teensy-audio/utility/dspinst.h

/* Audio Library for Teensy 3.X
 * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
 *
 * Development of this audio library was funded by PJRC.COM, LLC by sales of
 * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
 * open source software by purchasing Teensy or other PJRC products.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice, development funding notice, and this permission
 * notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef dspinst_h_
#define dspinst_h_

#include <stdint.h>

// computes limit((val >> rshift), 2**bits)
static inline int32_t signed_saturate_rshift(int32_t val, int bits, int rshift) __attribute__((always_inline, unused));
static inline int32_t signed_saturate_rshift(int32_t val, int bits, int rshift)
{
	int32_t out;
	asm volatile("ssat %0, %1, %2, asr %3" : "=r" (out) : "I" (bits), "r" (val), "I" (rshift));
	return out;
}

// computes ((a[31:0] * b[15:0]) >> 16)
static inline int32_t signed_multiply_32x16b(int32_t a, uint32_t b) __attribute__((always_inline, unused));
static inline int32_t signed_multiply_32x16b(int32_t a, uint32_t b)
{
	int32_t out;
	asm volatile("smulwb %0, %1, %2" : "=r" (out) : "r" (a), "r" (b));
	return out;
}

// computes ((a[31:0] * b[31:16]) >> 16)
static inline int32_t signed_multiply_32x16t(int32_t a, uint32_t b) __attribute__((always_inline, unused));
static inline int32_t signed_multiply_32x16t(int32_t a, uint32_t b)
{
	int32_t out;
	asm volatile("smulwt %0, %1, %2" : "=r" (out) : "r" (a), "r" (b));
	return out;
}

// computes (((int64_t)a[31:0] * (int64_t)b[31:0]) >> 32)
static inline int32_t multiply_32x32_rshift32(int32_t a, int32_t b) __attribute__((always_inline, unused));
static inline int32_t multiply_32x32_rshift32(int32_t a, int32_t b)
{
	int32_t out;
	asm volatile("smmul %0, %1, %2" : "=r" (out) : "r" (a), "r" (b));
	return out;
}

// computes (((int64_t)a[31:0] * (int64_t)b[31:0] + 0x8000000) >> 32)
static inline int32_t multiply_32x32_rshift32_rounded(int32_t a, int32_t b) __attribute__((always_inline, unused));
static inline int32_t multiply_32x32_rshift32_rounded(int32_t a, int32_t b)
{
	int32_t out;
	asm volatile("smmulr %0, %1, %2" : "=r" (out) : "r" (a), "r" (b));
	return out;
}

// computes sum + (((int64_t)a[31:0] * (int64_t)b[31:0] + 0x8000000) >> 32)
static inline int32_t multiply_accumulate_32x32_rshift32_rounded(int32_t sum, int32_t a, int32_t b) __attribute__((always_inline, unused));
static inline int32_t multiply_accumulate_32x32_rshift32_rounded(int32_t sum, int32_t a, int32_t b)
{
	int32_t out;
	asm volatile("smmlar %0, %2, %3, %1" : "=r" (out) : "r" (sum), "r" (a), "r" (b));
	return out;
}

// computes sum - (((int64_t)a[31:0] * (int64_t)b[31:0] + 0x8000000) >> 32)
static inline int32_t multiply_subtract_32x32_rshift32_rounded(int32_t sum, int32_t a, int32_t b) __attribute__((always_inline, unused));
static inline int32_t multiply_subtract_32x32_rshift32_rounded(int32_t sum, int32_t a, int32_t b)
{
	int32_t out;
	asm volatile("smmlsr %0, %2, %3, %1" : "=r" (out) : "r" (sum), "r" (a), "r" (b));
	return out;
}

// computes ((a[15:0] << 16) | b[15:0])
static inline uint32_t pack_16x16(int32_t a, int32_t b) __attribute__((always_inline, unused));
static inline uint32_t pack_16x16(int32_t a, int32_t b)
{
	int32_t out;
	asm volatile("pkhbt %0, %1, %2, lsl #16" : "=r" (out) : "r" (b), "r" (a));
	return out;
}

// computes (((a[31:16] + b[31:16]) << 16) | (a[15:0 + b[15:0]))
static inline uint32_t signed_add_16_and_16(uint32_t a, uint32_t b) __attribute__((always_inline, unused));
static inline uint32_t signed_add_16_and_16(uint32_t a, uint32_t b)
{
	int32_t out;
	asm volatile("qadd16 %0, %1, %2" : "=r" (out) : "r" (a), "r" (b));
	return out;
}

// computes (sum + ((a[31:0] * b[15:0]) >> 16))
static inline int32_t signed_multiply_accumulate_32x16b(int32_t sum, int32_t a, uint32_t b) __attribute__((always_inline, unused));
static inline int32_t signed_multiply_accumulate_32x16b(int32_t sum, int32_t a, uint32_t b)
{
	int32_t out;
	asm volatile("smlawb %0, %2, %3, %1" : "=r" (out) : "r" (sum), "r" (a), "r" (b));
	return out;
}

// computes (sum + ((a[31:0] * b[31:16]) >> 16))
static inline int32_t signed_multiply_accumulate_32x16t(int32_t sum, int32_t a, uint32_t b) __attribute__((always_inline, unused));
static inline int32_t signed_multiply_accumulate_32x16t(int32_t sum, int32_t a, uint32_t b)
{
	int32_t out;
	asm volatile("smlawt %0, %2, %3, %1" : "=r" (out) : "r" (sum), "r" (a), "r" (b));
	return out;
}

// computes logical and, forces compiler to allocate register and use single cycle instruction
static inline uint32_t logical_and(uint32_t a, uint32_t b) __attribute__((always_inline, unused));
static inline uint32_t logical_and(uint32_t a, uint32_t b)
{
	asm volatile("and %0, %1" : "+r" (a) : "r" (b));
	return a;
}

#endif