Anton Shepelev
e4a0e1dfcb
Closes #159378 #### Changes - This PR adds math approximation for targets that don't have hardware for floats - in other words, targets that don't have `LIBC_TARGET_CPU_HAS_FPU_FLOAT` - This PR also introduces Google Benchmark for rsqrtf16 - Fixed typo in `+inf` case. Should return +0 according to [F.10.4.9](https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3220.pdf)
106 lines
2.1 KiB
C++
106 lines
2.1 KiB
C++
#include "benchmark/benchmark.h"
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#include "src/__support/FPUtil/FPBits.h"
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#include "src/__support/math/rsqrtf16.h"
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#include <stddef.h>
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#include <stdint.h>
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namespace {
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using FPBits = LIBC_NAMESPACE::fputil::FPBits<float16>;
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constexpr uint16_t INPUTS[] = {
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// Subnormals.
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0x0001,
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0x0002,
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0x0004,
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0x0008,
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0x0010,
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0x0020,
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0x0040,
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0x0080,
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0x0100,
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0x0200,
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0x03ff,
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// Normals spread across all exponent ranges.
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0x0400,
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0x0401,
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0x047f,
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0x0555,
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0x07ff,
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0x0800,
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0x0c00,
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0x1000,
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0x1400,
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0x1800,
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0x1c00,
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0x2000,
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0x2400,
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0x2800,
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0x2c00,
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0x3000,
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0x3400,
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0x3800,
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0x3c00,
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0x3c01,
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0x3d55,
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0x3fff,
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0x4000,
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0x4400,
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0x4800,
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0x4c00,
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0x5000,
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0x5400,
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0x5800,
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0x5c00,
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0x6000,
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0x6400,
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0x6800,
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0x6c00,
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0x7000,
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0x7400,
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0x7800,
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0x7bff,
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};
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constexpr size_t INPUT_COUNT = sizeof(INPUTS) / sizeof(INPUTS[0]);
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float16 get_input(uint16_t bits) { return FPBits(bits).get_val(); }
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float16 rsqrtf16_integer_finite(float16 x) {
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FPBits xbits(x);
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return LIBC_NAMESPACE::math::rsqrtf16_internal::rsqrtf16_no_float(
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xbits.uintval() & 0x7fff);
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}
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void BM_Rsqrtf16HostFpu(benchmark::State &state) {
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for (auto _ : state) {
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for (uint16_t bits : INPUTS)
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benchmark::DoNotOptimize(LIBC_NAMESPACE::math::rsqrtf16(get_input(bits)));
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}
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state.SetItemsProcessed(state.iterations() * INPUT_COUNT);
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}
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void BM_Rsqrtf16IntegerFallbackFiniteWrapper(benchmark::State &state) {
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for (auto _ : state) {
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for (uint16_t bits : INPUTS)
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benchmark::DoNotOptimize(rsqrtf16_integer_finite(get_input(bits)));
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}
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state.SetItemsProcessed(state.iterations() * INPUT_COUNT);
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}
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void BM_Rsqrtf16IntegerFallback(benchmark::State &state) {
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for (auto _ : state) {
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for (uint16_t bits : INPUTS)
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benchmark::DoNotOptimize(
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LIBC_NAMESPACE::math::rsqrtf16_internal::rsqrtf16_no_float(bits));
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}
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state.SetItemsProcessed(state.iterations() * INPUT_COUNT);
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}
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} // namespace
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BENCHMARK(BM_Rsqrtf16HostFpu);
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BENCHMARK(BM_Rsqrtf16IntegerFallbackFiniteWrapper);
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BENCHMARK(BM_Rsqrtf16IntegerFallback);
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