0ad/source/lib/sysdep/ia32.asm
janwas b17fbf003d -move app-specific stuff out of lib/ and into "hooks". see new lib/app_hooks* (note X macro goodness)
-move tex_codec stuff out of tex.cpp and into tex_codec.cpp
-tex_codec: use linked list of codecs instead of array (simplifies code
and removes limit)
-ogl_tex: add override mechanism for s3tc/automipmapgen extension detect
-tired of keeping of debug_warn text in sync with function name; now use
__func__ everywhere (and emulate that with __FUNCTION__ on MSC)
-add ONCE_NOT (opposite of ONCE)
-fix 3!! stupid bugs in ia32_control87, its caller and the header that
were canceling each other out. float exceptions now enabled except for
"inexact result" (too common). (update: nicolai had already fixed 2 of
these)

This was SVN commit r2964.
2005-10-19 03:06:54 +00:00

450 lines
9.5 KiB
NASM

; set 32-bit attribute once for all sections and activate .text
section .data use32
section .bss use32
section .text use32
; Usage:
; use sym(ia32_cap) instead of _ia32_cap - on relevant platforms, sym() will add
; the underlines automagically, on others it won't
%ifdef DONT_USE_UNDERLINE
%define sym(a) a
%else
%define sym(a) _ %+ a
%endif
;-------------------------------------------------------------------------------
; fast general memcpy
;-------------------------------------------------------------------------------
; optimized for Athlon XP: 7.3% faster (cumulative) than VC7.1's memcpy over
; all 1..64 byte transfer lengths and misalignments. approaches maximum
; mem bandwidth (2000 MiB/s) for transfers >= 192KiB!
; Pentium III performance: about 3% faster in above small buffer benchmark.
;
; disables specialized large transfer (> 64KiB) implementations if SSE
; isn't available; we do assume MMX support, though (quite safe).
; *requires* (and does not verify the presence of) SSE instructions:
; prefetchnta and movntq. therefore, a P3+ or Athlon XP is required.
; rationale: older processors are too slow anyway and we don't bother.
; if memcpy size is greater than this,
; .. it's too big for L1. use non-temporal instructions.
UC_THRESHOLD equ 64*1024
; .. it also blows L2. pull chunks into L1 ("block prefetch").
BP_THRESHOLD equ 192*1024
; maximum that can be copied by IC_MOVSD.
; if you change this, be sure to expand the movs* table(s)!
IC_SIZE equ 67
; size of one block prefetch chunk.
; if you change this, make sure "push byte BP_SIZE/128" doesn't overflow!
BP_SIZE equ 8*1024
; > ecx = size (<= IC_SIZE)
; x eax, ecx
;
; determined to be fastest approach by testing. a movsd table followed by
; rep movsb is a bit smaller but 6.9% slower; everything else is much worse.
%macro IC_MOVSD 0
mov eax, ecx
shr ecx, 2 ; dword count
neg ecx
add ecx, %%movsd_table_end
jmp ecx
align 8
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
movsd
%%movsd_table_end:
and eax, 3
neg eax
add eax, %%movsb_table_end
jmp eax
movsb
movsb
movsb
%%movsb_table_end:
%endm
; align destination address to multiple of 8.
; not done for small transfers because it doesn't help IC_MOVSD.
