// Copyright 2014 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// MIPS version of lossless functions
//
// Author(s): Djordje Pesut (djordje.pesut@imgtec.com)
// Jovan Zelincevic (jovan.zelincevic@imgtec.com)
#include "./dsp.h"
#include "./lossless.h"
#if defined(WEBP_USE_MIPS32)
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#define APPROX_LOG_WITH_CORRECTION_MAX 65536
#define APPROX_LOG_MAX 4096
#define LOG_2_RECIPROCAL 1.44269504088896338700465094007086
static float FastSLog2Slow(uint32_t v) {
assert(v >= LOG_LOOKUP_IDX_MAX);
if (v < APPROX_LOG_WITH_CORRECTION_MAX) {
uint32_t log_cnt, y, correction;
const int c24 = 24;
const float v_f = (float)v;
uint32_t temp;
// Xf = 256 = 2^8
// log_cnt is index of leading one in upper 24 bits
__asm__ volatile(
"clz %[log_cnt], %[v] \n\t"
"addiu %[y], $zero, 1 \n\t"
"subu %[log_cnt], %[c24], %[log_cnt] \n\t"
"sllv %[y], %[y], %[log_cnt] \n\t"
"srlv %[temp], %[v], %[log_cnt] \n\t"
: [log_cnt]"=&r"(log_cnt), [y]"=&r"(y),
[temp]"=r"(temp)
: [c24]"r"(c24), [v]"r"(v)
);
// vf = (2^log_cnt) * Xf; where y = 2^log_cnt and Xf < 256
// Xf = floor(Xf) * (1 + (v % y) / v)
// log2(Xf) = log2(floor(Xf)) + log2(1 + (v % y) / v)
// The correction factor: log(1 + d) ~ d; for very small d values, so
// log2(1 + (v % y) / v) ~ LOG_2_RECIPROCAL * (v % y)/v
// LOG_2_RECIPROCAL ~ 23/16
// (v % y) = (v % 2^log_cnt) = v & (2^log_cnt - 1)
correction = (23 * (v & (y - 1))) >> 4;
return v_f * (kLog2Table[temp] + log_cnt) + correction;
} else {
return (float)(LOG_2_RECIPROCAL * v * log((double)v));
}
}
static float FastLog2Slow(uint32_t v) {
assert(v >= LOG_LOOKUP_IDX_MAX);
if (v < APPROX_LOG_WITH_CORRECTION_MAX) {
uint32_t log_cnt, y;
const int c24 = 24;
double log_2;
uint32_t temp;
__asm__ volatile(
"clz %[log_cnt], %[v] \n\t"
"addiu %[y], $zero, 1 \n\t"
"subu %[log_cnt], %[c24], %[log_cnt] \n\t"
"sllv %[y], %[y], %[log_cnt] \n\t"
"srlv %[temp], %[v], %[log_cnt] \n\t"
: [log_cnt]"=&r"(log_cnt), [y]"=&r"(y),
[temp]"=r"(temp)
: [c24]"r"(c24), [v]"r"(v)
);
log_2 = kLog2Table[temp] + log_cnt;
if (v >= APPROX_LOG_MAX) {
// Since the division is still expensive, add this correction factor only
// for large values of 'v'.
