[libc][math] Refactor cbrtf implementation to header-only in src/__support/math folder.#151846
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@llvm/pr-subscribers-libc Author: Muhammad Bassiouni (bassiounix) ChangesPart of #147386 in preparation for: https://discourse.llvm.org/t/rfc-make-clang-builtin-math-functions-constexpr-with-llvm-libc-to-support-c-23-constexpr-math-functions/86450 Full diff: https://github.com/llvm/llvm-project/pull/151846.diff 9 Files Affected:
diff --git a/libc/shared/math.h b/libc/shared/math.h
index 3714f380a27dc..ea645f0afedbc 100644
--- a/libc/shared/math.h
+++ b/libc/shared/math.h
@@ -31,6 +31,7 @@
#include "math/atanhf.h"
#include "math/atanhf16.h"
#include "math/cbrt.h"
+#include "math/cbrtf.h"
#include "math/erff.h"
#include "math/exp.h"
#include "math/exp10.h"
diff --git a/libc/shared/math/cbrtf.h b/libc/shared/math/cbrtf.h
new file mode 100644
index 0000000000000..09b86bed3fb7e
--- /dev/null
+++ b/libc/shared/math/cbrtf.h
@@ -0,0 +1,23 @@
+//===-- Shared cbrtf function -----------------------------------*- 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 LIBC_SHARED_MATH_CBRTF_H
+#define LIBC_SHARED_MATH_CBRTF_H
+
+#include "shared/libc_common.h"
+#include "src/__support/math/cbrtf.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using math::cbrtf;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_SHARED_MATH_CBRTF_H
diff --git a/libc/src/__support/math/CMakeLists.txt b/libc/src/__support/math/CMakeLists.txt
index e1076edf1e61c..fe928a8fadd5e 100644
--- a/libc/src/__support/math/CMakeLists.txt
+++ b/libc/src/__support/math/CMakeLists.txt
@@ -346,6 +346,17 @@ add_header_library(
libc.src.__support.integer_literals
)
+add_header_library(
+ cbrtf
+ HDRS
+ cbrtf.h
+ DEPENDS
+ libc.src.__support.FPUtil.fenv_impl
+ libc.src.__support.FPUtil.fp_bits
+ libc.src.__support.FPUtil.multiply_add
+ libc.src.__support.macros.optimization
+)
+
add_header_library(
erff
HDRS
diff --git a/libc/src/__support/math/cbrtf.h b/libc/src/__support/math/cbrtf.h
new file mode 100644
index 0000000000000..f82892bbbe61b
--- /dev/null
+++ b/libc/src/__support/math/cbrtf.h
@@ -0,0 +1,161 @@
+//===-- Implementation header for cbrtf -------------------------*- 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 LIBC_SRC___SUPPORT_MATH_CBRTF_H
+#define LIBC_SRC___SUPPORT_MATH_CBRTF_H
+
+#include "src/__support/FPUtil/FEnvImpl.h"
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/FPUtil/multiply_add.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/macros/optimization.h" // LIBC_UNLIKELY
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace math {
+
+LIBC_INLINE static constexpr float cbrtf(float x) {
+ // Look up table for 2^(i/3) for i = 0, 1, 2.
+ constexpr double CBRT2[3] = {1.0, 0x1.428a2f98d728bp0, 0x1.965fea53d6e3dp0};
+
+ // Degree-7 polynomials approximation of ((1 + x)^(1/3) - 1)/x for 0 <= x <= 1
+ // generated by Sollya with:
+ // > for i from 0 to 15 do {
+ // P = fpminimax(((1 + x)^(1/3) - 1)/x, 6, [|D...|], [i/16, (i + 1)/16]);
+ // print("{", coeff(P, 0), ",", coeff(P, 1), ",", coeff(P, 2), ",",
+ // coeff(P, 3), ",", coeff(P, 4), ",", coeff(P, 5), ",",
+ // coeff(P, 6), "},");
+ // };
+ // Then (1 + x)^(1/3) ~ 1 + x * P(x).