%macro IC_ALIGN 0
mov eax, 8
sub eax, edi
and eax, byte 7 ; eax = # misaligned bytes
sub ecx, eax ; reduce copy count
neg eax
add eax, %%align_table_end
jmp eax
align 4
movsb
movsb
movsb
movsb
movsb
movsb
movsb
movsb
%%align_table_end:
%endm
; > ecx = size
; x edx
%macro IC_MOVQ 0
align 16
mov edx, 64
%%loop:
cmp ecx, edx
jb %%done
prefetchnta [esi + (200*64/34+192)]
movq mm0, [esi+0]
movq mm1, [esi+8]
movq [edi+0], mm0
movq [edi+8], mm1
movq mm2, [esi+16]
movq mm3, [esi+24]
movq [edi+16], mm2
movq [edi+24], mm3
movq mm0, [esi+32]
movq mm1, [esi+40]
movq [edi+32], mm0
movq [edi+40], mm1
movq mm2, [esi+48]
movq mm3, [esi+56]
movq [edi+48], mm2
movq [edi+56], mm3
add esi, edx
add edi, edx
sub ecx, edx
jmp %%loop
%%done:
%endm
; > ecx = size (> 64)
; x
%macro UC_MOVNTQ 0
mov edx, 64
align 16
%%1:
prefetchnta [esi + (200*64/34+192)]
movq mm0,[esi+0]
add edi, edx
movq mm1,[esi+8]
add esi, edx
movq mm2,[esi-48]
movntq [edi-64], mm0
movq mm0,[esi-40]
movntq [edi-56], mm1
movq mm1,[esi-32]
movntq [edi-48], mm2
movq mm2,[esi-24]
movntq [edi-40], mm0
movq mm0,[esi-16]
movntq [edi-32], mm1
movq mm1,[esi-8]
movntq [edi-24], mm2
movntq [edi-16], mm0
sub ecx, edx
movntq [edi-8], mm1
cmp ecx, edx
jae %%1
%endm
; > ecx = size (> 8KiB)
; x eax, edx
;
; somewhat optimized for size (futile attempt to avoid near jump)
%macro UC_BP_MOVNTQ 0
%%prefetch_and_copy_chunk:
; touch each cache line within chunk in reverse order (prevents HW prefetch)
push byte BP_SIZE/128 ; # iterations
pop eax
add esi, BP_SIZE
align 8
%%prefetch_chunk:
mov edx, [esi-64]
mov edx, [esi-128]
sub esi, 128
dec eax
jnz %%prefetch_chunk
; copy 64 byte blocks
mov eax, BP_SIZE/64 ; # iterations (> signed 8 bit)
push byte 64
pop edx
align 8
%%copy_block:
movq mm0, [esi+ 0]
movq mm1, [esi+ 8]
movq mm2, [esi+16]
movq mm3, [esi+24]
movq mm4, [esi+32]
movq mm5, [esi+40]
movq mm6, [esi+48]
movq mm7, [esi+56]
add esi, edx
movntq [edi+ 0], mm0
movntq [edi+ 8], mm1
movntq [edi+16], mm2
movntq [edi+24], mm3
movntq [edi+32], mm4
movntq [edi+40], mm5
movntq [edi+48], mm6
movntq [edi+56], mm7
add edi, edx
dec eax
jnz %%copy_block
sub ecx, BP_SIZE
cmp ecx, BP_SIZE
jae %%prefetch_and_copy_chunk
%endm
[section .bss]
; this is somewhat "clever". the 2 specialized transfer implementations
; that use SSE are jumped to if transfer size is greater than a threshold.
; we simply set the requested transfer size to 0 if the CPU doesn't
; support SSE so that those are never reached (done by masking with this).
sse_mask resd 1
__SECT__
; void __declspec(naked) ia32_memcpy(void* dst, const void* src, size_t nbytes)
global sym(ia32_memcpy)
sym(ia32_memcpy):
push edi
push esi
mov edi, [esp+8+4+0] ; dst
mov esi, [esp+8+4+4] ; src
mov ecx, [esp+8+4+8] ; nbytes
cmp ecx, byte IC_SIZE
ja .choose_larger_method
.ic_movsd:
IC_MOVSD
pop esi
pop edi
ret
.choose_larger_method:
IC_ALIGN
mov eax, [sse_mask]
mov edx, ecx
and edx, eax ; edx = (SSE)? remaining_bytes : 0
cmp edx, BP_THRESHOLD
jae near .uc_bp_movntq
cmp edx, UC_THRESHOLD
jae .uc_movntq
.ic_movq:
IC_MOVQ
emms
jmp .ic_movsd
.uc_movntq:
UC_MOVNTQ
sfence
emms
jmp .ic_movsd
.uc_bp_movntq:
UC_BP_MOVNTQ
sfence
jmp .ic_movq
;-------------------------------------------------------------------------------
; CPUID support
;-------------------------------------------------------------------------------
[section .data]
; these are actually max_func+1, i.e. the first invalid value.
