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re PR tree-optimization/61306 (wrong code at -Os and above on x86_64-linux-gnu)

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2014-06-11  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/
    PR tree-optimization/61306
    * tree-ssa-math-opts.c (struct symbolic_number): Store type of
    expression instead of its size.
    (do_shift_rotate): Adapt to change in struct symbolic_number. Return
    false to prevent optimization when the result is unpredictable due to
    arithmetic right shift of signed type with highest byte is set.
    (verify_symbolic_number_p): Adapt to change in struct symbolic_number.
    (init_symbolic_number): Likewise.
    (find_bswap_or_nop_1): Likewise. Return NULL to prevent optimization
    when the result is unpredictable due to sign extension.

    gcc/testsuite/
    * gcc.c-torture/execute/pr61306-1.c: New test.
    * gcc.c-torture/execute/pr61306-2.c: Likewise.
    * gcc.c-torture/execute/pr61306-3.c: Likewise.

From-SVN: r211444
This commit is contained in:
Thomas Preud'homme 2014-06-11 10:04:33 +00:00 • committed by Thomas Preud'homme
parent 1d02d8b8cb
commit 698ff10718
6 changed files with 153 additions and 24 deletions
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13
gcc/ChangeLog
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@ -1,3 +1,16 @@
2014-06-11 Thomas Preud'homme <thomas.preudhomme@arm.com>
PR tree-optimization/61306
* tree-ssa-math-opts.c (struct symbolic_number): Store type of
expression instead of its size.
(do_shift_rotate): Adapt to change in struct symbolic_number. Return
false to prevent optimization when the result is unpredictable due to
arithmetic right shift of signed type with highest byte is set.
(verify_symbolic_number_p): Adapt to change in struct symbolic_number.
(init_symbolic_number): Likewise.
(find_bswap_or_nop_1): Likewise. Return NULL to prevent optimization
when the result is unpredictable due to sign extension.
2014-06-11 Terry Guo <terry.guo@arm.com>
* config/arm/arm.md (*thumb1_adddi3): Move into new file thumb1.md.

6
gcc/testsuite/ChangeLog
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@ -1,3 +1,9 @@
2014-06-11 Thomas Preud'homme <thomas.preudhomme@arm.com>
* gcc.c-torture/execute/pr61306-1.c: New test.
* gcc.c-torture/execute/pr61306-2.c: Likewise.
* gcc.c-torture/execute/pr61306-3.c: Likewise.
2014-06-11 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
* gcc.target/aarch64/acle/acle.exp: New.

39
gcc/testsuite/gcc.c-torture/execute/pr61306-1.c Normal file
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@ -0,0 +1,39 @@
#ifdef __INT32_TYPE__
typedef __INT32_TYPE__ int32_t;
#else
typedef int int32_t;
#endif
#ifdef __UINT32_TYPE__
typedef __UINT32_TYPE__ uint32_t;
#else
typedef unsigned uint32_t;
#endif
#define __fake_const_swab32(x) ((uint32_t)( \
(((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) | \
(((uint32_t)(x) & (uint32_t)0x0000ff00UL) << 8) | \
(((uint32_t)(x) & (uint32_t)0x00ff0000UL) >> 8) | \
(( (int32_t)(x) & (int32_t)0xff000000UL) >> 24)))
/* Previous version of bswap optimization failed to consider sign extension
and as a result would replace an expression *not* doing a bswap by a
bswap. */
__attribute__ ((noinline, noclone)) uint32_t
fake_bswap32 (uint32_t in)
{
return __fake_const_swab32 (in);
}
int
main(void)
{
if (sizeof (int32_t) * __CHAR_BIT__ != 32)
return 0;
if (sizeof (uint32_t) * __CHAR_BIT__ != 32)
return 0;
if (fake_bswap32 (0x87654321) != 0xffffff87)
__builtin_abort ();
return 0;
}