const uint32_t correction = (23 * (v & (y - 1))) >> 4;
log_2 += (double)correction / v;
}
return (float)log_2;
} else {
return (float)(LOG_2_RECIPROCAL * log((double)v));
}
}
// C version of this function:
// int i = 0;
// int64_t cost = 0;
// const uint32_t* pop = &population[4];
// const uint32_t* LoopEnd = &population[length];
// while (pop != LoopEnd) {
// ++i;
// cost += i * *pop;
// cost += i * *(pop + 1);
// pop += 2;
// }
// return (double)cost;
static double ExtraCost(const uint32_t* const population, int length) {
int i, temp0, temp1;
const uint32_t* pop = &population[4];
const uint32_t* const LoopEnd = &population[length];
__asm__ volatile(
"mult $zero, $zero \n\t"
"xor %[i], %[i], %[i] \n\t"
"beq %[pop], %[LoopEnd], 2f \n\t"
"1: \n\t"
"lw %[temp0], 0(%[pop]) \n\t"
"lw %[temp1], 4(%[pop]) \n\t"
"addiu %[i], %[i], 1 \n\t"
"addiu %[pop], %[pop], 8 \n\t"
"madd %[i], %[temp0] \n\t"
"madd %[i], %[temp1] \n\t"
"bne %[pop], %[LoopEnd], 1b \n\t"
"2: \n\t"
"mfhi %[temp0] \n\t"
"mflo %[temp1] \n\t"
: [temp0]"=&r"(temp0), [temp1]"=&r"(temp1),
[i]"=&r"(i), [pop]"+r"(pop)
: [LoopEnd]"r"(LoopEnd)
: "memory", "hi", "lo"
);
return (double)((int64_t)temp0 << 32 | temp1);
}
// C version of this function:
// int i = 0;
// int64_t cost = 0;
// const uint32_t* pX = &X[4];
// const uint32_t* pY = &Y[4];
// const uint32_t* LoopEnd = &X[length];
// while (pX != LoopEnd) {
// const uint32_t xy0 = *pX + *pY;
// const uint32_t xy1 = *(pX + 1) + *(pY + 1);
// ++i;
// cost += i * xy0;
// cost += i * xy1;
// pX += 2;
// pY += 2;
// }
// return (double)cost;
static double ExtraCostCombined(const uint32_t* const X,
const uint32_t* const Y, int length) {
int i, temp0, temp1, temp2, temp3;
const uint32_t* pX = &X[4];
const uint32_t* pY = &Y[4];
const uint32_t* const LoopEnd = &X[length];
__asm__ volatile(
"mult $zero, $zero \n\t"
"xor %[i], %[i], %[i] \n\t"
"beq %[pX], %[LoopEnd], 2f \n\t"
"1: \n\t"
"lw %[temp0], 0(%[pX]) \n\t"
"lw %[temp1], 0(%[pY]) \n\t"
"lw %[temp2], 4(%[pX]) \n\t"
"lw %[temp3], 4(%[pY]) \n\t"
"addiu %[i], %[i], 1 \n\t"
"addu %[temp0], %[temp0], %[temp1] \n\t"
"addu %[temp2], %[temp2], %[temp3] \n\t"
"addiu %[pX], %[pX], 8 \n\t"
"addiu %[pY], %[pY], 8 \n\t"
"madd %[i], %[temp0] \n\t"
"madd %[i], %[temp2] \n\t"
"bne %[pX], %[LoopEnd], 1b \n\t"
"2: \n\t"
"mfhi %[temp0] \n\t"
"mflo %[temp1] \n\t"
: [temp0]"=&r"(temp0), [temp1]"=&r"(temp1),
[temp2]"=&r"(temp2), [temp3]"=&r"(temp3),
[i]"=&r"(i), [pX]"+r"(pX), [pY]"+r"(pY)
: [LoopEnd]"r"(LoopEnd)
: "memory", "hi", "lo"
);
return (double)((int64_t)temp0 << 32 | temp1);
}
#define HUFFMAN_COST_PASS \
__asm__ volatile( \
"sll %[temp1], %[temp0], 3 \n\t" \
"addiu %[temp3], %[streak], -3 \n\t" \
"addu %[temp2], %[pstreaks], %[temp1] \n\t" \
"blez %[temp3], 1f \n\t" \
"srl %[temp1], %[temp1], 1 \n\t" \
"addu %[temp3], %[pcnts], %[temp1] \n\t" \
"lw %[temp0], 4(%[temp2]) \n\t" \
"lw %[temp1], 0(%[temp3]) \n\t" \
"addu %[temp0], %[temp0], %[streak] \n\t" \
