forked from OSchip/llvm-project
[libc] Implement correctly rounded log2f based on RLIBM library.
Implement log2f based on RLIBM library correctly rounded for all rounding modes. Reviewed By: sivachandra, michaelrj, santoshn, jpl169, zimmermann6 Differential Revision: https://reviews.llvm.org/D115828
This commit is contained in:
Tue Ly
parent
2a11fbb827
commit
63d2df003e
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@ -145,6 +145,7 @@ set(TARGET_LIBM_ENTRYPOINTS
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libc.src.math.ldexp
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libc.src.math.ldexpf
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libc.src.math.ldexpl
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libc.src.math.log2f
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libc.src.math.logf
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libc.src.math.logb
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libc.src.math.logbf
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@ -144,6 +144,7 @@ set(TARGET_LIBM_ENTRYPOINTS
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libc.src.math.llround
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libc.src.math.llroundf
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libc.src.math.llroundl
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libc.src.math.log2f
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libc.src.math.logf
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libc.src.math.logb
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libc.src.math.logbf
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@ -118,6 +118,7 @@ set(TARGET_LIBM_ENTRYPOINTS
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libc.src.math.llround
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libc.src.math.llroundf
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libc.src.math.llroundl
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libc.src.math.log2f
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libc.src.math.logf
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libc.src.math.logb
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libc.src.math.logbf
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@ -396,6 +396,8 @@ def StdC : StandardSpec<"stdc"> {
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FunctionSpec<"ldexpf", RetValSpec<FloatType>, [ArgSpec<FloatType>, ArgSpec<IntType>]>,
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FunctionSpec<"ldexpl", RetValSpec<LongDoubleType>, [ArgSpec<LongDoubleType>, ArgSpec<IntType>]>,
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FunctionSpec<"log2f", RetValSpec<FloatType>, [ArgSpec<FloatType>]>,
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FunctionSpec<"logf", RetValSpec<FloatType>, [ArgSpec<FloatType>]>,
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FunctionSpec<"logb", RetValSpec<DoubleType>, [ArgSpec<DoubleType>]>,
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@ -37,7 +37,9 @@ INLINE_FMA static inline T polyeval(T x, T a0, Ts... a) {
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#ifdef LLVM_LIBC_ARCH_X86_64
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#include "x86_64/PolyEval.h"
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// [DISABLED] There is a regression with using vectorized version for polyeval
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// compared to the naive Horner's scheme with fma. Need further investigation
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// #include "x86_64/PolyEval.h"
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#endif // LLVM_LIBC_ARCH_X86_64
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@ -116,6 +116,8 @@ add_math_entrypoint_object(ldexp)
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add_math_entrypoint_object(ldexpf)
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add_math_entrypoint_object(ldexpl)
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add_math_entrypoint_object(log2f)
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add_math_entrypoint_object(logf)
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add_math_entrypoint_object(logb)
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@ -645,6 +645,30 @@ add_entrypoint_object(
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-O2
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)
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add_object_library(
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common_constants
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HDRS
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common_constants.h
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SRCS
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common_constants.cpp
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COMPILE_OPTIONS
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-Wno-c++17-extensions
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)
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add_entrypoint_object(
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log2f
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SRCS
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log2f.cpp
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HDRS
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../log2f.h
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DEPENDS
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.common_constants
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libc.src.__support.FPUtil.fputil
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COMPILE_OPTIONS
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-O3
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-Wno-c++17-extensions
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)
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add_entrypoint_object(
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logf
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SRCS
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@ -652,6 +676,7 @@ add_entrypoint_object(
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HDRS
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../logf.h
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DEPENDS
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.common_constants
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libc.src.__support.FPUtil.fputil
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COMPILE_OPTIONS
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-O3
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@ -0,0 +1,59 @@
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//===-- Common constants for math functions ---------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "common_constants.h"
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namespace __llvm_libc {
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// Lookup table for (1/f) where f = 1 + n*2^(-7), n = 0..127.
