[libc][math][c23] Add fdimf16 C23 math function (#94354)

#93566
llvm · Jun 5, 2024 · c537f35 · c537f35
1 parent 07b8990
commit c537f35
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Showing 11 changed files with 94 additions and 10 deletions.
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
@@ -503,6 +503,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.ceilf16
     libc.src.math.copysignf16
     libc.src.math.fabsf16
+    libc.src.math.fdimf16
     libc.src.math.floorf16
     libc.src.math.fromfpf16
     libc.src.math.fromfpxf16

diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
@@ -536,6 +536,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
     libc.src.math.ceilf16
     libc.src.math.copysignf16
     libc.src.math.fabsf16
+    libc.src.math.fdimf16
     libc.src.math.floorf16
     libc.src.math.fromfpf16
     libc.src.math.fromfpxf16

diff --git a/libc/docs/math/index.rst b/libc/docs/math/index.rst
@@ -128,7 +128,7 @@ Basic Operations
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | fadd             | N/A              |                 |                        | N/A                  |                        | 7.12.14.1              | F.10.11                    |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
-| fdim             | |check|          | |check|         | |check|                |                      | |check|                | 7.12.12.1              | F.10.9.1                   |
+| fdim             | |check|          | |check|         | |check|                | |check|              | |check|                | 7.12.12.1              | F.10.9.1                   |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+
 | fdiv             | N/A              |                 |                        | N/A                  |                        | 7.12.14.4              | F.10.11                    |
 +------------------+------------------+-----------------+------------------------+----------------------+------------------------+------------------------+----------------------------+

diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
@@ -403,6 +403,7 @@ def StdC : StandardSpec<"stdc"> {
           FunctionSpec<"fdim", RetValSpec<DoubleType>, [ArgSpec<DoubleType>, ArgSpec<DoubleType>]>,
           FunctionSpec<"fdimf", RetValSpec<FloatType>, [ArgSpec<FloatType>, ArgSpec<FloatType>]>,
           FunctionSpec<"fdiml", RetValSpec<LongDoubleType>, [ArgSpec<LongDoubleType>, ArgSpec<LongDoubleType>]>,
+          GuardedFunctionSpec<"fdimf16", RetValSpec<Float16Type>, [ArgSpec<Float16Type>, ArgSpec<Float16Type>], "LIBC_TYPES_HAS_FLOAT16">,
           GuardedFunctionSpec<"fdimf128", RetValSpec<Float128Type>, [ArgSpec<Float128Type>, ArgSpec<Float128Type>], "LIBC_TYPES_HAS_FLOAT128">,
 
           FunctionSpec<"floor", RetValSpec<DoubleType>, [ArgSpec<DoubleType>]>,

diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
@@ -108,6 +108,7 @@ add_math_entrypoint_object(fabsf128)
 add_math_entrypoint_object(fdim)
 add_math_entrypoint_object(fdimf)
 add_math_entrypoint_object(fdiml)
+add_math_entrypoint_object(fdimf16)
 add_math_entrypoint_object(fdimf128)
 
 add_math_entrypoint_object(floor)

diff --git a/libc/src/math/fdimf16.h b/libc/src/math/fdimf16.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for fdimf16 -----------------------*- 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_FDIMF16_H
+#define LLVM_LIBC_SRC_MATH_FDIMF16_H
+
+#include "src/__support/macros/properties/types.h"
+
+namespace LIBC_NAMESPACE {
+
+float16 fdimf16(float16 x, float16 y);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_FDIMF16_H
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
@@ -2397,6 +2397,19 @@ add_entrypoint_object(
     libc.src.__support.FPUtil.basic_operations
 )
 