"addiu %[temp1], %[temp1], 1 \n\t" \
"sw %[temp0], 4(%[temp2]) \n\t" \
"sw %[temp1], 0(%[temp3]) \n\t" \
"b 2f \n\t" \
"1: \n\t" \
"lw %[temp0], 0(%[temp2]) \n\t" \
"addu %[temp0], %[temp0], %[streak] \n\t" \
"sw %[temp0], 0(%[temp2]) \n\t" \
"2: \n\t" \
: [temp1]"=&r"(temp1), [temp2]"=&r"(temp2), \
[temp3]"=&r"(temp3), [temp0]"+r"(temp0) \
: [pstreaks]"r"(pstreaks), [pcnts]"r"(pcnts), \
[streak]"r"(streak) \
: "memory" \
);
// Returns the various RLE counts
static VP8LStreaks HuffmanCostCount(const uint32_t* population, int length) {
int i;
int streak = 0;
VP8LStreaks stats;
int* const pstreaks = &stats.streaks[0][0];
int* const pcnts = &stats.counts[0];
int temp0, temp1, temp2, temp3;
memset(&stats, 0, sizeof(stats));
for (i = 0; i < length - 1; ++i) {
++streak;
if (population[i] == population[i + 1]) {
continue;
}
temp0 = (population[i] != 0);
HUFFMAN_COST_PASS
streak = 0;
}
++streak;
temp0 = (population[i] != 0);
HUFFMAN_COST_PASS
return stats;
}
static VP8LStreaks HuffmanCostCombinedCount(const uint32_t* X,
const uint32_t* Y, int length) {
int i;
int streak = 0;
VP8LStreaks stats;
int* const pstreaks = &stats.streaks[0][0];
int* const pcnts = &stats.counts[0];
int temp0, temp1, temp2, temp3;
memset(&stats, 0, sizeof(stats));
for (i = 0; i < length - 1; ++i) {
const uint32_t xy = X[i] + Y[i];
const uint32_t xy_next = X[i + 1] + Y[i + 1];
++streak;
if (xy == xy_next) {
continue;
}
temp0 = (xy != 0);
HUFFMAN_COST_PASS
streak = 0;
}
{
const uint32_t xy = X[i] + Y[i];
++streak;
temp0 = (xy != 0);
HUFFMAN_COST_PASS
}
return stats;
}
#define ASM_START \
__asm__ volatile( \
".set push \n\t" \
".set at \n\t" \
".set macro \n\t" \
"1: \n\t"
// P2 = P0 + P1
// A..D - offsets
// E - temp variable to tell macro
// if pointer should be incremented
// literal_ and successive histograms could be unaligned
// so we must use ulw and usw
#define ADD_TO_OUT(A, B, C, D, E, P0, P1, P2) \
"ulw %[temp0], "#A"(%["#P0"]) \n\t" \
"ulw %[temp1], "#B"(%["#P0"]) \n\t" \
"ulw %[temp2], "#C"(%["#P0"]) \n\t" \
"ulw %[temp3], "#D"(%["#P0"]) \n\t" \
"ulw %[temp4], "#A"(%["#P1"]) \n\t" \
"ulw %[temp5], "#B"(%["#P1"]) \n\t" \
"ulw %[temp6], "#C"(%["#P1"]) \n\t" \
"ulw %[temp7], "#D"(%["#P1"]) \n\t" \
"addu %[temp4], %[temp4], %[temp0] \n\t" \
"addu %[temp5], %[temp5], %[temp1] \n\t" \
"addu %[temp6], %[temp6], %[temp2] \n\t" \
"addu %[temp7], %[temp7], %[temp3] \n\t" \
"addiu %["#P0"], %["#P0"], 16 \n\t" \
".if "#E" == 1 \n\t" \
"addiu %["#P1"], %["#P1"], 16 \n\t" \
".endif \n\t" \
"usw %[temp4], "#A"(%["#P2"]) \n\t" \
"usw %[temp5], "#B"(%["#P2"]) \n\t" \
"usw %[temp6], "#C"(%["#P2"]) \n\t" \
"usw %[temp7], "#D"(%["#P2"]) \n\t" \
"addiu %["#P2"], %["#P2"], 16 \n\t" \
"bne %["#P0"], %[LoopEnd], 1b \n\t" \
".set pop \n\t" \
#define ASM_END_COMMON_0 \
: [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), \
[temp2]"=&r"(temp2), [temp3]"=&r"(temp3), \
[temp4]"=&r"(temp4), [temp5]"=&r"(temp5), \
