Add MMX SIMD implementation of computationally intensive routines.
git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@3648 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/common/jpeg/simd/jdmermmx.asm b/common/jpeg/simd/jdmermmx.asm
new file mode 100644
index 0000000..8d82e40
--- /dev/null
+++ b/common/jpeg/simd/jdmermmx.asm
@@ -0,0 +1,492 @@
+;
+; jdmermmx.asm - merged upsampling/color conversion (MMX)
+;
+; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
+;
+; Based on
+; x86 SIMD extension for IJG JPEG library
+; Copyright (C) 1999-2006, MIYASAKA Masaru.
+; For conditions of distribution and use, see copyright notice in jsimdext.inc
+;
+; This file should be assembled with NASM (Netwide Assembler),
+; can *not* be assembled with Microsoft's MASM or any compatible
+; assembler (including Borland's Turbo Assembler).
+; NASM is available from http://nasm.sourceforge.net/ or
+; http://sourceforge.net/project/showfiles.php?group_id=6208
+;
+; [TAB8]
+
+%include "simd/jsimdext.inc"
+%include "simd/jcolsamp.inc"
+
+; --------------------------------------------------------------------------
+
+%define SCALEBITS 16
+
+F_0_344 equ 22554 ; FIX(0.34414)
+F_0_714 equ 46802 ; FIX(0.71414)
+F_1_402 equ 91881 ; FIX(1.40200)
+F_1_772 equ 116130 ; FIX(1.77200)
+F_0_402 equ (F_1_402 - 65536) ; FIX(1.40200) - FIX(1)
+F_0_285 equ ( 65536 - F_0_714) ; FIX(1) - FIX(0.71414)
+F_0_228 equ (131072 - F_1_772) ; FIX(2) - FIX(1.77200)
+
+; --------------------------------------------------------------------------
+ SECTION SEG_CONST
+
+ alignz 16
+ global EXTN(jconst_merged_upsample_mmx)
+
+EXTN(jconst_merged_upsample_mmx):
+
+PW_F0402 times 4 dw F_0_402
+PW_MF0228 times 4 dw -F_0_228
+PW_MF0344_F0285 times 2 dw -F_0_344, F_0_285
+PW_ONE times 4 dw 1
+PD_ONEHALF times 2 dd 1 << (SCALEBITS-1)
+
+ alignz 16
+
+; --------------------------------------------------------------------------
+ SECTION SEG_TEXT
+ BITS 32
+;
+; Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.
+;
+; GLOBAL(void)
+; jsimd_h2v1_merged_upsample_mmx (JDIMENSION output_width,
+; JSAMPIMAGE input_buf,
+; JDIMENSION in_row_group_ctr,
+; JSAMPARRAY output_buf);
+;
+
+%define output_width(b) (b)+8 ; JDIMENSION output_width
+%define input_buf(b) (b)+12 ; JSAMPIMAGE input_buf
+%define in_row_group_ctr(b) (b)+16 ; JDIMENSION in_row_group_ctr
+%define output_buf(b) (b)+20 ; JSAMPARRAY output_buf
+
