jediacademy/codemp/unix/linux_common.c
2013-04-04 17:35:38 -05:00

323 lines
7.5 KiB
C

/**
* GAS syntax equivalents of the MSVC asm memory calls in common.c
*
* The following changes have been made to the asm:
* 1. Registers are loaded by the inline asm arguments when possible
* 2. Labels have been changed to local label format (0,1,etc.) to allow inlining
*
* HISTORY:
* AH - Created on 08 Dec 2000
*/
#include <unistd.h> // AH - for size_t
#include <string.h>
// bk001207 - we need something under Linux, too. Mac?
#if 1 // defined(C_ONLY) // bk010102 - dedicated?
void Com_Memcpy (void* dest, const void* src, const size_t count) {
memcpy(dest, src, count);
}
void Com_Memset (void* dest, const int val, const size_t count) {
memset(dest, val, count);
}
#else
typedef enum {
PRE_READ, // prefetch assuming that buffer is used for reading only
PRE_WRITE, // prefetch assuming that buffer is used for writing only
PRE_READ_WRITE // prefetch assuming that buffer is used for both reading and writing
} e_prefetch;
void Com_Prefetch (const void *s, const unsigned int bytes, e_prefetch type);
void _copyDWord (unsigned int* dest, const unsigned int constant, const unsigned int count) {
// MMX version not used on standard Pentium MMX
// because the dword version is faster (with
// proper destination prefetching)
__asm__ __volatile__ ("
//mov eax,constant // eax = val
//mov edx,dest // dest
//mov ecx,count
movd %%eax, %%mm0
punpckldq %%mm0, %%mm0
// ensure that destination is qword aligned
testl $7, %%edx // qword padding?
jz 0f
movl %%eax, (%%edx)
decl %%ecx
addl $4, %%edx
0: movl %%ecx, %%ebx
andl $0xfffffff0, %%ecx
jz 2f
jmp 1f
.align 16
// funny ordering here to avoid commands
// that cross 32-byte boundaries (the
// [edx+0] version has a special 3-byte opcode...
1: movq %%mm0, 8(%%edx)
movq %%mm0, 16(%%edx)
movq %%mm0, 24(%%edx)
movq %%mm0, 32(%%edx)
movq %%mm0, 40(%%edx)
movq %%mm0, 48(%%edx)
movq %%mm0, 56(%%edx)
movq %%mm0, (%%edx)
addl $64, %%edx
subl $16, %%ecx
jnz 1b
2:
movl %%ebx, %%ecx // ebx = cnt
andl $0xfffffff0, %%ecx // ecx = cnt&~15
subl %%ecx, %%ebx
jz 6f
cmpl $8, %%ebx
jl 3f
movq %%mm0, (%%edx)
movq %%mm0, 8(%%edx)
movq %%mm0, 16(%%edx)
movq %%mm0, 24(%%edx)
addl $32, %%edx
subl $8, %%ebx
jz 6f
3: cmpl $4, %%ebx
jl 4f
movq %%mm0, (%%edx)
movq %%mm0, 8(%%edx)
addl $16, %%edx
subl $4, %%ebx
4: cmpl $2, %%ebx
jl 5f
movq %%mm0, (%%edx)
addl $8, %%edx
subl $2, %%ebx
5: cmpl $1, %%ebx
jl 6f
movl %%eax, (%%edx)
6:
emms
"
: : "a" (constant), "c" (count), "d" (dest)
: "%ebx", "%edi", "%esi", "cc", "memory");
}
// optimized memory copy routine that handles all alignment
// cases and block sizes efficiently
void Com_Memcpy (void* dest, const void* src, const size_t count) {
Com_Prefetch (src, count, PRE_READ);
__asm__ __volatile__ ("
pushl %%edi
pushl %%esi
//mov ecx,count
cmpl $0, %%ecx // count = 0 check (just to be on the safe side)
je 6f
//mov edx,dest
movl %0, %%ebx
cmpl $32, %%ecx // padding only?