[temp6]"=&r"(temp6), [temp7]"=&r"(temp7), \
[pa]"+r"(pa), [pout]"+r"(pout)
#define ASM_END_COMMON_1 \
: [LoopEnd]"r"(LoopEnd) \
: "memory", "at" \
);
#define ASM_END_0 \
ASM_END_COMMON_0 \
, [pb]"+r"(pb) \
ASM_END_COMMON_1
#define ASM_END_1 \
ASM_END_COMMON_0 \
ASM_END_COMMON_1
#define ADD_VECTOR(A, B, OUT, SIZE, EXTRA_SIZE) do { \
const uint32_t* pa = (const uint32_t*)(A); \
const uint32_t* pb = (const uint32_t*)(B); \
uint32_t* pout = (uint32_t*)(OUT); \
const uint32_t* const LoopEnd = pa + (SIZE); \
assert((SIZE) % 4 == 0); \
ASM_START \
ADD_TO_OUT(0, 4, 8, 12, 1, pa, pb, pout) \
ASM_END_0 \
if ((EXTRA_SIZE) > 0) { \
const int last = (EXTRA_SIZE); \
int i; \
for (i = 0; i < last; ++i) pout[i] = pa[i] + pb[i]; \
} \
} while (0)
#define ADD_VECTOR_EQ(A, OUT, SIZE, EXTRA_SIZE) do { \
const uint32_t* pa = (const uint32_t*)(A); \
uint32_t* pout = (uint32_t*)(OUT); \
const uint32_t* const LoopEnd = pa + (SIZE); \
assert((SIZE) % 4 == 0); \
ASM_START \
ADD_TO_OUT(0, 4, 8, 12, 0, pa, pout, pout) \
ASM_END_1 \
if ((EXTRA_SIZE) > 0) { \
const int last = (EXTRA_SIZE); \
int i; \
for (i = 0; i < last; ++i) pout[i] += pa[i]; \
} \
} while (0)
static void HistogramAdd(const VP8LHistogram* const a,
const VP8LHistogram* const b,
VP8LHistogram* const out) {
uint32_t temp0, temp1, temp2, temp3, temp4, temp5, temp6, temp7;
const int extra_cache_size = VP8LHistogramNumCodes(a->palette_code_bits_)
- (NUM_LITERAL_CODES + NUM_LENGTH_CODES);
assert(a->palette_code_bits_ == b->palette_code_bits_);
if (b != out) {
ADD_VECTOR(a->literal_, b->literal_, out->literal_,
NUM_LITERAL_CODES + NUM_LENGTH_CODES, extra_cache_size);
ADD_VECTOR(a->distance_, b->distance_, out->distance_,
NUM_DISTANCE_CODES, 0);
ADD_VECTOR(a->red_, b->red_, out->red_, NUM_LITERAL_CODES, 0);
ADD_VECTOR(a->blue_, b->blue_, out->blue_, NUM_LITERAL_CODES, 0);
ADD_VECTOR(a->alpha_, b->alpha_, out->alpha_, NUM_LITERAL_CODES, 0);
} else {
ADD_VECTOR_EQ(a->literal_, out->literal_,
NUM_LITERAL_CODES + NUM_LENGTH_CODES, extra_cache_size);
ADD_VECTOR_EQ(a->distance_, out->distance_, NUM_DISTANCE_CODES, 0);
ADD_VECTOR_EQ(a->red_, out->red_, NUM_LITERAL_CODES, 0);
ADD_VECTOR_EQ(a->blue_, out->blue_, NUM_LITERAL_CODES, 0);
ADD_VECTOR_EQ(a->alpha_, out->alpha_, NUM_LITERAL_CODES, 0);
}
}
#undef ADD_VECTOR_EQ
#undef ADD_VECTOR
#undef ASM_END_1
#undef ASM_END_0
#undef ASM_END_COMMON_1
#undef ASM_END_COMMON_0
#undef ADD_TO_OUT
#undef ASM_START
#endif // WEBP_USE_MIPS32
//------------------------------------------------------------------------------
// Entry point
extern void VP8LDspInitMIPS32(void);
void VP8LDspInitMIPS32(void) {
#if defined(WEBP_USE_MIPS32)
VP8LFastSLog2Slow = FastSLog2Slow;
VP8LFastLog2Slow = FastLog2Slow;
VP8LExtraCost = ExtraCost;
VP8LExtraCostCombined = ExtraCostCombined;
VP8LHuffmanCostCount = HuffmanCostCount;
VP8LHuffmanCostCombinedCount = HuffmanCostCombinedCount;
VP8LHistogramAdd = HistogramAdd;
#endif // WEBP_USE_MIPS32
}