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-rw-r--r--gcc/fold-const.c440
1 files changed, 396 insertions, 44 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 632a241..e77d74e 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -7968,25 +7968,78 @@ native_encode_expr (const_tree expr, unsigned char *ptr, int len, int off)
}
}
+/* Try to find a type whose byte size is smaller or equal to LEN bytes larger
+ or equal to FIELDSIZE bytes, with underlying mode precision/size multiple
+ of BITS_PER_UNIT. As native_{interpret,encode}_int works in term of
+ machine modes, we can't just use build_nonstandard_integer_type. */
+
+tree
+find_bitfield_repr_type (int fieldsize, int len)
+{
+ machine_mode mode;
+ for (int pass = 0; pass < 2; pass++)
+ {
+ enum mode_class mclass = pass ? MODE_PARTIAL_INT : MODE_INT;
+ FOR_EACH_MODE_IN_CLASS (mode, mclass)
+ if (known_ge (GET_MODE_SIZE (mode), fieldsize)
+ && known_eq (GET_MODE_PRECISION (mode),
+ GET_MODE_BITSIZE (mode))
+ && known_le (GET_MODE_SIZE (mode), len))
+ {
+ tree ret = lang_hooks.types.type_for_mode (mode, 1);
+ if (ret && TYPE_MODE (ret) == mode)
+ return ret;
+ }
+ }
+
+ for (int i = 0; i < NUM_INT_N_ENTS; i ++)
+ if (int_n_enabled_p[i]
+ && int_n_data[i].bitsize >= (unsigned) (BITS_PER_UNIT * fieldsize)
+ && int_n_trees[i].unsigned_type)
+ {
+ tree ret = int_n_trees[i].unsigned_type;
+ mode = TYPE_MODE (ret);
+ if (known_ge (GET_MODE_SIZE (mode), fieldsize)
+ && known_eq (GET_MODE_PRECISION (mode),
+ GET_MODE_BITSIZE (mode))
+ && known_le (GET_MODE_SIZE (mode), len))
+ return ret;
+ }
+
+ return NULL_TREE;
+}
+
/* Similar to native_encode_expr, but also handle CONSTRUCTORs, VCEs,
- NON_LVALUE_EXPRs and nops. */
+ NON_LVALUE_EXPRs and nops. If MASK is non-NULL (then PTR has
+ to be non-NULL and OFF zero), then in addition to filling the
+ bytes pointed by PTR with the value also clear any bits pointed
+ by MASK that are known to be initialized, keep them as is for
+ e.g. uninitialized padding bits or uninitialized fields. */
int
native_encode_initializer (tree init, unsigned char *ptr, int len,
- int off)
+ int off, unsigned char *mask)
{
+ int r;
+
/* We don't support starting at negative offset and -1 is special. */
if (off < -1 || init == NULL_TREE)
return 0;
+ gcc_assert (mask == NULL || (off == 0 && ptr));
+
STRIP_NOPS (init);
switch (TREE_CODE (init))
{
case VIEW_CONVERT_EXPR:
case NON_LVALUE_EXPR:
- return native_encode_initializer (TREE_OPERAND (init, 0), ptr, len, off);
+ return native_encode_initializer (TREE_OPERAND (init, 0), ptr, len, off,
+ mask);
default:
- return native_encode_expr (init, ptr, len, off);
+ r = native_encode_expr (init, ptr, len, off);
+ if (mask)
+ memset (mask, 0, r);
+ return r;
case CONSTRUCTOR:
tree type = TREE_TYPE (init);