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const double ONE_OVER_F[128] = {
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0x1.0000000000000p+0, 0x1.fc07f01fc07f0p-1, 0x1.f81f81f81f820p-1,
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0x1.f44659e4a4271p-1, 0x1.f07c1f07c1f08p-1, 0x1.ecc07b301ecc0p-1,
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0x1.e9131abf0b767p-1, 0x1.e573ac901e574p-1, 0x1.e1e1e1e1e1e1ep-1,
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0x1.de5d6e3f8868ap-1, 0x1.dae6076b981dbp-1, 0x1.d77b654b82c34p-1,
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0x1.d41d41d41d41dp-1, 0x1.d0cb58f6ec074p-1, 0x1.cd85689039b0bp-1,
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0x1.ca4b3055ee191p-1, 0x1.c71c71c71c71cp-1, 0x1.c3f8f01c3f8f0p-1,
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0x1.c0e070381c0e0p-1, 0x1.bdd2b899406f7p-1, 0x1.bacf914c1bad0p-1,
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0x1.b7d6c3dda338bp-1, 0x1.b4e81b4e81b4fp-1, 0x1.b2036406c80d9p-1,
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0x1.af286bca1af28p-1, 0x1.ac5701ac5701bp-1, 0x1.a98ef606a63bep-1,
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0x1.a6d01a6d01a6dp-1, 0x1.a41a41a41a41ap-1, 0x1.a16d3f97a4b02p-1,
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0x1.9ec8e951033d9p-1, 0x1.9c2d14ee4a102p-1, 0x1.999999999999ap-1,
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0x1.970e4f80cb872p-1, 0x1.948b0fcd6e9e0p-1, 0x1.920fb49d0e229p-1,
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0x1.8f9c18f9c18fap-1, 0x1.8d3018d3018d3p-1, 0x1.8acb90f6bf3aap-1,
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0x1.886e5f0abb04ap-1, 0x1.8618618618618p-1, 0x1.83c977ab2beddp-1,
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0x1.8181818181818p-1, 0x1.7f405fd017f40p-1, 0x1.7d05f417d05f4p-1,
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0x1.7ad2208e0ecc3p-1, 0x1.78a4c8178a4c8p-1, 0x1.767dce434a9b1p-1,
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0x1.745d1745d1746p-1, 0x1.724287f46debcp-1, 0x1.702e05c0b8170p-1,
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0x1.6e1f76b4337c7p-1, 0x1.6c16c16c16c17p-1, 0x1.6a13cd1537290p-1,
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0x1.6816816816817p-1, 0x1.661ec6a5122f9p-1, 0x1.642c8590b2164p-1,
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0x1.623fa77016240p-1, 0x1.6058160581606p-1, 0x1.5e75bb8d015e7p-1,
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0x1.5c9882b931057p-1, 0x1.5ac056b015ac0p-1, 0x1.58ed2308158edp-1,
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0x1.571ed3c506b3ap-1, 0x1.5555555555555p-1, 0x1.5390948f40febp-1,
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0x1.51d07eae2f815p-1, 0x1.5015015015015p-1, 0x1.4e5e0a72f0539p-1,
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0x1.4cab88725af6ep-1, 0x1.4afd6a052bf5bp-1, 0x1.49539e3b2d067p-1,
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0x1.47ae147ae147bp-1, 0x1.460cbc7f5cf9ap-1, 0x1.446f86562d9fbp-1,
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0x1.42d6625d51f87p-1, 0x1.4141414141414p-1, 0x1.3fb013fb013fbp-1,
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0x1.3e22cbce4a902p-1, 0x1.3c995a47babe7p-1, 0x1.3b13b13b13b14p-1,
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0x1.3991c2c187f63p-1, 0x1.3813813813814p-1, 0x1.3698df3de0748p-1,
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0x1.3521cfb2b78c1p-1, 0x1.33ae45b57bcb2p-1, 0x1.323e34a2b10bfp-1,
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0x1.30d190130d190p-1, 0x1.2f684bda12f68p-1, 0x1.2e025c04b8097p-1,
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0x1.2c9fb4d812ca0p-1, 0x1.2b404ad012b40p-1, 0x1.29e4129e4129ep-1,
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0x1.288b01288b013p-1, 0x1.27350b8812735p-1, 0x1.25e22708092f1p-1,
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0x1.2492492492492p-1, 0x1.23456789abcdfp-1, 0x1.21fb78121fb78p-1,
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0x1.20b470c67c0d9p-1, 0x1.1f7047dc11f70p-1, 0x1.1e2ef3b3fb874p-1,
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0x1.1cf06ada2811dp-1, 0x1.1bb4a4046ed29p-1, 0x1.1a7b9611a7b96p-1,
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0x1.19453808ca29cp-1, 0x1.1811811811812p-1, 0x1.16e0689427379p-1,
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0x1.15b1e5f75270dp-1, 0x1.1485f0e0acd3bp-1, 0x1.135c81135c811p-1,
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0x1.12358e75d3033p-1, 0x1.1111111111111p-1, 0x1.0fef010fef011p-1,
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0x1.0ecf56be69c90p-1, 0x1.0db20a88f4696p-1, 0x1.0c9714fbcda3bp-1,
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0x1.0b7e6ec259dc8p-1, 0x1.0a6810a6810a7p-1, 0x1.0953f39010954p-1,
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0x1.0842108421084p-1, 0x1.073260a47f7c6p-1, 0x1.0624dd2f1a9fcp-1,
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0x1.05197f7d73404p-1, 0x1.0410410410410p-1, 0x1.03091b51f5e1ap-1,
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0x1.0204081020408p-1, 0x1.0101010101010p-1};
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} // namespace __llvm_libc
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@ -0,0 +1,19 @@
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//===-- Common constants for math functions ---------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_MATH_GENERIC_COMMON_CONSTANTS_H
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#define LLVM_LIBC_SRC_MATH_GENERIC_COMMON_CONSTANTS_H
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namespace __llvm_libc {
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// Lookup table for (1/f) where f = 1 + n*2^(-7), n = 0..127.
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extern const double ONE_OVER_F[128];
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} // namespace __llvm_libc
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#endif // LLVM_LIBC_SRC_MATH_GENERIC_COMMON_CONSTANTS_H
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@ -0,0 +1,154 @@
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//===-- Single-precision log2(x) function ---------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/math/log2f.h"
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#include "common_constants.h" // Lookup table for (1/f)
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#include "src/__support/FPUtil/BasicOperations.h"
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#include "src/__support/FPUtil/FEnvUtils.h"
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#include "src/__support/FPUtil/FMA.h"
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#include "src/__support/FPUtil/FPBits.h"
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#include "src/__support/FPUtil/PolyEval.h"
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#include "src/__support/common.h"
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// This is a correctly-rounded algorithm for log2(x) in single precision with
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// round-to-nearest, tie-to-even mode from the RLIBM project at:
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// https://people.cs.rutgers.edu/~sn349/rlibm
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// Step 1 - Range reduction:
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// For x = 2^m * 1.mant, log2(x) = m + log2(1.m)
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// If x is denormal, we normalize it by multiplying x by 2^23 and subtracting
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// m by 23.
