diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt index 283c7bd77b4e8..c439efcd3211f 100644 --- a/libc/config/linux/aarch64/entrypoints.txt +++ b/libc/config/linux/aarch64/entrypoints.txt @@ -671,6 +671,7 @@ if(LIBC_TYPES_HAS_FLOAT16) libc.src.math.scalbnf16 libc.src.math.setpayloadf16 libc.src.math.setpayloadsigf16 + libc.src.math.sinpif16 libc.src.math.totalorderf16 libc.src.math.totalordermagf16 libc.src.math.truncf16 diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt index 806ccbcdf820a..d6417bfb6c3ef 100644 --- a/libc/config/linux/x86_64/entrypoints.txt +++ b/libc/config/linux/x86_64/entrypoints.txt @@ -668,6 +668,7 @@ if(LIBC_TYPES_HAS_FLOAT16) libc.src.math.scalbnf16 libc.src.math.setpayloadf16 libc.src.math.setpayloadsigf16 + libc.src.math.sinpif16 libc.src.math.totalorderf16 libc.src.math.totalordermagf16 libc.src.math.truncf16 diff --git a/libc/docs/math/index.rst b/libc/docs/math/index.rst index 0e757e7978bfa..997cce8cef8a2 100644 --- a/libc/docs/math/index.rst +++ b/libc/docs/math/index.rst @@ -342,7 +342,7 @@ Higher Math Functions +-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+ | sinh | |check| | | | | | 7.12.5.5 | F.10.2.5 | +-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+ -| sinpi | |check| | | | | | 7.12.4.13 | F.10.1.13 | +| sinpi | |check| | | | |check| | | 7.12.4.13 | F.10.1.13 | +-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+ | sqrt | |check| | |check| | |check| | | |check| | 7.12.7.10 | F.10.4.10 | +-----------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+ diff --git a/libc/newhdrgen/yaml/math.yaml b/libc/newhdrgen/yaml/math.yaml index 04b6a073deace..2c6656c2a7756 100644 --- a/libc/newhdrgen/yaml/math.yaml +++ b/libc/newhdrgen/yaml/math.yaml @@ -2290,6 +2290,13 @@ functions: return_type: float arguments: - type: float + - name: sinpif16 + standards: + - stdc + return_type: _Float16 + arguments: + - type: _Float16 + guard: LIBC_TYPES_HAS_FLOAT16 - name: sqrt standards: - stdc diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt index 97e2d0d64a147..ad3f916130e86 100644 --- a/libc/src/math/CMakeLists.txt +++ b/libc/src/math/CMakeLists.txt @@ -474,6 +474,7 @@ add_math_entrypoint_object(sincosf) add_math_entrypoint_object(sin) add_math_entrypoint_object(sinf) add_math_entrypoint_object(sinpif) +add_math_entrypoint_object(sinpif16) add_math_entrypoint_object(sinh) add_math_entrypoint_object(sinhf) diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt index 93e632c38af23..4915b23bb383e 100644 --- a/libc/src/math/generic/CMakeLists.txt +++ b/libc/src/math/generic/CMakeLists.txt @@ -528,6 +528,25 @@ add_entrypoint_object( -O3 ) +add_entrypoint_object( + sinpif16 + SRCS + sinpif16.cpp + HDRS + ../sinpif16.h + DEPENDS + libc.src.__support.common + libc.src.__support.FPUtil.cast + libc.src.__support.FPUtil.fenv_impl + libc.src.__support.FPUtil.fp_bits + libc.src.__support.FPUtil.multiply_add + libc.src.__support.FPUtil.nearest_integer + libc.src.__support.FPUtil.polyeval + libc.src.