HOST_WIDE_INT total_bytes = int_size_in_bytes (type);
@@ -7999,7 +8052,7 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
{
HOST_WIDE_INT min_index;
unsigned HOST_WIDE_INT cnt;
- HOST_WIDE_INT curpos = 0, fieldsize;
+ HOST_WIDE_INT curpos = 0, fieldsize, valueinit = -1;
constructor_elt *ce;
if (TYPE_DOMAIN (type) == NULL_TREE
@@ -8014,12 +8067,22 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
if (ptr != NULL)
memset (ptr, '\0', MIN (total_bytes - off, len));
- FOR_EACH_VEC_SAFE_ELT (CONSTRUCTOR_ELTS (init), cnt, ce)
+ for (cnt = 0; ; cnt++)
{
- tree val = ce->value;
- tree index = ce->index;
+ tree val = NULL_TREE, index = NULL_TREE;
HOST_WIDE_INT pos = curpos, count = 0;
bool full = false;
+ if (vec_safe_iterate (CONSTRUCTOR_ELTS (init), cnt, &ce))
+ {
+ val = ce->value;
+ index = ce->index;
+ }
+ else if (mask == NULL
+ || CONSTRUCTOR_NO_CLEARING (init)
+ || curpos >= total_bytes)
+ break;
+ else
+ pos = total_bytes;
if (index && TREE_CODE (index) == RANGE_EXPR)
{
if (!tree_fits_shwi_p (TREE_OPERAND (index, 0))
@@ -8037,6 +8100,28 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
pos = (tree_to_shwi (index) - min_index) * fieldsize;
}
+ if (mask && !CONSTRUCTOR_NO_CLEARING (init) && curpos != pos)
+ {
+ if (valueinit == -1)
+ {
+ tree zero = build_constructor (TREE_TYPE (type), NULL);
+ r = native_encode_initializer (zero, ptr + curpos,
+ fieldsize, 0,
+ mask + curpos);
+ ggc_free (zero);
+ if (!r)
+ return 0;
+ valueinit = curpos;
+ curpos += fieldsize;
+ }
+ while (curpos != pos)
+ {
+ memcpy (ptr + curpos, ptr + valueinit, fieldsize);
+ memcpy (mask + curpos, mask + valueinit, fieldsize);
+ curpos += fieldsize;
+ }
+ }
+
curpos = pos;
if (val)
do
@@ -8051,6 +8136,8 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
if (ptr)
memcpy (ptr + (curpos - o), ptr + (pos - o),
fieldsize);
+ if (mask)
+ memcpy (mask + curpos, mask + pos, fieldsize);
}
else if (!native_encode_initializer (val,
ptr
@@ -8058,7 +8145,10 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
: NULL,
fieldsize,
off == -1 ? -1
- : 0))
+ : 0,
+ mask
+ ? mask + curpos
+ : NULL))
return 0;
else
{
@@ -8073,6 +8163,7 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
unsigned char *p = NULL;
int no = 0;
int l;
+ gcc_assert (mask == NULL);
if (curpos >= off)
{
if (ptr)
@@ -8086,7 +8177,7 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
no = off - curpos;
l = len;
}
- if (!native_encode_initializer (val, p, l, no))
+ if (!native_encode_initializer (val, p, l, no, NULL))
return 0;
}
curpos += fieldsize;
@@ -8100,22 +8191,74 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
{
unsigned HOST_WIDE_INT cnt;
constructor_elt *ce;
+ tree fld_base = TYPE_FIELDS (type);
+ tree to_free = NULL_TREE;
+ gcc_assert (TREE_CODE (type) == RECORD_TYPE || mask == NULL);
if (ptr != NULL)