+add_entrypoint_object(
+  fdimf16
+  SRCS
+    fdimf16.cpp
+  HDRS
+    ../fdimf16.h
+  COMPILE_OPTIONS
+    -O3
+  DEPENDS
+    libc.src.__support.macros.properties.types
+    libc.src.__support.FPUtil.basic_operations
+)
+
 add_entrypoint_object(
   fdimf128
   SRCS

diff --git a/libc/src/math/generic/fdimf16.cpp b/libc/src/math/generic/fdimf16.cpp
@@ -0,0 +1,19 @@
+//===-- Implementation of fdimf16 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/fdimf16.h"
+#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(float16, fdimf16, (float16 x, float16 y)) {
+  return fputil::fdim(x, y);
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/test/src/math/smoke/CMakeLists.txt b/libc/test/src/math/smoke/CMakeLists.txt
@@ -1635,7 +1635,7 @@ add_fp_unittest(
     FDimTest.h
   DEPENDS
     libc.src.math.fdimf
-    libc.src.__support.FPUtil.basic_operations
+    libc.src.__support.CPP.algorithm
     libc.src.__support.FPUtil.fp_bits
 )
 
@@ -1649,7 +1649,7 @@ add_fp_unittest(
     FDimTest.h
   DEPENDS
     libc.src.math.fdim
-    libc.src.__support.FPUtil.basic_operations
+    libc.src.__support.CPP.algorithm
     libc.src.__support.FPUtil.fp_bits
 )
 
@@ -1663,7 +1663,21 @@ add_fp_unittest(
     FDimTest.h
   DEPENDS
     libc.src.math.fdiml
-    libc.src.__support.FPUtil.basic_operations
+    libc.src.__support.CPP.algorithm
+    libc.src.__support.FPUtil.fp_bits
+)
+
+add_fp_unittest(
+  fdimf16_test
+  SUITE
+    libc-math-smoke-tests
+  SRCS
+    fdimf16_test.cpp
+  HDRS
+    FDimTest.h
+  DEPENDS
+    libc.src.math.fdimf16
+    libc.src.__support.CPP.algorithm
     libc.src.__support.FPUtil.fp_bits
 )
 
@@ -1677,7 +1691,7 @@ add_fp_unittest(
     FDimTest.h
   DEPENDS
     libc.src.math.fdimf128
-    libc.src.__support.FPUtil.basic_operations
+    libc.src.__support.CPP.algorithm
     libc.src.__support.FPUtil.fp_bits
 )
 

diff --git a/libc/test/src/math/smoke/FDimTest.h b/libc/test/src/math/smoke/FDimTest.h
@@ -6,7 +6,7 @@
 //
 //===---------------------------------------------------------------------===//
 
-#include "src/__support/FPUtil/BasicOperations.h"
+#include "src/__support/CPP/algorithm.h"
 #include "src/__support/FPUtil/FPBits.h"
 #include "test/UnitTest/FEnvSafeTest.h"
 #include "test/UnitTest/FPMatcher.h"
@@ -61,10 +61,11 @@ class FDimTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
   void test_in_range(FuncPtr func) {
     constexpr StorageType STORAGE_MAX =
         LIBC_NAMESPACE::cpp::numeric_limits<StorageType>::max();
-    constexpr StorageType COUNT = 100'001;
-    constexpr StorageType STEP = STORAGE_MAX / COUNT;
-    for (StorageType i = 0, v = 0, w = STORAGE_MAX; i <= COUNT;
-         ++i, v += STEP, w -= STEP) {
+    constexpr int COUNT = 100'001;
+    constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(
+        static_cast<StorageType>(STORAGE_MAX / COUNT), StorageType(1));
+    StorageType v = 0, w = STORAGE_MAX;
+    for (int i = 0; i <= COUNT; ++i, v += STEP, w -= STEP) {
       FPBits xbits(v), ybits(w);
       if (xbits.is_inf_or_nan())
         continue;

diff --git a/libc/test/src/math/smoke/fdimf16_test.cpp b/libc/test/src/math/smoke/fdimf16_test.cpp
@@ -0,0 +1,13 @@
+//===-- Unittests for fdimf16 ---------------------------------------------===//
+//
+// 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 "FDimTest.h"
+
+#include "src/math/fdimf16.h"
+
+LIST_FDIM_TESTS(float16, LIBC_NAMESPACE::fdimf16);