rockbox/apps/codecs/libtremor/asm_arm.h

/********************************************************************
 *                                                                  *
 * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
 *                                                                  *
 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
 *                                                                  *
 * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *
 * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
 *                                                                  *
 ********************************************************************

 function: arm7 and later wide math functions

 ********************************************************************/

#ifdef _ARM_ASSEM_

#if !defined(_V_WIDE_MATH) && !defined(_LOW_ACCURACY_)
#define _V_WIDE_MATH

static inline ogg_int32_t MULT32(ogg_int32_t x, ogg_int32_t y) {
  int lo,hi;
  asm volatile("smull\t%0, %1, %2, %3"
               : "=&r"(lo),"=&r"(hi)
               : "%r"(x),"r"(y) );
  return(hi);
}

static inline ogg_int32_t MULT31(ogg_int32_t x, ogg_int32_t y) {
  return MULT32(x,y)<<1;
}

static inline ogg_int32_t MULT31_SHIFT15(ogg_int32_t x, ogg_int32_t y) {
  int lo,hi;
  asm volatile("smull   %0, %1, %2, %3\n\t"
               "movs    %0, %0, lsr #15\n\t"
               "adc     %1, %0, %1, lsl #17\n\t"
               : "=&r"(lo),"=&r"(hi)
               : "%r"(x),"r"(y)
               : "cc");
  return(hi);
}

#ifndef _V_VECT_OPS
#define _V_VECT_OPS

/* asm versions of vector operations for block.c, window.c */
/* SOME IMPORTANT NOTES: this implementation of vect_mult_bw does
   NOT do a final shift, meaning that the result of vect_mult_bw is
   only 31 bits not 32.  This is so that we can do the shift in-place
   in vect_add_xxxx instead to save one instruction for each mult on arm */
static inline 
void vect_add_right_left(ogg_int32_t *x, const ogg_int32_t *y, int n)
{
  /* first arg is right subframe of previous frame and second arg
     is left subframe of current frame.  overlap left onto right overwriting
     the right subframe */
     
  do{
    asm volatile (
                  "ldmia %[x], {r0, r1, r2, r3};"
                  "ldmia %[y]!, {r4, r5, r6, r7};"
                  "add r0, r4, r0, lsl #1;"
                  "add r1, r5, r1, lsl #1;"
                  "add r2, r6, r2, lsl #1;"
                  "add r3, r7, r3, lsl #1;"
                  "stmia %[x]!, {r0, r1, r2, r3};"
                  "ldmia %[x], {r0, r1, r2, r3};"
                  "ldmia %[y]!, {r4, r5, r6, r7};"
                  "add r0, r4, r0, lsl #1;"
                  "add r1, r5, r1, lsl #1;"
                  "add r2, r6, r2, lsl #1;"
                  "add r3, r7, r3, lsl #1;"
                  "stmia %[x]!, {r0, r1, r2, r3};"
                  : [x] "+r" (x), [y] "+r" (y)
                  : : "r0", "r1", "r2", "r3",
                  "r4", "r5", "r6", "r7",
                  "memory");
    n -= 8;
  } while (n);
}

static inline 
void vect_add_left_right(ogg_int32_t *x, const ogg_int32_t *y, int n)
{
  /* first arg is left subframe of current frame and second arg
     is right subframe of previous frame.  overlap right onto left overwriting
     the LEFT subframe */
  do{
    asm volatile (
                  "ldmia %[x], {r0, r1, r2, r3};"
                  "ldmia %[y]!, {r4, r5, r6, r7};"
                  "add r0, r0, r4, lsl #1;"
                  "add r1, r1, r5, lsl #1;"
                  "add r2, r2, r6, lsl #1;"
                  "add r3, r3, r7, lsl #1;"
                  "stmia %[x]!, {r0, r1, r2, r3};"
                  "ldmia %[x], {r0, r1, r2, r3};"
                  "ldmia %[y]!, {r4, r5, r6, r7};"
                  "add r0, r0, r4, lsl #1;"
                  "add r1, r1, r5, lsl #1;"
                  "add r2, r2, r6, lsl #1;"
                  "add r3, r3, r7, lsl #1;"
                  "stmia %[x]!, {r0, r1, r2, r3};"
                  : [x] "+r" (x), [y] "+r" (y)
                  : : "r0", "r1", "r2", "r3",
                  "r4", "r5", "r6", "r7",
                  "memory");
    n -= 8;
  } while (n);
}

