476 changes: 476 additions & 0 deletions libc/src/math/generic/exp10.cpp
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8 changes: 4 additions & 4 deletions libc/src/math/generic/exp2.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -104,7 +104,7 @@ Float128 poly_approx_f128(const Float128 &dx) {
return p;
}

// Compute exp(x) using 128-bit precision.
// Compute 2^(x) using 128-bit precision.
// TODO(lntue): investigate triple-double precision implementation for this
// step.
Float128 exp2_f128(double x, int hi, int idx1, int idx2) {
Expand Down Expand Up @@ -192,7 +192,7 @@ double exp2_denorm(double x) {
// Check for exceptional cases when:
// * log2(1 - 2^-54) < x < log2(1 + 2^-53)
// * x >= 1024
// * x <= -1075
// * x <= -1022
// * x is inf or nan
double set_exceptional(double x) {
using FPBits = typename fputil::FPBits<double>;
Expand All @@ -208,9 +208,9 @@ double set_exceptional(double x) {
return fputil::multiply_add(x, 0.5, 1.0);
}

// x <= 2^-1075 || x >= 1024 or inf/nan.
// x <= -1022 || x >= 1024 or inf/nan.
if (x_u > 0xc08ff00000000000) {
// x <= 2^-1075 or -inf/nan
// x <= -1075 or -inf/nan
if (x_u >= 0xc090cc0000000000) {
// exp(-Inf) = 0
if (xbits.is_inf())
Expand Down
14 changes: 14 additions & 0 deletions libc/test/src/math/CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -647,6 +647,20 @@ add_fp_unittest(
libc.src.__support.FPUtil.fp_bits
)

add_fp_unittest(
exp10_test
NEED_MPFR
SUITE
libc_math_unittests
SRCS
exp10_test.cpp
DEPENDS
libc.src.errno.errno
libc.include.math
libc.src.math.exp10
libc.src.__support.FPUtil.fp_bits
)

add_fp_unittest(
copysign_test
SUITE
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150 changes: 150 additions & 0 deletions libc/test/src/math/exp10_test.cpp
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Original file line number Diff line number Diff line change
@@ -0,0 +1,150 @@
//===-- Unittests for 10^x ------------------------------------------------===//
//
// 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/errno/libc_errno.h"
#include "src/math/exp10.h"
#include "test/UnitTest/FPMatcher.h"
#include "test/UnitTest/Test.h"
#include "utils/MPFRWrapper/MPFRUtils.h"
#include <math.h>

#include <errno.h>
#include <stdint.h>

namespace mpfr = __llvm_libc::testing::mpfr;
using __llvm_libc::testing::tlog;

DECLARE_SPECIAL_CONSTANTS(double)

TEST(LlvmLibcExp10Test, SpecialNumbers) {
EXPECT_FP_EQ(aNaN, __llvm_libc::exp10(aNaN));
EXPECT_FP_EQ(inf, __llvm_libc::exp10(inf));
EXPECT_FP_EQ_ALL_ROUNDING(zero, __llvm_libc::exp10(neg_inf));
EXPECT_FP_EQ_WITH_EXCEPTION(zero, __llvm_libc::exp10(-0x1.0p20),
FE_UNDERFLOW);
EXPECT_FP_EQ_WITH_EXCEPTION(inf, __llvm_libc::exp10(0x1.0p20), FE_OVERFLOW);
EXPECT_FP_EQ_ALL_ROUNDING(1.0, __llvm_libc::exp10(0.0));
EXPECT_FP_EQ_ALL_ROUNDING(1.0, __llvm_libc::exp10(-0.0));
}