+%define original_ebp ebp+0
+%define wk(i) ebp-(WK_NUM-(i))*SIZEOF_MMWORD ; mmword wk[WK_NUM]
+%define WK_NUM 3
+%define gotptr wk(0)-SIZEOF_POINTER ; void * gotptr
+
+ align 16
+ global EXTN(jsimd_h2v1_merged_upsample_mmx)
+
+EXTN(jsimd_h2v1_merged_upsample_mmx):
+ push ebp
+ mov eax,esp ; eax = original ebp
+ sub esp, byte 4
+ and esp, byte (-SIZEOF_MMWORD) ; align to 64 bits
+ mov [esp],eax
+ mov ebp,esp ; ebp = aligned ebp
+ lea esp, [wk(0)]
+ pushpic eax ; make a room for GOT address
+ push ebx
+; push ecx ; need not be preserved
+; push edx ; need not be preserved
+ push esi
+ push edi
+
+ get_GOT ebx ; get GOT address
+ movpic POINTER [gotptr], ebx ; save GOT address
+
+ mov ecx, JDIMENSION [output_width(eax)] ; col
+ test ecx,ecx
+ jz near .return
+
+ push ecx
+
+ mov edi, JSAMPIMAGE [input_buf(eax)]
+ mov ecx, JDIMENSION [in_row_group_ctr(eax)]
+ mov esi, JSAMPARRAY [edi+0*SIZEOF_JSAMPARRAY]
+ mov ebx, JSAMPARRAY [edi+1*SIZEOF_JSAMPARRAY]
+ mov edx, JSAMPARRAY [edi+2*SIZEOF_JSAMPARRAY]
+ mov edi, JSAMPARRAY [output_buf(eax)]
+ mov esi, JSAMPROW [esi+ecx*SIZEOF_JSAMPROW] ; inptr0
+ mov ebx, JSAMPROW [ebx+ecx*SIZEOF_JSAMPROW] ; inptr1
+ mov edx, JSAMPROW [edx+ecx*SIZEOF_JSAMPROW] ; inptr2
+ mov edi, JSAMPROW [edi] ; outptr
+
+ pop ecx ; col
+
+ alignx 16,7
+.columnloop:
+ movpic eax, POINTER [gotptr] ; load GOT address (eax)
+
+ movq mm6, MMWORD [ebx] ; mm6=Cb(01234567)
+ movq mm7, MMWORD [edx] ; mm7=Cr(01234567)
+
+ pxor mm1,mm1 ; mm1=(all 0's)
+ pcmpeqw mm3,mm3
+ psllw mm3,7 ; mm3={0xFF80 0xFF80 0xFF80 0xFF80}
+
+ movq mm4,mm6
+ punpckhbw mm6,mm1 ; mm6=Cb(4567)=CbH
+ punpcklbw mm4,mm1 ; mm4=Cb(0123)=CbL
+ movq mm0,mm7
+ punpckhbw mm7,mm1 ; mm7=Cr(4567)=CrH
+ punpcklbw mm0,mm1 ; mm0=Cr(0123)=CrL
+
+ paddw mm6,mm3
+ paddw mm4,mm3
+ paddw mm7,mm3
+ paddw mm0,mm3
+
+ ; (Original)
+ ; R = Y + 1.40200 * Cr
+ ; G = Y - 0.34414 * Cb - 0.71414 * Cr
+ ; B = Y + 1.77200 * Cb
+ ;
+ ; (This implementation)
+ ; R = Y + 0.40200 * Cr + Cr
+ ; G = Y - 0.34414 * Cb + 0.28586 * Cr - Cr
+ ; B = Y - 0.22800 * Cb + Cb + Cb
+
+ movq mm5,mm6 ; mm5=CbH
+ movq mm2,mm4 ; mm2=CbL
+ paddw mm6,mm6 ; mm6=2*CbH
+ paddw mm4,mm4 ; mm4=2*CbL
+ movq mm1,mm7 ; mm1=CrH
+ movq mm3,mm0 ; mm3=CrL
+ paddw mm7,mm7 ; mm7=2*CrH
+ paddw mm0,mm0 ; mm0=2*CrL
+
+ pmulhw mm6,[GOTOFF(eax,PW_MF0228)] ; mm6=(2*CbH * -FIX(0.22800))
+ pmulhw mm4,[GOTOFF(eax,PW_MF0228)] ; mm4=(2*CbL * -FIX(0.22800))
