_goto in stmt.c; see there for detailed comments. */
if (targetm.have_nonlocal_goto ())
/* We have to pass a value to the nonlocal_goto pattern that will
get copied into the static_chain pointer, but it does not matter
what that value is, because builtin_setjmp does not use it. */
emit_insn (targetm.gen_nonlocal_goto (value, lab, stack, fp));