[libc-commits] [libc] [libc][math][c23] Add remainderf16 C23 math function (PR #94773)

via libc-commits libc-commits at lists.llvm.org
Fri Jun 7 10:23:40 PDT 2024


https://github.com/overmighty created https://github.com/llvm/llvm-project/pull/94773

None

>From 932ade6538f8b6335069ff42afc2da5a6cd2d21c Mon Sep 17 00:00:00 2001
From: OverMighty <its.overmighty at gmail.com>
Date: Fri, 7 Jun 2024 18:50:48 +0200
Subject: [PATCH] [libc][math][c23] Add remainderf16 C23 math function

---
 libc/config/linux/aarch64/entrypoints.txt |  1 +
 libc/config/linux/x86_64/entrypoints.txt  |  1 +
 libc/docs/math/index.rst                  |  2 +-
 libc/spec/stdc.td                         |  3 ++-
 libc/src/__support/FPUtil/NormalFloat.h   | 13 ++++++++-----
 libc/src/math/CMakeLists.txt              |  1 +
 libc/src/math/generic/CMakeLists.txt      | 13 +++++++++++++
 libc/src/math/generic/remainderf16.cpp    | 20 ++++++++++++++++++++
 libc/src/math/remainderf16.h              | 20 ++++++++++++++++++++
 9 files changed, 67 insertions(+), 7 deletions(-)
 create mode 100644 libc/src/math/generic/remainderf16.cpp
 create mode 100644 libc/src/math/remainderf16.h

diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 33ecff813a1fb..596c2c0e3b9d4 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -529,6 +529,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     # clang-12 and after: https://godbolt.org/z/8ceT9454c
     # libc.src.math.nexttowardf16
     libc.src.math.nextupf16
+    libc.src.math.remainderf16
     libc.src.math.rintf16
     libc.src.math.roundf16
     libc.src.math.roundevenf16
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index e3ca544ae0185..6871ac8a0d279 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -558,6 +558,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.nextdownf16
     libc.src.math.nexttowardf16
     libc.src.math.nextupf16
+    libc.src.math.remainderf16
     libc.src.math.rintf16
     libc.src.math.roundf16
     libc.src.math.roundevenf16
diff --git a/libc/docs/math/index.rst b/libc/docs/math/index.rst
index b9507f0887cd7..915d8fc4b7f91 100644
--- a/libc/docs/math/index.rst
+++ b/libc/docs/math/index.rst
@@ -198,7 +198,7 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | nextup           | |check|          | |check|         | |check|                | |check|              | |check|                | 7.12.11.5              | F.10.8.5                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
-| remainder        | |check|          | |check|         | |check|                |                      |                        | 7.12.10.2              | F.10.7.2                   |
+| remainder        | |check|          | |check|         | |check|                | |check|              |                        | 7.12.10.2              | F.10.7.2                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | remquo           | |check|          | |check|         | |check|                |                      |                        | 7.12.10.3              | F.10.7.3                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index 9a436c8ae38d2..7dae555048591 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -572,9 +572,10 @@ def StdC : StandardSpec<"stdc"> {
           FunctionSpec<"exp10", RetValSpec<DoubleType>, [ArgSpec<DoubleType>]>,
           FunctionSpec<"exp10f", RetValSpec<FloatType>, [ArgSpec<FloatType>]>,
 
-          FunctionSpec<"remainderf", RetValSpec<FloatType>, [ArgSpec<FloatType>, ArgSpec<FloatType>]>,
           FunctionSpec<"remainder", RetValSpec<DoubleType>, [ArgSpec<DoubleType>, ArgSpec<DoubleType>]>,
+          FunctionSpec<"remainderf", RetValSpec<FloatType>, [ArgSpec<FloatType>, ArgSpec<FloatType>]>,
           FunctionSpec<"remainderl", RetValSpec<LongDoubleType>, [ArgSpec<LongDoubleType>, ArgSpec<LongDoubleType>]>,
+          GuardedFunctionSpec<"remainderf16", RetValSpec<Float16Type>, [ArgSpec<Float16Type>, ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,
 
