blob: 4b0a26e5655181206a525658bbad60e298c0161d [file] [log] [blame]
/*
* Copyright 2021 Google LLC
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <cassert>
#include <cstdio>
#include <cstdint>
#include "QMath.h"
// Compile for x86_64 + ssse3 with:
// c++ -O3 --std=c++17 -mssse3 experimental/lowp-basic/lowp_experiments.cpp -o lowp
//
// Compile for aarch64 with (Mac os):
// c++ -O3 --std=c++17 -arch arm64 experimental/lowp-basic/lowp_experiments.cpp -o lowp
//
// View assembly:
// dumpobj -d lowp | less
template <int N, typename T> using V = T __attribute__((ext_vector_type(N)));
#if !defined(__clang__)
static_assert(false, "This only works on clang.");
#endif
#if defined(__SSSE3__)
#include <immintrin.h>
#endif
#if defined(__ARM_NEON)
// From section 5.5.5 of the ARM C Language Extensions (ACLE)
#include <arm_neon.h>
#endif
using Q15 = V<8, uint16_t>;
#if defined(__SSSE3__)
static void test_mm_mulhrs_epi16_simulation() {
for (int i = -32768; i < 32768; i++) {
for (int j = -32768; j < 32768; j++) {
Q15 a(i);
Q15 b(j);
Q15 simResult = simulate_ssse3_mm_mulhrs_epi16(a, b);
Q15 intrinsicResult = _mm_mulhrs_epi16(a, b);
for (int i = 0; i < 8; i++) {
if (simResult[i] != intrinsicResult[i]) {
printf("simulate_ssse3_mm_mulhrs_epi16 broken\n");
printf("i: %d, a: %hx b: %hx, intrinsic: %hx, sim: %hx\n",
i, a[i], b[i], intrinsicResult[i], simResult[i]);
exit(1);
}
}
}
}
}
// Use ssse3 to simulate saturating multiply on arm.
static Q15 ssse3_vqrdmulhq_s16(Q15 a, Q15 b) {
constexpr Q15 limit(0x8000);
const Q15 product = _mm_mulhrs_epi16(a, b);
const Q15 eq = _mm_cmpeq_epi16(product, limit);
return _mm_xor_si128(eq, product);
}
static void test_ssse3_vqrdmulhq_s16() {
for (int i = -32768; i < 32768; i++) {
for (int j = -32768; j < 32768; j++) {
Q15 a(i);
Q15 b(j);
Q15 simResult = ssse3_vqrdmulhq_s16(a, b);
Q15 realVqrdmulhqS16 = simulate_neon_vqrdmulhq_s16(a, b);
for (int i = 0; i < 8; i++) {
if (simResult[i] != realVqrdmulhqS16[i]) {
printf("simulating vqrdmulhq_s16 with ssse3 broken\n");
printf("i: %d, a: %hx b: %hx, intrinsic: %hx, sim: %hx\n",
i, a[i], b[i], realVqrdmulhqS16[i], simResult[i]);
exit(1);
}
}
}
}
}
#endif
#if defined(__ARM_NEON)
static void test_neon_vqrdmulhq_s16_simulation() {
for (int i = -32768; i < 32768; i++) {
for (int j = -32768; j < 32768; j++) {
Q15 a(i);
Q15 b(j);
Q15 simResult = simulate_neon_vqrdmulhq_s16(a, b);
Q15 intrinsicResult = vqrdmulhq_s16(a, b);
for (int i = 0; i < 8; i++) {
if (simResult[i] != intrinsicResult[i]) {
printf("simulate_neon_vqrdmulhq_s16 broken\n");
printf("i: %d, a: %hx b: %hx, intrinsic: %hx, sim: %hx\n",
i, a[i], b[i], intrinsicResult[i], simResult[i]);
exit(1);
}
}
}
}
}
#endif
int main() {
#if defined(__SSSE3__)
//test_mm_mulhrs_epi16_simulation();
test_ssse3_vqrdmulhq_s16();
#endif
#if defined(__ARM_NEON)
test_neon_vqrdmulhq_s16_simulation();
#endif
printf("Done.\n");
return 0;
}