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// Step 2 - Another range reduction:
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// To compute log(1.mant), let f be the highest 8 bits including the hidden
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// bit, and d be the difference (1.mant - f), i.e. the remaining 16 bits of the
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// mantissa. Then we have the following approximation formula:
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// log2(1.mant) = log2(f) + log2(1.mant / f)
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// = log2(f) + log2(1 + d/f)
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// ~ log2(f) + P(d/f)
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// since d/f is sufficiently small.
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// log2(f) and 1/f are then stored in two 2^7 = 128 entries look-up tables.
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// Step 3 - Polynomial approximation:
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// To compute P(d/f), we use a single degree-5 polynomial in double precision
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// which provides correct rounding for all but few exception values.
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// For more detail about how this polynomial is obtained, please refer to the
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// papers:
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// Lim, J. and Nagarakatte, S., "One Polynomial Approximation to Produce
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// Correctly Rounded Results of an Elementary Function for Multiple
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// Representations and Rounding Modes", Proceedings of the 49th ACM SIGPLAN
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// Symposium on Principles of Programming Languages (POPL-2022), Philadelphia,
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// USA, Jan. 16-22, 2022.
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// https://people.cs.rutgers.edu/~sn349/papers/rlibmall-popl-2022.pdf
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// Aanjaneya, M., Lim, J., and Nagarakatte, S., "RLibm-Prog: Progressive
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// Polynomial Approximations for Fast Correctly Rounded Math Libraries",
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// Dept. of Comp. Sci., Rutgets U., Technical Report DCS-TR-758, Nov. 2021.
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// https://arxiv.org/pdf/2111.12852.pdf.
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namespace __llvm_libc {
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// Lookup table for log2(f) = log2(1 + n*2^(-7)) where n = 0..127.
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static constexpr double LOG2_F[128] = {
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0x0.0000000000000p+0, 0x1.6fe50b6ef0851p-7, 0x1.6e79685c2d22ap-6,
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0x1.11cd1d5133413p-5, 0x1.6bad3758efd87p-5, 0x1.c4dfab90aab5fp-5,
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0x1.0eb389fa29f9bp-4, 0x1.3aa2fdd27f1c3p-4, 0x1.663f6fac91316p-4,
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0x1.918a16e46335bp-4, 0x1.bc84240adabbap-4, 0x1.e72ec117fa5b2p-4,
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0x1.08c588cda79e4p-3, 0x1.1dcd197552b7bp-3, 0x1.32ae9e278ae1ap-3,
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0x1.476a9f983f74dp-3, 0x1.5c01a39fbd688p-3, 0x1.70742d4ef027fp-3,
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0x1.84c2bd02f03b3p-3, 0x1.98edd077e70dfp-3, 0x1.acf5e2db4ec94p-3,
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0x1.c0db6cdd94deep-3, 0x1.d49ee4c325970p-3, 0x1.e840be74e6a4dp-3,
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0x1.fbc16b902680ap-3, 0x1.0790adbb03009p-2, 0x1.11307dad30b76p-2,
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0x1.1ac05b291f070p-2, 0x1.24407ab0e073ap-2, 0x1.2db10fc4d9aafp-2,
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0x1.37124cea4cdedp-2, 0x1.406463b1b0449p-2, 0x1.49a784bcd1b8bp-2,
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0x1.52dbdfc4c96b3p-2, 0x1.5c01a39fbd688p-2, 0x1.6518fe4677ba7p-2,
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0x1.6e221cd9d0cdep-2, 0x1.771d2ba7efb3cp-2, 0x1.800a563161c54p-2,
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0x1.88e9c72e0b226p-2, 0x1.91bba891f1709p-2, 0x1.9a802391e232fp-2,
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0x1.a33760a7f6051p-2, 0x1.abe18797f1f49p-2, 0x1.b47ebf73882a1p-2,
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||||
0x1.bd0f2e9e79031p-2, 0x1.c592fad295b56p-2, 0x1.ce0a4923a587dp-2,
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0x1.d6753e032ea0fp-2, 0x1.ded3fd442364cp-2, 0x1.e726aa1e754d2p-2,
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0x1.ef6d67328e220p-2, 0x1.f7a8568cb06cfp-2, 0x1.ffd799a83ff9bp-2,
