Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 460 insertions, 0 deletions

diff --git a/media/libjpeg/simd/i386/jdmrgext-mmx.asm b/media/libjpeg/simd/i386/jdmrgext-mmx.asm
new file mode 100644
index 0000000000..eb3e36b475
--- /dev/null
+++ b/media/libjpeg/simd/i386/jdmrgext-mmx.asm
@@ -0,0 +1,460 @@
+;
+; jdmrgext.asm - merged upsampling/color conversion (MMX)
+;
+; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
+; Copyright (C) 2016, D. R. Commander.
+;
+; Based on the 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
+
+%include "jcolsamp.inc"
+
+; --------------------------------------------------------------------------
+;
+; 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       32
+    GLOBAL_FUNCTION(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          near .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       32
+    GLOBAL_FUNCTION(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
+
+; For some reason, the OS X linker does not honor the request to align the
+; segment unless we do this.
+    align       32