+ constexpr double COEFFS[16][7] = {
+ {0x1.55555555554ebp-2, -0x1.c71c71c678c0cp-4, 0x1.f9add2776de81p-5,
+ -0x1.511e10aa964a7p-5, 0x1.ee44165937fa2p-6, -0x1.7c5c9e059345dp-6,
+ 0x1.047f75e0aff14p-6},
+ {0x1.5555554d1149ap-2, -0x1.c71c676fcb5bp-4, 0x1.f9ab127dc57ebp-5,
+ -0x1.50ea8fd1d4c15p-5, 0x1.e9d68f28ced43p-6, -0x1.60e0e1e661311p-6,
+ 0x1.716eca1d6e3bcp-7},
+ {0x1.5555546377d45p-2, -0x1.c71bc1c6d49d2p-4, 0x1.f9924cc0ed24dp-5,
+ -0x1.4fea3beb53b3bp-5, 0x1.de028a9a07b1bp-6, -0x1.3b090d2233524p-6,
+ 0x1.0aeca34893785p-7},
+ {0x1.55554dce9f649p-2, -0x1.c7188b34b98f8p-4, 0x1.f93e1af34af49p-5,
+ -0x1.4d9a06be75c63p-5, 0x1.cb943f4f68992p-6, -0x1.139a685a5e3c4p-6,
+ 0x1.88410674c6a5dp-8},
+ {0x1.5555347d211c3p-2, -0x1.c70f2a4b1a5fap-4, 0x1.f88420e8602c3p-5,
+ -0x1.49becfa4ed3ep-5, 0x1.b475cd9013162p-6, -0x1.dcfee1dd2f8efp-7,
+ 0x1.249bb51a1c498p-8},
+ {0x1.5554f01b33dbap-2, -0x1.c6facb929dbf1p-4, 0x1.f73fb7861252ep-5,
+ -0x1.4459a4a0071fap-5, 0x1.9a8df2b504fc2p-6, -0x1.9a7ce3006d06ep-7,
+ 0x1.ba9230918fa2ep-9},
+ {0x1.55545c695db5fp-2, -0x1.c6d6089f20275p-4, 0x1.f556e0ea80efp-5,
+ -0x1.3d91372d083f4p-5, 0x1.7f66cff331f4p-6, -0x1.606a562491737p-7,
+ 0x1.52e3e17c71069p-9},
+ {0x1.55534a879232ap-2, -0x1.c69b836998b84p-4, 0x1.f2bb26dac0e4cp-5,
+ -0x1.359eed43716d7p-5, 0x1.64218cd824fbcp-6, -0x1.2e703e2e091e8p-7,
+ 0x1.0677d9af6aad4p-9},
+ {0x1.5551836bb5494p-2, -0x1.c64658c15353bp-4, 0x1.ef68517451a6ep-5,
+ -0x1.2cc20a980dceep-5, 0x1.49843e0fad93ap-6, -0x1.03c59ccb68e54p-7,
+ 0x1.9ad325dc7adcbp-10},
+ {0x1.554ecacb0d035p-2, -0x1.c5d2664026ffcp-4, 0x1.eb624796ba809p-5,
+ -0x1.233803d19a535p-5, 0x1.300decb1c3c28p-6, -0x1.befe18031ec3dp-8,
+ 0x1.449f5ee175c69p-10},
+ {0x1.554ae1f5ae815p-2, -0x1.c53c6b14ff6b2p-4, 0x1.e6b2d5127bb5bp-5,
+ -0x1.19387336788a3p-5, 0x1.180955a6ab255p-6, -0x1.81696703ba369p-8,
+ 0x1.02cb36389bd79p-10},
+ {0x1.55458a59f356ep-2, -0x1.c4820dd631ae9p-4, 0x1.e167af818bd15p-5,
+ -0x1.0ef35f6f72e52p-5, 0x1.019c33b65e4ebp-6, -0x1.4d25bdd52d3a5p-8,
+ 0x1.a008ae91f5936p-11},
+ {0x1.553e878eafee1p-2, -0x1.c3a1d0b2a3db2p-4, 0x1.db90d8ed9f89bp-5,
+ -0x1.0490e20f1ae91p-5, 0x1.d9a5d1fc42fe3p-7, -0x1.20bf8227c2abfp-8,
+ 0x1.50f8174cdb6e9p-11},
+ {0x1.5535a0dedf1b1p-2, -0x1.c29afb8bd01a1p-4, 0x1.d53f6371c1e27p-5,
+ -0x1.f463209b433e2p-6, 0x1.b35222a17e44p-7, -0x1.f5efbf505e133p-9,
+ 0x1.12e0e94e8586dp-11},
+ {0x1.552aa25e57bfdp-2, -0x1.c16d811e4acadp-4, 0x1.ce8489b47aa51p-5,