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0x1.03fda8b97997fp-1, 0x1.0809cf27f703dp-1, 0x1.0c10500d63aa6p-1,
|
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0x1.10113b153c8eap-1, 0x1.140c9faa1e544p-1, 0x1.18028cf72976ap-1,
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||||
0x1.1bf311e95d00ep-1, 0x1.1fde3d30e8126p-1, 0x1.23c41d42727c8p-1,
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||||
0x1.27a4c0585cbf8p-1, 0x1.2b803473f7ad1p-1, 0x1.2f56875eb3f26p-1,
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0x1.3327c6ab49ca7p-1, 0x1.36f3ffb6d9162p-1, 0x1.3abb3faa02167p-1,
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0x1.3e7d9379f7016p-1, 0x1.423b07e986aa9p-1, 0x1.45f3a98a20739p-1,
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0x1.49a784bcd1b8bp-1, 0x1.4d56a5b33cec4p-1, 0x1.510118708a8f9p-1,
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0x1.54a6e8ca5438ep-1, 0x1.5848226989d34p-1, 0x1.5be4d0cb51435p-1,
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0x1.5f7cff41e09afp-1, 0x1.6310b8f553048p-1, 0x1.66a008e4788ccp-1,
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0x1.6a2af9e5a0f0ap-1, 0x1.6db196a76194ap-1, 0x1.7133e9b156c7cp-1,
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0x1.74b1fd64e0754p-1, 0x1.782bdbfdda657p-1, 0x1.7ba18f93502e4p-1,
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||||
0x1.7f1322182cf16p-1, 0x1.82809d5be7073p-1, 0x1.85ea0b0b27b26p-1,
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||||
0x1.894f74b06ef8bp-1, 0x1.8cb0e3b4b3bbep-1, 0x1.900e6160002cdp-1,
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0x1.9367f6da0ab2fp-1, 0x1.96bdad2acb5f6p-1, 0x1.9a0f8d3b0e050p-1,
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0x1.9d5d9fd5010b3p-1, 0x1.a0a7eda4c112dp-1, 0x1.a3ee7f38e181fp-1,
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||||
0x1.a7315d02f20c8p-1, 0x1.aa708f58014d3p-1, 0x1.adac1e711c833p-1,
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0x1.b0e4126bcc86cp-1, 0x1.b418734a9008cp-1, 0x1.b74948f5532dap-1,
|
||||
0x1.ba769b39e4964p-1, 0x1.bda071cc67e6ep-1, 0x1.c0c6d447c5dd3p-1,
|
||||
0x1.c3e9ca2e1a055p-1, 0x1.c7095ae91e1c7p-1, 0x1.ca258dca93316p-1,
|
||||
0x1.cd3e6a0ca8907p-1, 0x1.d053f6d260896p-1, 0x1.d3663b27f31d5p-1,
|
||||
0x1.d6753e032ea0fp-1, 0x1.d9810643d6615p-1, 0x1.dc899ab3ff56cp-1,
|
||||
0x1.df8f02086af2cp-1, 0x1.e29142e0e0140p-1, 0x1.e59063c8822cep-1,
|
||||
0x1.e88c6b3626a73p-1, 0x1.eb855f8ca88fbp-1, 0x1.ee7b471b3a950p-1,
|
||||
0x1.f16e281db7630p-1, 0x1.f45e08bcf0655p-1, 0x1.f74aef0efafaep-1,
|
||||
0x1.fa34e1177c233p-1, 0x1.fd1be4c7f2af9p-1};
|
||||
|
||||
INLINE_FMA
|
||||
LLVM_LIBC_FUNCTION(float, log2f, (float x)) {
|
||||
using FPBits = typename fputil::FPBits<float>;
|
||||
FPBits xbits(x);
|
||||
int m = 0;
|
||||
|
||||
// Hard to round value(s).
|
||||
if (FPBits(x).uintval() == 0x3f81d0b5U) {
|
||||
int rounding_mode = fputil::get_round();
|
||||
if (rounding_mode == FE_DOWNWARD || rounding_mode == FE_TOWARDZERO) {
|
||||
return 0x1.4cdc4cp-6f;
|
||||
}
|
||||
}
|
||||
|
||||
// Exceptional inputs.
|
||||
if (xbits.uintval() < FPBits::MIN_NORMAL ||
|
||||
xbits.uintval() > FPBits::MAX_NORMAL) {
|
||||
if (xbits.is_zero()) {
|
||||
return static_cast<float>(FPBits::neg_inf());
|
||||
}
|
||||
if (xbits.get_sign() && !xbits.is_nan()) {
|
||||
return FPBits::build_nan(1 << (fputil::MantissaWidth<float>::VALUE - 1));
|
||||
}
|
||||
if (xbits.is_inf_or_nan()) {
|
||||
return x;
|
||||
}
|
||||
// Normalize denormal inputs.
|
||||
xbits.val *= 0x1.0p23f;
|
||||
m = -23;
|
||||
}
|
||||
|
||||
m += xbits.get_exponent();
|
||||
// Set bits to 1.m
|
||||
xbits.set_unbiased_exponent(0x7F);
|
||||
// Get the 8 highest bits, use 7 bits (excluding the implicit hidden bit) for
|
||||
// lookup tables.
|
||||
int f_index = xbits.get_mantissa() >> 16;
|
||||
|
||||
FPBits f(xbits.val);
|
||||
// Clear the lowest 16 bits.
|
||||
f.bits &= ~0x0000'FFFF;
|
||||
|
||||
double d = static_cast<float>(xbits) - static_cast<float>(f);
|
||||
d *= ONE_OVER_F[f_index];
|
||||
|
||||
double extra_factor = static_cast<double>(m) + LOG2_F[f_index];
|
||||
double r = __llvm_libc::fputil::polyeval(
|
||||
d, extra_factor, 0x1.71547652bd4fp+0, -0x1.7154769b978c7p-1,
|
||||
0x1.ec71a99e349c8p-2, -0x1.720d90e6aac6cp-2, 0x1.5132da3583dap-2);
|
||||
|
||||
return static_cast<float>(r);
|
||||
}
|
||||
|
||||
} // namespace __llvm_libc
|
||||
|
|
@ -7,6 +7,7 @@
|
|||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "src/math/logf.h"
|
||||
#include "common_constants.h" // Lookup table for (1/f)
|
||||
#include "src/__support/FPUtil/BasicOperations.h"
|
||||
#include "src/__support/FPUtil/FMA.h"
|
||||
#include "src/__support/FPUtil/FPBits.h"
|
||||
|
|
@ -95,52 +96,6 @@ static constexpr double LOG_F[128] = {
|
|||
0x1.58cadb5cd7989p-1, 0x1.5ad404c359f2cp-1, 0x1.5cdb1dc6c1764p-1,
|
||||
0x1.5ee02a9241675p-1, 0x1.60e32f44788d8p-1};
|
||||
|
||||
// Lookup table for (1/f) where f = 1 + n*2^(-7), n = 0..127.