memset (ptr, '\0', MIN (total_bytes - off, len));
- FOR_EACH_VEC_SAFE_ELT (CONSTRUCTOR_ELTS (init), cnt, ce)
+ for (cnt = 0; ; cnt++)
{
- tree field = ce->index;
- tree val = ce->value;
- HOST_WIDE_INT pos, fieldsize;
+ tree val = NULL_TREE, field = NULL_TREE;
+ HOST_WIDE_INT pos = 0, fieldsize;
unsigned HOST_WIDE_INT bpos = 0, epos = 0;
- if (field == NULL_TREE)
- return 0;
+ if (to_free)
+ {
+ ggc_free (to_free);
+ to_free = NULL_TREE;
+ }
- pos = int_byte_position (field);
- if (off != -1 && (HOST_WIDE_INT) off + len <= pos)
- continue;
+ if (vec_safe_iterate (CONSTRUCTOR_ELTS (init), cnt, &ce))
+ {
+ val = ce->value;
+ field = ce->index;
+ if (field == NULL_TREE)
+ return 0;
+
+ pos = int_byte_position (field);
+ if (off != -1 && (HOST_WIDE_INT) off + len <= pos)
+ continue;
+ }
+ else if (mask == NULL
+ || CONSTRUCTOR_NO_CLEARING (init))
+ break;
+ else
+ pos = total_bytes;
+
+ if (mask && !CONSTRUCTOR_NO_CLEARING (init))
+ {
+ tree fld;
+ for (fld = fld_base; fld; fld = DECL_CHAIN (fld))
+ {
+ if (TREE_CODE (fld) != FIELD_DECL)
+ continue;
+ if (fld == field)
+ break;
+ if (DECL_PADDING_P (fld))
+ continue;
+ if (DECL_SIZE_UNIT (fld) == NULL_TREE
+ || !tree_fits_shwi_p (DECL_SIZE_UNIT (fld)))
+ return 0;
+ if (integer_zerop (DECL_SIZE_UNIT (fld)))
+ continue;
+ break;
+ }
+ if (fld == NULL_TREE)
+ {
+ if (ce == NULL)
+ break;
+ return 0;
+ }
+ fld_base = DECL_CHAIN (fld);
+ if (fld != field)
+ {
+ cnt--;
+ field = fld;
+ val = build_constructor (TREE_TYPE (fld), NULL);
+ to_free = val;
+ }
+ }
if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
&& TYPE_DOMAIN (TREE_TYPE (field))
@@ -8156,30 +8299,49 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN)
return 0;
- tree repr = DECL_BIT_FIELD_REPRESENTATIVE (field);
- if (repr == NULL_TREE
- || TREE_CODE (val) != INTEGER_CST
- || !INTEGRAL_TYPE_P (TREE_TYPE (repr)))
+ if (TREE_CODE (val) != INTEGER_CST)
return 0;
- HOST_WIDE_INT rpos = int_byte_position (repr);
+ tree repr = DECL_BIT_FIELD_REPRESENTATIVE (field);
+ tree repr_type = NULL_TREE;
+ HOST_WIDE_INT rpos = 0;
+ if (repr && INTEGRAL_TYPE_P (TREE_TYPE (repr)))
+ {
+ rpos = int_byte_position (repr);
+ repr_type = TREE_TYPE (repr);
+ }
+ else
+ {
+ repr_type = find_bitfield_repr_type (fieldsize, len);
+ if (repr_type == NULL_TREE)
+ return 0;
+ HOST_WIDE_INT repr_size = int_size_in_bytes (repr_type);
+ gcc_assert (repr_size > 0 && repr_size <= len);
+ if (pos + repr_size <= len)
+ rpos = pos;
+ else
+ {
+ rpos = len - repr_size;
+ gcc_assert (rpos <= pos);
+ }
+ }
+
if (rpos > pos)
return 0;
- wide_int w = wi::to_wide (val,
- TYPE_PRECISION (TREE_TYPE (repr)));
- int diff = (TYPE_PRECISION (TREE_TYPE (repr))
+ wide_int w = wi::to_wide (val, TYPE_PRECISION (repr_type));
+ int diff = (TYPE_PRECISION (repr_type)
- TYPE_PRECISION (TREE_TYPE (field)));