+ -0x1.dfde7ff758ea8p-6, 0x1.901f43aac38c8p-7, -0x1.b581d07df5ad5p-9,
+ 0x1.c3726535f1fc6p-12},
+ {0x1.551d5d9b204d3p-2, -0x1.c019e328f8db1p-4, 0x1.c7710f44fc3cep-5,
+ -0x1.cbbbe25ea8ba4p-6, 0x1.6fe270088623dp-7, -0x1.7e6fc79733761p-9,
+ 0x1.75077abf18d84p-12},
+ };
+
+ using FloatBits = typename fputil::FPBits<float>;
+ using DoubleBits = typename fputil::FPBits<double>;
+
+ FloatBits x_bits(x);
+
+ uint32_t x_abs = x_bits.uintval() & 0x7fff'ffff;
+ uint32_t sign_bit = (x_bits.uintval() >> 31) << DoubleBits::EXP_LEN;
+
+ if (LIBC_UNLIKELY(x == 0.0f || x_abs >= 0x7f80'0000)) {
+ // x is 0, Inf, or NaN.
+ // Make sure it works for FTZ/DAZ modes.
+ return x + x;
+ }
+
+ double xd = static_cast<double>(x);
+ DoubleBits xd_bits(xd);
+
+ // When using biased exponent of x in double precision,
+ // x_e = real_exponent_of_x + 1023
+ // Then:
+ // x_e / 3 = real_exponent_of_x / 3 + 1023/3
+ // = real_exponent_of_x / 3 + 341
+ // So to make it the correct biased exponent of x^(1/3), we add
+ // 1023 - 341 = 682
+ // to the quotient x_e / 3.
+ unsigned x_e = static_cast<unsigned>(xd_bits.get_biased_exponent());
+ unsigned out_e = (x_e / 3 + 682) | sign_bit;
+ unsigned shift_e = x_e % 3;
+
+ // Set x_m = 2^(x_e % 3) * (1.mantissa)
+ uint64_t x_m = xd_bits.get_mantissa();
+ // Use the leading 4 bits for look up table
+ unsigned idx = static_cast<unsigned>(x_m >> (DoubleBits::FRACTION_LEN - 4));
+
+ x_m |= static_cast<uint64_t>(DoubleBits::EXP_BIAS)
+ << DoubleBits::FRACTION_LEN;
+
+ double x_reduced = DoubleBits(x_m).get_val();
+ double dx = x_reduced - 1.0;
+
+ double dx_sq = dx * dx;
+ double c0 = fputil::multiply_add(dx, COEFFS[idx][0], 1.0);
+ double c1 = fputil::multiply_add(dx, COEFFS[idx][2], COEFFS[idx][1]);
+ double c2 = fputil::multiply_add(dx, COEFFS[idx][4], COEFFS[idx][3]);
+ double c3 = fputil::multiply_add(dx, COEFFS[idx][6], COEFFS[idx][5]);
+
+ double dx_4 = dx_sq * dx_sq;
+ double p0 = fputil::multiply_add(dx_sq, c1, c0);
+ double p1 = fputil::multiply_add(dx_sq, c3, c2);
+
+ double r = fputil::multiply_add(dx_4, p1, p0) * CBRT2[shift_e];
+
+ uint64_t r_m = DoubleBits(r).get_mantissa();
+ // Check if the output is exact. To be exact, the smallest 1-bit of the
+ // output has to be at least 2^-7 or higher. So we check the lowest 44 bits
+ // to see if they are within 2^(-52 + 3) errors from all zeros, then the
+ // result cube root is exact.
