[libc-commits] [libc] [libc][stdfix] Implement sqrtfx for remaining fixed point types (PR #214741)

[via libc-commits]

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@@ -181,31 +200,67 @@ sqrt_core(typename Config::Type x_frac) {
 
 template <typename T>
 LIBC_INLINE constexpr cpp::enable_if_t<cpp::is_fixed_point_v<T>, T> sqrt(T x) {
-  using BitType = typename FXRep<T>::StorageType;
-  BitType x_bit = cpp::bit_cast<BitType>(x);
-
-  if (LIBC_UNLIKELY(x_bit == 0))
-    return FXRep<T>::ZERO();
-
-  int leading_zeros = cpp::countl_zero(x_bit);
-  constexpr int STORAGE_LENGTH = sizeof(BitType) * CHAR_BIT;
-  constexpr int EXP_ADJUSTMENT = STORAGE_LENGTH - FXRep<T>::FRACTION_LEN - 1;
-  // x_exp is the real exponent of the leading bit of x.
-  int x_exp = EXP_ADJUSTMENT - leading_zeros;
-  int shift = EXP_ADJUSTMENT - 1 - (x_exp & (~1));
-  // Normalize.
-  x_bit <<= shift;
-  using FracType = typename internal::SqrtConfig<T>::Type;
-  FracType x_frac = cpp::bit_cast<FracType>(x_bit);
-
-  // Compute sqrt(x_frac) using Newton-method.
-  FracType r = sqrt_core<internal::SqrtConfig<T>>(x_frac);
-
-  // Re-scaling
-  r >>= EXP_ADJUSTMENT - (x_exp >> 1);
-
-  // Return result.
-  return cpp::bit_cast<T>(r);
+  if constexpr (FXRep<T>::SIGN_LEN > 0) {
+    LIBC_CRASH_ON_VALUE(x < FXRep<T>::ZERO(), true);
+    return static_cast<T>(
+        sqrt(static_cast<typename internal::FXUnsigned<T>::Type>(x)));
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sohail103 wrote:

Thanks for catching this, I've removed the LIBC_CRASH_ON_VALUE.

https://github.com/llvm/llvm-project/pull/214741