jl 1f
movl %%ecx, %%edi
andl $0xfffffe00, %%edi // edi = count&~31
subl $32, %%edi
.align 16
0:
movl (%%ebx, %%edi, 1), %%eax
movl 4(%%ebx, %%edi, 1), %%esi
movl %%eax, (%%edx, %%edi, 1)
movl %%esi, 4(%%edx, %%edi, 1)
movl 8(%%ebx, %%edi, 1), %%eax
movl 12(%%ebx, %%edi, 1), %%esi
movl %%eax, 8(%%edx, %%edi, 1)
movl %%esi, 12(%%edx, %%edi, 1)
movl 16(%%ebx, %%edi, 1), %%eax
movl 20(%%ebx, %%edi, 1), %%esi
movl %%eax, 16(%%edx, %%edi, 1)
movl %%esi, 20(%%edx, %%edi, 1)
movl 24(%%ebx, %%edi, 1), %%eax
movl 28(%%ebx, %%edi, 1), %%esi
movl %%eax, 24(%%edx, %%edi, 1)
movl %%esi, 28(%%edx, %%edi, 1)
subl $32, %%edi
jge 0b
movl %%ecx, %%edi
andl $0xfffffe00, %%edi
addl %%edi, %%ebx // increase src pointer
addl %%edi, %%edx // increase dst pointer
andl $31, %%ecx // new count
jz 6f // if count = 0, get outta here
1:
cmpl $16, %%ecx
jl 2f
movl (%%ebx), %%eax
movl %%eax, (%%edx)
movl 4(%%ebx), %%eax
movl %%eax, 4(%%edx)
movl 8(%%ebx), %%eax
movl %%eax, 8(%%edx)
movl 12(%%ebx), %%eax
movl %%eax, 12(%%edx)
subl $16, %%ecx
addl $16, %%ebx
addl $16, %%edx
2:
cmpl $8, %%ecx
jl 3f
movl (%%ebx), %%eax
movl %%eax, (%%edx)
movl 4(%%ebx), %%eax
subl $8, %%ecx
movl %%eax, 4(%%edx)
addl $8, %%ebx
addl $8, %%edx
3:
cmpl $4, %%ecx
jl 4f
movl (%%ebx), %%eax // here 4-7 bytes
addl $4, %%ebx
subl $4, %%ecx
movl %%eax, (%%edx)
addl $4, %%edx
4: // 0-3 remaining bytes
cmpl $2, %%ecx
jl 5f
movw (%%ebx), %%ax // two bytes
cmpl $3, %%ecx // less than 3?
movw %%ax, (%%edx)
jl 6f
movb 2(%%ebx), %%al // last byte
movb %%al, 2(%%edx)
jmp 6f
5:
cmpl $1, %%ecx
jl 6f
movb (%%ebx), %%al
movb %%al, (%%edx)
6:
popl %%esi
popl %%edi
"
: : "m" (src), "d" (dest), "c" (count)
: "%eax", "%ebx", "%edi", "%esi", "cc", "memory");
}
void Com_Memset (void* dest, const int val, const size_t count)
{
unsigned int fillval;
if (count < 8)
{
__asm__ __volatile__ ("
//mov edx,dest
//mov eax, val
movb %%al, %%ah
movl %%eax, %%ebx
andl $0xffff, %%ebx
shll $16, %%eax
addl %%ebx, %%eax // eax now contains pattern
//mov ecx,count
cmpl $4, %%ecx
jl 0f
movl %%eax, (%%edx) // copy first dword
addl $4, %%edx
subl $4, %%ecx
0: cmpl $2, %%ecx
jl 1f
movw %%ax, (%%edx) // copy 2 bytes
addl $2, %%edx
subl $2, %%ecx
1: cmpl $0, %%ecx
je 2f
movb %%al, (%%edx) // copy single byte
2:
"
: : "d" (dest), "a" (val), "c" (count)
: "%ebx", "%edi", "%esi", "cc", "memory");
return;
}
fillval = val;
fillval = fillval|(fillval<<8);
fillval = fillval|(fillval<<16); // fill dword with 8-bit pattern
_copyDWord ((unsigned int*)(dest),fillval, count/4);
__asm__ __volatile__ (" // padding of 0-3 bytes
//mov ecx,count
movl %%ecx, %%eax
andl $3, %%ecx
jz 1f
andl $0xffffff00, %%eax
//mov ebx,dest
addl %%eax, %%edx
movl %0, %%eax
cmpl $2, %%ecx
jl 0f
movw %%ax, (%%edx)
cmpl $2, %%ecx
je 1f
movb %%al, 2(%%edx)
jmp 1f
0:
cmpl $0, %%ecx
je 1f
movb %%al, (%%edx)
1:
"
: : "m" (fillval), "c" (count), "d" (dest)
: "%eax", "%ebx", "%edi", "%esi", "cc", "memory");
}
void Com_Prefetch (const void *s, const unsigned int bytes, e_prefetch type)
{
// write buffer prefetching is performed only if
// the processor benefits from it. Read and read/write
// prefetching is always performed.
switch (type)
{
case PRE_WRITE : break;
case PRE_READ:
case PRE_READ_WRITE:
__asm__ __volatile__ ("
//mov ebx,s
//mov ecx,bytes
cmpl $4096, %%ecx // clamp to 4kB
jle 0f
movl $4096, %%ecx
0:
addl $0x1f, %%ecx
shrl $5, %%ecx // number of cache lines
jz 2f
jmp 1f
.align 16
1: testb %%al, (%%edx)
addl $32, %%edx
decl %%ecx
jnz 1b
2:
"
: : "d" (s), "c" (bytes)
: "%eax", "%ebx", "%edi", "%esi", "memory", "cc");
break;
}
}
#endif