+ if (LIBC_UNLIKELY(((r_m + 8) & 0xfffffffffff) <= 16)) {
+ if ((r_m & 0xfffffffffff) <= 8)
+ r_m &= 0xffff'ffff'ffff'ffe0;
+ else
+ r_m = (r_m & 0xffff'ffff'ffff'ffe0) + 0x20;
+ fputil::clear_except_if_required(FE_INEXACT);
+ }
+ // Adjust exponent and sign.
+ uint64_t r_bits =
+ r_m | (static_cast<uint64_t>(out_e) << DoubleBits::FRACTION_LEN);
+
+ return static_cast<float>(DoubleBits(r_bits).get_val());
+}
+
+} // namespace math
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LIBC_SRC___SUPPORT_MATH_CBRTF_H
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index a86619576cfc6..44c17cf5b0770 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -4739,11 +4739,7 @@ add_entrypoint_object(
HDRS
../cbrtf.h
DEPENDS
- libc.hdr.fenv_macros
- libc.src.__support.FPUtil.fenv_impl
- libc.src.__support.FPUtil.fp_bits
- libc.src.__support.FPUtil.multiply_add
- libc.src.__support.macros.optimization
+ libc.src.__support.math.cbrtf
)
add_entrypoint_object(
diff --git a/libc/src/math/generic/cbrtf.cpp b/libc/src/math/generic/cbrtf.cpp
index 71b23c4a8c742..0bd8f71365300 100644
--- a/libc/src/math/generic/cbrtf.cpp
+++ b/libc/src/math/generic/cbrtf.cpp
@@ -7,153 +7,10 @@
//===----------------------------------------------------------------------===//
#include "src/math/cbrtf.h"
-#include "hdr/fenv_macros.h"
-#include "src/__support/FPUtil/FEnvImpl.h"
-#include "src/__support/FPUtil/FPBits.h"
-#include "src/__support/FPUtil/multiply_add.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
-#include "src/__support/macros/optimization.h" // LIBC_UNLIKELY
+#include "src/__support/math/cbrtf.h"
namespace LIBC_NAMESPACE_DECL {
-namespace {
-
-// Look up table for 2^(i/3) for i = 0, 1, 2.
-constexpr double CBRT2[3] = {1.0, 0x1.428a2f98d728bp0, 0x1.965fea53d6e3dp0};
-
-// Degree-7 polynomials approximation of ((1 + x)^(1/3) - 1)/x for 0 <= x <= 1
-// generated by Sollya with:
-// > for i from 0 to 15 do {
-// P = fpminimax(((1 + x)^(1/3) - 1)/x, 6, [|D...|], [i/16, (i + 1)/16]);
-// print("{", coeff(P, 0), ",", coeff(P, 1), ",", coeff(P, 2), ",",
-// coeff(P, 3), ",", coeff(P, 4), ",", coeff(P, 5), ",",
-// coeff(P, 6), "},");
-// };
-// Then (1 + x)^(1/3) ~ 1 + x * P(x).