|
||||
static constexpr double ONE_OVER_F[128] = {
|
||||
0x1.0000000000000p+0, 0x1.fc07f01fc07f0p-1, 0x1.f81f81f81f820p-1,
|
||||
0x1.f44659e4a4271p-1, 0x1.f07c1f07c1f08p-1, 0x1.ecc07b301ecc0p-1,
|
||||
0x1.e9131abf0b767p-1, 0x1.e573ac901e574p-1, 0x1.e1e1e1e1e1e1ep-1,
|
||||
0x1.de5d6e3f8868ap-1, 0x1.dae6076b981dbp-1, 0x1.d77b654b82c34p-1,
|
||||
0x1.d41d41d41d41dp-1, 0x1.d0cb58f6ec074p-1, 0x1.cd85689039b0bp-1,
|
||||
0x1.ca4b3055ee191p-1, 0x1.c71c71c71c71cp-1, 0x1.c3f8f01c3f8f0p-1,
|
||||
0x1.c0e070381c0e0p-1, 0x1.bdd2b899406f7p-1, 0x1.bacf914c1bad0p-1,
|
||||
0x1.b7d6c3dda338bp-1, 0x1.b4e81b4e81b4fp-1, 0x1.b2036406c80d9p-1,
|
||||
0x1.af286bca1af28p-1, 0x1.ac5701ac5701bp-1, 0x1.a98ef606a63bep-1,
|
||||
0x1.a6d01a6d01a6dp-1, 0x1.a41a41a41a41ap-1, 0x1.a16d3f97a4b02p-1,
|
||||
0x1.9ec8e951033d9p-1, 0x1.9c2d14ee4a102p-1, 0x1.999999999999ap-1,
|
||||
0x1.970e4f80cb872p-1, 0x1.948b0fcd6e9e0p-1, 0x1.920fb49d0e229p-1,
|
||||
0x1.8f9c18f9c18fap-1, 0x1.8d3018d3018d3p-1, 0x1.8acb90f6bf3aap-1,
|
||||
0x1.886e5f0abb04ap-1, 0x1.8618618618618p-1, 0x1.83c977ab2beddp-1,
|
||||
0x1.8181818181818p-1, 0x1.7f405fd017f40p-1, 0x1.7d05f417d05f4p-1,
|
||||
0x1.7ad2208e0ecc3p-1, 0x1.78a4c8178a4c8p-1, 0x1.767dce434a9b1p-1,
|
||||
0x1.745d1745d1746p-1, 0x1.724287f46debcp-1, 0x1.702e05c0b8170p-1,
|
||||
0x1.6e1f76b4337c7p-1, 0x1.6c16c16c16c17p-1, 0x1.6a13cd1537290p-1,
|
||||
0x1.6816816816817p-1, 0x1.661ec6a5122f9p-1, 0x1.642c8590b2164p-1,
|
||||
0x1.623fa77016240p-1, 0x1.6058160581606p-1, 0x1.5e75bb8d015e7p-1,
|
||||
0x1.5c9882b931057p-1, 0x1.5ac056b015ac0p-1, 0x1.58ed2308158edp-1,
|
||||
0x1.571ed3c506b3ap-1, 0x1.5555555555555p-1, 0x1.5390948f40febp-1,
|
||||
0x1.51d07eae2f815p-1, 0x1.5015015015015p-1, 0x1.4e5e0a72f0539p-1,
|
||||
0x1.4cab88725af6ep-1, 0x1.4afd6a052bf5bp-1, 0x1.49539e3b2d067p-1,
|
||||
0x1.47ae147ae147bp-1, 0x1.460cbc7f5cf9ap-1, 0x1.446f86562d9fbp-1,
|
||||
0x1.42d6625d51f87p-1, 0x1.4141414141414p-1, 0x1.3fb013fb013fbp-1,
|
||||
0x1.3e22cbce4a902p-1, 0x1.3c995a47babe7p-1, 0x1.3b13b13b13b14p-1,
|
||||
0x1.3991c2c187f63p-1, 0x1.3813813813814p-1, 0x1.3698df3de0748p-1,
|
||||
0x1.3521cfb2b78c1p-1, 0x1.33ae45b57bcb2p-1, 0x1.323e34a2b10bfp-1,
|
||||
0x1.30d190130d190p-1, 0x1.2f684bda12f68p-1, 0x1.2e025c04b8097p-1,
|
||||
0x1.2c9fb4d812ca0p-1, 0x1.2b404ad012b40p-1, 0x1.29e4129e4129ep-1,
|
||||
0x1.288b01288b013p-1, 0x1.27350b8812735p-1, 0x1.25e22708092f1p-1,
|
||||
0x1.2492492492492p-1, 0x1.23456789abcdfp-1, 0x1.21fb78121fb78p-1,
|
||||
0x1.20b470c67c0d9p-1, 0x1.1f7047dc11f70p-1, 0x1.1e2ef3b3fb874p-1,
|
||||
0x1.1cf06ada2811dp-1, 0x1.1bb4a4046ed29p-1, 0x1.1a7b9611a7b96p-1,
|
||||
0x1.19453808ca29cp-1, 0x1.1811811811812p-1, 0x1.16e0689427379p-1,
|
||||
0x1.15b1e5f75270dp-1, 0x1.1485f0e0acd3bp-1, 0x1.135c81135c811p-1,
|
||||
0x1.12358e75d3033p-1, 0x1.1111111111111p-1, 0x1.0fef010fef011p-1,
|
||||
0x1.0ecf56be69c90p-1, 0x1.0db20a88f4696p-1, 0x1.0c9714fbcda3bp-1,
|
||||
0x1.0b7e6ec259dc8p-1, 0x1.0a6810a6810a7p-1, 0x1.0953f39010954p-1,
|
||||
0x1.0842108421084p-1, 0x1.073260a47f7c6p-1, 0x1.0624dd2f1a9fcp-1,
|
||||
0x1.05197f7d73404p-1, 0x1.0410410410410p-1, 0x1.03091b51f5e1ap-1,
|
||||
0x1.0204081020408p-1, 0x1.0101010101010p-1};
|
||||
|
||||
INLINE_FMA
|
||||
LLVM_LIBC_FUNCTION(float, logf, (float x)) {
|
||||
constexpr double LOG_2 = 0x1.62e42fefa39efp-1;
|
||||
|
|
|
|||
|
|
@ -0,0 +1,18 @@
