[libc][math] Refactor fma implementation to header-only in src/__support/math folder.

Author: bassiounix

libc/shared/math.h

@@ -57,6 +57,7 @@
 #include "math/expm1.h"
 #include "math/expm1f.h"
 #include "math/expm1f16.h"
+#include "math/fma.h"
 #include "math/frexpf.h"
 #include "math/frexpf128.h"
 #include "math/frexpf16.h"

libc/shared/math/fma.h

@@ -0,0 +1,23 @@
+//===-- Shared fma 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 LLVM_LIBC_SHARED_MATH_FMA_H
+#define LLVM_LIBC_SHARED_MATH_FMA_H
+
+#include "shared/libc_common.h"
+#include "src/__support/math/fma.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using math::fma;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SHARED_MATH_FMA_H

libc/src/__support/math/CMakeLists.txt

@@ -593,6 +593,14 @@ add_header_library(
     libc.src.__support.math.exp10_float16_constants
 )
 
+add_header_library(
+  fma
+  HDRS
+    fma.h
+  DEPENDS
+    libc.src.__support.FPUtil.fma
+)
+
 add_header_library(
   frexpf128
   HDRS

libc/src/__support/math/fma.h

@@ -0,0 +1,27 @@
+//===-- Implementation header for fma ---------------------------*- 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___SUPPORT_MATH_FMA_H
+#define LLVM_LIBC_SRC___SUPPORT_MATH_FMA_H
+
+#include "src/__support/FPUtil/FMA.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+namespace math {
+
+LIBC_INLINE static double fma(double x, double y, double z) {
+  return fputil::fma<double>(x, y, z);
+}
+
+} // namespace math
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_MATH_FMA_H

libc/src/math/generic/CMakeLists.txt

@@ -4722,7 +4722,7 @@ add_entrypoint_object(
   HDRS
     ../fma.h
   DEPENDS
-    libc.src.__support.FPUtil.fma
+    libc.src.__support.math.fma
 )
 
 add_entrypoint_object(

libc/src/math/generic/fma.cpp

@@ -7,15 +7,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/math/fma.h"
-#include "src/__support/common.h"
-
-#include "src/__support/FPUtil/FMA.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/math/fma.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(double, fma, (double x, double y, double z)) {
-  return fputil::fma<double>(x, y, z);
+  return math::fma(x, y, z);
 }
 
 } // namespace LIBC_NAMESPACE_DECL

libc/test/shared/CMakeLists.txt

@@ -53,6 +53,7 @@ add_fp_unittest(
     libc.src.__support.math.exp10f16
     libc.src.__support.math.expf
     libc.src.__support.math.expf16
+    libc.src.__support.math.fma
     libc.src.__support.math.frexpf
     libc.src.__support.math.frexpf128
     libc.src.__support.math.frexpf16

libc/test/shared/shared_math_test.cpp

@@ -90,6 +90,7 @@ TEST(LlvmLibcSharedMathTest, AllDouble) {
   EXPECT_FP_EQ(0x1p+0, LIBC_NAMESPACE::shared::exp2(0.0));
   EXPECT_FP_EQ(0x1p+0, LIBC_NAMESPACE::shared::exp10(0.0));
   EXPECT_FP_EQ(0x0p+0, LIBC_NAMESPACE::shared::expm1(0.0));
+  EXPECT_FP_EQ(0x0p+0, LIBC_NAMESPACE::shared::fma(0.0, 0.0, 0.0));
 }
 
 #ifdef LIBC_TYPES_HAS_FLOAT128

utils/bazel/llvm-project-overlay/libc/BUILD.bazel

@@ -2791,6 +2791,14 @@ libc_support_library(
     ],
 )
 
+libc_support_library(
+    name = "__support_math_fma",
+    hdrs = ["src/__support/math/fma.h"],
+    deps = [
+        ":__support_fputil_fma",
+    ],
+)
+
 libc_support_library(
     name = "__support_math_frexpf128",
     hdrs = ["src/__support/math/frexpf128.h"],
@@ -3093,15 +3101,15 @@ libc_support_library(
     name = "__support_math_expm1f16",
     hdrs = ["src/__support/math/expm1f16.h"],
     deps = [
+        ":__support_fputil_except_value_utils",
         ":__support_fputil_fma",
         ":__support_fputil_multiply_add",
         ":__support_fputil_nearest_integer",
         ":__support_fputil_polyeval",
         ":__support_fputil_rounding_mode",
-        ":__support_fputil_except_value_utils",
         ":__support_macros_optimization",
         ":__support_macros_properties_cpu_features",
-        ":__support_math_expxf16_utils"
+        ":__support_math_expxf16_utils",
     ],
 )
 
@@ -4001,7 +4009,7 @@ libc_math_function(name = "floorf16")
 libc_math_function(
     name = "fma",
     additional_deps = [
-        ":__support_fputil_fma",
+        ":__support_math_fma",
     ],
 )