/*
 * jsimd_arm64.c
 *
 * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
 * Copyright (C) 2009-2011, 2013-2014, 2016, D. R. Commander.
 * Copyright (C) 2015-2016, Matthieu Darbois.
 *
 * 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 contains the interface between the "normal" portions
 * of the library and the SIMD implementations when running on a
 * 64-bit ARM architecture.
 */

#define JPEG_INTERNALS

#include "../jinclude.h"
#include "../jpeglib.h"
#include "../jsimd.h"
#include "../jdct.h"
#include "../jsimddct.h"
#include "jsimd.h"

#include <stdio.h>
#include <string.h>
#include <ctype.h>

#define JSIMD_FASTLD3 1
#define JSIMD_FASTST3 2
#define JSIMD_FASTTBL 4

static unsigned int simd_support = ~0;
static unsigned int simd_huffman = 1;
static unsigned int simd_features = JSIMD_FASTLD3 | JSIMD_FASTST3 |
                                    JSIMD_FASTTBL;

#if defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)

#define SOMEWHAT_SANE_PROC_CPUINFO_SIZE_LIMIT (1024 * 1024)

LOCAL(int)
check_cpuinfo(char *buffer, const char *field, char *value) {
	char *p;
	if (*value == 0)
		return 0;
	if (strncmp(buffer, field, strlen(field)) != 0)
		return 0;
	buffer += strlen(field);
	while (isspace(*buffer))
		buffer++;

	/* Check if 'value' is present in the buffer as a separate word */
	while ((p = strstr(buffer, value))) {
		if (p > buffer && !isspace(*(p - 1))) {
			buffer++;
			continue;
		}
		p += strlen(value);
		if (*p != 0 && !isspace(*p)) {
			buffer++;
			continue;
		}
		return 1;
	}
	return 0;
}

LOCAL(int)
parse_proc_cpuinfo(int bufsize) {
	char *buffer = (char *) malloc(bufsize);
	FILE *fd;

	if (!buffer)
		return 0;

	fd = fopen("/proc/cpuinfo", "r");
	if (fd) {
		while (fgets(buffer, bufsize, fd)) {
			if (!strchr(buffer, '\n') && !feof(fd)) {
				/* "impossible" happened - insufficient size of the buffer! */
				fclose(fd);
				free(buffer);
				return 0;
			}
			if (check_cpuinfo(buffer, "CPU part", "0xd03") ||
			    check_cpuinfo(buffer, "CPU part", "0xd07"))
				/* The Cortex-A53 has a slow tbl implementation.  We can gain a few
				   percent speedup by disabling the use of that instruction.  The
				   speedup on Cortex-A57 is more subtle but still measurable. */
				simd_features &= ~JSIMD_FASTTBL;
			else if (check_cpuinfo(buffer, "CPU part", "0x0a1"))
				/* The SIMD version of Huffman encoding is slower than the C version on
				   Cavium ThunderX.  Also, ld3 and st3 are abyssmally slow on that
				   CPU. */
				simd_huffman = simd_features = 0;
		}
		fclose(fd);
	}
	free(buffer);
	return 1;
}

#endif

/*
 * Check what SIMD accelerations are supported.
 *
 * FIXME: This code is racy under a multi-threaded environment.
 */

/*
 * ARMv8 architectures support NEON extensions by default.
 * It is no longer optional as it was with ARMv7.
 */


LOCAL(void)
init_simd(void) {
	char *env = NULL;
#if defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)
	int bufsize = 1024; /* an initial guess for the line buffer size limit */
#endif

	if (simd_support != ~0U)
		return;

	simd_support = 0;

	simd_support |= JSIMD_ARM_NEON;
#if defined(__linux__) || defined(ANDROID) || defined(__ANDROID__)
	while (!parse_proc_cpuinfo(bufsize)) {
		bufsize *= 2;
		if (bufsize > SOMEWHAT_SANE_PROC_CPUINFO_SIZE_LIMIT)
			break;
	}
#endif

	/* Force different settings through environment variables */
	env = getenv("JSIMD_FORCENEON");
	if ((env != NULL) && (strcmp(env, "1") == 0))
		simd_support &= JSIMD_ARM_NEON;
	env = getenv("JSIMD_FORCENONE");
	if ((env != NULL) && (strcmp(env, "1") == 0))
		simd_support = 0;
	env = getenv("JSIMD_NOHUFFENC");
	if ((env != NULL) && (strcmp(env, "1") == 0))
		simd_huffman = 0;
	env = getenv("JSIMD_FASTLD3");
	if ((env != NULL) && (strcmp(env, "1") == 0))
		simd_features |= JSIMD_FASTLD3;
	if ((env != NULL) && (strcmp(env, "0") == 0))
		simd_features &= ~JSIMD_FASTLD3;
	env = getenv("JSIMD_FASTST3");
	if ((env != NULL) && (strcmp(env, "1") == 0))
		simd_features |= JSIMD_FASTST3;
	if ((env != NULL) && (strcmp(env, "0") == 0))
		simd_features &= ~JSIMD_FASTST3;
}

