fix build on i386 without SSE2 #302
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Commit 3cba6b1 ("Use _Float16 for half conversions if available") added support for using half-width float support in the compiler to perform encoding operations, using the FLT16_MANT_DIG macro to check for support on the given target. However, on x86 GCC only supports this when SSE2 is enabled[1]. Unlike clang and the other architectures where support for this is conditional, GCC *does* define those macros even without SSE2 support, causing a build failure: In file included from cborencoder_float.c:29: cborinternal_p.h: In function ‘encode_half’: cborinternal_p.h:56:5: error: invalid conversion to type ‘_Float16’ without option ‘-msse2’ 56 | _Float16 f = (_Float16)x; | ^~~~~~~~ cborinternal_p.h: In function ‘decode_half’: cborinternal_p.h:65:5: error: invalid conversion from type ‘_Float16’ without option ‘-msse2’ 65 | return (float)f; | Work around this by additionally checking for this specific condition. [1] https://gcc.gnu.org/onlinedocs/gcc/Half-Precision.html Signed-off-by: Florian Larysch <[email protected]>
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Thank you for the patch. |
thiagomacieira
approved these changes
Aug 19, 2025
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Commit 3cba6b1 ("Use _Float16 for half conversions if available") added support for using half-width float support in the compiler to perform encoding operations, using the FLT16_MANT_DIG macro to check for support on the given target.
However, on x86 GCC only supports this when SSE2 is enabled[1]. Unlike clang and the other architectures where support for this is conditional, GCC does define those macros even without SSE2 support, causing a build failure:
Work around this by additionally checking for this specific condition.
[1] https://gcc.gnu.org/onlinedocs/gcc/Half-Precision.html