[libc][NFC] Move Sign type to separate header (llvm#85930)

Author: gchatelet

libc/src/__support/CMakeLists.txt

@@ -41,6 +41,14 @@ add_header_library(
     libc.src.__support.macros.config
 )
 
+add_header_library(
+  sign
+  HDRS
+    sign.h
+  DEPENDS
+    libc.src.__support.macros.attributes
+)
+
 add_header_library(
   error_or
   HDRS

libc/src/__support/FPUtil/CMakeLists.txt

@@ -35,6 +35,7 @@ add_header_library(
     libc.src.__support.macros.attributes
     libc.src.__support.macros.properties.types
     libc.src.__support.math_extras
+    libc.src.__support.sign
     libc.src.__support.uint128
 )
 

libc/src/__support/FPUtil/FPBits.h

@@ -17,6 +17,7 @@
 #include "src/__support/macros/attributes.h" // LIBC_INLINE, LIBC_INLINE_VAR
 #include "src/__support/macros/properties/types.h" // LIBC_TYPES_HAS_FLOAT128
 #include "src/__support/math_extras.h"             // mask_trailing_ones
+#include "src/__support/sign.h"                    // Sign
 
 #include <stdint.h>
 
@@ -32,32 +33,6 @@ enum class FPType {
   X86_Binary80,
 };
 
-// A type to interact with floating point type signs.
-// This may be moved outside of 'fputil' if useful.
-struct Sign {
-  LIBC_INLINE constexpr bool is_pos() const { return !is_negative; }
-  LIBC_INLINE constexpr bool is_neg() const { return is_negative; }
-
-  LIBC_INLINE friend constexpr bool operator==(Sign a, Sign b) {
-    return a.is_negative == b.is_negative;
-  }
-  LIBC_INLINE friend constexpr bool operator!=(Sign a, Sign b) {
-    return !(a == b);
-  }
-
-  static const Sign POS;
-  static const Sign NEG;
-
-private:
-  LIBC_INLINE constexpr explicit Sign(bool is_negative)
-      : is_negative(is_negative) {}
-
-  bool is_negative;
-};
-
-LIBC_INLINE_VAR constexpr Sign Sign::NEG = Sign(true);
-LIBC_INLINE_VAR constexpr Sign Sign::POS = Sign(false);
-
 // The classes hierarchy is as follows:
 //
 //             ┌───────────────────┐

libc/src/__support/FPUtil/fpbits_str.h

@@ -35,7 +35,6 @@ using ZeroPaddedHexFmt = IntegerToString<
 //    floating encoding.
 template <typename T> LIBC_INLINE cpp::string str(fputil::FPBits<T> x) {
   using StorageType = typename fputil::FPBits<T>::StorageType;
-  using Sign = fputil::Sign;
 
   if (x.is_nan())
     return "(NaN)";

libc/src/__support/sign.h

@@ -0,0 +1,40 @@
+//===-- A simple sign type --------------------------------------*- 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_SIGN_H
+#define LLVM_LIBC_SRC___SUPPORT_SIGN_H
+
+#include "src/__support/macros/attributes.h" // LIBC_INLINE, LIBC_INLINE_VAR
+
+// A type to interact with signed arithmetic types.
+struct Sign {
+  LIBC_INLINE constexpr bool is_pos() const { return !is_negative; }
+  LIBC_INLINE constexpr bool is_neg() const { return is_negative; }
+
+  LIBC_INLINE friend constexpr bool operator==(Sign a, Sign b) {
+    return a.is_negative == b.is_negative;
+  }
+
+  LIBC_INLINE friend constexpr bool operator!=(Sign a, Sign b) {
+    return !(a == b);
+  }
+
+  static const Sign POS;
+  static const Sign NEG;
+
+private:
+  LIBC_INLINE constexpr explicit Sign(bool is_negative)
+      : is_negative(is_negative) {}
+
+  bool is_negative;
+};
+
+LIBC_INLINE_VAR constexpr Sign Sign::NEG = Sign(true);
+LIBC_INLINE_VAR constexpr Sign Sign::POS = Sign(false);
+
+#endif // LLVM_LIBC_SRC___SUPPORT_SIGN_H

libc/src/__support/str_to_float.h

@@ -513,7 +513,6 @@ clinger_fast_path(ExpandedFloat<T> init_num,
                   RoundDirection round = RoundDirection::Nearest) {
   using FPBits = typename fputil::FPBits<T>;
   using StorageType = typename FPBits::StorageType;
-  using Sign = fputil::Sign;
 
   StorageType mantissa = init_num.mantissa;
   int32_t exp10 = init_num.exponent;
@@ -1085,7 +1084,6 @@ template <class T>
 LIBC_INLINE StrToNumResult<T> strtofloatingpoint(const char *__restrict src) {
   using FPBits = typename fputil::FPBits<T>;
   using StorageType = typename FPBits::StorageType;
-  using Sign = fputil::Sign;
 
   FPBits result = FPBits();
   bool seen_digit = false;
@@ -1223,7 +1221,7 @@ template <class T> LIBC_INLINE StrToNumResult<T> strtonan(const char *arg) {
   if (arg[index] == '\0')
     nan_mantissa = nan_mantissa_from_ncharseq<T>(cpp::string_view(arg, index));
 
-  result = FPBits::quiet_nan(fputil::Sign::POS, nan_mantissa);
+  result = FPBits::quiet_nan(Sign::POS, nan_mantissa);
   return {result.get_val(), 0, error};
 }
 

libc/src/math/generic/acosf.cpp

@@ -38,7 +38,7 @@ static constexpr fputil::ExceptValues<float, N_EXCEPTS> ACOSF_EXCEPTS = {{
 
 LLVM_LIBC_FUNCTION(float, acosf, (float x)) {
   using FPBits = typename fputil::FPBits<float>;
-  using Sign = fputil::Sign;
+
   FPBits xbits(x);
   uint32_t x_uint = xbits.uintval();
   uint32_t x_abs = xbits.uintval() & 0x7fff'ffffU;

libc/src/math/generic/asinf.cpp

@@ -44,7 +44,7 @@ static constexpr fputil::ExceptValues<float, N_EXCEPTS> ASINF_EXCEPTS_HI = {{
 
 LLVM_LIBC_FUNCTION(float, asinf, (float x)) {
   using FPBits = typename fputil::FPBits<float>;
-  using Sign = fputil::Sign;
+
   FPBits xbits(x);
   uint32_t x_uint = xbits.uintval();
   uint32_t x_abs = xbits.uintval() & 0x7fff'ffffU;

libc/src/math/generic/atanf.cpp

@@ -20,7 +20,6 @@ namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(float, atanf, (float x)) {
   using FPBits = typename fputil::FPBits<float>;
-  using Sign = fputil::Sign;
 
   constexpr double FINAL_SIGN[2] = {1.0, -1.0};
   constexpr double SIGNED_PI_OVER_2[2] = {0x1.921fb54442d18p0,

libc/src/math/generic/atanhf.cpp

@@ -15,7 +15,7 @@ namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(float, atanhf, (float x)) {
   using FPBits = typename fputil::FPBits<float>;
-  using Sign = fputil::Sign;
+
   FPBits xbits(x);
   Sign sign = xbits.sign();
   uint32_t x_abs = xbits.abs().uintval();