#if ARM_ARCH >= 6
static inline 
void vect_mult_fw(ogg_int32_t *data, LOOKUP_T *window, int n)
{
  /* Note, mult_fw uses MULT31 */
  do{
    asm volatile (
                  "ldmia %[d], {r0, r1, r2, r3};"
                  "ldmia %[w]!, {r4, r5, r6, r7};"
                  "smmul r0, r4, r0;"
                  "smmul r1, r5, r1;"
                  "smmul r2, r6, r2;"
                  "smmul r3, r7, r3;"
                  "mov   r0, r0, lsl #1;"
                  "mov   r1, r1, lsl #1;"
                  "mov   r2, r2, lsl #1;"
                  "mov   r3, r3, lsl #1;"
                  "stmia %[d]!, {r0, r1, r2, r3};"
                  : [d] "+r" (data), [w] "+r" (window)
                  : : "r0", "r1", "r2", "r3",
                  "r4", "r5", "r6", "r7",
                  "memory" );
    n -= 4;
  } while (n);
}
#else
static inline 
void vect_mult_fw(ogg_int32_t *data, LOOKUP_T *window, int n)
{
  /* Note, mult_fw uses MULT31 */
  do{
    asm volatile (
                  "ldmia %[d], {r0, r1, r2, r3};"
                  "ldmia %[w]!, {r4, r5, r6, r7};"
                  "smull r8, r0, r4, r0;"
                  "mov   r0, r0, lsl #1;"
                  "smull r8, r1, r5, r1;"
                  "mov   r1, r1, lsl #1;"
                  "smull r8, r2, r6, r2;"
                  "mov   r2, r2, lsl #1;"
                  "smull r8, r3, r7, r3;"
                  "mov   r3, r3, lsl #1;"
                  "stmia %[d]!, {r0, r1, r2, r3};"
                  : [d] "+r" (data), [w] "+r" (window)
                  : : "r0", "r1", "r2", "r3",
                  "r4", "r5", "r6", "r7", "r8",
                  "memory" );
    n -= 4;
  } while (n);
}
#endif

#if ARM_ARCH >= 6
static inline
void vect_mult_bw(ogg_int32_t *data, LOOKUP_T *window, int n)
{
  /* NOTE mult_bw uses MULT_32 i.e. doesn't shift result left at end */
  /* On ARM, we can do the shift at the same time as the overlap-add */
  do{
    asm volatile ("ldmia %[d], {r0, r1, r2, r3};"
                  "ldmda %[w]!, {r4, r5, r6, r7};"
                  "smmul r0, r7, r0;"
                  "smmul r1, r6, r1;"
                  "smmul r2, r5, r2;"
                  "smmul r3, r4, r3;"
                  "stmia %[d]!, {r0, r1, r2, r3};"
                  : [d] "+r" (data), [w] "+r" (window)
                  : : "r0", "r1", "r2", "r3",
                  "r4", "r5", "r6", "r7",
                  "memory" );
    n -= 4;
  } while (n);
}
#else
static inline
void vect_mult_bw(ogg_int32_t *data, LOOKUP_T *window, int n)
{
  /* NOTE mult_bw uses MULT_32 i.e. doesn't shift result left at end */
  /* On ARM, we can do the shift at the same time as the overlap-add */
  do{
    asm volatile ("ldmia %[d], {r0, r1, r2, r3};"
                  "ldmda %[w]!, {r4, r5, r6, r7};"
                  "smull r8, r0, r7, r0;"
                  "smull r7, r1, r6, r1;"
                  "smull r6, r2, r5, r2;"
                  "smull r5, r3, r4, r3;"
                  "stmia %[d]!, {r0, r1, r2, r3};"
                  : [d] "+r" (data), [w] "+r" (window)
                  : : "r0", "r1", "r2", "r3",
                  "r4", "r5", "r6", "r7", "r8",
                  "memory" );
    n -= 4;
  } while (n);
}
#endif

static inline void vect_copy(ogg_int32_t *x, const ogg_int32_t *y, int n)
{
  memcpy(x,y,n*sizeof(ogg_int32_t));
}

#endif

#endif

#ifndef _V_CLIP_MATH
#define _V_CLIP_MATH

static inline ogg_int32_t CLIP_TO_15(ogg_int32_t x) {
  int tmp;
  asm volatile("subs    %1, %0, #32768\n\t"
               "movpl   %0, #0x7f00\n\t"
               "orrpl   %0, %0, #0xff\n"
               "adds    %1, %0, #32768\n\t"
               "movmi   %0, #0x8000"
               : "+r"(x),"=r"(tmp)
               :
               : "cc");
  return(x);
}

