[libc-commits] [libc] [libc][math][c23] Add f16fmaf C23 math function (PR #95483)

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@@ -144,21 +173,24 @@ template <> LIBC_INLINE double fma<double>(double x, double y, double z) {
   // - prod :     1bb...bb....b
   // In that case, in order to store the exact result, we need at least
   //   (Length of prod) - (MantissaLength of z) = 2*(52 + 1) - 52 = 54.
+  // TODO:                            53? (Explicit mantissa.) ^
   // Overall, before aligning the mantissas and exponents, we can simply left-
   // shift the mantissa of z by at least 54, and left-shift the product of x*y
   // by (that amount - 52).  After that, it is enough to align the least
+  // TODO:             ^ 54?
   // significant bit, given that we keep track of the round and sticky bits
   // after the least significant bit.
   // We pick shifting z_mant by 64 bits so that technically we can simply use
   // the original mantissa as high part when constructing 128-bit z_mant. So the
   // mantissa of prod will be left-shifted by 64 - 54 = 10 initially.
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overmighty wrote:

I need to update these comments.

https://github.com/llvm/llvm-project/pull/95483