GLOBAL(int)
jsimd_can_rgb_ycc(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;
	if ((RGB_PIXELSIZE != 3) && (RGB_PIXELSIZE != 4))
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_rgb_gray(void) {
	init_simd();

	return 0;
}

GLOBAL(int)
jsimd_can_ycc_rgb(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;
	if ((RGB_PIXELSIZE != 3) && (RGB_PIXELSIZE != 4))
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_ycc_rgb565(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(void)
jsimd_rgb_ycc_convert(j_compress_ptr cinfo,
                      JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
                      JDIMENSION output_row, int num_rows) {
	void (*neonfct)(JDIMENSION, JSAMPARRAY, JSAMPIMAGE, JDIMENSION, int);

	switch (cinfo->in_color_space) {
		case JCS_EXT_RGB:
			if (simd_features & JSIMD_FASTLD3)
				neonfct = jsimd_extrgb_ycc_convert_neon;
			else
				neonfct = jsimd_extrgb_ycc_convert_neon_slowld3;
			break;
		case JCS_EXT_RGBX:
		case JCS_EXT_RGBA:
			neonfct = jsimd_extrgbx_ycc_convert_neon;
			break;
		case JCS_EXT_BGR:
			if (simd_features & JSIMD_FASTLD3)
				neonfct = jsimd_extbgr_ycc_convert_neon;
			else
				neonfct = jsimd_extbgr_ycc_convert_neon_slowld3;
			break;
		case JCS_EXT_BGRX:
		case JCS_EXT_BGRA:
			neonfct = jsimd_extbgrx_ycc_convert_neon;
			break;
		case JCS_EXT_XBGR:
		case JCS_EXT_ABGR:
			neonfct = jsimd_extxbgr_ycc_convert_neon;
			break;
		case JCS_EXT_XRGB:
		case JCS_EXT_ARGB:
			neonfct = jsimd_extxrgb_ycc_convert_neon;
			break;
		default:
			if (simd_features & JSIMD_FASTLD3)
				neonfct = jsimd_extrgb_ycc_convert_neon;
			else
				neonfct = jsimd_extrgb_ycc_convert_neon_slowld3;
			break;
	}

	neonfct(cinfo->image_width, input_buf, output_buf, output_row, num_rows);
}

GLOBAL(void)
jsimd_rgb_gray_convert(j_compress_ptr cinfo,
                       JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
                       JDIMENSION output_row, int num_rows) {
}

GLOBAL(void)
jsimd_ycc_rgb_convert(j_decompress_ptr cinfo,
                      JSAMPIMAGE input_buf, JDIMENSION input_row,
                      JSAMPARRAY output_buf, int num_rows) {
	void (*neonfct)(JDIMENSION, JSAMPIMAGE, JDIMENSION, JSAMPARRAY, int);

	switch (cinfo->out_color_space) {
		case JCS_EXT_RGB:
			if (simd_features & JSIMD_FASTST3)
				neonfct = jsimd_ycc_extrgb_convert_neon;
			else
				neonfct = jsimd_ycc_extrgb_convert_neon_slowst3;
			break;
		case JCS_EXT_RGBX:
		case JCS_EXT_RGBA:
			neonfct = jsimd_ycc_extrgbx_convert_neon;
			break;
		case JCS_EXT_BGR:
			if (simd_features & JSIMD_FASTST3)
				neonfct = jsimd_ycc_extbgr_convert_neon;
			else
				neonfct = jsimd_ycc_extbgr_convert_neon_slowst3;
			break;
		case JCS_EXT_BGRX:
		case JCS_EXT_BGRA:
			neonfct = jsimd_ycc_extbgrx_convert_neon;
			break;
		case JCS_EXT_XBGR:
		case JCS_EXT_ABGR:
			neonfct = jsimd_ycc_extxbgr_convert_neon;
			break;
		case JCS_EXT_XRGB:
		case JCS_EXT_ARGB:
			neonfct = jsimd_ycc_extxrgb_convert_neon;
			break;
		default:
			if (simd_features & JSIMD_FASTST3)
				neonfct = jsimd_ycc_extrgb_convert_neon;
			else
				neonfct = jsimd_ycc_extrgb_convert_neon_slowst3;
			break;
	}

	neonfct(cinfo->output_width, input_buf, input_row, output_buf, num_rows);
}

GLOBAL(void)
jsimd_ycc_rgb565_convert(j_decompress_ptr cinfo,
                         JSAMPIMAGE input_buf, JDIMENSION input_row,
                         JSAMPARRAY output_buf, int num_rows) {
	jsimd_ycc_rgb565_convert_neon(cinfo->output_width, input_buf, input_row,
	                              output_buf, num_rows);
}