-constexpr double COEFFS[16][7] = {
- {0x1.55555555554ebp-2, -0x1.c71c71c678c0cp-4, 0x1.f9add2776de81p-5,
- -0x1.511e10aa964a7p-5, 0x1.ee44165937fa2p-6, -0x1.7c5c9e059345dp-6,
- 0x1.047f75e0aff14p-6},
- {0x1.5555554d1149ap-2, -0x1.c71c676fcb5bp-4, 0x1.f9ab127dc57ebp-5,
- -0x1.50ea8fd1d4c15p-5, 0x1.e9d68f28ced43p-6, -0x1.60e0e1e661311p-6,
- 0x1.716eca1d6e3bcp-7},
- {0x1.5555546377d45p-2, -0x1.c71bc1c6d49d2p-4, 0x1.f9924cc0ed24dp-5,
- -0x1.4fea3beb53b3bp-5, 0x1.de028a9a07b1bp-6, -0x1.3b090d2233524p-6,
- 0x1.0aeca34893785p-7},
- {0x1.55554dce9f649p-2, -0x1.c7188b34b98f8p-4, 0x1.f93e1af34af49p-5,
- -0x1.4d9a06be75c63p-5, 0x1.cb943f4f68992p-6, -0x1.139a685a5e3c4p-6,
- 0x1.88410674c6a5dp-8},
- {0x1.5555347d211c3p-2, -0x1.c70f2a4b1a5fap-4, 0x1.f88420e8602c3p-5,
- -0x1.49becfa4ed3ep-5, 0x1.b475cd9013162p-6, -0x1.dcfee1dd2f8efp-7,
- 0x1.249bb51a1c498p-8},
- {0x1.5554f01b33dbap-2, -0x1.c6facb929dbf1p-4, 0x1.f73fb7861252ep-5,
- -0x1.4459a4a0071fap-5, 0x1.9a8df2b504fc2p-6, -0x1.9a7ce3006d06ep-7,
- 0x1.ba9230918fa2ep-9},
- {0x1.55545c695db5fp-2, -0x1.c6d6089f20275p-4, 0x1.f556e0ea80efp-5,
- -0x1.3d91372d083f4p-5, 0x1.7f66cff331f4p-6, -0x1.606a562491737p-7,
- 0x1.52e3e17c71069p-9},
- {0x1.55534a879232ap-2, -0x1.c69b836998b84p-4, 0x1.f2bb26dac0e4cp-5,
- -0x1.359eed43716d7p-5, 0x1.64218cd824fbcp-6, -0x1.2e703e2e091e8p-7,
- 0x1.0677d9af6aad4p-9},
- {0x1.5551836bb5494p-2, -0x1.c64658c15353bp-4, 0x1.ef68517451a6ep-5,
- -0x1.2cc20a980dceep-5, 0x1.49843e0fad93ap-6, -0x1.03c59ccb68e54p-7,
- 0x1.9ad325dc7adcbp-10},
- {0x1.554ecacb0d035p-2, -0x1.c5d2664026ffcp-4, 0x1.eb624796ba809p-5,
- -0x1.233803d19a535p-5, 0x1.300decb1c3c28p-6, -0x1.befe18031ec3dp-8,
- 0x1.449f5ee175c69p-10},
- {0x1.554ae1f5ae815p-2, -0x1.c53c6b14ff6b2p-4, 0x1.e6b2d5127bb5bp-5,
- -0x1.19387336788a3p-5, 0x1.180955a6ab255p-6, -0x1.81696703ba369p-8,
- 0x1.02cb36389bd79p-10},
- {0x1.55458a59f356ep-2, -0x1.c4820dd631ae9p-4, 0x1.e167af818bd15p-5,
- -0x1.0ef35f6f72e52p-5, 0x1.019c33b65e4ebp-6, -0x1.4d25bdd52d3a5p-8,
- 0x1.a008ae91f5936p-11},
- {0x1.553e878eafee1p-2, -0x1.c3a1d0b2a3db2p-4, 0x1.db90d8ed9f89bp-5,
- -0x1.0490e20f1ae91p-5, 0x1.d9a5d1fc42fe3p-7, -0x1.20bf8227c2abfp-8,
- 0x1.50f8174cdb6e9p-11},
- {0x1.5535a0dedf1b1p-2, -0x1.c29afb8bd01a1p-4, 0x1.d53f6371c1e27p-5,
- -0x1.f463209b433e2p-6, 0x1.b35222a17e44p-7, -0x1.f5efbf505e133p-9,
- 0x1.12e0e94e8586dp-11},
- {0x1.552aa25e57bfdp-2, -0x1.c16d811e4acadp-4, 0x1.ce8489b47aa51p-5,
