diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt
index 0e0556f4eecfd..17f03a6b6c4a0 100644
--- a/libc/src/__support/CMakeLists.txt
+++ b/libc/src/__support/CMakeLists.txt
@@ -87,7 +87,7 @@ add_header_library(
     endian_internal.h
     macros/properties/architectures.h
     macros/attributes.h
-    macros/properties/cpu_features.h
+    macros/config.h
 )
 
 add_header_library(
diff --git a/libc/src/__support/FPUtil/CMakeLists.txt b/libc/src/__support/FPUtil/CMakeLists.txt
index 522b4afefd48d..bfe0170f09fd9 100644
--- a/libc/src/__support/FPUtil/CMakeLists.txt
+++ b/libc/src/__support/FPUtil/CMakeLists.txt
@@ -110,6 +110,7 @@ add_header_library(
   DEPENDS
     libc.src.__support.common
     libc.src.__support.FPUtil.generic.sqrt
+    libc.src.__support.macros.properties.cpu_features
 )
 
 add_header_library(
@@ -120,6 +121,7 @@ add_header_library(
     libc.src.__support.common
     libc.src.__support.CPP.type_traits
     libc.src.__support.FPUtil.generic.fma
+    libc.src.__support.macros.properties.cpu_features
   FLAGS
     FMA_OPT
 )
@@ -130,6 +132,7 @@ add_header_library(
     multiply_add.h
   DEPENDS
     libc.src.__support.common
+    libc.src.__support.macros.properties.cpu_features
   FLAGS
     FMA_OPT
 )
@@ -150,6 +153,7 @@ add_header_library(
   DEPENDS
     libc.src.__support.common
     libc.src.__support.macros.optimization
+    libc.src.__support.macros.properties.cpu_features
   FLAGS
     ROUND_OPT
 )
@@ -161,6 +165,7 @@ add_header_library(
   DEPENDS
     libc.src.__support.common
     libc.src.__support.number_pair
+    libc.src.__support.macros.properties.cpu_features
     .multiply_add
 )
 
diff --git a/libc/src/dirent/readdir.h b/libc/src/dirent/readdir.h
index 2dcf5360ebd35..bc46a1bbfbf4a 100644
--- a/libc/src/dirent/readdir.h
+++ b/libc/src/dirent/readdir.h
@@ -9,7 +9,7 @@
 #ifndef LLVM_LIBC_SRC_DIRENT_READDIR_H
 #define LLVM_LIBC_SRC_DIRENT_READDIR_H
 
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h" // LIBC_NAMESPACE_DECL
 #include <dirent.h>
 
 namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/string/allocating_string_utils.h b/libc/src/string/allocating_string_utils.h
index b3a8663c2f477..1dece510e7969 100644
--- a/libc/src/string/allocating_string_utils.h
+++ b/libc/src/string/allocating_string_utils.h
@@ -11,7 +11,7 @@
 
 #include "src/__support/CPP/new.h"
 #include "src/__support/CPP/optional.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h" // LIBC_NAMESPACE_DECL
 #include "src/string/memory_utils/inline_memcpy.h"
 #include "src/string/string_utils.h"
 
diff --git a/libc/src/string/memory_utils/aarch64/inline_bcmp.h b/libc/src/string/memory_utils/aarch64/inline_bcmp.h
index 93196415f2662..e41ac202dbaac 100644
--- a/libc/src/string/memory_utils/aarch64/inline_bcmp.h
+++ b/libc/src/string/memory_utils/aarch64/inline_bcmp.h
@@ -9,7 +9,7 @@
 #define LIBC_SRC_STRING_MEMORY_UTILS_AARCH64_INLINE_BCMP_H
 