__support.macros.properties.types + COMPILE_OPTIONS + -O3 +) + add_entrypoint_object( tan SRCS diff --git a/libc/src/math/generic/sinpif16.cpp b/libc/src/math/generic/sinpif16.cpp new file mode 100644 index 0000000000000..17cca583e0c0e --- /dev/null +++ b/libc/src/math/generic/sinpif16.cpp @@ -0,0 +1,136 @@ +//===-- Half-precision sinpif function ------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "src/math/sinpif16.h" +#include "src/__support/FPUtil/FEnvImpl.h" +#include "src/__support/FPUtil/FPBits.h" +#include "src/__support/FPUtil/PolyEval.h" +#include "src/__support/FPUtil/cast.h" +#include "src/__support/FPUtil/multiply_add.h" +#include "src/__support/FPUtil/nearest_integer.h" +#include "src/__support/common.h" +#include "src/__support/macros/config.h" + +namespace LIBC_NAMESPACE_DECL { + +// Lookup table for sin(k * pi / 32) with k = 0, ..., 63. +// Table is generated with Sollya as follows: +// > display = hexadecimmal; +// > for k from 0 to 63 do { round(sin(k * pi/32), SG, RN); }; +static constexpr float SIN_K_PI_OVER_32[64] = { + 0x0.0p0, 0x1.917a6cp-4, 0x1.8f8b84p-3, 0x1.294062p-2, + 0x1.87de2ap-2, 0x1.e2b5d4p-2, 0x1.1c73b4p-1, 0x1.44cf32p-1, + 0x1.6a09e6p-1, 0x1.8bc806p-1, 0x1.a9b662p-1, 0x1.c38b3p-1, + 0x1.d906bcp-1, 0x1.e9f416p-1, 0x1.f6297cp-1, 0x1.fd88dap-1, + 0x1p0, 0x1.fd88dap-1, 0x1.f6297cp-1, 0x1.e9f416p-1, + 0x1.d906bcp-1, 0x1.c38b3p-1, 0x1.a9b662p-1, 0x1.8bc806p-1, + 0x1.6a09e6p-1, 0x1.44cf32p-1, 0x1.1c73b4p-1, 0x1.e2b5d4p-2, + 0x1.87de2ap-2, 0x1.294062p-2, 0x1.8f8b84p-3, 0x1.917a6cp-4, + 0x0.0p0, -0x1.917a6cp-4, -0x1.8f8b84p-3, -0x1.294062p-2, + -0x1.87de2ap-2, -0x1.e2b5d4p-2, -0x1.1c73b4p-1, -0x1.44cf32p-1, + -0x1.6a09e6p-1, -0x1.8bc806p-1, -0x1.a9b662p-1, -0x1.c38b3p-1, + -0x1.d906bcp-1, -0x1.e9f416p-1, -0x1.f6297ep-1, -0x1.fd88dap-1, + -0x1p0, -0x1.fd88dap-1, -0x1.f6297cp-1, -0x1.e9f416p-1, + -0x1.d906bcp-1, -0x1.c38b3p-1, -0x1.a9b662p-1, -0x1.8bc806p-1, + -0x1.6a09e6p-1, -0x1.44cf32p-1, -0x1.1c73b4p-1, -0x1.e2b5d4p-2, + -0x1.87de2ap-2, -0x1.294062p-2, -0x1.8f8b84p-3, -0x1.917a6cp-4}; + +static LIBC_INLINE int32_t range_reduction(float x, float &y) { + float kf = fputil::nearest_integer(x * 32); + y = fputil::multiply_add(x, 32.0, -kf); + + return static_cast(kf); +} + +LLVM_LIBC_FUNCTION(float16, sinpif16, (float16 x)) { + using FPBits = typename fputil::FPBits; + FPBits xbits(x); + + uint16_t x_u = xbits.uintval(); + uint16_t x_abs = x_u & 0x7fff; + + // Range reduction: + // For |x| > 1/32, we perform range reduction as follows: + // Find k and y such that: + // x = (k + y) * 1/32 + // k is an integer + // |y| < 0.5 + // + // This is done by performing: + // k = round(x * 32) + // y = x * 32 - k + // + // Once k and y are computed, we then deduce the answer by the sine of sum + // formula: + // sin(x * pi) = sin((k + y) * pi/32) + // = sin(k * pi/32) * cos(y * pi/32) + sin (y * pi/32) * cos (k * + // pi/32) + // The values of sin(k * pi/32) and cos (k * pi/32) for k = 0...63 are + // precomputed and stored using a vector of 64 single precision floats. sin(y + // * pi/32) and cos(y * pi/32) are computed using degree-9 chebyshev + // polynomials generated by Sollya. + + // For signed zeros + if (LIBC_UNLIKELY(x_abs == 0U)) + return x; + + // Numbers greater or equal to 2^10 are integers, or infinity, or NaN + if (LIBC_UNLIKELY(x_abs >= 0x6400)) { + // Check for NaN or infinity values + if (LIBC_UNLIKELY(x_abs >= 0x7c00)) { + // If value is equal to infinity + if (x_abs == 0x7c00) { + fputil::set_errno_if_required(EDOM); + fputil::raise_except_if_required(FE_INVALID); + } + + return x + FPBits::quiet_nan().get_val(); + } + return FPBits::zero(xbits.sign()).get_val(); + } + + float f32 = x; + float y; + int32_t k = range_reduction(f32, y); + + float sin_k = SIN_K_PI_OVER_32[k & 63]; + float cos_k = SIN_K_PI_OVER_32[(k + 16) & 63]; + + // Recall; + // sin(x * pi/32) = sin((k + y) * pi/32) + // = sin(y * pi/32) * cos(k * pi/32) + cos(y * pi/32) * sin(k * + // pi/32) Recall, after range reduction, -0.5 <= y <= 0.5. For very small + // values of y, calculating sin(y * p/32) can be inaccurate. Generating a + // polynomial for sin(y * p/32)/y instead significantly reduces the relative + // errors. + float ysq = y * y; + + // Degree-6 minimax even polynomial for sin(y*pi/32)/y generated by Sollya + // with: > Q = fpminimax(sin(y*pi/32)/y, [|0, 2, 4, 6|], [|SG...