+ pmulhw mm7,[GOTOFF(eax,PW_F0402)] ; mm7=(2*CrH * FIX(0.40200))
+ pmulhw mm0,[GOTOFF(eax,PW_F0402)] ; mm0=(2*CrL * FIX(0.40200))
+
+ paddw mm6,[GOTOFF(eax,PW_ONE)]
+ paddw mm4,[GOTOFF(eax,PW_ONE)]
+ psraw mm6,1 ; mm6=(CbH * -FIX(0.22800))
+ psraw mm4,1 ; mm4=(CbL * -FIX(0.22800))
+ paddw mm7,[GOTOFF(eax,PW_ONE)]
+ paddw mm0,[GOTOFF(eax,PW_ONE)]
+ psraw mm7,1 ; mm7=(CrH * FIX(0.40200))
+ psraw mm0,1 ; mm0=(CrL * FIX(0.40200))
+
+ paddw mm6,mm5
+ paddw mm4,mm2
+ paddw mm6,mm5 ; mm6=(CbH * FIX(1.77200))=(B-Y)H
+ paddw mm4,mm2 ; mm4=(CbL * FIX(1.77200))=(B-Y)L
+ paddw mm7,mm1 ; mm7=(CrH * FIX(1.40200))=(R-Y)H
+ paddw mm0,mm3 ; mm0=(CrL * FIX(1.40200))=(R-Y)L
+
+ movq MMWORD [wk(0)], mm6 ; wk(0)=(B-Y)H
+ movq MMWORD [wk(1)], mm7 ; wk(1)=(R-Y)H
+
+ movq mm6,mm5
+ movq mm7,mm2
+ punpcklwd mm5,mm1
+ punpckhwd mm6,mm1
+ pmaddwd mm5,[GOTOFF(eax,PW_MF0344_F0285)]
+ pmaddwd mm6,[GOTOFF(eax,PW_MF0344_F0285)]
+ punpcklwd mm2,mm3
+ punpckhwd mm7,mm3
+ pmaddwd mm2,[GOTOFF(eax,PW_MF0344_F0285)]
+ pmaddwd mm7,[GOTOFF(eax,PW_MF0344_F0285)]
+
+ paddd mm5,[GOTOFF(eax,PD_ONEHALF)]
+ paddd mm6,[GOTOFF(eax,PD_ONEHALF)]
+ psrad mm5,SCALEBITS
+ psrad mm6,SCALEBITS
+ paddd mm2,[GOTOFF(eax,PD_ONEHALF)]
+ paddd mm7,[GOTOFF(eax,PD_ONEHALF)]
+ psrad mm2,SCALEBITS
+ psrad mm7,SCALEBITS
+
+ packssdw mm5,mm6 ; mm5=CbH*-FIX(0.344)+CrH*FIX(0.285)
+ packssdw mm2,mm7 ; mm2=CbL*-FIX(0.344)+CrL*FIX(0.285)
+ psubw mm5,mm1 ; mm5=CbH*-FIX(0.344)+CrH*-FIX(0.714)=(G-Y)H
+ psubw mm2,mm3 ; mm2=CbL*-FIX(0.344)+CrL*-FIX(0.714)=(G-Y)L
+
+ movq MMWORD [wk(2)], mm5 ; wk(2)=(G-Y)H
+
+ mov al,2 ; Yctr
+ jmp short .Yloop_1st
+ alignx 16,7
+
+.Yloop_2nd:
+ movq mm0, MMWORD [wk(1)] ; mm0=(R-Y)H
+ movq mm2, MMWORD [wk(2)] ; mm2=(G-Y)H
+ movq mm4, MMWORD [wk(0)] ; mm4=(B-Y)H
+ alignx 16,7
+
+.Yloop_1st:
+ movq mm7, MMWORD [esi] ; mm7=Y(01234567)
+
+ pcmpeqw mm6,mm6
+ psrlw mm6,BYTE_BIT ; mm6={0xFF 0x00 0xFF 0x00 ..}
+ pand mm6,mm7 ; mm6=Y(0246)=YE
+ psrlw mm7,BYTE_BIT ; mm7=Y(1357)=YO
+
+ movq mm1,mm0 ; mm1=mm0=(R-Y)(L/H)
+ movq mm3,mm2 ; mm3=mm2=(G-Y)(L/H)
+ movq mm5,mm4 ; mm5=mm4=(B-Y)(L/H)
+
+ paddw mm0,mm6 ; mm0=((R-Y)+YE)=RE=(R0 R2 R4 R6)
+ paddw mm1,mm7 ; mm1=((R-Y)+YO)=RO=(R1 R3 R5 R7)
+ packuswb mm0,mm0 ; mm0=(R0 R2 R4 R6 ** ** ** **)
+ packuswb mm1,mm1 ; mm1=(R1 R3 R5 R7 ** ** ** **)
+
+ paddw mm2,mm6 ; mm2=((G-Y)+YE)=GE=(G0 G2 G4 G6)
+ paddw mm3,mm7 ; mm3=((G-Y)+YO)=GO=(G1 G3 G5 G7)
+ packuswb mm2,mm2 ; mm2=(G0 G2 G4 G6 ** ** ** **)