 #include "src/__support/macros/attributes.h"   // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h"       // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/optimization.h" // LIBC_UNLIKELY
 #include "src/string/memory_utils/op_aarch64.h"
 #include "src/string/memory_utils/op_generic.h"
diff --git a/libc/src/string/memory_utils/aarch64/inline_memset.h b/libc/src/string/memory_utils/aarch64/inline_memset.h
index a2c05534aa330..efcbfd0705983 100644
--- a/libc/src/string/memory_utils/aarch64/inline_memset.h
+++ b/libc/src/string/memory_utils/aarch64/inline_memset.h
@@ -9,7 +9,7 @@
 #define LIBC_SRC_STRING_MEMORY_UTILS_AARCH64_INLINE_MEMSET_H
 
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/string/memory_utils/op_aarch64.h"
 #include "src/string/memory_utils/op_generic.h"
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
diff --git a/libc/src/string/memory_utils/generic/builtin.h b/libc/src/string/memory_utils/generic/builtin.h
index 5670a4e610565..2b9ecc0c046eb 100644
--- a/libc/src/string/memory_utils/generic/builtin.h
+++ b/libc/src/string/memory_utils/generic/builtin.h
@@ -10,7 +10,7 @@
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_GENERIC_BUILTIN_H
 
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
 
 #include <stddef.h> // size_t
diff --git a/libc/src/string/memory_utils/inline_bcmp.h b/libc/src/string/memory_utils/inline_bcmp.h
index 14cf16ebb6b69..52c738d3a4ce2 100644
--- a/libc/src/string/memory_utils/inline_bcmp.h
+++ b/libc/src/string/memory_utils/inline_bcmp.h
@@ -10,7 +10,8 @@
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_BCMP_H
 
 #include "src/__support/common.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h" // LIBC_TARGET_ARCH_IS_
 
 #include <stddef.h> // size_t
diff --git a/libc/src/string/memory_utils/inline_bzero.h b/libc/src/string/memory_utils/inline_bzero.h
index 4a92e8b57a68e..a131b68725de7 100644
--- a/libc/src/string/memory_utils/inline_bzero.h
+++ b/libc/src/string/memory_utils/inline_bzero.h
@@ -10,7 +10,8 @@
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_BZERO_H
 
 #include "src/__support/common.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/string/memory_utils/inline_memset.h"
 
 #include <stddef.h> // size_t
diff --git a/libc/src/string/memory_utils/inline_memmem.h b/libc/src/string/memory_utils/inline_memmem.h
index 15e3d633985d6..1e9649c6e65e3 100644
--- a/libc/src/string/memory_utils/inline_memmem.h
+++ b/libc/src/string/memory_utils/inline_memmem.h
@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_MEMMEM_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_MEMMEM_H
 
-#include "src/__support/macros/attributes.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 
 #include <stddef.h>
 
diff --git a/libc/src/string/memory_utils/inline_memmove.h b/libc/src/string/memory_utils/inline_memmove.h
index 85d0159701ece..84671c5c1797e 100644
--- a/libc/src/string/memory_utils/inline_memmove.h
+++ b/libc/src/string/memory_utils/inline_memmove.h
@@ -9,7 +9,8 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_MEMMOVE_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_MEMMOVE_H
 
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include <stddef.h> // size_t, ptrdiff_t
 
 #if defined(LIBC_TARGET_ARCH_IS_X86)
diff --git a/libc/src/string/memory_utils/inline_strcmp.h b/libc/src/string/memory_utils/inline_strcmp.h
index 281d5b14c6cba..6758e79ae9ca3 100644
--- a/libc/src/string/memory_utils/inline_strcmp.h
+++ b/libc/src/string/memory_utils/inline_strcmp.h
@@ -9,7 +9,8 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRCMP_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRCMP_H
 
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include <stddef.h>
 
 namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/string/memory_utils/inline_strstr.h b/libc/src/string/memory_utils/inline_strstr.h
index 9c99e920b4b57..5495cc4803ec9 100644
--- a/libc/src/string/memory_utils/inline_strstr.h
+++ b/libc/src/string/memory_utils/inline_strstr.h
@@ -9,7 +9,8 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRSTR_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_INLINE_STRSTR_H
 