|], [0, 0.5]); + float sin_y = y * fputil::polyeval(ysq, 0x1.921fb6p-4f, -0x1.4aeabcp-13f, + 0x1.a03354p-21f, -0x1.ad02d2p-20f); + + // Note that cosm1_y = cos(y*pi/32) - 1 = cos_y - 1 + // Derivation: + // sin(x * pi) = sin((k + y) * pi/32) + // = sin_y * cos_k + cos_y * sin_k + // = cos_k * sin_y + sin_k * (1 + cos_y - 1) + // Degree-6 minimax even polynomial for cos(y*pi/32) generated by Sollya with: + // > P = fpminimax(cos(y*pi/32), [|0, 2, 4, 6|],[|1, SG...|], [0, 0.5]); + float cosm1_y = ysq * fputil::polyeval(ysq, -0x1.3bd3ccp-8f, 0x1.03a61ap-18f, + 0x1.a6f7a2p-29f); + + if (LIBC_UNLIKELY(sin_y == 0 && sin_k == 0)) + return FPBits::zero(xbits.sign()).get_val(); + + // Since, cosm1_y = cos_y - 1, therefore: + // sin(x * pi) = cos_k * sin_y + sin_k + (cosm1_y * sin_k) + return fputil::cast(fputil::multiply_add( + sin_y, cos_k, fputil::multiply_add(cosm1_y, sin_k, sin_k))); +} +} // namespace LIBC_NAMESPACE_DECL diff --git a/libc/src/math/sinpif16.h b/libc/src/math/sinpif16.h new file mode 100644 index 0000000000000..33a0ae2658401 --- /dev/null +++ b/libc/src/math/sinpif16.h @@ -0,0 +1,21 @@ +//===-- Implementation header for sinpif16 ---------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache Licese v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===---------------------------------------------------------------------===// + +#ifndef LLVM_LIBC_SRC_MATH_SINPIF16_H +#define LLVM_LIBC_SRC_MATH_SINPIF16_H + +#include "src/__support/macros/config.h" +#include "src/__support/macros/properties/types.h" + +namespace LIBC_NAMESPACE_DECL { + +float16 sinpif16(float16 x); + +} // namespace LIBC_NAMESPACE_DECL + +#endif // LLVM_LIBC_SRC_MATH_SINPIF16_H diff --git a/libc/test/src/math/CMakeLists.txt b/libc/test/src/math/CMakeLists.txt index 0c4118c369454..8464c909721ec 100644 --- a/libc/test/src/math/CMakeLists.txt +++ b/libc/test/src/math/CMakeLists.txt @@ -90,6 +90,17 @@ add_fp_unittest( libc.src.__support.FPUtil.fp_bits ) +add_fp_unittest( + sinpif16_test + NEED_MPFR + SUITE + libc-math-unittests + SRCS + sinpif16_test.cpp + DEPENDS + libc.src.math.sinpif16 +) + add_fp_unittest( sin_test NEED_MPFR diff --git a/libc/test/src/math/sinpif16_test.cpp b/libc/test/src/math/sinpif16_test.cpp new file mode 100644 index 0000000000000..8477124b2e6e3 --- /dev/null +++ b/libc/test/src/math/sinpif16_test.cpp @@ -0,0 +1,40 @@ +//===-- Exhaustive test for sinpif16 --------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===---------------------------------------------------------------------===// + +#include "src/math/sinpif16.h" +#include "test/UnitTest/FPMatcher.h" +#include "test/UnitTest/Test.h" +#include "utils/MPFRWrapper/MPFRUtils.h" + +using LlvmLibcSinpif16Test = LIBC_NAMESPACE::testing::FPTest; + +namespace mpfr = LIBC_NAMESPACE::testing::mpfr; + +// Range: [0, Inf] +static constexpr uint16_t POS_START = 0x0000U; +static constexpr uint16_t POS_STOP = 0x7c00U; + +// Range: [-Inf, 0] +static constexpr uint16_t NEG_START = 0x8000U; +static constexpr uint16_t