[libc] move non <bit> functions to math_extras (llvm#84818)

As per TODOs added in llvm@48b0bc8.
TIFitis · Mar 12, 2024 · 0ebf511 · 0ebf511
1 parent 261e564
commit 0ebf511
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Showing 31 changed files with 154 additions and 139 deletions.
diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt
@@ -34,6 +34,7 @@ add_header_library(
   HDRS
     math_extras.h
   DEPENDS
+    libc.src.__support.CPP.bit
     libc.src.__support.CPP.limits
     libc.src.__support.CPP.type_traits
     libc.src.__support.macros.attributes

diff --git a/libc/src/__support/CPP/bit.h b/libc/src/__support/CPP/bit.h
@@ -239,36 +239,6 @@ LIBC_INLINE constexpr To bit_or_static_cast(const From &from) {
   }
 }
 
-// TODO: remove from 'bit.h' as it is not a standard function.
-template <typename T>
-[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
-first_leading_zero(T value) {
-  return value == cpp::numeric_limits<T>::max() ? 0 : countl_one(value) + 1;
-}
-
-// TODO: remove from 'bit.h' as it is not a standard function.
-template <typename T>
-[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
-first_leading_one(T value) {
-  return first_leading_zero(static_cast<T>(~value));
-}
-
-// TODO: remove from 'bit.h' as it is not a standard function.
-template <typename T>
-[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
-first_trailing_zero(T value) {
-  return value == cpp::numeric_limits<T>::max()
-             ? 0
-             : countr_zero(static_cast<T>(~value)) + 1;
-}
-
-// TODO: remove from 'bit.h' as it is not a standard function.
-template <typename T>
-[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
-first_trailing_one(T value) {
-  return value == cpp::numeric_limits<T>::max() ? 0 : countr_zero(value) + 1;
-}
-
 /// Count number of 1's aka population count or Hamming weight.
 ///
 /// Only unsigned integral types are allowed.
@@ -294,13 +264,6 @@ ADD_SPECIALIZATION(unsigned long long, __builtin_popcountll)
 // TODO: 128b specializations?
 #undef ADD_SPECIALIZATION
 
-// TODO: remove from 'bit.h' as it is not a standard function.
-template <typename T>
-[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
-count_zeros(T value) {
-  return popcount<T>(static_cast<T>(~value));
-}
-
 } // namespace LIBC_NAMESPACE::cpp
 
 #endif // LLVM_LIBC_SRC___SUPPORT_CPP_BIT_H
diff --git a/libc/src/__support/math_extras.h b/libc/src/__support/math_extras.h
@@ -10,7 +10,8 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_MATH_EXTRAS_H
 #define LLVM_LIBC_SRC___SUPPORT_MATH_EXTRAS_H
 
-#include "src/__support/CPP/limits.h"        // CHAR_BIT
+#include "src/__support/CPP/bit.h"           // countl_one, countr_zero
+#include "src/__support/CPP/limits.h"        // CHAR_BIT, numeric_limits
 #include "src/__support/CPP/type_traits.h"   // is_unsigned_v
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
 #include "src/__support/macros/config.h"     // LIBC_HAS_BUILTIN
@@ -226,6 +227,40 @@ sub_with_borrow<unsigned long long>(unsigned long long a, unsigned long long b,
 
 #endif // LIBC_HAS_BUILTIN(__builtin_subc)
 
+template <typename T>
+[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
+first_leading_zero(T value) {
+  return value == cpp::numeric_limits<T>::max() ? 0
+                                                : cpp::countl_one(value) + 1;
+}
+
+template <typename T>
+[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
+first_leading_one(T value) {
+  return first_leading_zero(static_cast<T>(~value));
+}
+
+template <typename T>
+[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
+first_trailing_zero(T value) {
+  return value == cpp::numeric_limits<T>::max()
+             ? 0
+             : cpp::countr_zero(static_cast<T>(~value)) + 1;
+}
+
+template <typename T>
+[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
+first_trailing_one(T value) {
+  return value == cpp::numeric_limits<T>::max() ? 0
+                                                : cpp::countr_zero(value) + 1;
+}
+
+template <typename T>
+[[nodiscard]] LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_unsigned_v<T>, int>
+count_zeros(T value) {
+  return cpp::popcount<T>(static_cast<T>(~value));
+}
+
 } // namespace LIBC_NAMESPACE
 
