mirror of
https://github.com/php/php-src.git
synced 2024-11-27 11:53:33 +08:00
879004dae3
On startup, PHP deliberately changes the floating point control word to enforce binary64 format for the calculations for best consistency across platforms. However, this is unnessary for x86_64 architectures, because in this case SSE instructions are used by default, and there is no good reason to pass `-mfpmath=i387` or such. Therefore, we can skip the modification, which has the benefit that system libraries are free to work in the mode of their liking.
416 lines
15 KiB
C
416 lines
15 KiB
C
/*
|
|
+----------------------------------------------------------------------+
|
|
| Zend Engine |
|
|
+----------------------------------------------------------------------+
|
|
| Copyright (c) Zend Technologies Ltd. (http://www.zend.com) |
|
|
+----------------------------------------------------------------------+
|
|
| This source file is subject to version 2.00 of the Zend license, |
|
|
| that is bundled with this package in the file LICENSE, and is |
|
|
| available through the world-wide-web at the following url: |
|
|
| http://www.zend.com/license/2_00.txt. |
|
|
| If you did not receive a copy of the Zend license and are unable to |
|
|
| obtain it through the world-wide-web, please send a note to |
|
|
| license@zend.com so we can mail you a copy immediately. |
|
|
+----------------------------------------------------------------------+
|
|
| Authors: Christian Seiler <chris_se@gmx.net> |
|
|
+----------------------------------------------------------------------+
|
|
*/
|
|
|
|
#ifndef ZEND_FLOAT_H
|
|
#define ZEND_FLOAT_H
|
|
|
|
BEGIN_EXTERN_C()
|
|
|
|
/*
|
|
Define functions for FP initialization and de-initialization.
|
|
*/
|
|
extern ZEND_API void zend_init_fpu(void);
|
|
extern ZEND_API void zend_shutdown_fpu(void);
|
|
extern ZEND_API void zend_ensure_fpu_mode(void);
|
|
|
|
END_EXTERN_C()
|
|
|
|
/* Copy of the contents of xpfpa.h (which is under public domain)
|
|
See http://wiki.php.net/rfc/rounding for details.
|
|
|
|
Cross Platform Floating Point Arithmetics
|
|
|
|
This header file defines several platform-dependent macros that ensure
|
|
equal and deterministic floating point behaviour across several platforms,
|
|
compilers and architectures.
|
|
|
|
The current macros are currently only used on x86 and x86_64 architectures,
|
|
on every other architecture, these macros expand to NOPs. This assumes that
|
|
other architectures do not have an internal precision and the operhand types
|
|
define the computational precision of floating point operations. This
|
|
assumption may be false, in that case, the author is interested in further
|
|
details on the other platform.
|
|
|
|
For further details, please visit:
|
|
http://www.christian-seiler.de/projekte/fpmath/
|
|
|
|
Version: 20090317 */
|
|
|
|
/*
|
|
Implementation notes:
|
|
|
|
x86_64:
|
|
- Since all x86_64 compilers use SSE by default, we do not define these
|
|
macros there. We ignore the compiler option -mfpmath=i387, because there is
|
|
no reason to use it on x86_64.
|
|
|
|
General:
|
|
- It would be nice if one could detect whether SSE if used for math via some
|
|
funky compiler defines and if so, make the macros go to NOPs. Any ideas
|
|
on how to do that?
|
|
|
|
MS Visual C:
|
|
- Since MSVC users typically don't use autoconf or CMake, we will detect
|
|
MSVC via compile time define.
