/*

	decode_i586_dither: asm synth with dither noise

	copyright ?-2007 by the mpg123 project - free software under the terms of the LGPL 2.1

	see COPYING and AUTHORS files in distribution or http://mpg123.org

	initially written by Stefan Bieschewski as decode_i586.s without dither

	This version uses "circular" 64k dither noise.

	(Patch by Adrian <adrian.bacon@xs4all.nl>)

	Thomas learned something about assembler and the stack while making this one thread safe (removing static data).

*/

#include "mangle.h"

.data

#ifndef __APPLE__

		.section	.rodata

#endif

	ALIGN8

.LC0:

	.long 0x0,0x40dfffc0

	ALIGN8

.LC1:

	.long 0x0,0xc0e00000

	ALIGN8

.text

/* int synth_1to1_i586_asm_dither(real *bandPtr, int channel, unsigned char *out, unsigned char *buffs, int bo_and_ditherindex[2], real *decwin, real* dithernoise); */

.globl ASM_NAME(synth_1to1_i586_asm_dither)

ASM_NAME(synth_1to1_i586_asm_dither):

	subl $16,%esp

	pushl %ebp

	pushl %edi

	pushl %esi

	pushl %ebx

/* stack: 0(%esp)=%ebx 4=esi 8=edi 12=ebp 16,20,24,28=local 32=back 36=bandptr 40=channel 44=out 48=buffs 52=bo 56=decwin 60=dithernoise */

#define BANDPTR 36(%esp)

#define CHANNEL 40(%esp)

#define OUT     44(%esp)

#define BUFFS   48(%esp)

#define BO      52(%esp)

#define DECWIN  56(%esp)

#define DITHERNOISE 60(%esp)

/*#define DITHERNOISE $(ASM_NAME(dithernoise))*/

#define LOC0    16(%esp)

#define LOC1    20(%esp)

#define LOC2    24(%esp)

#define DITHERINDEX  28(%esp)

/* During application of the dithering, we need the shifted locations because there's an additional value on the stack. */

#define DITHERNOISE2 64(%esp)

#define DITHERINDEX2 32(%esp)

	movl BANDPTR,%eax

	movl OUT,%esi

	movl BO, %ebx

	movl (%ebx),%ebp    /* get bo value */

	movl 4(%ebx),%edi;  /* get the ditherindex behind bo */

	movl %edi,DITHERINDEX

	xorl %edi,%edi

	cmpl %edi,CHANNEL

	jne .L48

	decl %ebp

	andl $15,%ebp

	movl %ebp,(%ebx)   /* save bo back */

	movl BUFFS,%ecx

	jmp .L49

.L48:

/*       In stereo mode , "rewind" dither pointer 32 samples , so 2nd channel */

/*       has same dither values. Tested OK for mono and stereo MP2 and MP3 */

	subl $128,DITHERINDEX /* better move to %edi for the two calculations? */

	andl $0x0003fffc,DITHERINDEX

	addl $2,%esi

	movl BUFFS,%ecx

	addl $2176,%ecx

.L49:

/* now the call of dct64 is prepared, stuff pushed to the stack, but soon after it's removed again */

	testl $1,%ebp

	je .L50

	movl %ecx,%ebx

	movl %ebp,LOC0

	pushl %eax

	movl LOC1,%edx

	leal (%ebx,%edx,4),%eax

	pushl %eax

	movl LOC2,%eax

	incl %eax

	andl $15,%eax

	leal 1088(,%eax,4),%eax

	addl %ebx,%eax

	jmp .L74

.L50:

	leal 1088(%ecx),%ebx

	leal 1(%ebp),%edx

	movl %edx,LOC0

	pushl %eax

	leal 1092(%ecx,%ebp,4),%eax

	pushl %eax

	leal (%ecx,%ebp,4),%eax

.L74:

	pushl %eax

	call FUNC(dct64_i386)

	addl $12,%esp

/* Now removed the parameters.

   stack: 0(%esp)=%ebx 4=esi 8=edi 12=ebp 16,20,24,28=local 32=back 36=bandptr 40=channel 44=out 48=buffs 52=bo 56=decwin 60=dithernoise */

	movl LOC0,%edx

	leal 0(,%edx,4),%edx

	/* movl ASM_VALUE(decwin)+64,%eax */

	movl DECWIN,%eax

	addl $64,%eax

	movl %eax,%ecx

	subl %edx,%ecx

	movl $16,%ebp

.L55:

	flds (%ecx)

	fmuls (%ebx)

	flds 4(%ecx)

	fmuls 4(%ebx)

	fxch %st(1)

	flds 8(%ecx)

	fmuls 8(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds 12(%ecx)

	fmuls 12(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 16(%ecx)

	fmuls 16(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds 20(%ecx)

	fmuls 20(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 24(%ecx)

	fmuls 24(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds 28(%ecx)

	fmuls 28(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 32(%ecx)

	fmuls 32(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds 36(%ecx)

	fmuls 36(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 40(%ecx)

	fmuls 40(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds 44(%ecx)

	fmuls 44(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 48(%ecx)

	fmuls 48(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds 52(%ecx)

	fmuls 52(%ebx)

	fxch %st(2)         

	faddp %st,%st(1)

	flds 56(%ecx)

	fmuls 56(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds 60(%ecx)

	fmuls 60(%ebx)

	fxch %st(2)

	subl $4,%esp

	faddp %st,%st(1)

	fxch %st(1)

	fsubrp %st,%st(1)

	addl $4,DITHERINDEX2

	andl $0x0003fffc,DITHERINDEX2

	movl DITHERNOISE2,%edi

	addl DITHERINDEX2,%edi	

	fadds (%edi)