|
|||
//===-- Implementation header for log2f -------------------------*- C++ -*-===//
|
||||
//
|
||||
// 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
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#ifndef LLVM_LIBC_SRC_MATH_LOG2F_H
|
||||
#define LLVM_LIBC_SRC_MATH_LOG2F_H
|
||||
|
||||
namespace __llvm_libc {
|
||||
|
||||
float log2f(float x);
|
||||
|
||||
} // namespace __llvm_libc
|
||||
|
||||
#endif // LLVM_LIBC_SRC_MATH_LOG2F_H
|
||||
|
|
@ -1194,6 +1194,19 @@ add_fp_unittest(
|
|||
libc.src.__support.FPUtil.fputil
|
||||
)
|
||||
|
||||
add_fp_unittest(
|
||||
log2f_test
|
||||
NEED_MPFR
|
||||
SUITE
|
||||
libc_math_unittests
|
||||
SRCS
|
||||
log2f_test.cpp
|
||||
DEPENDS
|
||||
libc.include.math
|
||||
libc.src.math.log2f
|
||||
libc.src.__support.FPUtil.fputil
|
||||
)
|
||||
|
||||
add_subdirectory(generic)
|
||||
add_subdirectory(exhaustive)
|
||||
add_subdirectory(differential_testing)
|
||||
|
|
|
|||
|
|
@ -233,6 +233,28 @@ add_diff_binary(
|
|||
-fno-builtin
|
||||
)
|
||||
|
||||
add_diff_binary(
|
||||
log2f_diff
|
||||
SRCS
|
||||
log2f_diff.cpp
|
||||
DEPENDS
|
||||
.single_input_single_output_diff
|
||||
libc.src.math.log2f
|
||||
COMPILE_OPTIONS
|
||||
-fno-builtin
|
||||
)
|
||||
|
||||
add_diff_binary(
|
||||
log2f_perf
|
||||
SRCS
|
||||
log2f_perf.cpp
|
||||
DEPENDS
|
||||
.single_input_single_output_diff
|
||||
libc.src.math.log2f
|
||||
COMPILE_OPTIONS
|
||||
-fno-builtin
|
||||
)
|
||||
|
||||
add_diff_binary(
|
||||
logf_diff
|
||||
SRCS
|
||||
|
|
|
|||
|
|
@ -0,0 +1,16 @@
|
|||
//===-- Differential test for log2f ---------------------------------------===//
|
||||
//
|
||||
// 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 "SingleInputSingleOutputDiff.h"
|
||||
|
||||
#include "src/math/log2f.h"
|
||||
|
||||
#include <math.h>
|
||||
|
||||
SINGLE_INPUT_SINGLE_OUTPUT_DIFF(float, __llvm_libc::log2f, ::log2f,
|
||||
"log2f_diff.log")
|
||||
|
|
@ -0,0 +1,16 @@
|
|||
//===-- Differential test for log2f ---------------------------------------===//
|
||||
//
|
||||
// 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 "SingleInputSingleOutputDiff.h"
|
||||
|
||||
#include "src/math/log2f.h"
|
||||
|
||||
#include <math.h>
|
||||
|
||||
SINGLE_INPUT_SINGLE_OUTPUT_PERF(float, __llvm_libc::log2f, ::log2f,
|
||||
"log2f_perf.log")
|
||||
|
|
@ -78,3 +78,20 @@ add_fp_unittest(
|
|||
LINK_OPTIONS
|
||||
-lpthread
|
||||
)
|
||||
|
||||
add_fp_unittest(
|
||||
log2f_test
|
||||
NO_RUN_POSTBUILD
|
||||
NEED_MPFR
|
||||
SUITE
|
||||
libc_math_exhaustive_tests
|
||||
SRCS
|
||||
log2f_test.cpp
|
||||
DEPENDS
|
||||
.exhaustive_test
|
||||
libc.include.math
|
||||
libc.src.math.log2f
|
||||
libc.src.__support.FPUtil.fputil
|
||||
LINK_OPTIONS
|
||||
-lpthread
|
||||
)
|
||||
|
|
|
|||
|
|
@ -0,0 +1,51 @@
|
|||
//===-- Exhaustive test for log2f -----------------------------------------===//
|
||||
//
|
||||
// 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 "exhaustive_test.h"
|
||||
#include "src/__support/FPUtil/FPBits.h"
|
||||
#include "src/math/log2f.h"
|
||||
#include "utils/MPFRWrapper/MPFRUtils.h"
|
||||
#include "utils/UnitTest/FPMatcher.h"
|
||||
|
||||
using FPBits = __llvm_libc::fputil::FPBits<float>;
|
||||
|
||||
namespace mpfr = __llvm_libc::testing::mpfr;
|
||||
|
||||