|
|
*/
|
|
|
|
/* MSVC detection (MSVC people usually don't use autoconf) */
|
|
#if defined(_MSC_VER) && !defined(_WIN64)
|
|
# define HAVE__CONTROLFP_S
|
|
#endif /* _MSC_VER */
|
|
|
|
#if defined(HAVE__CONTROLFP_S) && !defined(__x86_64__)
|
|
|
|
/* float.h defines _controlfp_s */
|
|
# include <float.h>
|
|
|
|
# define XPFPA_HAVE_CW 1
|
|
# define XPFPA_CW_DATATYPE \
|
|
unsigned int
|
|
|
|
# define XPFPA_STORE_CW(vptr) do { \
|
|
_controlfp_s((unsigned int *)(vptr), 0, 0); \
|
|
} while (0)
|
|
|
|
# define XPFPA_RESTORE_CW(vptr) do { \
|
|
unsigned int _xpfpa_fpu_cw; \
|
|
_controlfp_s(&_xpfpa_fpu_cw, *((unsigned int *)(vptr)), _MCW_PC); \
|
|
} while (0)
|
|
|
|
# define XPFPA_DECLARE \
|
|
unsigned int _xpfpa_fpu_oldcw, _xpfpa_fpu_cw;
|
|
|
|
# define XPFPA_SWITCH_DOUBLE() do { \
|
|
_controlfp_s(&_xpfpa_fpu_cw, 0, 0); \
|
|
_xpfpa_fpu_oldcw = _xpfpa_fpu_cw; \
|
|
_controlfp_s(&_xpfpa_fpu_cw, _PC_53, _MCW_PC); \
|
|
} while (0)
|
|
# define XPFPA_SWITCH_SINGLE() do { \
|
|
_controlfp_s(&_xpfpa_fpu_cw, 0, 0); \
|
|
_xpfpa_fpu_oldcw = _xpfpa_fpu_cw; \
|
|
_controlfp_s(&_xpfpa_fpu_cw, _PC_24, _MCW_PC); \
|
|
} while (0)
|
|
/* NOTE: This only sets internal precision. MSVC does NOT support double-
|
|
extended precision! */
|
|
# define XPFPA_SWITCH_DOUBLE_EXTENDED() do { \
|
|
_controlfp_s(&_xpfpa_fpu_cw, 0, 0); \
|
|
_xpfpa_fpu_oldcw = _xpfpa_fpu_cw; \
|
|
_controlfp_s(&_xpfpa_fpu_cw, _PC_64, _MCW_PC); \
|
|
} while (0)
|
|
# define XPFPA_RESTORE() \
|
|
_controlfp_s(&_xpfpa_fpu_cw, _xpfpa_fpu_oldcw, _MCW_PC)
|
|
/* We do NOT use the volatile return trick since _controlfp_s is a function
|
|
call and thus FP registers are saved in memory anyway. However, we do use
|
|
a variable to ensure that the expression passed into val will be evaluated
|
|
*before* switching back contexts. */
|
|
# define XPFPA_RETURN_DOUBLE(val) \
|
|
do { \
|
|
double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
# define XPFPA_RETURN_SINGLE(val) \
|
|
do { \
|
|
float _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
/* This won't work, but we add a macro for it anyway. */
|
|
# define XPFPA_RETURN_DOUBLE_EXTENDED(val) \
|
|
do { \
|
|
long double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
|
|
#elif defined(HAVE__CONTROLFP) && !defined(__x86_64__)
|
|
|
|
/* float.h defines _controlfp */
|
|
# include <float.h>
|
|
|
|
# define XPFPA_DECLARE \
|
|
unsigned int _xpfpa_fpu_oldcw;
|
|
|
|
# define XPFPA_HAVE_CW 1
|
|
# define XPFPA_CW_DATATYPE \
|
|
unsigned int
|
|
|
|
# define XPFPA_STORE_CW(vptr) do { \
|
|
*((unsigned int *)(vptr)) = _controlfp(0, 0); \
|
|
} while (0)
|
|
|
|
# define XPFPA_RESTORE_CW(vptr) do { \
|
|
_controlfp(*((unsigned int *)(vptr)), _MCW_PC); \
|
|
} while (0)
|
|
|
|