GLOBAL(int)
jsimd_can_h2v2_downsample(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_h2v1_downsample(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(void)
jsimd_h2v2_downsample(j_compress_ptr cinfo, jpeg_component_info *compptr,
                      JSAMPARRAY input_data, JSAMPARRAY output_data) {
	jsimd_h2v2_downsample_neon(cinfo->image_width, cinfo->max_v_samp_factor,
	                           compptr->v_samp_factor, compptr->width_in_blocks,
	                           input_data, output_data);
}

GLOBAL(void)
jsimd_h2v1_downsample(j_compress_ptr cinfo, jpeg_component_info *compptr,
                      JSAMPARRAY input_data, JSAMPARRAY output_data) {
	jsimd_h2v1_downsample_neon(cinfo->image_width, cinfo->max_v_samp_factor,
	                           compptr->v_samp_factor, compptr->width_in_blocks,
	                           input_data, output_data);
}

GLOBAL(int)
jsimd_can_h2v2_upsample(void) {
	init_simd();

	return 0;
}

GLOBAL(int)
jsimd_can_h2v1_upsample(void) {
	init_simd();

	return 0;
}

GLOBAL(void)
jsimd_h2v2_upsample(j_decompress_ptr cinfo,
                    jpeg_component_info *compptr,
                    JSAMPARRAY input_data,
                    JSAMPARRAY *output_data_ptr) {
}

GLOBAL(void)
jsimd_h2v1_upsample(j_decompress_ptr cinfo,
                    jpeg_component_info *compptr,
                    JSAMPARRAY input_data,
                    JSAMPARRAY *output_data_ptr) {
}

GLOBAL(int)
jsimd_can_h2v2_fancy_upsample(void) {
	init_simd();

	return 0;
}

GLOBAL(int)
jsimd_can_h2v1_fancy_upsample(void) {
	init_simd();

	return 0;
}

GLOBAL(void)
jsimd_h2v2_fancy_upsample(j_decompress_ptr cinfo,
                          jpeg_component_info *compptr,
                          JSAMPARRAY input_data,
                          JSAMPARRAY *output_data_ptr) {
}

GLOBAL(void)
jsimd_h2v1_fancy_upsample(j_decompress_ptr cinfo,
                          jpeg_component_info *compptr,
                          JSAMPARRAY input_data,
                          JSAMPARRAY *output_data_ptr) {
}

GLOBAL(int)
jsimd_can_h2v2_merged_upsample(void) {
	init_simd();

	return 0;
}

GLOBAL(int)
jsimd_can_h2v1_merged_upsample(void) {
	init_simd();

	return 0;
}

GLOBAL(void)
jsimd_h2v2_merged_upsample(j_decompress_ptr cinfo,
                           JSAMPIMAGE input_buf,
                           JDIMENSION in_row_group_ctr,
                           JSAMPARRAY output_buf) {
}

GLOBAL(void)
jsimd_h2v1_merged_upsample(j_decompress_ptr cinfo,
                           JSAMPIMAGE input_buf,
                           JDIMENSION in_row_group_ctr,
                           JSAMPARRAY output_buf) {
}

GLOBAL(int)
jsimd_can_convsamp(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (DCTSIZE != 8)
		return 0;
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;
	if (sizeof(DCTELEM) != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_convsamp_float(void) {
	init_simd();

	return 0;
}

GLOBAL(void)
jsimd_convsamp(JSAMPARRAY sample_data, JDIMENSION start_col,
               DCTELEM *workspace) {
	jsimd_convsamp_neon(sample_data, start_col, workspace);
}

GLOBAL(void)
jsimd_convsamp_float(JSAMPARRAY sample_data, JDIMENSION start_col,
                     FAST_FLOAT *workspace) {
}