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/string/memory_utils/inline_memmem.h"
 #include "src/string/string_utils.h"
 #include <stddef.h>
diff --git a/libc/src/string/memory_utils/op_aarch64.h b/libc/src/string/memory_utils/op_aarch64.h
index 1090ea2617f09..868c64474c0b4 100644
--- a/libc/src/string/memory_utils/op_aarch64.h
+++ b/libc/src/string/memory_utils/op_aarch64.h
@@ -13,7 +13,8 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_OP_AARCH64_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_OP_AARCH64_H
 
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h"
 
 #if defined(LIBC_TARGET_ARCH_IS_AARCH64)
diff --git a/libc/src/string/memory_utils/op_builtin.h b/libc/src/string/memory_utils/op_builtin.h
index d7c1b1f870115..27b621d97f01a 100644
--- a/libc/src/string/memory_utils/op_builtin.h
+++ b/libc/src/string/memory_utils/op_builtin.h
@@ -16,7 +16,8 @@
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_OP_BUILTIN_H
 
 #include "src/__support/CPP/type_traits.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/string/memory_utils/utils.h"
 
 namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/string/memory_utils/op_generic.h b/libc/src/string/memory_utils/op_generic.h
index da20a84dede4d..9349cfdd1d020 100644
--- a/libc/src/string/memory_utils/op_generic.h
+++ b/libc/src/string/memory_utils/op_generic.h
@@ -27,7 +27,8 @@
 #include "src/__support/CPP/type_traits.h"
 #include "src/__support/common.h"
 #include "src/__support/endian_internal.h"
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/optimization.h"
 #include "src/__support/macros/properties/types.h" // LIBC_TYPES_HAS_INT64
 #include "src/string/memory_utils/op_builtin.h"
diff --git a/libc/src/string/memory_utils/op_riscv.h b/libc/src/string/memory_utils/op_riscv.h
index 2d211de0facfc..4292d7a627a54 100644
--- a/libc/src/string/memory_utils/op_riscv.h
+++ b/libc/src/string/memory_utils/op_riscv.h
@@ -12,7 +12,8 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_OP_RISCV_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_OP_RISCV_H
 
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h"
 
 #if defined(LIBC_TARGET_ARCH_IS_ANY_RISCV)
diff --git a/libc/src/string/memory_utils/op_x86.h b/libc/src/string/memory_utils/op_x86.h
index 309610e4ad630..8bd84120c4ffa 100644
--- a/libc/src/string/memory_utils/op_x86.h
+++ b/libc/src/string/memory_utils/op_x86.h
@@ -12,7 +12,8 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_OP_X86_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_OP_X86_H
 
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h"
 
 #if defined(LIBC_TARGET_ARCH_IS_X86)
diff --git a/libc/src/string/memory_utils/riscv/inline_bcmp.h b/libc/src/string/memory_utils/riscv/inline_bcmp.h
index 4bdde27cd16be..666ad6382412e 100644
--- a/libc/src/string/memory_utils/riscv/inline_bcmp.h
+++ b/libc/src/string/memory_utils/riscv/inline_bcmp.h
@@ -9,7 +9,7 @@
 #define LIBC_SRC_STRING_MEMORY_UTILS_RISCV_INLINE_BCMP_H
 
 #include "src/__support/macros/attributes.h"               // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h" // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h" // LIBC_TARGET_ARCH_IS_RISCV64
 #include "src/string/memory_utils/generic/aligned_access.h"
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
diff --git a/libc/src/string/memory_utils/riscv/inline_memcmp.h b/libc/src/string/memory_utils/riscv/inline_memcmp.h
index ca834952d331e..c49e8d0a4ff2f 100644
--- a/libc/src/string/memory_utils/riscv/inline_memcmp.h
+++ b/libc/src/string/memory_utils/riscv/inline_memcmp.h
@@ -9,7 +9,7 @@
 #define LIBC_SRC_STRING_MEMORY_UTILS_RISCV_INLINE_MEMCMP_H
 
