mirror of
https://gitlab.winehq.org/wine/wine-gecko.git
synced 2024-09-13 09:24:08 -07:00
124 lines
3.7 KiB
C++
124 lines
3.7 KiB
C++
/*
|
|
* Copyright (C) 2011, Google Inc. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
|
|
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
|
|
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
|
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef DenormalDisabler_h
|
|
#define DenormalDisabler_h
|
|
|
|
#include <wtf/MathExtras.h>
|
|
|
|
namespace WebCore {
|
|
|
|
// Deal with denormals. They can very seriously impact performance on x86.
|
|
|
|
// Define HAVE_DENORMAL if we support flushing denormals to zero.
|
|
#if OS(WINDOWS) && COMPILER(MSVC)
|
|
#define HAVE_DENORMAL
|
|
#endif
|
|
|
|
#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
|
|
#define HAVE_DENORMAL
|
|
#endif
|
|
|
|
#ifdef HAVE_DENORMAL
|
|
class DenormalDisabler {
|
|
public:
|
|
DenormalDisabler()
|
|
: m_savedCSR(0)
|
|
{
|
|
#if OS(WINDOWS) && COMPILER(MSVC)
|
|
// Save the current state, and set mode to flush denormals.
|
|
//
|
|
// http://stackoverflow.com/questions/637175/possible-bug-in-controlfp-s-may-not-restore-control-word-correctly
|
|
_controlfp_s(&m_savedCSR, 0, 0);
|
|
unsigned int unused;
|
|
_controlfp_s(&unused, _DN_FLUSH, _MCW_DN);
|
|
#else
|
|
m_savedCSR = getCSR();
|
|
setCSR(m_savedCSR | 0x8040);
|
|
#endif
|
|
}
|
|
|
|
~DenormalDisabler()
|
|
{
|
|
#if OS(WINDOWS) && COMPILER(MSVC)
|
|
unsigned int unused;
|
|
_controlfp_s(&unused, m_savedCSR, _MCW_DN);
|
|
#else
|
|
setCSR(m_savedCSR);
|
|
#endif
|
|
}
|
|
|
|
// This is a nop if we can flush denormals to zero in hardware.
|
|
static inline float flushDenormalFloatToZero(float f)
|
|
{
|
|
#if OS(WINDOWS) && COMPILER(MSVC) && (!_M_IX86_FP)
|
|
// For systems using x87 instead of sse, there's no hardware support
|
|
// to flush denormals automatically. Hence, we need to flush
|
|
// denormals to zero manually.
|
|
return (fabs(f) < FLT_MIN) ? 0.0f : f;
|
|
#else
|
|
return f;
|
|
#endif
|
|
}
|
|
private:
|
|
#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
|
|
inline int getCSR()
|
|
{
|
|
int result;
|
|
asm volatile("stmxcsr %0" : "=m" (result));
|
|
return result;
|
|
}
|
|
|
|
inline void setCSR(int a)
|
|
{
|
|
int temp = a;
|
|
asm volatile("ldmxcsr %0" : : "m" (temp));
|
|
}
|
|
|
|
#endif
|
|
|
|
unsigned int m_savedCSR;
|
|
};
|
|
|
|
#else
|
|
// FIXME: add implementations for other architectures and compilers
|
|
class DenormalDisabler {
|
|
public:
|
|
DenormalDisabler() { }
|
|
|
|
// Assume the worst case that other architectures and compilers
|
|
// need to flush denormals to zero manually.
|
|
static inline float flushDenormalFloatToZero(float f)
|
|
{
|
|
return (fabs(f) < FLT_MIN) ? 0.0f : f;
|
|
}
|
|
};
|
|
|
|
#endif
|
|
|
|
} // WebCore
|
|
|
|
#undef HAVE_DENORMAL
|
|
#endif // DenormalDisabler_h
|