+ packuswb mm3,mm3 ; mm3=(G1 G3 G5 G7 ** ** ** **)
+
+ paddw mm4,mm6 ; mm4=((B-Y)+YE)=BE=(B0 B2 B4 B6)
+ paddw mm5,mm7 ; mm5=((B-Y)+YO)=BO=(B1 B3 B5 B7)
+ packuswb mm4,mm4 ; mm4=(B0 B2 B4 B6 ** ** ** **)
+ packuswb mm5,mm5 ; mm5=(B1 B3 B5 B7 ** ** ** **)
+
+%if RGB_PIXELSIZE == 3 ; ---------------
+
+ ; mmA=(00 02 04 06 ** ** ** **), mmB=(01 03 05 07 ** ** ** **)
+ ; mmC=(10 12 14 16 ** ** ** **), mmD=(11 13 15 17 ** ** ** **)
+ ; mmE=(20 22 24 26 ** ** ** **), mmF=(21 23 25 27 ** ** ** **)
+ ; mmG=(** ** ** ** ** ** ** **), mmH=(** ** ** ** ** ** ** **)
+
+ punpcklbw mmA,mmC ; mmA=(00 10 02 12 04 14 06 16)
+ punpcklbw mmE,mmB ; mmE=(20 01 22 03 24 05 26 07)
+ punpcklbw mmD,mmF ; mmD=(11 21 13 23 15 25 17 27)
+
+ movq mmG,mmA
+ movq mmH,mmA
+ punpcklwd mmA,mmE ; mmA=(00 10 20 01 02 12 22 03)
+ punpckhwd mmG,mmE ; mmG=(04 14 24 05 06 16 26 07)
+
+ psrlq mmH,2*BYTE_BIT ; mmH=(02 12 04 14 06 16 -- --)
+ psrlq mmE,2*BYTE_BIT ; mmE=(22 03 24 05 26 07 -- --)
+
+ movq mmC,mmD
+ movq mmB,mmD
+ punpcklwd mmD,mmH ; mmD=(11 21 02 12 13 23 04 14)
+ punpckhwd mmC,mmH ; mmC=(15 25 06 16 17 27 -- --)
+
+ psrlq mmB,2*BYTE_BIT ; mmB=(13 23 15 25 17 27 -- --)
+
+ movq mmF,mmE
+ punpcklwd mmE,mmB ; mmE=(22 03 13 23 24 05 15 25)
+ punpckhwd mmF,mmB ; mmF=(26 07 17 27 -- -- -- --)
+
+ punpckldq mmA,mmD ; mmA=(00 10 20 01 11 21 02 12)
+ punpckldq mmE,mmG ; mmE=(22 03 13 23 04 14 24 05)
+ punpckldq mmC,mmF ; mmC=(15 25 06 16 26 07 17 27)
+
+ cmp ecx, byte SIZEOF_MMWORD
+ jb short .column_st16
+
+ movq MMWORD [edi+0*SIZEOF_MMWORD], mmA
+ movq MMWORD [edi+1*SIZEOF_MMWORD], mmE
+ movq MMWORD [edi+2*SIZEOF_MMWORD], mmC
+
+ sub ecx, byte SIZEOF_MMWORD
+ jz short .endcolumn
+
+ add edi, byte RGB_PIXELSIZE*SIZEOF_MMWORD ; outptr
+ add esi, byte SIZEOF_MMWORD ; inptr0
+ dec al ; Yctr
+ jnz near .Yloop_2nd
+
+ add ebx, byte SIZEOF_MMWORD ; inptr1
+ add edx, byte SIZEOF_MMWORD ; inptr2
+ jmp near .columnloop
+ alignx 16,7
+
+.column_st16:
+ lea ecx, [ecx+ecx*2] ; imul ecx, RGB_PIXELSIZE
+ cmp ecx, byte 2*SIZEOF_MMWORD
+ jb short .column_st8
+ movq MMWORD [edi+0*SIZEOF_MMWORD], mmA
+ movq MMWORD [edi+1*SIZEOF_MMWORD], mmE
+ movq mmA,mmC
+ sub ecx, byte 2*SIZEOF_MMWORD
+ add edi, byte 2*SIZEOF_MMWORD
+ jmp short .column_st4
+.column_st8:
+ cmp ecx, byte SIZEOF_MMWORD
+ jb short .column_st4
+ movq MMWORD [edi+0*SIZEOF_MMWORD], mmA
+ movq mmA,mmE
+ sub ecx, byte SIZEOF_MMWORD
+ add edi, byte SIZEOF_MMWORD
