[libc][stdfix] Add FXRep helper class for fixed point types. (#81272)

3 files changed, 185 insertions, 0 deletions

diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt
index 013627788940..1a4b3e9a2145 100644
--- a/libc/src/__support/CMakeLists.txt
+++ b/libc/src/__support/CMakeLists.txt
@@ -280,3 +280,5 @@ add_subdirectory(threads)
 add_subdirectory(File)
 
 add_subdirectory(HashTable)
+
+add_subdirectory(fixed_point)
diff --git a/libc/src/__support/fixed_point/CMakeLists.txt b/libc/src/__support/fixed_point/CMakeLists.txt
new file mode 100644
index 000000000000..644cbff37aaa
--- /dev/null
+++ b/libc/src/__support/fixed_point/CMakeLists.txt
@@ -0,0 +1,8 @@
+add_header_library(
+  fx_rep
+  HDRS
+    fx_rep.h
+  DEPENDS
+    libc.include.llvm-libc-macros.stdfix_macros
+    libc.src.__support.macros.attributes
+)
diff --git a/libc/src/__support/fixed_point/fx_rep.h b/libc/src/__support/fixed_point/fx_rep.h
new file mode 100644
index 000000000000..88cba3c95c66
--- /dev/null
+++ b/libc/src/__support/fixed_point/fx_rep.h
@@ -0,0 +1,175 @@
+//===-- Utility class to manipulate fixed point numbers. --*- 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_FIXEDPOINT_FXREP_H
+#define LLVM_LIBC_SRC___SUPPORT_FIXEDPOINT_FXREP_H
+
+#include "include/llvm-libc-macros/stdfix-macros.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE, LIBC_INLINE_VAR
+
+#ifdef LIBC_COMPILER_HAS_FIXED_POINT
+
+namespace LIBC_NAMESPACE::fixed_point {
+
+template <typename T> struct FXRep;
+
+template <> struct FXRep<short fract> {
+  using Type = short _Fract;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 1;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = SFRACT_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return SFRACT_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return SFRACT_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0HR; }
+  LIBC_INLINE static constexpr Type EPS() { return SFRACT_EPSILON; }
+};
+
+template <> struct FXRep<unsigned short fract> {
+  using Type = unsigned short fract;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = USFRACT_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return USFRACT_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return USFRACT_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0UHR; }
+  LIBC_INLINE static constexpr Type EPS() { return USFRACT_EPSILON; }
+};
+
+template <> struct FXRep<fract> {
+  using Type = fract;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 1;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = FRACT_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return FRACT_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return FRACT_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0R; }
+  LIBC_INLINE static constexpr Type EPS() { return FRACT_EPSILON; }
+};
+
+template <> struct FXRep<unsigned fract> {
+  using Type = unsigned fract;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = UFRACT_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return UFRACT_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return UFRACT_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0UR; }
+  LIBC_INLINE static constexpr Type EPS() { return UFRACT_EPSILON; }
+};
+
+template <> struct FXRep<long fract> {
+  using Type = long fract;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 1;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = LFRACT_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return LFRACT_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return LFRACT_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0LR; }
+  LIBC_INLINE static constexpr Type EPS() { return LFRACT_EPSILON; }
+};
+
+template <> struct FXRep<unsigned long fract> {
+  using Type = unsigned long fract;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = ULFRACT_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return ULFRACT_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return ULFRACT_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0ULR; }
+  LIBC_INLINE static constexpr Type EPS() { return ULFRACT_EPSILON; }
+};
+
+template <> struct FXRep<short accum> {
+  using Type = short accum;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 1;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = SACCUM_IBIT;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = SACCUM_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return SACCUM_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return SACCUM_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0HK; }
+  LIBC_INLINE static constexpr Type EPS() { return SACCUM_EPSILON; }
+};
+
+template <> struct FXRep<unsigned short accum> {
+  using Type = unsigned short accum;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = UACCUM_IBIT;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = USACCUM_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return USACCUM_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return USACCUM_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0UHK; }
+  LIBC_INLINE static constexpr Type EPS() { return USACCUM_EPSILON; }
+};
+
+template <> struct FXRep<accum> {
+  using Type = accum;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 1;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = ACCUM_IBIT;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = ACCUM_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return ACCUM_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return ACCUM_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0K; }
+  LIBC_INLINE static constexpr Type EPS() { return ACCUM_EPSILON; }
+};
+
+template <> struct FXRep<unsigned accum> {
+  using Type = unsigned accum;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = UACCUM_IBIT;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = UACCUM_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return UACCUM_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return UACCUM_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0UK; }
+  LIBC_INLINE static constexpr Type EPS() { return UACCUM_EPSILON; }
+};
+
+template <> struct FXRep<long accum> {
+  using Type = long accum;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 1;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = LACCUM_IBIT;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = LACCUM_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return LACCUM_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return LACCUM_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0LK; }
+  LIBC_INLINE static constexpr Type EPS() { return LACCUM_EPSILON; }
+};
+
+template <> struct FXRep<unsigned long accum> {
+  using Type = unsigned long accum;
+  LIBC_INLINE_VAR static constexpr int SIGN_LEN = 0;
+  LIBC_INLINE_VAR static constexpr int INTEGRAL_LEN = ULACCUM_IBIT;
+  LIBC_INLINE_VAR static constexpr int FRACTION_LEN = ULACCUM_FBIT;
+  LIBC_INLINE static constexpr Type MIN() { return ULACCUM_MIN; }
+  LIBC_INLINE static constexpr Type MAX() { return ULACCUM_MIN; }
+  LIBC_INLINE static constexpr Type ZERO() { return 0.0ULK; }
+  LIBC_INLINE static constexpr Type EPS() { return ULACCUM_EPSILON; }
+};
+
+template <> struct FXRep<short sat fract> : FXRep<short fract> {};
+template <> struct FXRep<sat fract> : FXRep<fract> {};
+template <> struct FXRep<long sat fract> : FXRep<long fract> {};
+template <>
+struct FXRep<unsigned short sat fract> : FXRep<unsigned short fract> {};
+template <> struct FXRep<unsigned sat fract> : FXRep<unsigned fract> {};
+template <>
+struct FXRep<unsigned long sat fract> : FXRep<unsigned long fract> {};
+
+template <> struct FXRep<short sat accum> : FXRep<short accum> {};
+template <> struct FXRep<sat accum> : FXRep<accum> {};
+template <> struct FXRep<long sat accum> : FXRep<long accum> {};
+template <>
+struct FXRep<unsigned short sat accum> : FXRep<unsigned short accum> {};
+template <> struct FXRep<unsigned sat accum> : FXRep<unsigned accum> {};
+template <>
+struct FXRep<unsigned long sat accum> : FXRep<unsigned long accum> {};
+
+} // namespace LIBC_NAMESPACE::fixed_point
+
+#endif // LIBC_COMPILER_HAS_FIXED_POINT
+
+#endif // LLVM_LIBC_SRC___SUPPORT_FIXEDPOINT_FXREP_H