From e7a29e09157dc9753c9ea17b7813d0b0aded80b6 Mon Sep 17 00:00:00 2001
From: HedgehogInTheCPP <a.rainman@gmail.com>
Date: Thu, 20 Aug 2026 18:45:31 +0300
Subject: [PATCH] Documentation updated and hardware level detection cleanup.

---
 README.md                         |  4 ++--
 include/fast_float/ascii_number.h |  2 +-
 include/fast_float/float_common.h | 22 ++++++++--------------
 3 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/README.md b/README.md
index 296fabb..706df84 100644
--- a/README.md
+++ b/README.md
@@ -51,10 +51,10 @@ Introduced new optional macros to minimize overhead when certain parsing feature
   Automatically uses std::bit_cast if available to reduce code size and speed up.
   
 * **`FASTFLOAT_X86_SIMD`**
-  Automatically uses reworking SSE parsing algorithms to improve performance on x86 machines.
+  Automatically uses reworking SSE parsing algorithms to improve performance on x86 machines. And hardware level also can be set manually by user.
   
 * **`FASTFLOAT_USE_SIMD`**
-  Add possibility to completely disable manual algorithms realization and give compiler more freedom
+  Can be set to 0 for completely disable manually optimized SIMD paths and use compiler + linker to give the best possible result automatically
 
 ---
 
diff --git a/include/fast_float/ascii_number.h b/include/fast_float/ascii_number.h
index fc8a94e..fdb484d 100644
--- a/include/fast_float/ascii_number.h
+++ b/include/fast_float/ascii_number.h
@@ -109,7 +109,7 @@ fastfloat_really_inline uint64_t simd_read8(char16_t const *chars) {
   FASTFLOAT_SIMD_RESTORE_WARNINGS
 }
 
-#elif defined(FASTFLOAT_ARM_NEON)
+#elif FASTFLOAT_ARM_NEON
 
 fastfloat_really_inline uint64_t simd_read8(uint16x8_t const &data) {
   uint8x8_t utf8_packed = vmovn_u16(data);
diff --git a/include/fast_float/float_common.h b/include/fast_float/float_common.h
index 14efd3a..a0f650d 100644
--- a/include/fast_float/float_common.h
+++ b/include/fast_float/float_common.h
@@ -186,14 +186,14 @@ using parse_options = parse_options_t<char>;
 #endif
 #endif
 
-#ifdef FASTFLOAT_USE_SIMD // user defined
-#else
-#ifdef FASTFLOAT_X86_SIMD // user defined level
+#ifdef FASTFLOAT_USE_SIMD
+// user defined
+#elif defined(FASTFLOAT_X86_SIMD)
+// user defined level
 static_assert(FASTFLOAT_X86_SIMD == 20 || FASTFLOAT_X86_SIMD == 42 ||
-                  FASTFLOAT_X86_SIMD == 52,
+                  FASTFLOAT_X86_SIMD == 52 || FASTFLOAT_ARM_NEON,
               "FASTFLOAT_X86_SIMD should be 20(SSE2), 42(SSE4.2) and 52(AVX2)");
-#else                     // auto detect
-#if defined(__AVX2__)
+#elif defined(__AVX2__)
 #define FASTFLOAT_X86_SIMD 52
 #elif defined(__AVX__)
 // On MSVC there's no way to check for SSE4.2 specifically so check AVX.
@@ -210,18 +210,13 @@ static_assert(FASTFLOAT_X86_SIMD == 20 || FASTFLOAT_X86_SIMD == 42 ||
                             (defined(_M_AMD64) || defined(_M_X64) ||           \
                              (defined(_M_IX86_FP) && _M_IX86_FP == 2)))
 #define FASTFLOAT_X86_SIMD 20
-#endif
-#endif
-
-#if defined(__aarch64__) || defined(_M_ARM64)
+#elif defined(__aarch64__) || defined(_M_ARM64)
 #define FASTFLOAT_ARM_NEON 1
 #endif
 
-#if defined(FASTFLOAT_X86_SIMD) || defined(FASTFLOAT_ARM_NEON)
+#if FASTFLOAT_X86_SIMD || FASTFLOAT_ARM_NEON
 #define FASTFLOAT_USE_SIMD 1
-#endif
 
-#if FASTFLOAT_USE_SIMD
 #if defined(__GNUC__)
 // disable -Wcast-align=strict (GCC only)
 #define FASTFLOAT_SIMD_DISABLE_WARNINGS                                        \
@@ -234,7 +229,6 @@ static_assert(FASTFLOAT_X86_SIMD == 20 || FASTFLOAT_X86_SIMD == 42 ||
 #define FASTFLOAT_SIMD_RESTORE_WARNINGS
 #endif
 #endif
-#endif
 
 #ifdef FASTFLOAT_VISUAL_STUDIO
 #define fastfloat_really_inline __forceinline