+.column_st4:
+ movd eax,mmA
+ cmp ecx, byte SIZEOF_DWORD
+ jb short .column_st2
+ mov DWORD [edi+0*SIZEOF_DWORD], eax
+ psrlq mmA,DWORD_BIT
+ movd eax,mmA
+ sub ecx, byte SIZEOF_DWORD
+ add edi, byte SIZEOF_DWORD
+.column_st2:
+ cmp ecx, byte SIZEOF_WORD
+ jb short .column_st1
+ mov WORD [edi+0*SIZEOF_WORD], ax
+ shr eax,WORD_BIT
+ sub ecx, byte SIZEOF_WORD
+ add edi, byte SIZEOF_WORD
+.column_st1:
+ cmp ecx, byte SIZEOF_BYTE
+ jb short .endcolumn
+ mov BYTE [edi+0*SIZEOF_BYTE], al
+
+%else ; RGB_PIXELSIZE == 4 ; -----------
+
+%ifdef RGBX_FILLER_0XFF
+ pcmpeqb mm6,mm6 ; mm6=(X0 X2 X4 X6 ** ** ** **)
+ pcmpeqb mm7,mm7 ; mm7=(X1 X3 X5 X7 ** ** ** **)
+%else
+ pxor mm6,mm6 ; mm6=(X0 X2 X4 X6 ** ** ** **)
+ pxor mm7,mm7 ; mm7=(X1 X3 X5 X7 ** ** ** **)
+%endif
+ ; mmA=(00 02 04 06 ** ** ** **), mmB=(01 03 05 07 ** ** ** **)
+ ; mmC=(10 12 14 16 ** ** ** **), mmD=(11 13 15 17 ** ** ** **)
+ ; mmE=(20 22 24 26 ** ** ** **), mmF=(21 23 25 27 ** ** ** **)
+ ; mmG=(30 32 34 36 ** ** ** **), mmH=(31 33 35 37 ** ** ** **)
+
+ punpcklbw mmA,mmC ; mmA=(00 10 02 12 04 14 06 16)
+ punpcklbw mmE,mmG ; mmE=(20 30 22 32 24 34 26 36)
+ punpcklbw mmB,mmD ; mmB=(01 11 03 13 05 15 07 17)
+ punpcklbw mmF,mmH ; mmF=(21 31 23 33 25 35 27 37)
+
+ movq mmC,mmA
+ punpcklwd mmA,mmE ; mmA=(00 10 20 30 02 12 22 32)
+ punpckhwd mmC,mmE ; mmC=(04 14 24 34 06 16 26 36)
+ movq mmG,mmB
+ punpcklwd mmB,mmF ; mmB=(01 11 21 31 03 13 23 33)
+ punpckhwd mmG,mmF ; mmG=(05 15 25 35 07 17 27 37)
+
+ movq mmD,mmA
+ punpckldq mmA,mmB ; mmA=(00 10 20 30 01 11 21 31)
+ punpckhdq mmD,mmB ; mmD=(02 12 22 32 03 13 23 33)
+ movq mmH,mmC
+ punpckldq mmC,mmG ; mmC=(04 14 24 34 05 15 25 35)
+ punpckhdq mmH,mmG ; mmH=(06 16 26 36 07 17 27 37)
+
+ cmp ecx, byte SIZEOF_MMWORD
+ jb short .column_st16
+
+ movq MMWORD [edi+0*SIZEOF_MMWORD], mmA
+ movq MMWORD [edi+1*SIZEOF_MMWORD], mmD
+ movq MMWORD [edi+2*SIZEOF_MMWORD], mmC
+ movq MMWORD [edi+3*SIZEOF_MMWORD], mmH
+
+ sub ecx, byte SIZEOF_MMWORD
+ jz short .endcolumn
+
+ add edi, byte RGB_PIXELSIZE*SIZEOF_MMWORD ; outptr
+ add esi, byte SIZEOF_MMWORD ; inptr0
+ dec al ; Yctr
+ jnz near .Yloop_2nd
+
+ add ebx, byte SIZEOF_MMWORD ; inptr1
+ add edx, byte SIZEOF_MMWORD ; inptr2
+ jmp near .columnloop
+ alignx 16,7
+
+.column_st16:
+ cmp ecx, byte SIZEOF_MMWORD/2
+ jb short .column_st8
+ movq MMWORD [edi+0*SIZEOF_MMWORD], mmA
+ movq MMWORD [edi+1*SIZEOF_MMWORD], mmD