- -0x1.dfde7ff758ea8p-6, 0x1.901f43aac38c8p-7, -0x1.b581d07df5ad5p-9,
- 0x1.c3726535f1fc6p-12},
- {0x1.551d5d9b204d3p-2, -0x1.c019e328f8db1p-4, 0x1.c7710f44fc3cep-5,
- -0x1.cbbbe25ea8ba4p-6, 0x1.6fe270088623dp-7, -0x1.7e6fc79733761p-9,
- 0x1.75077abf18d84p-12},
-};
-
-} // anonymous namespace
-
-LLVM_LIBC_FUNCTION(float, cbrtf, (float x)) {
- using FloatBits = typename fputil::FPBits<float>;
- using DoubleBits = typename fputil::FPBits<double>;
-
- FloatBits x_bits(x);
-
- uint32_t x_abs = x_bits.uintval() & 0x7fff'ffff;
- uint32_t sign_bit = (x_bits.uintval() >> 31) << DoubleBits::EXP_LEN;
-
- if (LIBC_UNLIKELY(x == 0.0f || x_abs >= 0x7f80'0000)) {
- // x is 0, Inf, or NaN.
- // Make sure it works for FTZ/DAZ modes.
- return x + x;
- }
-
- double xd = static_cast<double>(x);
- DoubleBits xd_bits(xd);
-
- // When using biased exponent of x in double precision,
- // x_e = real_exponent_of_x + 1023
- // Then:
- // x_e / 3 = real_exponent_of_x / 3 + 1023/3
- // = real_exponent_of_x / 3 + 341
- // So to make it the correct biased exponent of x^(1/3), we add
- // 1023 - 341 = 682
- // to the quotient x_e / 3.
- unsigned x_e = static_cast<unsigned>(xd_bits.get_biased_exponent());
- unsigned out_e = (x_e / 3 + 682) | sign_bit;
- unsigned shift_e = x_e % 3;
-
- // Set x_m = 2^(x_e % 3) * (1.mantissa)
- uint64_t x_m = xd_bits.get_mantissa();
- // Use the leading 4 bits for look up table
- unsigned idx = static_cast<unsigned>(x_m >> (DoubleBits::FRACTION_LEN - 4));
-
- x_m |= static_cast<uint64_t>(DoubleBits::EXP_BIAS)
- << DoubleBits::FRACTION_LEN;
-
- double x_reduced = DoubleBits(x_m).get_val();
- double dx = x_reduced - 1.0;
-
- double dx_sq = dx * dx;
- double c0 = fputil::multiply_add(dx, COEFFS[idx][0], 1.0);
- double c1 = fputil::multiply_add(dx, COEFFS[idx][2], COEFFS[idx][1]);
- double c2 = fputil::multiply_add(dx, COEFFS[idx][4], COEFFS[idx][3]);
- double c3 = fputil::multiply_add(dx, COEFFS[idx][6], COEFFS[idx][5]);
-
- double dx_4 = dx_sq * dx_sq;
- double p0 = fputil::multiply_add(dx_sq, c1, c0);
- double p1 = fputil::multiply_add(dx_sq, c3, c2);
-
- double r = fputil::multiply_add(dx_4, p1, p0) * CBRT2[shift_e];
-
- uint64_t r_m = DoubleBits(r).get_mantissa();
- // Check if the output is exact. To be exact, the smallest 1-bit of the
- // output has to be at least 2^-7 or higher. So we check the lowest 44 bits
- // to see if they are within 2^(-52 + 3) errors from all zeros, then the
- // result cube root is exact.