; the idea here is to avoid a separate cpuid_available flag;
; using signed values doesn't work because ext_funcs are >= 0x80000000.
max_func dd 0
max_ext_func dd 0
__SECT__
; extern "C" bool __cdecl ia32_cpuid(u32 func, u32* regs)
global sym(ia32_cpuid)
sym(ia32_cpuid):
push ebx
push edi
mov ecx, [esp+8+4+0] ; func
mov edi, [esp+8+4+4] ; -> regs
; compare against max supported func and fail if above
xor eax, eax ; return value on failure
test ecx, ecx
mov edx, [max_ext_func]
js .is_ext_func
mov edx, [max_func]
.is_ext_func:
cmp ecx, edx
jae .ret ; (see max_func decl)
; issue CPUID and store result registers in array
mov eax, ecx
cpuid
stosd
xchg eax, ebx
stosd
xchg eax, ecx
stosd
xchg eax, edx
stosd
; success
xor eax, eax
inc eax
.ret:
pop edi
pop ebx
ret
;-------------------------------------------------------------------------------
; misc
;-------------------------------------------------------------------------------
; extern "C" uint __cdecl ia32_control87(uint new_cw, uint mask)
global sym(ia32_control87)
sym(ia32_control87):
push eax
fnstcw [esp]
pop eax ; old_cw
mov ecx, [esp+4] ; new_val
mov edx, [esp+8] ; mask
and ecx, edx ; new_val & mask
not edx ; ~mask
and eax, edx ; old_cw & ~mask
or eax, ecx ; (old_cw & ~mask) | (new_val & mask)
push eax ; = new_cw
fldcw [esp]
pop eax
xor eax, eax ; return value
ret
;-------------------------------------------------------------------------------
; init
;-------------------------------------------------------------------------------
; extern "C" bool __cdecl ia32_init()
global sym(ia32_init)
sym(ia32_init):
push ebx
; check if CPUID is supported
pushfd
or byte [esp+2], 32
popfd
pushfd
pop eax
xor edx, edx
shr eax, 22 ; bit 21 toggled?
jnc .no_cpuid
; determine max supported CPUID function
xor eax, eax
cpuid
inc eax ; (see max_func decl)
mov [max_func], eax
mov eax, 0x80000000
cpuid
inc eax ; (see max_func decl)
mov [max_ext_func], eax
.no_cpuid:
; check if SSE is supported (used by memcpy code)
extern sym(ia32_cap)
push byte 32+25 ; ia32.h's SSE cap (won't change)
call sym(ia32_cap)
pop edx ; remove stack param
neg eax ; SSE? ~0 : 0
mov [sse_mask], eax
pop ebx
ret
;-------------------------------------------------------------------------------
; Color conversion (SSE)
;-------------------------------------------------------------------------------
; extern "C" u32 ConvertRGBColorTo4ub(const RGBColor& color)
[section .data]
align 16
zero:
dd 0.0
twofivefive:
dd 255.0
__SECT__
align 16
global sym(sse_ConvertRGBColorTo4ub)
sym(sse_ConvertRGBColorTo4ub):
mov eax, [esp+4]
; xmm0, 1, 2 = R, G, B
movss xmm4, [zero]
movss xmm0, [eax+8]
movss xmm1, [eax+4]
movss xmm2, [eax]
movss xmm5, [twofivefive]
; C = min(255, 255*max(C, 0)) ( == clamp(255*C, 0, 255) )
maxss xmm0, xmm4
maxss xmm1, xmm4
maxss xmm2, xmm4
mulss xmm0, xmm5
mulss xmm1, xmm5
mulss xmm2, xmm5
minss xmm0, xmm5
minss xmm1, xmm5
minss xmm2, xmm5
; convert to integer and combine channels using bit logic
cvtss2si eax, xmm0
cvtss2si ecx, xmm1
cvtss2si edx, xmm2
shl eax, 16
shl ecx, 8
or eax, 0xff000000
or edx, ecx
or eax, edx
ret