NEG_STOP = 0xfc00U; + +TEST_F(LlvmLibcSinpif16Test, PositiveRange) { + for (uint16_t v = POS_START; v <= POS_STOP; ++v) { + float16 x = FPBits(v).get_val(); + EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Sinpi, x, + LIBC_NAMESPACE::sinpif16(x), 0.5); + } +} + +TEST_F(LlvmLibcSinpif16Test, NegativeRange) { + for (uint16_t v = NEG_START; v <= NEG_STOP; ++v) { + float16 x = FPBits(v).get_val(); + EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Sinpi, x, + LIBC_NAMESPACE::sinpif16(x), 0.5); + } +} diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt index a70b65f23f4b7..67466c896f30c 100644 --- a/libc/test/src/math/smoke/CMakeLists.txt +++ b/libc/test/src/math/smoke/CMakeLists.txt @@ -51,6 +51,17 @@ add_fp_unittest( libc.src.__support.FPUtil.fp_bits ) +add_fp_unittest( + sinpif16_test + SUITE + libc-math-smoke-tests + SRCS + sinpif16_test.cpp + DEPENDS + libc.src.errno.errno + libc.src.math.sinpif16 +) + add_fp_unittest( sincosf_test SUITE diff --git a/libc/test/src/math/smoke/sinpif16_test.cpp b/libc/test/src/math/smoke/sinpif16_test.cpp new file mode 100644 index 0000000000000..0bcd38a60d849 --- /dev/null +++ b/libc/test/src/math/smoke/sinpif16_test.cpp @@ -0,0 +1,42 @@ +//===-- Unittests for sinpif16 --------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "src/errno/libc_errno.h" +#include "src/math/sinpif16.h" +#include "test/UnitTest/FPMatcher.h" +#include "test/UnitTest/Test.h" + +using LlvmLibcSinpif16Test = LIBC_NAMESPACE::testing::FPTest; + +TEST_F(LlvmLibcSinpif16Test, SpecialNumbers) { + LIBC_NAMESPACE::libc_errno = 0; + + EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::sinpif16(aNaN)); + EXPECT_MATH_ERRNO(0); + + EXPECT_FP_EQ(zero, LIBC_NAMESPACE::sinpif16(zero)); + EXPECT_MATH_ERRNO(0); + + EXPECT_FP_EQ(neg_zero, LIBC_NAMESPACE::sinpif16(neg_zero)); + EXPECT_MATH_ERRNO(0); + + EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::sinpif16(inf)); + EXPECT_MATH_ERRNO(EDOM); + + EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::sinpif16(neg_inf)); + EXPECT_MATH_ERRNO(EDOM); +} + +TEST_F(LlvmLibcSinpif16Test, Integers) { + EXPECT_FP_EQ(neg_zero, LIBC_NAMESPACE::sinpif16(-0x420)); + EXPECT_FP_EQ(neg_zero, LIBC_NAMESPACE::sinpif16(-0x1p+10)); + EXPECT_FP_EQ(neg_zero, LIBC_NAMESPACE::sinpif16(-0x1.4p+14)); + EXPECT_FP_EQ(zero, LIBC_NAMESPACE::sinpif16(0x420)); + EXPECT_FP_EQ(zero, LIBC_NAMESPACE::sinpif16(0x1.cp+15)); + EXPECT_FP_EQ(zero, LIBC_NAMESPACE::sinpif16(0x1.cp+7)); +} diff --git a/libc/utils/MPFRWrapper/MPFRUtils.cpp b/libc/utils/MPFRWrapper/MPFRUtils.cpp index 27ff1f7190ef9..eecffc782c1a7 100644 --- a/libc/utils/MPFRWrapper/MPFRUtils.cpp +++ b/libc/utils/MPFRWrapper/MPFRUtils.cpp @@ -488,14 +488,28 @@ class MPFRNumber { (MPFR_VERSION_MAJOR == 4 && MPFR_VERSION_MINOR >= 2) mpfr_sinpi(result.value, value, mpfr_rounding); + return result; #else + if (mpfr_integer_p(value)) { + mpfr_set_si(result.value, 0, mpfr_rounding); + return result; + } + + MPFRNumber value_mul_two(*this); + mpfr_mul_si(value_mul_two.value, value, 2, MPFR_RNDN); + + if (mpfr_integer_p(value_mul_two.value)) { + auto d = mpfr_get_si(value, MPFR_RNDD); + mpfr_set_si(result.value, (d & 1) ? -1 : 1, mpfr_rounding); + return result; + } + MPFRNumber value_pi(0.0, 1280); mpfr_const_pi(value_pi.value, MPFR_RNDN); mpfr_mul(value_pi.value, value_pi.value, value, MPFR_RNDN); mpfr_sin(result.value, value_pi.value, mpfr_rounding); -#endif - return result; +#endif } MPFRNumber sinh() const {