/* fistpl and popl as a unit keep the stack unchanged */

	fistpl (%esp)

	popl %eax

	cmpl $32767,%eax

	jg 1f

	cmpl $-32768,%eax

	jl 2f

	movw %ax,(%esi)

	jmp 4f

1:	movw $32767,(%esi)

	jmp 3f

2:	movw $-32768,(%esi)

3:

/*	incl %edi */

4:

.L54:

	addl $64,%ebx

	subl $-128,%ecx

	addl $4,%esi

	decl %ebp

	jnz .L55

	flds (%ecx)

	fmuls (%ebx)

	flds 8(%ecx)

	fmuls 8(%ebx)

	flds 16(%ecx)

	fmuls 16(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 24(%ecx)

	fmuls 24(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 32(%ecx)

	fmuls 32(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 40(%ecx)

	fmuls 40(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 48(%ecx)

	fmuls 48(%ebx)

	fxch %st(2)

	faddp %st,%st(1)

	flds 56(%ecx)

	fmuls 56(%ebx)

	fxch %st(2)

	subl $4,%esp

	faddp %st,%st(1)

	fxch %st(1)

	faddp %st,%st(1)

	addl $4,DITHERINDEX2

	andl $0x0003fffc,DITHERINDEX2

	movl DITHERNOISE2,%edi

	addl DITHERINDEX2,%edi	

	fadds (%edi)

/* fistpl and popl as a unit keep the stack unchanged */

	fistpl (%esp)

	popl %eax

	cmpl $32767,%eax

	jg 1f

	cmpl $-32768,%eax

	jl 2f

	movw %ax,(%esi)

	jmp 4f

1:	movw $32767,(%esi)

	jmp 3f

2:	movw $-32768,(%esi)

3:

/*	incl %edi */

4:

.L62:

	addl $-64,%ebx

	addl $4,%esi

	movl LOC0,%edx

	leal -128(%ecx,%edx,8),%ecx

	movl $15,%ebp

.L68:

	flds -4(%ecx)

	fchs

	fmuls (%ebx)

	flds -8(%ecx)

	fmuls 4(%ebx)

	fxch %st(1)

	flds -12(%ecx)

	fmuls 8(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -16(%ecx)

	fmuls 12(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -20(%ecx)

	fmuls 16(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -24(%ecx)

	fmuls 20(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -28(%ecx)

	fmuls 24(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -32(%ecx)

	fmuls 28(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -36(%ecx)

	fmuls 32(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -40(%ecx)

	fmuls 36(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -44(%ecx)

	fmuls 40(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -48(%ecx)

	fmuls 44(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -52(%ecx)

	fmuls 48(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -56(%ecx)

	fmuls 52(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds -60(%ecx)

	fmuls 56(%ebx)

	fxch %st(2)

	fsubrp %st,%st(1)

	flds (%ecx)

	fmuls 60(%ebx)

	fxch %st(2)

	subl $4,%esp

	fsubrp %st,%st(1)

	fxch %st(1)

	fsubrp %st,%st(1)

	addl $4,DITHERINDEX2

	andl $0x0003fffc,DITHERINDEX2

	movl DITHERNOISE2,%edi

	addl DITHERINDEX2,%edi	

	fadds (%edi)

/* fistpl and popl as a unit keep the stack unchanged */

	fistpl (%esp)

	popl %eax

	cmpl $32767,%eax

	jg 1f

	cmpl $-32768,%eax

	jl 2f

	movw %ax,(%esi)

	jmp 4f

1:	movw $32767,(%esi)

	jmp 3f

2:	movw $-32768,(%esi)

3:

/*	incl %edi */

4:

.L67:

	addl $-64,%ebx

	addl $-128,%ecx

	addl $4,%esi

	decl %ebp

	jnz .L68

/* return ipv edi 0 in eax */

	movl $0,%eax

/* save ditherindex */

	movl BO,%ebx

	movl DITHERINDEX,%esi

	movl %esi,4(%ebx);

/* stack: 0=ebx 4=esi 8=edi 12=ebp 16,20,24,28=local 32=back 36=bandptr 40=channel 44=out 48=buffs 52=bo */

	popl %ebx

	popl %esi

	popl %edi

	popl %ebp

	addl $16,%esp

/* The stack must be now: 0=back 4=bandptr 8=channel 12=out 16=buffs 20=bo */

	ret

#if defined(PIC) && defined(__APPLE__)

	.section __IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5

L_dct64_i386:

	.indirect_symbol ASM_NAME(dct64_i386)

	hlt ; hlt ; hlt ; hlt ; hlt

#endif

NONEXEC_STACK