 #include "src/__support/macros/attributes.h"               // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h" // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h" // LIBC_TARGET_ARCH_IS_RISCV64
 #include "src/string/memory_utils/generic/aligned_access.h"
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
diff --git a/libc/src/string/memory_utils/riscv/inline_memcpy.h b/libc/src/string/memory_utils/riscv/inline_memcpy.h
index 8eb87e0f38ce5..e907ae4c079e0 100644
--- a/libc/src/string/memory_utils/riscv/inline_memcpy.h
+++ b/libc/src/string/memory_utils/riscv/inline_memcpy.h
@@ -9,7 +9,7 @@
 #define LIBC_SRC_STRING_MEMORY_UTILS_RISCV_INLINE_MEMCPY_H
 
 #include "src/__support/macros/attributes.h"               // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h" // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h" // LIBC_TARGET_ARCH_IS_RISCV64
 #include "src/string/memory_utils/generic/aligned_access.h"
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
diff --git a/libc/src/string/memory_utils/riscv/inline_memmove.h b/libc/src/string/memory_utils/riscv/inline_memmove.h
index 28de4c240260d..01a9fa5c4bbdc 100644
--- a/libc/src/string/memory_utils/riscv/inline_memmove.h
+++ b/libc/src/string/memory_utils/riscv/inline_memmove.h
@@ -9,7 +9,7 @@
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_RISCV_INLINE_MEMMOVE_H
 
 #include "src/__support/macros/attributes.h"               // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h" // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h" // LIBC_TARGET_ARCH_IS_RISCV64
 #include "src/string/memory_utils/generic/byte_per_byte.h"
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
diff --git a/libc/src/string/memory_utils/riscv/inline_memset.h b/libc/src/string/memory_utils/riscv/inline_memset.h
index d6ab523f16414..09a7a765e4cb6 100644
--- a/libc/src/string/memory_utils/riscv/inline_memset.h
+++ b/libc/src/string/memory_utils/riscv/inline_memset.h
@@ -9,7 +9,7 @@
 #define LIBC_SRC_STRING_MEMORY_UTILS_RISCV_INLINE_MEMSET_H
 
 #include "src/__support/macros/attributes.h"               // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h" // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h" // LIBC_TARGET_ARCH_IS_RISCV64
 #include "src/string/memory_utils/generic/aligned_access.h"
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
diff --git a/libc/src/string/memory_utils/utils.h b/libc/src/string/memory_utils/utils.h
index cae65bddd92f6..5c9bc72208f85 100644
--- a/libc/src/string/memory_utils/utils.h
+++ b/libc/src/string/memory_utils/utils.h
@@ -14,7 +14,7 @@
 #include "src/__support/CPP/type_traits.h"
 #include "src/__support/endian_internal.h"
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h"
 
 #include <stddef.h> // size_t
diff --git a/libc/src/string/memory_utils/x86_64/inline_bcmp.h b/libc/src/string/memory_utils/x86_64/inline_bcmp.h
index cc54c4140ee6e..8be391b428910 100644
--- a/libc/src/string/memory_utils/x86_64/inline_bcmp.h
+++ b/libc/src/string/memory_utils/x86_64/inline_bcmp.h
@@ -9,7 +9,7 @@
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_BCMP_H
 
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/string/memory_utils/op_generic.h"
 #include "src/string/memory_utils/op_x86.h"
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr
diff --git a/libc/src/string/memory_utils/x86_64/inline_memset.h b/libc/src/string/memory_utils/x86_64/inline_memset.h
index 9f8e584d2bbb4..35719a89fa600 100644
--- a/libc/src/string/memory_utils/x86_64/inline_memset.h
+++ b/libc/src/string/memory_utils/x86_64/inline_memset.h
@@ -8,8 +8,8 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_MEMSET_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_MEMSET_H
 
-#include "src/__support/macros/attributes.h" // LIBC_INLINE
-#include "src/__support/macros/config.h"
+#include "src/__support/macros/attributes.h" // LIBC_INLINE, LIBC_INLINE_VAR
+#include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/string/memory_utils/op_generic.h"
 #include "src/string/memory_utils/op_x86.h"
 #include "src/string/memory_utils/utils.h" // Ptr, CPtr