[libcxx-commits] [libcxx] [libc++] Implement std::gcd using the binary version (PR #77747)

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github-actions[bot] wrote:

<!--LLVM CODE FORMAT COMMENT: {clang-format}-->


:warning: C/C++ code formatter, clang-format found issues in your code. :warning:

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``````````bash
git-clang-format --diff 9ef2ac3ad1bd5aa9e589f63047e8abeac11ad1b2 798e74b42b85c045edde6473ddcf305b40ca6a62 -- libcxx/include/__bit/countr.h libcxx/include/__numeric/gcd_lcm.h libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
``````````

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<details>
<summary>
View the diff from clang-format here.
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``````````diff
diff --git a/libcxx/include/__numeric/gcd_lcm.h b/libcxx/include/__numeric/gcd_lcm.h
index 55199547fa..bcf2fbe688 100644
--- a/libcxx/include/__numeric/gcd_lcm.h
+++ b/libcxx/include/__numeric/gcd_lcm.h
@@ -53,24 +53,24 @@ struct __ct_abs<_Result, _Source, false> {
 
 template <class _Tp>
 _LIBCPP_CONSTEXPR _LIBCPP_HIDDEN _Tp __gcd(_Tp __a, _Tp __b) {
-    static_assert((!is_signed<_Tp>::value), "");
-    if (__a == 0)
-        return __b;
-    if (__b == 0)
-        return __a;
-
-    int __az    = std::__countr_zero(__a);
-    int __bz    = std::__countr_zero(__b);
-    int __shift = std::min(__az, __bz);
-    __b >>= __bz;
-    while (__a != 0) {
-        __a >>= __az;
-        _Tp __absdiff = __a > __b ? __a - __b : __b - __a;
-        __b           = std::min(__a, __b);
-        __a           = __absdiff;
-        __az          = std::__countr_zero(__absdiff);
-    }
-    return __b << __shift;
+  static_assert((!is_signed<_Tp>::value), "");
+  if (__a == 0)
+    return __b;
+  if (__b == 0)
+    return __a;
+
+  int __az    = std::__countr_zero(__a);
+  int __bz    = std::__countr_zero(__b);
+  int __shift = std::min(__az, __bz);
+  __b >>= __bz;
+  while (__a != 0) {
+    __a >>= __az;
+    _Tp __absdiff = __a > __b ? __a - __b : __b - __a;
+    __b           = std::min(__a, __b);
+    __a           = __absdiff;
+    __az          = std::__countr_zero(__absdiff);
+  }
+  return __b << __shift;
 }
 
 template <class _Tp, class _Up>
diff --git a/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp b/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
index 0435575bd8..acf8986eab 100644
--- a/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
+++ b/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
@@ -56,20 +56,18 @@ T basic_gcd(T m, T n) {
 
 template <typename Input>
 void do_fuzzy_tests() {
-
   std::random_device rd;
   std::mt19937 gen(rd());
   std::uniform_int_distribution<Input> distrib;
 
   constexpr int nb_rounds = 10000;
-  for(int i = 0; i < nb_rounds; ++i) {
+  for (int i = 0; i < nb_rounds; ++i) {
     Input n = distrib(gen);
     Input m = distrib(gen);
     assert(std::gcd(n, m) == basic_gcd(n, m));
   }
 }
 
-
 template <typename Input1, typename Input2 = Input1>
 constexpr bool do_test(int = 0)
 {
@@ -169,5 +167,5 @@ int main(int argc, char**)
     do_fuzzy_tests<std::uint32_t>();
     do_fuzzy_tests<std::uint64_t>();
 
-  return 0;
+    return 0;
 }

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https://github.com/llvm/llvm-project/pull/77747