 #endif // LLVM_LIBC_SRC___SUPPORT_MATH_EXTRAS_H
diff --git a/libc/src/stdbit/CMakeLists.txt b/libc/src/stdbit/CMakeLists.txt
@@ -1,30 +1,38 @@
+function(declare_dependencies prefixes dependencies)
+  set(suffixes c s i l ll)
+  foreach(prefix ${prefixes})
+    foreach(suffix IN LISTS suffixes)
+      add_entrypoint_object(
+        stdc_${prefix}_u${suffix}
+        SRCS
+          stdc_${prefix}_u${suffix}.cpp
+        HDRS
+          stdc_${prefix}_u${suffix}.h
+        DEPENDS
+          ${dependencies}
+      )
+    endforeach()
+  endforeach()
+endfunction()
+
+
 set(prefixes
   leading_zeros
   leading_ones
   trailing_zeros
   trailing_ones
-  first_leading_zero
-  first_leading_one
-  first_trailing_zero
-  first_trailing_one
-  count_zeros
   count_ones
   has_single_bit
   bit_width
   bit_floor
   bit_ceil
 )
-set(suffixes c s i l ll)
-foreach(prefix IN LISTS prefixes)
-  foreach(suffix IN LISTS suffixes)
-    add_entrypoint_object(
-      stdc_${prefix}_u${suffix}
-      SRCS
-        stdc_${prefix}_u${suffix}.cpp
-      HDRS
-        stdc_${prefix}_u${suffix}.h
-      DEPENDS
-        libc.src.__support.CPP.bit
-    )
-  endforeach()
-endforeach()
+declare_dependencies("${prefixes}" libc.src.__support.CPP.bit)
+set(prefixes
+  first_leading_zero
+  first_leading_one
+  first_trailing_zero
+  first_trailing_one
+  count_zeros
+)
+declare_dependencies("${prefixes}" libc.src.__support.math_extras)
diff --git a/libc/src/stdbit/stdc_count_zeros_uc.cpp b/libc/src/stdbit/stdc_count_zeros_uc.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_count_zeros_uc.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_count_zeros_uc, (unsigned char value)) {
-  return static_cast<unsigned>(cpp::count_zeros(value));
+  return static_cast<unsigned>(count_zeros(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_count_zeros_ui.cpp b/libc/src/stdbit/stdc_count_zeros_ui.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_count_zeros_ui.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_count_zeros_ui, (unsigned value)) {
-  return static_cast<unsigned>(cpp::count_zeros(value));
+  return static_cast<unsigned>(count_zeros(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_count_zeros_ul.cpp b/libc/src/stdbit/stdc_count_zeros_ul.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_count_zeros_ul.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_count_zeros_ul, (unsigned long value)) {
-  return static_cast<unsigned>(cpp::count_zeros(value));
+  return static_cast<unsigned>(count_zeros(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_count_zeros_ull.cpp b/libc/src/stdbit/stdc_count_zeros_ull.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_count_zeros_ull.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_count_zeros_ull, (unsigned long long value)) {
-  return static_cast<unsigned>(cpp::count_zeros(value));
+  return static_cast<unsigned>(count_zeros(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_count_zeros_us.cpp b/libc/src/stdbit/stdc_count_zeros_us.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_count_zeros_us.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_count_zeros_us, (unsigned short value)) {
-  return static_cast<unsigned>(cpp::count_zeros(value));
+  return static_cast<unsigned>(count_zeros(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_one_uc.cpp b/libc/src/stdbit/stdc_first_leading_one_uc.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_first_leading_one_uc.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_one_uc, (unsigned char value)) {
-  return static_cast<unsigned>(cpp::first_leading_one(value));
+  return static_cast<unsigned>(first_leading_one(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_one_ui.cpp b/libc/src/stdbit/stdc_first_leading_one_ui.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_first_leading_one_ui.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_one_ui, (unsigned value)) {
-  return static_cast<unsigned>(cpp::first_leading_one(value));
+  return static_cast<unsigned>(first_leading_one(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_one_ul.cpp b/libc/src/stdbit/stdc_first_leading_one_ul.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_first_leading_one_ul.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_one_ul, (unsigned long value)) {
-  return static_cast<unsigned>(cpp::first_leading_one(value));
+  return static_cast<unsigned>(first_leading_one(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_one_ull.cpp b/libc/src/stdbit/stdc_first_leading_one_ull.cpp
@@ -8,14 +8,14 @@
 
 #include "src/stdbit/stdc_first_leading_one_ull.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_one_ull,
                    (unsigned long long value)) {
-  return static_cast<unsigned>(cpp::first_leading_one(value));
+  return static_cast<unsigned>(first_leading_one(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_one_us.cpp b/libc/src/stdbit/stdc_first_leading_one_us.cpp
@@ -8,14 +8,14 @@
 
 #include "src/stdbit/stdc_first_leading_one_us.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_one_us,
                    (unsigned short value)) {
-  return static_cast<unsigned>(cpp::first_leading_one(value));
+  return static_cast<unsigned>(first_leading_one(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_zero_uc.cpp b/libc/src/stdbit/stdc_first_leading_zero_uc.cpp
@@ -8,14 +8,14 @@
 
 #include "src/stdbit/stdc_first_leading_zero_uc.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_zero_uc,
                    (unsigned char value)) {
-  return static_cast<unsigned>(cpp::first_leading_zero(value));
+  return static_cast<unsigned>(first_leading_zero(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_zero_ui.cpp b/libc/src/stdbit/stdc_first_leading_zero_ui.cpp
@@ -8,13 +8,13 @@
 
 #include "src/stdbit/stdc_first_leading_zero_ui.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_zero_ui, (unsigned value)) {
-  return static_cast<unsigned>(cpp::first_leading_zero(value));
+  return static_cast<unsigned>(first_leading_zero(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_zero_ul.cpp b/libc/src/stdbit/stdc_first_leading_zero_ul.cpp
@@ -8,14 +8,14 @@
 
 #include "src/stdbit/stdc_first_leading_zero_ul.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_zero_ul,
                    (unsigned long value)) {
-  return static_cast<unsigned>(cpp::first_leading_zero(value));
+  return static_cast<unsigned>(first_leading_zero(value));
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdbit/stdc_first_leading_zero_ull.cpp b/libc/src/stdbit/stdc_first_leading_zero_ull.cpp
@@ -8,14 +8,14 @@
 
 #include "src/stdbit/stdc_first_leading_zero_ull.h"
 
-#include "src/__support/CPP/bit.h"
 #include "src/__support/common.h"
+#include "src/__support/math_extras.h"
 
 namespace LIBC_NAMESPACE {
 
 LLVM_LIBC_FUNCTION(unsigned, stdc_first_leading_zero_ull,
                    (unsigned long long value)) {
-  return static_cast<unsigned>(cpp::first_leading_zero(value));
+  return static_cast<unsigned>(first_leading_zero(value));
 }
 
 } // namespace LIBC_NAMESPACE