struct LlvmLibcLog2fExhaustiveTest : public LlvmLibcExhaustiveTest<uint32_t> {
|
||||
void check(uint32_t start, uint32_t stop,
|
||||
mpfr::RoundingMode rounding) override {
|
||||
mpfr::ForceRoundingMode r(rounding);
|
||||
uint32_t bits = start;
|
||||
do {
|
||||
FPBits xbits(bits);
|
||||
float x = float(xbits);
|
||||
EXPECT_MPFR_MATCH(mpfr::Operation::Log2, x, __llvm_libc::log2f(x), 0.5,
|
||||
rounding);
|
||||
} while (bits++ < stop);
|
||||
}
|
||||
};
|
||||
|
||||
TEST_F(LlvmLibcLog2fExhaustiveTest, RoundNearestTieToEven) {
|
||||
test_full_range(/*start=*/0U, /*stop=*/0x7f80'0000U, /*nthreads=*/16,
|
||||
mpfr::RoundingMode::Nearest);
|
||||
}
|
||||
|
||||
TEST_F(LlvmLibcLog2fExhaustiveTest, RoundUp) {
|
||||
test_full_range(/*start=*/0U, /*stop=*/0x7f80'0000U, /*nthreads=*/16,
|
||||
mpfr::RoundingMode::Upward);
|
||||
}
|
||||
|
||||
TEST_F(LlvmLibcLog2fExhaustiveTest, RoundDown) {
|
||||
test_full_range(/*start=*/0U, /*stop=*/0x7f80'0000U, /*nthreads=*/16,
|
||||
mpfr::RoundingMode::Downward);
|
||||
}
|
||||
|
||||
TEST_F(LlvmLibcLog2fExhaustiveTest, RoundTowardZero) {
|
||||
test_full_range(/*start=*/0U, /*stop=*/0x7f80'0000U, /*nthreads=*/16,
|
||||
mpfr::RoundingMode::TowardZero);
|
||||
}
|
||||
|
|
@ -0,0 +1,64 @@
|
|||
//===-- Unittests for log2f -----------------------------------------------===//
|
||||
//
|
||||
// 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/__support/FPUtil/FPBits.h"
|
||||
#include "src/math/log2f.h"
|
||||
#include "utils/MPFRWrapper/MPFRUtils.h"
|
||||
#include "utils/UnitTest/FPMatcher.h"
|
||||
#include "utils/UnitTest/Test.h"
|
||||
#include <math.h>
|
||||
|
||||
#include <errno.h>
|
||||
#include <stdint.h>
|
||||
|
||||
namespace mpfr = __llvm_libc::testing::mpfr;
|
||||
|
||||
DECLARE_SPECIAL_CONSTANTS(float)
|
||||
|
||||
TEST(LlvmLibcLog2fTest, SpecialNumbers) {
|
||||
EXPECT_FP_EQ(aNaN, __llvm_libc::log2f(aNaN));
|
||||
EXPECT_FP_EQ(inf, __llvm_libc::log2f(inf));
|
||||
EXPECT_TRUE(FPBits(__llvm_libc::log2f(neg_inf)).is_nan());
|
||||
EXPECT_FP_EQ(neg_inf, __llvm_libc::log2f(0.0f));
|
||||
EXPECT_FP_EQ(neg_inf, __llvm_libc::log2f(-0.0f));
|
||||
EXPECT_TRUE(FPBits(__llvm_libc::log2f(-1.0f)).is_nan());
|
||||
EXPECT_FP_EQ(zero, __llvm_libc::log2f(1.0f));
|
||||
}
|
||||
|
||||
TEST(LlvmLibcLog2fTest, TrickyInputs) {
|
||||
constexpr int N = 9;
|
||||
constexpr uint32_t INPUTS[N] = {0x3f7d57f5U, 0x3f7ed848U, 0x3f7fd6ccU,
|
||||
0x3f7fffffU, 0x3f80079bU, 0x3f81d0b5U,
|
||||
0x3f82e602U, 0x3f83c98dU, 0x3f8cba39U};
|
||||
|
||||
for (int i = 0; i < N; ++i) {
|
||||
float x = float(FPBits(INPUTS[i]));
|
||||
EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log2, x,
|
||||
__llvm_libc::log2f(x), 0.5);
|
||||
}
|
||||
}
|
||||
|
||||
TEST(LlvmLibcLog2fTest, InFloatRange) {
|
||||
constexpr uint32_t COUNT = 1000000;
|
||||
constexpr uint32_t STEP = UINT32_MAX / COUNT;
|
||||
for (uint32_t i = 0, v = 0; i <= COUNT; ++i, v += STEP) {
|
||||
float x = float(FPBits(v));
|
||||
if (isnan(x) || isinf(x))
|
||||
continue;
|
||||
errno = 0;
|
||||
float result = __llvm_libc::log2f(x);
|
||||
// If the computation resulted in an error or did not produce valid result
|
||||
// in the single-precision floating point range, then ignore comparing with
|
||||
// MPFR result as MPFR can still produce valid results because of its
|
||||
// wider precision.