40
gcc/testsuite/gcc.c-torture/execute/pr61306-2.c Normal file
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@ -0,0 +1,40 @@
#ifdef __INT16_TYPE__
typedef __INT16_TYPE__ int16_t;
#else
typedef short int16_t;
#endif
#ifdef __UINT32_TYPE__
typedef __UINT32_TYPE__ uint32_t;
#else
typedef unsigned uint32_t;
#endif
#define __fake_const_swab32(x) ((uint32_t)( \
(((uint32_t) (x) & (uint32_t)0x000000ffUL) << 24) | \
(((uint32_t)(int16_t)(x) & (uint32_t)0x00ffff00UL) << 8) | \
(((uint32_t) (x) & (uint32_t)0x00ff0000UL) >> 8) | \
(((uint32_t) (x) & (uint32_t)0xff000000UL) >> 24)))
/* Previous version of bswap optimization failed to consider sign extension
and as a result would replace an expression *not* doing a bswap by a
bswap. */
__attribute__ ((noinline, noclone)) uint32_t
fake_bswap32 (uint32_t in)
{
return __fake_const_swab32 (in);
}
int
main(void)
{
if (sizeof (uint32_t) * __CHAR_BIT__ != 32)
return 0;
if (sizeof (int16_t) * __CHAR_BIT__ != 16)
return 0;
if (fake_bswap32 (0x81828384) != 0xff838281)
__builtin_abort ();
return 0;
}

13
gcc/testsuite/gcc.c-torture/execute/pr61306-3.c Normal file
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@ -0,0 +1,13 @@
short a = -1;
int b;
char c;
int
main ()
{
c = a;
b = a | c;
if (b != -1)
__builtin_abort ();
return 0;
}

