refactor(misc): use MSVC compiler builtin for xctz()

Problem: `xctz()` uses a fallback algorithm for MSVC, even though a compiler builtin exists.

Solution: Make `xctz()` use the compiler builtin for MSVC compiler.
This commit is contained in:
Famiu Haque 2024-03-22 01:43:53 +06:00
parent 563a369a1b
commit 1dde678757
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@ -4,6 +4,10 @@
#include <stdint.h>
#include <string.h>
#ifdef _MSC_VER
# include <intrin.h> // Required for _BitScanForward64
#endif
#include "nvim/math.h"
#ifdef INCLUDE_GENERATED_DECLARATIONS
@ -52,6 +56,10 @@ int xctz(uint64_t x)
// Use compiler builtin if possible.
#if defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 4))
return __builtin_ctzll(x);
#elif defined(_MSC_VER)
unsigned long index;
_BitScanForward64(&index, x);
return (int)index;
#else
int count = 0;
// Set x's trailing zeroes to ones and zero the rest.