# define XPFPA_SWITCH_DOUBLE() do { \
|
|
_xpfpa_fpu_oldcw = _controlfp(0, 0); \
|
|
_controlfp(_PC_53, _MCW_PC); \
|
|
} while (0)
|
|
# define XPFPA_SWITCH_SINGLE() do { \
|
|
_xpfpa_fpu_oldcw = _controlfp(0, 0); \
|
|
_controlfp(_PC_24, _MCW_PC); \
|
|
} while (0)
|
|
/* NOTE: This will only work as expected on MinGW. */
|
|
# define XPFPA_SWITCH_DOUBLE_EXTENDED() do { \
|
|
_xpfpa_fpu_oldcw = _controlfp(0, 0); \
|
|
_controlfp(_PC_64, _MCW_PC); \
|
|
} while (0)
|
|
# define XPFPA_RESTORE() \
|
|
_controlfp(_xpfpa_fpu_oldcw, _MCW_PC)
|
|
/* We do NOT use the volatile return trick since _controlfp is a function
|
|
call and thus FP registers are saved in memory anyway. However, we do use
|
|
a variable to ensure that the expression passed into val will be evaluated
|
|
*before* switching back contexts. */
|
|
# define XPFPA_RETURN_DOUBLE(val) \
|
|
do { \
|
|
double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
# define XPFPA_RETURN_SINGLE(val) \
|
|
do { \
|
|
float _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
/* This will only work on MinGW */
|
|
# define XPFPA_RETURN_DOUBLE_EXTENDED(val) \
|
|
do { \
|
|
long double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
|
|
#elif defined(HAVE__FPU_SETCW) && !defined(__x86_64__) /* glibc systems */
|
|
|
|
/* fpu_control.h defines _FPU_[GS]ETCW */
|
|
# include <fpu_control.h>
|
|
|
|
# define XPFPA_DECLARE \
|
|
fpu_control_t _xpfpa_fpu_oldcw, _xpfpa_fpu_cw;
|
|
|
|
# define XPFPA_HAVE_CW 1
|
|
# define XPFPA_CW_DATATYPE \
|
|
fpu_control_t
|
|
|
|
# define XPFPA_STORE_CW(vptr) do { \
|
|
_FPU_GETCW((*((fpu_control_t *)(vptr)))); \
|
|
} while (0)
|
|
|
|
# define XPFPA_RESTORE_CW(vptr) do { \
|
|
_FPU_SETCW((*((fpu_control_t *)(vptr)))); \
|
|
} while (0)
|
|
|
|
# define XPFPA_SWITCH_DOUBLE() do { \
|
|
_FPU_GETCW(_xpfpa_fpu_oldcw); \
|
|
_xpfpa_fpu_cw = (_xpfpa_fpu_oldcw & ~_FPU_EXTENDED & ~_FPU_SINGLE) | _FPU_DOUBLE; \
|
|
_FPU_SETCW(_xpfpa_fpu_cw); \
|
|
} while (0)
|
|
# define XPFPA_SWITCH_SINGLE() do { \
|
|
_FPU_GETCW(_xpfpa_fpu_oldcw); \
|
|
_xpfpa_fpu_cw = (_xpfpa_fpu_oldcw & ~_FPU_EXTENDED & ~_FPU_DOUBLE) | _FPU_SINGLE; \
|
|
_FPU_SETCW(_xpfpa_fpu_cw); \
|
|
} while (0)
|
|
# define XPFPA_SWITCH_DOUBLE_EXTENDED() do { \
|
|
_FPU_GETCW(_xpfpa_fpu_oldcw); \
|
|
_xpfpa_fpu_cw = (_xpfpa_fpu_oldcw & ~_FPU_SINGLE & ~_FPU_DOUBLE) | _FPU_EXTENDED; \
|
|
_FPU_SETCW(_xpfpa_fpu_cw); \
|
|
} while (0)
|
|
# define XPFPA_RESTORE() \
|
|
_FPU_SETCW(_xpfpa_fpu_oldcw)
|
|
/* We use a temporary volatile variable (in a new block) in order to ensure
|
|
that the optimizer does not mis-optimize the instructions. Also, a volatile
|
|
variable ensures truncation to correct precision. */
|
|
# define XPFPA_RETURN_DOUBLE(val) \
|
|
do { \
|
|