GLOBAL(int)
jsimd_can_fdct_islow(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(DCTELEM) != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_fdct_ifast(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(DCTELEM) != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_fdct_float(void) {
	init_simd();

	return 0;
}

GLOBAL(void)
jsimd_fdct_islow(DCTELEM *data) {
	jsimd_fdct_islow_neon(data);
}

GLOBAL(void)
jsimd_fdct_ifast(DCTELEM *data) {
	jsimd_fdct_ifast_neon(data);
}

GLOBAL(void)
jsimd_fdct_float(FAST_FLOAT *data) {
}

GLOBAL(int)
jsimd_can_quantize(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(JCOEF) != 2)
		return 0;
	if (sizeof(DCTELEM) != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_quantize_float(void) {
	init_simd();

	return 0;
}

GLOBAL(void)
jsimd_quantize(JCOEFPTR coef_block, DCTELEM *divisors,
               DCTELEM *workspace) {
	jsimd_quantize_neon(coef_block, divisors, workspace);
}

GLOBAL(void)
jsimd_quantize_float(JCOEFPTR coef_block, FAST_FLOAT *divisors,
                     FAST_FLOAT *workspace) {
}

GLOBAL(int)
jsimd_can_idct_2x2(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(JCOEF) != 2)
		return 0;
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;
	if (sizeof(ISLOW_MULT_TYPE) != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_idct_4x4(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(JCOEF) != 2)
		return 0;
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;
	if (sizeof(ISLOW_MULT_TYPE) != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(void)
jsimd_idct_2x2(j_decompress_ptr cinfo, jpeg_component_info *compptr,
               JCOEFPTR coef_block, JSAMPARRAY output_buf,
               JDIMENSION output_col) {
	jsimd_idct_2x2_neon(compptr->dct_table, coef_block, output_buf,
	                    output_col);
}

GLOBAL(void)
jsimd_idct_4x4(j_decompress_ptr cinfo, jpeg_component_info *compptr,
               JCOEFPTR coef_block, JSAMPARRAY output_buf,
               JDIMENSION output_col) {
	jsimd_idct_4x4_neon(compptr->dct_table, coef_block, output_buf,
	                    output_col);
}

GLOBAL(int)
jsimd_can_idct_islow(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(JCOEF) != 2)
		return 0;
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;
	if (sizeof(ISLOW_MULT_TYPE) != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_idct_ifast(void) {
	init_simd();

	/* The code is optimised for these values only */
	if (DCTSIZE != 8)
		return 0;
	if (sizeof(JCOEF) != 2)
		return 0;
	if (BITS_IN_JSAMPLE != 8)
		return 0;
	if (sizeof(JDIMENSION) != 4)
		return 0;
	if (sizeof(IFAST_MULT_TYPE) != 2)
		return 0;
	if (IFAST_SCALE_BITS != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON)
		return 1;

	return 0;
}

GLOBAL(int)
jsimd_can_idct_float(void) {
	init_simd();

	return 0;
}

GLOBAL(void)
jsimd_idct_islow(j_decompress_ptr cinfo, jpeg_component_info *compptr,
                 JCOEFPTR coef_block, JSAMPARRAY output_buf,
                 JDIMENSION output_col) {
	jsimd_idct_islow_neon(compptr->dct_table, coef_block, output_buf,
	                      output_col);
}

GLOBAL(void)
jsimd_idct_ifast(j_decompress_ptr cinfo, jpeg_component_info *compptr,
                 JCOEFPTR coef_block, JSAMPARRAY output_buf,
                 JDIMENSION output_col) {
	jsimd_idct_ifast_neon(compptr->dct_table, coef_block, output_buf,
	                      output_col);
}

GLOBAL(void)
jsimd_idct_float(j_decompress_ptr cinfo, jpeg_component_info *compptr,
                 JCOEFPTR coef_block, JSAMPARRAY output_buf,
                 JDIMENSION output_col) {
}

GLOBAL(int)
jsimd_can_huff_encode_one_block(void) {
	init_simd();

	if (DCTSIZE != 8)
		return 0;
	if (sizeof(JCOEF) != 2)
		return 0;

	if (simd_support & JSIMD_ARM_NEON && simd_huffman)
		return 1;

	return 0;
}

GLOBAL(JOCTET*)
jsimd_huff_encode_one_block(void *state, JOCTET *buffer, JCOEFPTR block,
                            int last_dc_val, c_derived_tbl *dctbl,
                            c_derived_tbl *actbl) {
	if (simd_features & JSIMD_FASTTBL)
		return jsimd_huff_encode_one_block_neon(state, buffer, block, last_dc_val,
		                                        dctbl, actbl);
	else
		return jsimd_huff_encode_one_block_neon_slowtbl(state, buffer, block,
		                                                last_dc_val, dctbl, actbl);
}