HOST_WIDE_INT bitoff = (pos - rpos) * BITS_PER_UNIT + bpos;
if (!BYTES_BIG_ENDIAN)
w = wi::lshift (w, bitoff);
else
w = wi::lshift (w, diff - bitoff);
- val = wide_int_to_tree (TREE_TYPE (repr), w);
+ val = wide_int_to_tree (repr_type, w);
unsigned char buf[MAX_BITSIZE_MODE_ANY_INT
/ BITS_PER_UNIT + 1];
int l = native_encode_int (val, buf, sizeof buf, 0);
- if (l * BITS_PER_UNIT != TYPE_PRECISION (TREE_TYPE (repr)))
+ if (l * BITS_PER_UNIT != TYPE_PRECISION (repr_type))
return 0;
if (ptr == NULL)
@@ -8192,15 +8354,31 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
{
if (!BYTES_BIG_ENDIAN)
{
- int mask = (1 << bpos) - 1;
- buf[pos - rpos] &= ~mask;
- buf[pos - rpos] |= ptr[pos - o] & mask;
+ int msk = (1 << bpos) - 1;
+ buf[pos - rpos] &= ~msk;
+ buf[pos - rpos] |= ptr[pos - o] & msk;
+ if (mask)
+ {
+ if (fieldsize > 1 || epos == 0)
+ mask[pos] &= msk;
+ else
+ mask[pos] &= (msk | ~((1 << epos) - 1));
+ }
}
else
{
- int mask = (1 << (BITS_PER_UNIT - bpos)) - 1;
- buf[pos - rpos] &= mask;
- buf[pos - rpos] |= ptr[pos - o] & ~mask;
+ int msk = (1 << (BITS_PER_UNIT - bpos)) - 1;
+ buf[pos - rpos] &= msk;
+ buf[pos - rpos] |= ptr[pos - o] & ~msk;
+ if (mask)
+ {
+ if (fieldsize > 1 || epos == 0)
+ mask[pos] &= ~msk;
+ else
+ mask[pos] &= (~msk
+ | ((1 << (BITS_PER_UNIT - epos))
+ - 1));
+ }
}
}
/* If the bitfield does not end at byte boundary, handle
@@ -8211,27 +8389,37 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
{
if (!BYTES_BIG_ENDIAN)
{
- int mask = (1 << epos) - 1;
- buf[pos - rpos + fieldsize - 1] &= mask;
+ int msk = (1 << epos) - 1;
+ buf[pos - rpos + fieldsize - 1] &= msk;
buf[pos - rpos + fieldsize - 1]
- |= ptr[pos + fieldsize - 1 - o] & ~mask;
+ |= ptr[pos + fieldsize - 1 - o] & ~msk;
+ if (mask && (fieldsize > 1 || bpos == 0))
+ mask[pos + fieldsize - 1] &= ~msk;
}
else
{
- int mask = (1 << (BITS_PER_UNIT - epos)) - 1;
- buf[pos - rpos + fieldsize - 1] &= ~mask;
+ int msk = (1 << (BITS_PER_UNIT - epos)) - 1;
+ buf[pos - rpos + fieldsize - 1] &= ~msk;
buf[pos - rpos + fieldsize - 1]
- |= ptr[pos + fieldsize - 1 - o] & mask;
+ |= ptr[pos + fieldsize - 1 - o] & msk;
+ if (mask && (fieldsize > 1 || bpos == 0))
+ mask[pos + fieldsize - 1] &= msk;
}
}
if (off == -1
|| (pos >= off
&& (pos + fieldsize <= (HOST_WIDE_INT) off + len)))
- memcpy (ptr + pos - o, buf + (pos - rpos), fieldsize);
+ {
+ memcpy (ptr + pos - o, buf + (pos - rpos), fieldsize);
+ if (mask && (fieldsize > (bpos != 0) + (epos != 0)))
+ memset (mask + pos + (bpos != 0), 0,
+ fieldsize - (bpos != 0) - (epos != 0));
+ }
else
{
/* Partial overlap. */
HOST_WIDE_INT fsz = fieldsize;
+ gcc_assert (mask == NULL);
if (pos < off)
{
fsz -= (off - pos);
@@ -8251,7 +8439,8 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
if (!native_encode_initializer (val, ptr ? ptr + pos - o