volatile double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
# define XPFPA_RETURN_SINGLE(val) \
|
|
do { \
|
|
volatile float _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
# define XPFPA_RETURN_DOUBLE_EXTENDED(val) \
|
|
do { \
|
|
volatile long double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
|
|
#elif defined(HAVE_FPSETPREC) && !defined(__x86_64__) /* FreeBSD */
|
|
|
|
/* fpu_control.h defines _FPU_[GS]ETCW */
|
|
# include <machine/ieeefp.h>
|
|
|
|
# define XPFPA_DECLARE \
|
|
fp_prec_t _xpfpa_fpu_oldprec;
|
|
|
|
# define XPFPA_HAVE_CW 1
|
|
# define XPFPA_CW_DATATYPE \
|
|
fp_prec_t
|
|
|
|
# define XPFPA_STORE_CW(vptr) do { \
|
|
*((fp_prec_t *)(vptr)) = fpgetprec(); \
|
|
} while (0)
|
|
|
|
# define XPFPA_RESTORE_CW(vptr) do { \
|
|
fpsetprec(*((fp_prec_t *)(vptr))); \
|
|
} while (0)
|
|
|
|
# define XPFPA_SWITCH_DOUBLE() do { \
|
|
_xpfpa_fpu_oldprec = fpgetprec(); \
|
|
fpsetprec(FP_PD); \
|
|
} while (0)
|
|
# define XPFPA_SWITCH_SINGLE() do { \
|
|
_xpfpa_fpu_oldprec = fpgetprec(); \
|
|
fpsetprec(FP_PS); \
|
|
} while (0)
|
|
# define XPFPA_SWITCH_DOUBLE_EXTENDED() do { \
|
|
_xpfpa_fpu_oldprec = fpgetprec(); \
|
|
fpsetprec(FP_PE); \
|
|
} while (0)
|
|
# define XPFPA_RESTORE() \
|
|
fpsetprec(_xpfpa_fpu_oldprec)
|
|
/* We use a temporary volatile variable (in a new block) in order to ensure
|
|
that the optimizer does not mis-optimize the instructions. Also, a volatile
|
|
variable ensures truncation to correct precision. */
|
|
# define XPFPA_RETURN_DOUBLE(val) \
|
|
do { \
|
|
volatile double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
# define XPFPA_RETURN_SINGLE(val) \
|
|
do { \
|
|
volatile float _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
# define XPFPA_RETURN_DOUBLE_EXTENDED(val) \
|
|
do { \
|
|
volatile long double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
|
|
#elif defined(HAVE_FPU_INLINE_ASM_X86) && !defined(__x86_64__)
|
|
|
|
/*
|
|
Custom x86 inline assembler implementation.
|
|
|
|
This implementation does not use predefined wrappers of the OS / compiler
|
|
but rather uses x86/x87 inline assembler directly. Basic instructions:
|
|
|
|
fnstcw - Store the FPU control word in a variable
|
|
fldcw - Load the FPU control word from a variable
|
|
|
|
Bits (only bits 8 and 9 are relevant, bits 0 to 7 are for other things):
|
|
0x0yy: Single precision
|
|
0x1yy: Reserved
|
|
0x2yy: Double precision
|
|
0x3yy: Double-extended precision
|
|
|
|
We use an unsigned int for the datatype. glibc sources add __mode__ (__HI__)
|
|
attribute to it (HI stands for half-integer according to docs). It is unclear
|
|
what the does exactly and how portable it is.
|
|
|
|
The assembly syntax works with GNU CC, Intel CC and Sun CC.