TEST(LlvmLibcExp10Test, TrickyInputs) {
constexpr int N = 41;
constexpr uint64_t INPUTS[N] = {
0x40033093317082F8, 0x3FD79289C6E6A5C0,
0x3FD05DE80A173EA0, // 0x1.05de80a173eap-2
0xbf1eb7a4cb841fcc, // -0x1.eb7a4cb841fccp-14
0xbf19a61fb925970d,
0x3fda7b764e2cf47a, // 0x1.a7b764e2cf47ap-2
0xc04757852a4b93aa, // -0x1.757852a4b93aap+5
0x4044c19e5712e377, // x=0x1.4c19e5712e377p+5
0xbf19a61fb925970d, // x=-0x1.9a61fb925970dp-14
0xc039a74cdab36c28, // x=-0x1.9a74cdab36c28p+4
0xc085b3e4e2e3bba9, // x=-0x1.5b3e4e2e3bba9p+9
0xc086960d591aec34, // x=-0x1.6960d591aec34p+9
0xc086232c09d58d91, // x=-0x1.6232c09d58d91p+9
0xc0874910d52d3051, // x=-0x1.74910d52d3051p9
0xc0867a172ceb0990, // x=-0x1.67a172ceb099p+9
0xc08ff80000000000, // x=-0x1.ff8p+9
0xbc971547652b82fe, // x=-0x1.71547652b82fep-54
0x0000000000000000, // x = 0
0x3ff0000000000000, // x = 1
0x4000000000000000, // x = 2
0x4008000000000000, // x = 3
0x4010000000000000, // x = 4
0x4014000000000000, // x = 5
0x4018000000000000, // x = 6
0x401c000000000000, // x = 7
0x4020000000000000, // x = 8
0x4022000000000000, // x = 9
0x4024000000000000, // x = 10
0x4026000000000000, // x = 11
0x4028000000000000, // x = 12
0x402a000000000000, // x = 13
0x402c000000000000, // x = 14
0x402e000000000000, // x = 15
0x4030000000000000, // x = 16
0x4031000000000000, // x = 17
0x4032000000000000, // x = 18
0x4033000000000000, // x = 19
0x4034000000000000, // x = 20
0x4035000000000000, // x = 21
0x4036000000000000, // x = 22
0x4037000000000000, // x = 23
};
for (int i = 0; i < N; ++i) {
double x = double(FPBits(INPUTS[i]));
EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp10, x,
__llvm_libc::exp10(x), 0.5);
}
}

TEST(LlvmLibcExp10Test, InDoubleRange) {
constexpr uint64_t COUNT = 1'231;
uint64_t START = __llvm_libc::fputil::FPBits<double>(0.25).uintval();
uint64_t STOP = __llvm_libc::fputil::FPBits<double>(4.0).uintval();
uint64_t STEP = (STOP - START) / COUNT;

auto test = [&](mpfr::RoundingMode rounding_mode) {
mpfr::ForceRoundingMode __r(rounding_mode);
if (!__r.success)
return;

uint64_t fails = 0;
uint64_t count = 0;
uint64_t cc = 0;
double mx, mr = 0.0;
double tol = 0.5;

for (uint64_t i = 0, v = START; i <= COUNT; ++i, v += STEP) {
double x = FPBits(v).get_val();
if (isnan(x) || isinf(x) || x < 0.0)
continue;
libc_errno = 0;
double result = __llvm_libc::exp10(x);
++cc;
if (isnan(result) || isinf(result))
continue;

++count;

if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Exp10, x, result,
0.5, rounding_mode)) {
++fails;
while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Exp10, x,
result, tol, rounding_mode)) {
mx = x;
mr = result;

if (tol > 1000.0)
break;

tol *= 2.0;
}
}
}
tlog << " Exp10 failed: " << fails << "/" << count << "/" << cc
<< " tests.\n";
tlog << " Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
if (fails) {
EXPECT_MPFR_MATCH(mpfr::Operation::Exp10, mx, mr, 0.5, rounding_mode);
}
};

tlog << " Test Rounding To Nearest...\n";
test(mpfr::RoundingMode::Nearest);

tlog << " Test Rounding Downward...\n";
test(mpfr::RoundingMode::Downward);

tlog << " Test Rounding Upward...\n";
test(mpfr::RoundingMode::Upward);

tlog << " Test Rounding Toward Zero...\n";
test(mpfr::RoundingMode::TowardZero);
}
16 changes: 16 additions & 0 deletions utils/bazel/llvm-project-overlay/libc/BUILD.bazel
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Original file line number Diff line number Diff line change
Expand Up @@ -1246,6 +1246,22 @@ libc_math_function(
],
)

libc_math_function(
name = "exp10",
additional_deps = [
":__support_fputil_double_double",
":__support_fputil_dyadic_float",
":__support_fputil_multiply_add",
":__support_fputil_nearest_integer",
":__support_fputil_polyeval",
":__support_fputil_rounding_mode",
":__support_fputil_triple_double",
":__support_macros_optimization",
":common_constants",
":explogxf",
],
)

libc_math_function(
name = "exp10f",
additional_deps = [
Expand Down
7 changes: 7 additions & 0 deletions utils/bazel/llvm-project-overlay/libc/test/src/math/BUILD.bazel
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Original file line number Diff line number Diff line change
Expand Up @@ -755,6 +755,13 @@ math_test(
],
)

math_test(
name = "exp10",
deps = [
"//libc/utils/MPFRWrapper:mpfr_wrapper",
],
)

math_test(
name = "fmod",
hdrs = ["FModTest.h"],
Expand Down