: NULL,
fieldsize,
- off == -1 ? -1 : 0))
+ off == -1 ? -1 : 0,
+ mask ? mask + pos : NULL))
return 0;
}
else
@@ -8260,6 +8449,7 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
unsigned char *p = NULL;
int no = 0;
int l;
+ gcc_assert (mask == NULL);
if (pos >= off)
{
if (ptr)
@@ -8273,7 +8463,7 @@ native_encode_initializer (tree init, unsigned char *ptr, int len,
no = off - pos;
l = len;
}
- if (!native_encode_initializer (val, p, l, no))
+ if (!native_encode_initializer (val, p, l, no, NULL))
return 0;
}
}
@@ -8549,6 +8739,168 @@ can_native_interpret_type_p (tree type)
}
}
+/* Attempt to interpret aggregate of TYPE from bytes encoded in target
+ byte order at PTR + OFF with LEN bytes. Does not handle unions. */
+
+tree
+native_interpret_aggregate (tree type, const unsigned char *ptr, int off,
+ int len)
+{
+ vec<constructor_elt, va_gc> *elts = NULL;
+ if (TREE_CODE (type) == ARRAY_TYPE)
+ {
+ HOST_WIDE_INT eltsz = int_size_in_bytes (TREE_TYPE (type));
+ if (eltsz < 0 || eltsz > len || TYPE_DOMAIN (type) == NULL_TREE)
+ return NULL_TREE;
+
+ HOST_WIDE_INT cnt = 0;
+ if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)))
+ {
+ if (!tree_fits_shwi_p (TYPE_MAX_VALUE (TYPE_DOMAIN (type))))
+ return NULL_TREE;
+ cnt = tree_to_shwi (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) + 1;
+ }
+ if (eltsz == 0)
+ cnt = 0;
+ HOST_WIDE_INT pos = 0;
+ for (HOST_WIDE_INT i = 0; i < cnt; i++, pos += eltsz)
+ {
+ tree v = NULL_TREE;
+ if (pos >= len || pos + eltsz > len)
+ return NULL_TREE;
+ if (can_native_interpret_type_p (TREE_TYPE (type)))
+ {
+ v = native_interpret_expr (TREE_TYPE (type),
+ ptr + off + pos, eltsz);
+ if (v == NULL_TREE)
+ return NULL_TREE;
+ }
+ else if (TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE
+ || TREE_CODE (TREE_TYPE (type)) == ARRAY_TYPE)
+ v = native_interpret_aggregate (TREE_TYPE (type), ptr, off + pos,
+ eltsz);
+ if (v == NULL_TREE)
+ return NULL_TREE;
+ CONSTRUCTOR_APPEND_ELT (elts, size_int (i), v);
+ }
+ return build_constructor (type, elts);
+ }
+ if (TREE_CODE (type) != RECORD_TYPE)
+ return NULL_TREE;
+ for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
+ {
+ if (TREE_CODE (field) != FIELD_DECL || DECL_PADDING_P (field))
+ continue;
+ tree fld = field;
+ HOST_WIDE_INT bitoff = 0, pos = 0, sz = 0;
+ int diff = 0;
+ tree v = NULL_TREE;
+ if (DECL_BIT_FIELD (field))
+ {
+ fld = DECL_BIT_FIELD_REPRESENTATIVE (field);
+ if (fld && INTEGRAL_TYPE_P (TREE_TYPE (fld)))
+ {
+ poly_int64 bitoffset;
+ poly_uint64 field_offset, fld_offset;
+ if (poly_int_tree_p (DECL_FIELD_OFFSET (field), &field_offset)
+ && poly_int_tree_p (DECL_FIELD_OFFSET (fld), &fld_offset))
+ bitoffset = (field_offset - fld_offset) * BITS_PER_UNIT;
+ else
+ bitoffset = 0;
+ bitoffset += (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field))
