[libc] Provide isnan, isnanf and isnanl functions (#96008)

petrhosek · web-flow · commit b6e41c159b22 · 2024-07-09T21:28:51.000-07:00
While C99 defines type generic isnan macro, BSD provided isnan, isnanf
and isnanl in prior C standards and existing code still relies on these.
diff --git a/libc/config/baremetal/arm/entrypoints.txt b/libc/config/baremetal/arm/entrypoints.txt
@@ -314,6 +314,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.ilogb
     libc.src.math.ilogbf
     libc.src.math.ilogbl
+    libc.src.math.isnan
+    libc.src.math.isnanf
+    libc.src.math.isnanl
     libc.src.math.ldexp
     libc.src.math.ldexpf
     libc.src.math.ldexpl
diff --git a/libc/config/baremetal/riscv/entrypoints.txt b/libc/config/baremetal/riscv/entrypoints.txt
@@ -309,6 +309,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.ilogb
     libc.src.math.ilogbf
     libc.src.math.ilogbl
+    libc.src.math.isnan
+    libc.src.math.isnanf
+    libc.src.math.isnanl
     libc.src.math.ldexp
     libc.src.math.ldexpf
     libc.src.math.ldexpl
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
@@ -424,6 +424,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.ilogb
     libc.src.math.ilogbf
     libc.src.math.ilogbl
+    libc.src.math.isnan
+    libc.src.math.isnanf
+    libc.src.math.isnanl
     libc.src.math.ldexp
     libc.src.math.ldexpf
     libc.src.math.ldexpl
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
@@ -426,6 +426,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.ilogb
     libc.src.math.ilogbf
     libc.src.math.ilogbl
+    libc.src.math.isnan
+    libc.src.math.isnanf
+    libc.src.math.isnanl
     libc.src.math.ldexp
     libc.src.math.ldexpf
     libc.src.math.ldexpl
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
@@ -450,6 +450,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.ilogb
     libc.src.math.ilogbf
     libc.src.math.ilogbl
+    libc.src.math.isnan
+    libc.src.math.isnanf
+    libc.src.math.isnanl
     libc.src.math.ldexp
     libc.src.math.ldexpf
     libc.src.math.ldexpl
diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
@@ -122,6 +122,7 @@ add_gen_header(
     .llvm_libc_common_h
     .llvm-libc-macros.float16_macros
     .llvm-libc-macros.math_macros
+    .llvm-libc-macros.math_function_macros
     .llvm-libc-types.double_t
     .llvm-libc-types.float_t
     .llvm-libc-types.float128
diff --git a/libc/include/llvm-libc-macros/CMakeLists.txt b/libc/include/llvm-libc-macros/CMakeLists.txt
@@ -117,6 +117,12 @@ add_macro_header(
     .limits_macros
 )
 
+add_macro_header(
+  math_function_macros
+  HDR
+    math-function-macros.h
+)
+
 add_macro_header(
   offsetof_macro
   HDR
diff --git a/libc/include/llvm-libc-macros/math-function-macros.h b/libc/include/llvm-libc-macros/math-function-macros.h
@@ -0,0 +1,16 @@
+//===-- Definition of function macros from math.h -------------------------===//
+//
+// 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_MACROS_MATH_FUNCTION_MACROS_H
+#define LLVM_LIBC_MACROS_MATH_FUNCTION_MACROS_H
+
+#define isfinite(x) __builtin_isfinite(x)
+#define isinf(x) __builtin_isinf(x)
+#define isnan(x) __builtin_isnan(x)
+
+#endif // LLVM_LIBC_MACROS_MATH_FUNCTION_MACROS_H
diff --git a/libc/include/llvm-libc-macros/math-macros.h b/libc/include/llvm-libc-macros/math-macros.h
@@ -49,9 +49,4 @@
 #define math_errhandling (MATH_ERRNO | MATH_ERREXCEPT)
 #endif
 
-// TODO: Move generic functional math macros to a separate header file.
-#define isfinite(x) __builtin_isfinite(x)
-#define isinf(x) __builtin_isinf(x)
-#define isnan(x) __builtin_isnan(x)
-
 #endif // LLVM_LIBC_MACROS_MATH_MACROS_H
diff --git a/libc/include/math.h.def b/libc/include/math.h.def
@@ -17,4 +17,7 @@
 
 %%public_api()
 