66
gcc/tree-ssa-math-opts.c
View file

@ -1622,7 +1622,7 @@ make_pass_cse_sincos (gcc::context *ctxt)
struct symbolic_number {
uint64_t n;
int size;
tree type;
tree base_addr;
tree offset;
HOST_WIDE_INT bytepos;
@ -1652,13 +1652,15 @@ do_shift_rotate (enum tree_code code,
struct symbolic_number *n,
int count)
{
int bitsize = TYPE_PRECISION (n->type);
if (count % 8 != 0)
return false;
/* Zero out the extra bits of N in order to avoid them being shifted
into the significant bits. */
if (n->size < (int)sizeof (int64_t))
n->n &= ((uint64_t)1 << (n->size * BITS_PER_UNIT)) - 1;
if (bitsize < 8 * (int)sizeof (int64_t))
n->n &= ((uint64_t)1 << bitsize) - 1;
switch (code)
{
@ -1666,20 +1668,23 @@ do_shift_rotate (enum tree_code code,
n->n <<= count;
break;
case RSHIFT_EXPR:
/* Arithmetic shift of signed type: result is dependent on the value. */
if (!TYPE_UNSIGNED (n->type) && (n->n & (0xff << (bitsize - 8))))
return false;
n->n >>= count;
break;
case LROTATE_EXPR:
n->n = (n->n << count) | (n->n >> ((n->size * BITS_PER_UNIT) - count));
n->n = (n->n << count) | (n->n >> (bitsize - count));
break;
case RROTATE_EXPR:
n->n = (n->n >> count) | (n->n << ((n->size * BITS_PER_UNIT) - count));
n->n = (n->n >> count) | (n->n << (bitsize - count));
break;
default:
return false;
}
/* Zero unused bits for size. */
if (n->size < (int)sizeof (int64_t))
n->n &= ((uint64_t)1 << (n->size * BITS_PER_UNIT)) - 1;
if (bitsize < 8 * (int)sizeof (int64_t))
n->n &= ((uint64_t)1 << bitsize) - 1;
return true;
}
@ -1696,7 +1701,7 @@ verify_symbolic_number_p (struct symbolic_number *n, gimple stmt)
if (TREE_CODE (lhs_type) != INTEGER_TYPE)
return false;
if (TYPE_PRECISION (lhs_type) != n->size * BITS_PER_UNIT)
if (TYPE_PRECISION (lhs_type) != TYPE_PRECISION (n->type))
return false;
return true;
@ -1708,20 +1713,23 @@ verify_symbolic_number_p (struct symbolic_number *n, gimple stmt)
static bool
init_symbolic_number (struct symbolic_number *n, tree src)
{
int size;
n->base_addr = n->offset = n->alias_set = n->vuse = NULL_TREE;
/* Set up the symbolic number N by setting each byte to a value between 1 and
the byte size of rhs1. The highest order byte is set to n->size and the
lowest order byte to 1. */
n->size = TYPE_PRECISION (TREE_TYPE (src));
if (n->size % BITS_PER_UNIT != 0)
n->type = TREE_TYPE (src);
size = TYPE_PRECISION (n->type);
if (size % BITS_PER_UNIT != 0)
return false;
n->size /= BITS_PER_UNIT;
n->range = n->size;
size /= BITS_PER_UNIT;
n->range = size;
n->n = CMPNOP;
if (n->size < (int)sizeof (int64_t))
n->n &= ((uint64_t)1 << (n->size * BITS_PER_UNIT)) - 1;
if (size < (int)sizeof (int64_t))
n->n &= ((uint64_t)1 << (size * BITS_PER_UNIT)) - 1;
return true;
}
@ -1858,12 +1866,12 @@ find_bswap_or_nop_1 (gimple stmt, struct symbolic_number *n, int limit)
{
case BIT_AND_EXPR:
{
int i;
int i, size = TYPE_PRECISION (n->type) / BITS_PER_UNIT;
uint64_t val = int_cst_value (rhs2);
uint64_t tmp = val;
/* Only constants masking full bytes are allowed. */
for (i = 0; i < n->size; i++, tmp >>= BITS_PER_UNIT)
for (i = 0; i < size; i++, tmp >>= BITS_PER_UNIT)
if ((tmp & 0xff) != 0 && (tmp & 0xff) != 0xff)
return NULL_TREE;
@ -1879,21 +1887,30 @@ find_bswap_or_nop_1 (gimple stmt, struct symbolic_number *n, int limit)
break;
CASE_CONVERT:
{
int type_size;
int type_size, old_type_size;
tree type;
type_size = TYPE_PRECISION (gimple_expr_type (stmt));
type = gimple_expr_type (stmt);
type_size = TYPE_PRECISION (type);
if (type_size % BITS_PER_UNIT != 0)
return NULL_TREE;
/* Sign extension: result is dependent on the value. */
old_type_size = TYPE_PRECISION (n->type);
if (!TYPE_UNSIGNED (n->type)
&& type_size > old_type_size
&& n->n & (0xff << (old_type_size - 8)))
return NULL_TREE;
if (type_size / BITS_PER_UNIT < (int)(sizeof (int64_t)))
{
/* If STMT casts to a smaller type mask out the bits not
belonging to the target type. */
n->n &= ((uint64_t)1 << type_size) - 1;
}
n->size = type_size / BITS_PER_UNIT;
n->type = type;
if (!n->base_addr)
n->range = n->size;
n->range = type_size / BITS_PER_UNIT;
}
break;
default:
@ -1906,7 +1923,7 @@ find_bswap_or_nop_1 (gimple stmt, struct symbolic_number *n, int limit)
if (rhs_class == GIMPLE_BINARY_RHS)
{
int i;
int i, size;
struct symbolic_number n1, n2;
uint64_t mask;
tree source_expr2;
@ -1932,7 +1949,7 @@ find_bswap_or_nop_1 (gimple stmt, struct symbolic_number *n, int limit)
if (!source_expr2)
return NULL_TREE;
if (n1.size != n2.size)
if (TYPE_PRECISION (n1.type) != TYPE_PRECISION (n2.type))
return NULL_TREE;
if (!n1.vuse != !n2.vuse ||
@ -1998,8 +2015,9 @@ find_bswap_or_nop_1 (gimple stmt, struct symbolic_number *n, int limit)
n->base_addr = n1.base_addr;
n->offset = n1.offset;
n->bytepos = n1.bytepos;
n->size = n1.size;
for (i = 0, mask = 0xff; i < n->size; i++, mask <<= BITS_PER_UNIT)
n->type = n1.type;
size = TYPE_PRECISION (n->type) / BITS_PER_UNIT;
for (i = 0, mask = 0xff; i < size; i++, mask <<= BITS_PER_UNIT)
{
uint64_t masked1, masked2;