+ - tree_to_uhwi (DECL_FIELD_BIT_OFFSET (fld)));
+ diff = (TYPE_PRECISION (TREE_TYPE (fld))
+ - TYPE_PRECISION (TREE_TYPE (field)));
+ if (!bitoffset.is_constant (&bitoff)
+ || bitoff < 0
+ || bitoff > diff)
+ return NULL_TREE;
+ }
+ else
+ {
+ if (!tree_fits_uhwi_p (DECL_FIELD_BIT_OFFSET (field)))
+ return NULL_TREE;
+ int fieldsize = TYPE_PRECISION (TREE_TYPE (field));
+ int bpos = tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field));
+ bpos %= BITS_PER_UNIT;
+ fieldsize += bpos;
+ fieldsize += BITS_PER_UNIT - 1;
+ fieldsize /= BITS_PER_UNIT;
+ tree repr_type = find_bitfield_repr_type (fieldsize, len);
+ if (repr_type == NULL_TREE)
+ return NULL_TREE;
+ sz = int_size_in_bytes (repr_type);
+ if (sz < 0 || sz > len)
+ return NULL_TREE;
+ pos = int_byte_position (field);
+ if (pos < 0 || pos > len || pos + fieldsize > len)
+ return NULL_TREE;
+ HOST_WIDE_INT rpos;
+ if (pos + sz <= len)
+ rpos = pos;
+ else
+ {
+ rpos = len - sz;
+ gcc_assert (rpos <= pos);
+ }
+ bitoff = (HOST_WIDE_INT) (pos - rpos) * BITS_PER_UNIT + bpos;
+ pos = rpos;
+ diff = (TYPE_PRECISION (repr_type)
+ - TYPE_PRECISION (TREE_TYPE (field)));
+ v = native_interpret_expr (repr_type, ptr + off + pos, sz);
+ if (v == NULL_TREE)
+ return NULL_TREE;
+ fld = NULL_TREE;
+ }
+ }
+
+ if (fld)
+ {
+ sz = int_size_in_bytes (TREE_TYPE (fld));
+ if (sz < 0 || sz > len)
+ return NULL_TREE;
+ tree byte_pos = byte_position (fld);
+ if (!tree_fits_shwi_p (byte_pos))
+ return NULL_TREE;
+ pos = tree_to_shwi (byte_pos);
+ if (pos < 0 || pos > len || pos + sz > len)
+ return NULL_TREE;
+ }
+ if (fld == NULL_TREE)
+ /* Already handled above. */;
+ else if (can_native_interpret_type_p (TREE_TYPE (fld)))
+ {
+ v = native_interpret_expr (TREE_TYPE (fld),
+ ptr + off + pos, sz);
+ if (v == NULL_TREE)
+ return NULL_TREE;
+ }
+ else if (TREE_CODE (TREE_TYPE (fld)) == RECORD_TYPE
+ || TREE_CODE (TREE_TYPE (fld)) == ARRAY_TYPE)
+ v = native_interpret_aggregate (TREE_TYPE (fld), ptr, off + pos, sz);
+ if (v == NULL_TREE)
+ return NULL_TREE;
+ if (fld != field)
+ {
+ if (TREE_CODE (v) != INTEGER_CST)
+ return NULL_TREE;
+
+ /* FIXME: Figure out how to handle PDP endian bitfields. */
+ if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN)
+ return NULL_TREE;
+ if (!BYTES_BIG_ENDIAN)
+ v = wide_int_to_tree (TREE_TYPE (field),
+ wi::lrshift (wi::to_wide (v), bitoff));
+ else
+ v = wide_int_to_tree (TREE_TYPE (field),
+ wi::lrshift (wi::to_wide (v),
+ diff - bitoff));
+ }
+ CONSTRUCTOR_APPEND_ELT (elts, field, v);
+ }
+ return build_constructor (type, elts);
+}
+
/* Routines for manipulation of native_encode_expr encoded data if the encoded
or extracted constant positions and/or sizes aren't byte aligned. */
generated by cgit v1.1 at 2025-04-03 15:10:32 +0000