[libc-commits] [libc] [libc] Fix strfromf handling inf/nan. (PR #225805)

[via libc-commits]

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@@ -26,30 +26,53 @@ namespace LIBC_NAMESPACE_DECL {
 namespace printf_core {
 
 struct FloatHexExpFPBitsProperties {
-  bool is_negative;
-  int exponent;
   AnyFloatStorageType mantissa;
-  bool is_inf_or_nan;
+  int exponent;
   uint32_t fraction_bits;
+  bool is_negative;
+  bool is_inf_or_nan;
+  bool mantissa_is_zero;
 };
 
 template <typename T>
-FloatHexExpFPBitsProperties
-get_float_hex_exp_fp_bits_properties(AnyFloatStorageType float_raw) {
-  fputil::FPBits<T> float_bits(
-      static_cast<typename fputil::FPBits<T>::StorageType>(float_raw));
+LIBC_INLINE FloatHexExpFPBitsProperties
+get_float_hex_exp_fp_bits_properties_typed(fputil::FPBits<T> float_bits) {
   return {
-      .is_negative = float_bits.is_neg(),
-      .exponent = float_bits.get_explicit_exponent(),
       .mantissa = float_bits.get_explicit_mantissa(),
-      .is_inf_or_nan = float_bits.is_inf_or_nan(),
+      .exponent = float_bits.get_explicit_exponent(),
       .fraction_bits = fputil::FPBits<T>::FRACTION_LEN,
+      .is_negative = float_bits.is_neg(),
+      .is_inf_or_nan = float_bits.is_inf_or_nan(),
+      .mantissa_is_zero = float_bits.get_mantissa() == 0,
   };
 }
 
+// Returns relevant floating point properties for conversion using
+// `to_conv.length_modifier` to infer the conversion value type.
+LIBC_INLINE FloatHexExpFPBitsProperties
+get_float_hex_exp_fp_bits_properties_lm(const FormatSection &to_conv) {
+#if defined(LIBC_INTERNAL_PRINTF_CONVERT_FLOAT128)
+  if (to_conv.length_modifier == LengthModifier::Q)
+    return get_float_hex_exp_fp_bits_properties_typed<float128>(
+        fputil::FPBits<float128>(to_conv.conv_val_raw));
+#endif // LIBC_INTERNAL_PRINTF_CONVERT_FLOAT128
+#ifndef LIBC_TYPES_LONG_DOUBLE_IS_DOUBLE_DOUBLE
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lntue wrote:

why don't we have to deal with other long double options here?

https://github.com/llvm/llvm-project/pull/225805