#endif

#ifndef _V_LSP_MATH_ASM
#define _V_LSP_MATH_ASM

static inline void lsp_loop_asm(ogg_uint32_t *qip,ogg_uint32_t *pip,
                                ogg_int32_t *qexpp,
                                ogg_int32_t *ilsp,ogg_int32_t wi,
                                ogg_int32_t m){
  
  ogg_uint32_t qi=*qip,pi=*pip;
  ogg_int32_t qexp=*qexpp;

  asm("mov     r0,%3;"
      "mov     r1,%5,asr#1;"
      "add     r0,r0,r1,lsl#3;"
      "1:"
      
      "ldmdb   r0!,{r1,r3};"
      "subs    r1,r1,%4;"          //ilsp[j]-wi
      "rsbmi   r1,r1,#0;"          //labs(ilsp[j]-wi)
      "umull   %0,r2,r1,%0;"       //qi*=labs(ilsp[j]-wi)
      
      "subs    r1,r3,%4;"          //ilsp[j+1]-wi
      "rsbmi   r1,r1,#0;"          //labs(ilsp[j+1]-wi)
      "umull   %1,r3,r1,%1;"       //pi*=labs(ilsp[j+1]-wi)
      
      "cmn     r2,r3;"             // shift down 16?
      "beq     0f;"
      "add     %2,%2,#16;"
      "mov     %0,%0,lsr #16;"
      "orr     %0,%0,r2,lsl #16;"
      "mov     %1,%1,lsr #16;"
      "orr     %1,%1,r3,lsl #16;"
      "0:"
      "cmp     r0,%3;\n"
      "bhi     1b;\n"
      
      // odd filter assymetry
      "ands    r0,%5,#1;\n"
      "beq     2f;\n"
      "add     r0,%3,%5,lsl#2;\n"
      
      "ldr     r1,[r0,#-4];\n"
      "mov     r0,#0x4000;\n"
      
      "subs    r1,r1,%4;\n"          //ilsp[j]-wi
      "rsbmi   r1,r1,#0;\n"          //labs(ilsp[j]-wi)
      "umull   %0,r2,r1,%0;\n"       //qi*=labs(ilsp[j]-wi)
      "umull   %1,r3,r0,%1;\n"       //pi*=labs(ilsp[j+1]-wi)
      
      "cmn     r2,r3;\n"             // shift down 16?
      "beq     2f;\n"
      "add     %2,%2,#16;\n"
      "mov     %0,%0,lsr #16;\n"
      "orr     %0,%0,r2,lsl #16;\n"
      "mov     %1,%1,lsr #16;\n"
      "orr     %1,%1,r3,lsl #16;\n"
      
      //qi=(pi>>shift)*labs(ilsp[j]-wi);
      //pi=(qi>>shift)*labs(ilsp[j+1]-wi);
      //qexp+=shift;

      //}

      /* normalize to max 16 sig figs */
      "2:"
      "mov     r2,#0;"
      "orr     r1,%0,%1;"
      "tst     r1,#0xff000000;"
      "addne   r2,r2,#8;"
      "movne   r1,r1,lsr #8;"
      "tst     r1,#0x00f00000;"
      "addne   r2,r2,#4;"
      "movne   r1,r1,lsr #4;"
      "tst     r1,#0x000c0000;"
      "addne   r2,r2,#2;"
      "movne   r1,r1,lsr #2;"
      "tst     r1,#0x00020000;"
      "addne   r2,r2,#1;"
      "movne   r1,r1,lsr #1;"
      "tst     r1,#0x00010000;"
      "addne   r2,r2,#1;"
      "mov     %0,%0,lsr r2;"
      "mov     %1,%1,lsr r2;"
      "add     %2,%2,r2;"
      
      : "+r"(qi),"+r"(pi),"+r"(qexp)
      : "r"(ilsp),"r"(wi),"r"(m)
      : "r0","r1","r2","r3","cc");
  
  *qip=qi;
  *pip=pi;
  *qexpp=qexp;
}

static inline void lsp_norm_asm(ogg_uint32_t *qip,ogg_int32_t *qexpp){

  ogg_uint32_t qi=*qip;
  ogg_int32_t qexp=*qexpp;

  asm("tst     %0,#0x0000ff00;"
      "moveq   %0,%0,lsl #8;"
      "subeq   %1,%1,#8;"
      "tst     %0,#0x0000f000;"
      "moveq   %0,%0,lsl #4;"
      "subeq   %1,%1,#4;"
      "tst     %0,#0x0000c000;"
      "moveq   %0,%0,lsl #2;"
      "subeq   %1,%1,#2;"
      "tst     %0,#0x00008000;"
      "moveq   %0,%0,lsl #1;"
      "subeq   %1,%1,#1;"
      : "+r"(qi),"+r"(qexp)
      :
      : "cc");
  *qip=qi;
  *qexpp=qexp;
}

#endif
#endif