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libwebp/src/dsp/lossless_enc_mips32.c
Vincent Rabaud 828b4ce062 Switch ExtraCost to ints and implement it in SSE. 
The histograms count the occurrences of len/dist in entropy images.
Those (at most (1<<14) by (1<<14)) are sub-sampled by at least
MIN_HUFFMAN_BITS == 2, hence at most 24 bits in a histogram value.
At most, we multiply by 19 (because the longest histogram is of
size 40 and we do 40>>1, cf code) for the bit cost. So it all fits
in 32 bits.

Change-Id: Ife24b035f54794851ff31f2fac07901f724c6d7f
2023-06-01 10:17:13 +02:00

398 lines
14 KiB
C
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// Copyright 2015 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 "src/dsp/dsp.h"
#include "src/dsp/lossless.h"
#include "src/dsp/lossless_common.h"
#if defined(WEBP_USE_MIPS32)
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
static float FastSLog2Slow_MIPS32(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_MIPS32(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 cost;
static uint32_t ExtraCost_MIPS32(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 ((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 cost;
static uint32_t ExtraCostCombined_MIPS32(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 ((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 WEBP_INLINE void GetEntropyUnrefinedHelper(
uint32_t val, int i, uint32_t* const val_prev, int* const i_prev,
VP8LBitEntropy* const bit_entropy, VP8LStreaks* const stats) {
int* const pstreaks = &stats->streaks[0][0];
int* const pcnts = &stats->counts[0];
int temp0, temp1, temp2, temp3;
const int streak = i - *i_prev;
// Gather info for the bit entropy.
if (*val_prev != 0) {
bit_entropy->sum += (*val_prev) * streak;
bit_entropy->nonzeros += streak;
bit_entropy->nonzero_code = *i_prev;
bit_entropy->entropy -= VP8LFastSLog2(*val_prev) * streak;
if (bit_entropy->max_val < *val_prev) {
bit_entropy->max_val = *val_prev;
}
}
// Gather info for the Huffman cost.
temp0 = (*val_prev != 0);
HUFFMAN_COST_PASS
*val_prev = val;
*i_prev = i;
}
static void GetEntropyUnrefined_MIPS32(const uint32_t X[], int length,
VP8LBitEntropy* const bit_entropy,
VP8LStreaks* const stats) {
int i;
int i_prev = 0;
uint32_t x_prev = X[0];
memset(stats, 0, sizeof(*stats));
VP8LBitEntropyInit(bit_entropy);
for (i = 1; i < length; ++i) {
const uint32_t x = X[i];
if (x != x_prev) {
GetEntropyUnrefinedHelper(x, i, &x_prev, &i_prev, bit_entropy, stats);
}
}
GetEntropyUnrefinedHelper(0, i, &x_prev, &i_prev, bit_entropy, stats);
bit_entropy->entropy += VP8LFastSLog2(bit_entropy->sum);
}
static void GetCombinedEntropyUnrefined_MIPS32(const uint32_t X[],
const uint32_t Y[],
int length,
VP8LBitEntropy* const entropy,
VP8LStreaks* const stats) {
int i = 1;
int i_prev = 0;
uint32_t xy_prev = X[0] + Y[0];
memset(stats, 0, sizeof(*stats));
VP8LBitEntropyInit(entropy);
for (i = 1; i < length; ++i) {
const uint32_t xy = X[i] + Y[i];
if (xy != xy_prev) {
GetEntropyUnrefinedHelper(xy, i, &xy_prev, &i_prev, entropy, stats);
}
}
GetEntropyUnrefinedHelper(0, i, &xy_prev, &i_prev, entropy, stats);
entropy->entropy += VP8LFastSLog2(entropy->sum);
}
#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
static void AddVector_MIPS32(const uint32_t* pa, const uint32_t* pb,
uint32_t* pout, int size) {
uint32_t temp0, temp1, temp2, temp3, temp4, temp5, temp6, temp7;
const int end = ((size) / 4) * 4;
const uint32_t* const LoopEnd = pa + end;
int i;
ASM_START
ADD_TO_OUT(0, 4, 8, 12, 1, pa, pb, pout)
ASM_END_0
for (i = 0; i < size - end; ++i) pout[i] = pa[i] + pb[i];
}
static void AddVectorEq_MIPS32(const uint32_t* pa, uint32_t* pout, int size) {
uint32_t temp0, temp1, temp2, temp3, temp4, temp5, temp6, temp7;
const int end = ((size) / 4) * 4;
const uint32_t* const LoopEnd = pa + end;
int i;
ASM_START
ADD_TO_OUT(0, 4, 8, 12, 0, pa, pout, pout)
ASM_END_1
for (i = 0; i < size - end; ++i) pout[i] += pa[i];
}
#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
//------------------------------------------------------------------------------
// Entry point
extern void VP8LEncDspInitMIPS32(void);
WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInitMIPS32(void) {
VP8LFastSLog2Slow = FastSLog2Slow_MIPS32;
VP8LFastLog2Slow = FastLog2Slow_MIPS32;
VP8LExtraCost = ExtraCost_MIPS32;
VP8LExtraCostCombined = ExtraCostCombined_MIPS32;
VP8LGetEntropyUnrefined = GetEntropyUnrefined_MIPS32;
VP8LGetCombinedEntropyUnrefined = GetCombinedEntropyUnrefined_MIPS32;
VP8LAddVector = AddVector_MIPS32;
VP8LAddVectorEq = AddVectorEq_MIPS32;
}
#else // !WEBP_USE_MIPS32
WEBP_DSP_INIT_STUB(VP8LEncDspInitMIPS32)
#endif // WEBP_USE_MIPS32
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