- if (LIBC_UNLIKELY(((r_m + 8) & 0xfffffffffff) <= 16)) {
- if ((r_m & 0xfffffffffff) <= 8)
- r_m &= 0xffff'ffff'ffff'ffe0;
- else
- r_m = (r_m & 0xffff'ffff'ffff'ffe0) + 0x20;
- fputil::clear_except_if_required(FE_INEXACT);
- }
- // Adjust exponent and sign.
- uint64_t r_bits =
- r_m | (static_cast<uint64_t>(out_e) << DoubleBits::FRACTION_LEN);
-
- return static_cast<float>(DoubleBits(r_bits).get_val());
-}
+LLVM_LIBC_FUNCTION(float, cbrtf, (float x)) { return math::cbrtf(x); }
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/shared/CMakeLists.txt b/libc/test/shared/CMakeLists.txt
index f5ea510180366..9685aeaee7d8d 100644
--- a/libc/test/shared/CMakeLists.txt
+++ b/libc/test/shared/CMakeLists.txt
@@ -27,6 +27,7 @@ add_fp_unittest(
libc.src.__support.math.atanhf
libc.src.__support.math.atanhf16
libc.src.__support.math.cbrt
+ libc.src.__support.math.cbrtf
libc.src.__support.math.erff
libc.src.__support.math.exp
libc.src.__support.math.exp10
diff --git a/libc/test/shared/shared_math_test.cpp b/libc/test/shared/shared_math_test.cpp
index 3d64e5e68882b..5e57c49ed23d9 100644
--- a/libc/test/shared/shared_math_test.cpp
+++ b/libc/test/shared/shared_math_test.cpp
@@ -49,6 +49,7 @@ TEST(LlvmLibcSharedMathTest, AllFloat) {
EXPECT_FP_EQ(0x0p+0f, LIBC_NAMESPACE::shared::atan2f(0.0f, 0.0f));
EXPECT_FP_EQ(0x0p+0f, LIBC_NAMESPACE::shared::atanf(0.0f));
EXPECT_FP_EQ(0x0p+0f, LIBC_NAMESPACE::shared::atanhf(0.0f));
+ EXPECT_FP_EQ(0x0p+0f, LIBC_NAMESPACE::shared::cbrtf(0.0f));
EXPECT_FP_EQ(0x0p+0f, LIBC_NAMESPACE::shared::erff(0.0f));
EXPECT_FP_EQ(0x1p+0f, LIBC_NAMESPACE::shared::exp10f(0.0f));
EXPECT_FP_EQ(0x1p+0f, LIBC_NAMESPACE::shared::expf(0.0f));
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index b46f334512979..d30c725524d17 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -2412,6 +2412,18 @@ libc_support_library(
],
)
+libc_support_library(
+ name = "__support_math_cbrtf",
+ hdrs = ["src/__support/math/cbrtf.h"],
+ deps = [
+ ":__support_fputil_double_double",
+ ":__support_fputil_polyeval",
+ ":__support_fputil_fenv_impl",
+ ":__support_fputil_dyadic_float",
+ ":__support_integer_literals",
+ ],
+)
+
libc_support_library(
name = "__support_math_erff",
hdrs = ["src/__support/math/erff.h"],
@@ -3088,7 +3100,7 @@ libc_math_function(
libc_math_function(
name = "cbrtf",
additional_deps = [
- ":__support_fputil_polyeval",
+ ":__support_math_cbrtf",
],
)
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[libc][math] Refactor exp10m1f16 implementation to header-only in src/__support/math folder.
#161119
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Part of #147386
in preparation for: https://discourse.llvm.org/t/rfc-make-clang-builtin-math-functions-constexpr-with-llvm-libc-to-support-c-23-constexpr-math-functions/86450