           FunctionSpec<"remquof", RetValSpec<FloatType>, [ArgSpec<FloatType>, ArgSpec<FloatType>, ArgSpec<IntPtr>]>,
           FunctionSpec<"remquo", RetValSpec<DoubleType>, [ArgSpec<DoubleType>, ArgSpec<DoubleType>, ArgSpec<IntPtr>]>,
diff --git a/libc/src/__support/FPUtil/NormalFloat.h b/libc/src/__support/FPUtil/NormalFloat.h
index 8bc1fecd653bf..413d20430090b 100644
--- a/libc/src/__support/FPUtil/NormalFloat.h
+++ b/libc/src/__support/FPUtil/NormalFloat.h
@@ -52,7 +52,7 @@ template <typename T> struct NormalFloat {
       return;
 
     unsigned normalization_shift = evaluate_normalization_shift(mantissa);
-    mantissa = mantissa << normalization_shift;
+    mantissa <<= normalization_shift;
     exponent -= normalization_shift;
   }
 
@@ -110,9 +110,11 @@ template <typename T> struct NormalFloat {
       if (shift <= FPBits<T>::FRACTION_LEN + 1) {
         // Generate a subnormal number. Might lead to loss of precision.
         // We round to nearest and round halfway cases to even.
-        const StorageType shift_out_mask = (StorageType(1) << shift) - 1;
+        const StorageType shift_out_mask =
+            static_cast<StorageType>(StorageType(1) << shift) - 1;
         const StorageType shift_out_value = mantissa & shift_out_mask;
-        const StorageType halfway_value = StorageType(1) << (shift - 1);
+        const StorageType halfway_value =
+            static_cast<StorageType>(StorageType(1) << (shift - 1));
         result.set_biased_exponent(0);
         result.set_mantissa(mantissa >> shift);
         StorageType new_mantissa = result.get_mantissa();
@@ -135,7 +137,8 @@ template <typename T> struct NormalFloat {
       }
     }
 
-    result.set_biased_exponent(exponent + FPBits<T>::EXP_BIAS);
+    result.set_biased_exponent(
+        static_cast<StorageType>(exponent + FPBits<T>::EXP_BIAS));
     result.set_mantissa(mantissa);
     return result.get_val();
   }
@@ -155,7 +158,7 @@ template <typename T> struct NormalFloat {
     // Normalize subnormal numbers.
     if (bits.is_subnormal()) {
       unsigned shift = evaluate_normalization_shift(bits.get_mantissa());
-      mantissa = StorageType(bits.get_mantissa()) << shift;
+      mantissa = static_cast<StorageType>(bits.get_mantissa() << shift);
       exponent = 1 - FPBits<T>::EXP_BIAS - shift;
     } else {
       exponent = bits.get_biased_exponent() - FPBits<T>::EXP_BIAS;
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
index 7a349ddc53724..2ab8fd7c5c710 100644
--- a/libc/src/math/CMakeLists.txt
+++ b/libc/src/math/CMakeLists.txt
@@ -306,6 +306,7 @@ add_math_entrypoint_object(powf)
 add_math_entrypoint_object(remainder)
 add_math_entrypoint_object(remainderf)
 add_math_entrypoint_object(remainderl)
+add_math_entrypoint_object(remainderf16)
 
 add_math_entrypoint_object(remquo)
 add_math_entrypoint_object(remquof)
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
index b1d786fc6b29f..d46684b6626fa 100644
--- a/libc/src/math/generic/CMakeLists.txt
+++ b/libc/src/math/generic/CMakeLists.txt
@@ -2476,6 +2476,19 @@ add_entrypoint_object(
     -O2
 )
 
+add_entrypoint_object(
+  remainderf16
+  SRCS
+    remainderf16.cpp
+  HDRS
+    ../remainderf16.h
+  DEPENDS
+    libc.src.__support.macros.properties.types
+    libc.src.__support.FPUtil.division_and_remainder_operations
+  COMPILE_OPTIONS
+    -O2
+)
+
 add_entrypoint_object(
   hypotf
   SRCS
diff --git a/libc/src/math/generic/remainderf16.cpp b/libc/src/math/generic/remainderf16.cpp
new file mode 100644
index 0000000000000..35177228acdbf
--- /dev/null
+++ b/libc/src/math/generic/remainderf16.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of remainderf16 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/remainderf16.h"
+#include "src/__support/FPUtil/DivisionAndRemainderOperations.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(float16, remainderf16, (float16 x, float16 y)) {
+  int quotient;
+  return fputil::remquo(x, y, quotient);
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/math/remainderf16.h b/libc/src/math/remainderf16.h
new file mode 100644
index 0000000000000..e23eead4bae2c
--- /dev/null
+++ b/libc/src/math/remainderf16.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for remainderf16 ------------------*- 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_REMAINDERF16_H
+#define LLVM_LIBC_SRC_MATH_REMAINDERF16_H
+
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE {
+
+float16 remainderf16(float16 x, float16 y);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_REMAINDERF16_H



More information about the libc-commits mailing list