+ movq mmA,mmC
+ movq mmD,mmH
+ sub ecx, byte SIZEOF_MMWORD/2
+ add edi, byte 2*SIZEOF_MMWORD
+.column_st8:
+ cmp ecx, byte SIZEOF_MMWORD/4
+ jb short .column_st4
+ movq MMWORD [edi+0*SIZEOF_MMWORD], mmA
+ movq mmA,mmD
+ sub ecx, byte SIZEOF_MMWORD/4
+ add edi, byte 1*SIZEOF_MMWORD
+.column_st4:
+ cmp ecx, byte SIZEOF_MMWORD/8
+ jb short .endcolumn
+ movd DWORD [edi+0*SIZEOF_DWORD], mmA
+
+%endif ; RGB_PIXELSIZE ; ---------------
+
+.endcolumn:
+ emms ; empty MMX state
+
+.return:
+ pop edi
+ pop esi
+; pop edx ; need not be preserved
+; pop ecx ; need not be preserved
+ pop ebx
+ mov esp,ebp ; esp <- aligned ebp
+ pop esp ; esp <- original ebp
+ pop ebp
+ ret
+
+; --------------------------------------------------------------------------
+;
+; Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.
+;
+; GLOBAL(void)
+; jsimd_h2v2_merged_upsample_mmx (JDIMENSION output_width,
+; JSAMPIMAGE input_buf,
+; JDIMENSION in_row_group_ctr,
+; JSAMPARRAY output_buf);
+;
+
+%define output_width(b) (b)+8 ; JDIMENSION output_width
+%define input_buf(b) (b)+12 ; JSAMPIMAGE input_buf
+%define in_row_group_ctr(b) (b)+16 ; JDIMENSION in_row_group_ctr
+%define output_buf(b) (b)+20 ; JSAMPARRAY output_buf
+
+ align 16
+ global EXTN(jsimd_h2v2_merged_upsample_mmx)
+
+EXTN(jsimd_h2v2_merged_upsample_mmx):
+ push ebp
+ mov ebp,esp
+ push ebx
+; push ecx ; need not be preserved
+; push edx ; need not be preserved
+ push esi
+ push edi
+
+ mov eax, JDIMENSION [output_width(ebp)]
+
+ mov edi, JSAMPIMAGE [input_buf(ebp)]
+ mov ecx, JDIMENSION [in_row_group_ctr(ebp)]
+ mov esi, JSAMPARRAY [edi+0*SIZEOF_JSAMPARRAY]
+ mov ebx, JSAMPARRAY [edi+1*SIZEOF_JSAMPARRAY]
+ mov edx, JSAMPARRAY [edi+2*SIZEOF_JSAMPARRAY]
+ mov edi, JSAMPARRAY [output_buf(ebp)]
+ lea esi, [esi+ecx*SIZEOF_JSAMPROW]
+
+ push edx ; inptr2
+ push ebx ; inptr1
+ push esi ; inptr00
+ mov ebx,esp
+
+ push edi ; output_buf (outptr0)
+ push ecx ; in_row_group_ctr
+ push ebx ; input_buf
+ push eax ; output_width
+
+ call near EXTN(jsimd_h2v1_merged_upsample_mmx)
+
+ add esi, byte SIZEOF_JSAMPROW ; inptr01
+ add edi, byte SIZEOF_JSAMPROW ; outptr1
+ mov POINTER [ebx+0*SIZEOF_POINTER], esi
+ mov POINTER [ebx-1*SIZEOF_POINTER], edi
+
+ call near EXTN(jsimd_h2v1_merged_upsample_mmx)
+
+ add esp, byte 7*SIZEOF_DWORD
+
+ pop edi
+ pop esi
+; pop edx ; need not be preserved
+; pop ecx ; need not be preserved
+ pop ebx
+ pop ebp
+ ret
+