NLMISC::CFastMem Class Reference

#include <fast_mem.h>

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Detailed Description

Functions for Fast Memory manipulation with Pentium-class processors. From http://www.sgi.com/developers/technology/irix/resources/asc_cpu.html

Author:

Lionel Berenguier

Nevrax France

Date:

2002

Definition at line 44 of file fast_mem.h.

Static Public Member Functions
void *	memcpySSE (void *dst, const void *src, size_t nbytes)
void	precache (const void *src, uint nbytes)
void	precacheMMX (const void *src, uint nbytes)
void	precacheSSE (const void *src, uint nbytes)
Static Public Attributes
void *(*	memcpy )(void *dts, const void *src, size_t nbytes)

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Member Function Documentation

void * NLMISC::CFastMem::memcpySSE (  void *  dst, const void *  src, size_t  nbytes )  [static]

Fast memcpy using SSE instructions: prefetchnta and movntq. Can be called only if SSE and MMX is supported NB: Copy per block of 4K through L1 cache Result is typically 420 Mo/s instead of 150 Mo/s. Definition at line 205 of file fast_mem.cpp. References memcpy, and src. { // Use std memcpy. return memcpy(dst, src, nbytes); }

void NLMISC::CFastMem::precache (  const void *  src, uint  nbytes )  [static]

Fast precaching of memory in L1 cache using SSE or MMX where available (NB: others methods don't do the test) nbytes should not override 4K Definition at line 218 of file fast_mem.cpp. References src, and uint. { // no-op. }

void NLMISC::CFastMem::precacheMMX (  const void *  src, uint  nbytes )  [static]

Fast precaching of memory in L1 cache using MMX instructions only: movq Result is typically 720 Mo/s (surely slower because of overhead). Hence prefer precacheSSE() when available. nbytes should not override 4K Definition at line 214 of file fast_mem.cpp. References src, and uint. { // no-op. }

void NLMISC::CFastMem::precacheSSE (  const void *  src, uint  nbytes )  [static]

Fast precaching of memory in L1 cache using MMX/SSE instructions: movq and prefetchnta Result is typically 880 Mo/s (surely slower because of overhead). nbytes should not override 4K Definition at line 210 of file fast_mem.cpp. References src, and uint. { // no-op. }

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Field Documentation

void *(* NLMISC::CFastMem::memcpy)(void *dts, const void *src, size_t nbytes)=findBestmemcpy() [static]

This is a function pointer that points on the best memcpy function available depending of the OS and proc. In the best case, it will use memcpySSE(), and in worst case, it'll use the libc memcpy() Simply use it this way: CFastMem::memcpy(dst, src, size); Definition at line 239 of file fast_mem.cpp. Referenced by NLSOUND::CContextSoundContainer< NbJoker, UseRandom, Shift >::init(), and memcpySSE().

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The documentation for this class was generated from the following files:

• fast_mem.h
• fast_mem.cpp

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