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

[via libc-commits]

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@@ -10,20 +10,28 @@
 #define LLVM_LIBC_SRC___SUPPORT_FPUTIL_GENERIC_FMA_H
 
 #include "src/__support/CPP/bit.h"
+#include "src/__support/CPP/limits.h"
 #include "src/__support/CPP/type_traits.h"
-#include "src/__support/FPUtil/FEnvImpl.h"
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/FPUtil/rounding_mode.h"
+#include "src/__support/big_int.h"
 #include "src/__support/macros/attributes.h"   // LIBC_INLINE
 #include "src/__support/macros/optimization.h" // LIBC_UNLIKELY
-#include "src/__support/uint128.h"
+
+#include "hdr/fenv_macros.h"
 
 namespace LIBC_NAMESPACE {
 namespace fputil {
 namespace generic {
 
-template <typename T> LIBC_INLINE T fma(T x, T y, T z);
+template <typename OutType, typename InType>
+LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<OutType> &&
+                                 cpp::is_floating_point_v<InType> &&
+                                 sizeof(OutType) <= sizeof(InType),
+                             OutType>
+fma(InType x, InType y, InType z);
 
+#ifndef LIBC_TARGET_CPU_HAS_FMA
 // TODO(lntue): Implement fmaf that is correctly rounded to all rounding modes.
 // The implementation below only is only correct for the default rounding mode,
 // round-to-nearest tie-to-even.
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overmighty wrote:

Should we use the type-generic `fma` from this PR to implement `fmaf` correctly rounded for all rounding modes, or is a specialized implementation that is both faster and correct for all rounding modes planned?

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