|
|
*/
|
|
|
|
# define XPFPA_DECLARE \
|
|
unsigned int _xpfpa_fpu_oldcw, _xpfpa_fpu_cw;
|
|
|
|
# define XPFPA_HAVE_CW 1
|
|
# define XPFPA_CW_DATATYPE \
|
|
unsigned int
|
|
|
|
# define XPFPA_STORE_CW(vptr) do { \
|
|
__asm__ __volatile__ ("fnstcw %0" : "=m" (*((unsigned int *)(vptr)))); \
|
|
} while (0)
|
|
|
|
# define XPFPA_RESTORE_CW(vptr) do { \
|
|
__asm__ __volatile__ ("fldcw %0" : : "m" (*((unsigned int *)(vptr)))); \
|
|
} while (0)
|
|
|
|
# define XPFPA_SWITCH_DOUBLE() do { \
|
|
__asm__ __volatile__ ("fnstcw %0" : "=m" (*&_xpfpa_fpu_oldcw)); \
|
|
_xpfpa_fpu_cw = (_xpfpa_fpu_oldcw & ~0x100) | 0x200; \
|
|
__asm__ __volatile__ ("fldcw %0" : : "m" (*&_xpfpa_fpu_cw)); \
|
|
} while (0)
|
|
# define XPFPA_SWITCH_SINGLE() do { \
|
|
__asm__ __volatile__ ("fnstcw %0" : "=m" (*&_xpfpa_fpu_oldcw)); \
|
|
_xpfpa_fpu_cw = (_xpfpa_fpu_oldcw & ~0x300); \
|
|
__asm__ __volatile__ ("fldcw %0" : : "m" (*&_xpfpa_fpu_cw)); \
|
|
} while (0)
|
|
# define XPFPA_SWITCH_DOUBLE_EXTENDED() do { \
|
|
__asm__ __volatile__ ("fnstcw %0" : "=m" (*&_xpfpa_fpu_oldcw)); \
|
|
_xpfpa_fpu_cw = _xpfpa_fpu_oldcw | 0x300; \
|
|
__asm__ __volatile__ ("fldcw %0" : : "m" (*&_xpfpa_fpu_cw)); \
|
|
} while (0)
|
|
# define XPFPA_RESTORE() \
|
|
__asm__ __volatile__ ("fldcw %0" : : "m" (*&_xpfpa_fpu_oldcw))
|
|
/* We use a temporary volatile variable (in a new block) in order to ensure
|
|
that the optimizer does not mis-optimize the instructions. Also, a volatile
|
|
variable ensures truncation to correct precision. */
|
|
# define XPFPA_RETURN_DOUBLE(val) \
|
|
do { \
|
|
volatile double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
# define XPFPA_RETURN_SINGLE(val) \
|
|
do { \
|
|
volatile float _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
# define XPFPA_RETURN_DOUBLE_EXTENDED(val) \
|
|
do { \
|
|
volatile long double _xpfpa_result = (val); \
|
|
XPFPA_RESTORE(); \
|
|
return _xpfpa_result; \
|
|
} while (0)
|
|
|
|
#else /* FPU CONTROL */
|
|
|
|
/*
|
|
This is either not an x87 FPU or the inline assembly syntax was not
|
|
recognized. In any case, default to NOPs for the macros and hope the
|
|
generated code will behave as planned.
|
|
*/
|
|
# define XPFPA_DECLARE /* NOP */
|
|
# define XPFPA_HAVE_CW 0
|
|
# define XPFPA_CW_DATATYPE unsigned int
|
|
# define XPFPA_STORE_CW(variable) /* NOP */
|
|
# define XPFPA_RESTORE_CW(variable) /* NOP */
|
|
# define XPFPA_SWITCH_DOUBLE() /* NOP */
|
|
# define XPFPA_SWITCH_SINGLE() /* NOP */
|
|
# define XPFPA_SWITCH_DOUBLE_EXTENDED() /* NOP */
|
|
# define XPFPA_RESTORE() /* NOP */
|
|
# define XPFPA_RETURN_DOUBLE(val) return (val)
|
|
# define XPFPA_RETURN_SINGLE(val) return (val)
|
|
# define XPFPA_RETURN_DOUBLE_EXTENDED(val) return (val)
|
|
|
|
#endif /* FPU CONTROL */
|
|
|
|
#endif
|