+
+#include "llvm-libc-macros/math-function-macros.h"
+
 #endif // LLVM_LIBC_MATH_H
diff --git a/libc/spec/bsd_ext.td b/libc/spec/bsd_ext.td
@@ -1,4 +1,16 @@
 def BsdExtensions : StandardSpec<"BSDExtensions"> {
+  HeaderSpec Math = HeaderSpec<
+      "math.h",
+      [], // Macros
+      [], // Types
+      [], // Enumerations
+      [
+          FunctionSpec<"isnan", RetValSpec<IntType>, [ArgSpec<DoubleType>]>,
+          FunctionSpec<"isnanf", RetValSpec<IntType>, [ArgSpec<FloatType>]>,
+          FunctionSpec<"isnanl", RetValSpec<IntType>, [ArgSpec<LongDoubleType>]>,
+      ]
+  >;
+
   HeaderSpec String = HeaderSpec<
       "string.h",
       [], // Macros
@@ -67,6 +79,7 @@ def BsdExtensions : StandardSpec<"BSDExtensions"> {
   >;
 
   let Headers = [
+    Math,
     String,
     Strings,
     SysWait,
diff --git a/libc/src/math/CMakeLists.txt b/libc/src/math/CMakeLists.txt
@@ -245,6 +245,10 @@ add_math_entrypoint_object(ilogbl)
 add_math_entrypoint_object(ilogbf16)
 add_math_entrypoint_object(ilogbf128)
 
+add_math_entrypoint_object(isnan)
+add_math_entrypoint_object(isnanf)
+add_math_entrypoint_object(isnanl)
+
 add_math_entrypoint_object(llogb)
 add_math_entrypoint_object(llogbf)
 add_math_entrypoint_object(llogbl)
diff --git a/libc/src/math/generic/CMakeLists.txt b/libc/src/math/generic/CMakeLists.txt
@@ -2848,6 +2848,36 @@ add_entrypoint_object(
     -O3
 )
 
+add_entrypoint_object(
+  isnan
+  SRCS
+    isnan.cpp
+  HDRS
+    ../isnan.h
+  COMPILE_OPTIONS
+    -O3
+)
+
+add_entrypoint_object(
+  isnanf
+  SRCS
+    isnanf.cpp
+  HDRS
+    ../isnanf.h
+  COMPILE_OPTIONS
+    -O3
+)
+
+add_entrypoint_object(
+  isnanl
+  SRCS
+    isnanl.cpp
+  HDRS
+    ../isnanl.h
+  COMPILE_OPTIONS
+    -O3
+)
+
 add_entrypoint_object(
   nan
   SRCS
diff --git a/libc/src/math/generic/isnan.cpp b/libc/src/math/generic/isnan.cpp
@@ -0,0 +1,16 @@
+//===-- Implementation of isnan 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/isnan.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, isnan, (double x)) { return __builtin_isnan(x); }
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/math/generic/isnanf.cpp b/libc/src/math/generic/isnanf.cpp
@@ -0,0 +1,16 @@
+//===-- Implementation of isnanf 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/isnanf.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, isnanf, (float x)) { return __builtin_isnan(x); }
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/math/generic/isnanl.cpp b/libc/src/math/generic/isnanl.cpp
@@ -0,0 +1,16 @@
+//===-- Implementation of isnanl 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/isnanl.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, isnanl, (long double x)) { return __builtin_isnan(x); }
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/math/isnan.h b/libc/src/math/isnan.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for isnan -------------------------*- 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_ISNAN_H
+#define LLVM_LIBC_SRC_MATH_ISNAN_H
+
+namespace LIBC_NAMESPACE {
+
+int isnan(double x);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_ISNAN_H
diff --git a/libc/src/math/isnanf.h b/libc/src/math/isnanf.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for isnanf ------------------------*- 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_ISNANF_H
+#define LLVM_LIBC_SRC_MATH_ISNANF_H
+
+namespace LIBC_NAMESPACE {
+
+int isnanf(float x);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_ISNANF_H
diff --git a/libc/src/math/isnanl.h b/libc/src/math/isnanl.h
@@ -0,0 +1,18 @@
+//===-- Implementation header for isnanl ------------------------*- 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_ISNANL_H
+#define LLVM_LIBC_SRC_MATH_ISNANL_H
+
+namespace LIBC_NAMESPACE {
+
+int isnanl(long double x);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_MATH_ISNANL_H