|
||||
if (isnan(result) || isinf(result) || errno != 0)
|
||||
continue;
|
||||
ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log2, x,
|
||||
__llvm_libc::log2f(x), 0.5);
|
||||
}
|
||||
}
|
||||
|
|
@ -267,6 +267,12 @@ public:
|
|||
return result;
|
||||
}
|
||||
|
||||
MPFRNumber log2() const {
|
||||
MPFRNumber result(*this);
|
||||
mpfr_log2(result.value, value, mpfr_rounding);
|
||||
return result;
|
||||
}
|
||||
|
||||
MPFRNumber remquo(const MPFRNumber &divisor, int "ient) {
|
||||
MPFRNumber remainder(*this);
|
||||
long q;
|
||||
|
|
@ -494,6 +500,8 @@ unary_operation(Operation op, InputType input, unsigned int precision,
|
|||
return mpfrInput.floor();
|
||||
case Operation::Log:
|
||||
return mpfrInput.log();
|
||||
case Operation::Log2:
|
||||
return mpfrInput.log2();
|
||||
case Operation::Mod2PI:
|
||||
return mpfrInput.mod_2pi();
|
||||
case Operation::ModPIOver2:
|
||||
|
|
|
|||
|
|
@ -31,6 +31,7 @@ enum class Operation : int {
|
|||
Expm1,
|
||||
Floor,
|
||||
Log,
|
||||
Log2,
|
||||
Mod2PI,
|
||||
ModPIOver2,
|
||||
ModPIOver4,
|
||||
|
|
@ -325,6 +326,23 @@ template <typename T> bool round_to_long(T x, RoundingMode mode, long &result);
|
|||
EXPECT_MPFR_MATCH_DEFAULT, GET_MPFR_DUMMY_ARG) \
|
||||
(__VA_ARGS__)
|
||||
|
||||
#define EXPECT_MPFR_MATCH_ALL_ROUNDING(op, input, match_value, ulp_tolerance) \
|
||||
{ \
|
||||
namespace mpfr = __llvm_libc::testing::mpfr; \
|
||||
mpfr::ForceRoundingMode __r1(mpfr::RoundingMode::Nearest); \
|
||||
EXPECT_MPFR_MATCH(op, input, match_value, ulp_tolerance, \
|
||||
mpfr::RoundingMode::Nearest); \
|
||||
mpfr::ForceRoundingMode __r2(mpfr::RoundingMode::Upward); \
|
||||
EXPECT_MPFR_MATCH(op, input, match_value, ulp_tolerance, \
|
||||
mpfr::RoundingMode::Upward); \
|
||||
mpfr::ForceRoundingMode __r3(mpfr::RoundingMode::Downward); \
|
||||
EXPECT_MPFR_MATCH(op, input, match_value, ulp_tolerance, \
|
||||
mpfr::RoundingMode::Downward); \
|
||||
mpfr::ForceRoundingMode __r4(mpfr::RoundingMode::TowardZero); \
|
||||
EXPECT_MPFR_MATCH(op, input, match_value, ulp_tolerance, \
|
||||
mpfr::RoundingMode::TowardZero); \
|
||||
}
|
||||
|
||||
#define ASSERT_MPFR_MATCH_DEFAULT(op, input, match_value, ulp_tolerance) \
|
||||
ASSERT_THAT(match_value, \
|
||||
__llvm_libc::testing::mpfr::get_mpfr_matcher<op>( \
|
||||
|
|
@ -341,4 +359,21 @@ template <typename T> bool round_to_long(T x, RoundingMode mode, long &result);
|
|||
ASSERT_MPFR_MATCH_DEFAULT, GET_MPFR_DUMMY_ARG) \
|
||||
(__VA_ARGS__)
|
||||
|
||||
#define ASSERT_MPFR_MATCH_ALL_ROUNDING(op, input, match_value, ulp_tolerance) \
|
||||
{ \
|
||||
namespace mpfr = __llvm_libc::testing::mpfr; \
|
||||
mpfr::ForceRoundingMode __r1(mpfr::RoundingMode::Nearest); \
|
||||
ASSERT_MPFR_MATCH(op, input, match_value, ulp_tolerance, \
|
||||
mpfr::RoundingMode::Nearest); \
|
||||
mpfr::ForceRoundingMode __r2(mpfr::RoundingMode::Upward); \
|
||||
ASSERT_MPFR_MATCH(op, input, match_value, ulp_tolerance, \
|
||||
mpfr::RoundingMode::Upward); \
|
||||
mpfr::ForceRoundingMode __r3(mpfr::RoundingMode::Downward); \
|
||||
ASSERT_MPFR_MATCH(op, input, match_value, ulp_tolerance, \
|
||||
mpfr::RoundingMode::Downward); \
|
||||
mpfr::ForceRoundingMode __r4(mpfr::RoundingMode::TowardZero); \
|
||||
ASSERT_MPFR_MATCH(op, input, match_value, ulp_tolerance, \
|
||||
mpfr::RoundingMode::TowardZero); \
|
||||
}
|
||||
|
||||
#endif // LLVM_LIBC_UTILS_TESTUTILS_MPFRUTILS_H
|
||||
|
|
|
|||
Loading…
Reference in New Issue