[flac-dev] [PATCH] for configure.ac

lvqcl lvqcl.mail at gmail.com
Mon Oct 13 13:49:53 PDT 2014

Erik de Castro Lopo wrote:

> This is also a little misleading as its not the OS we are checking
> for SSE support but the compiler. I'll fix this.

How so? ./configure script tests a compiler by checking the existence of x86intrin.h.
If the file exist then it is assumed that a compiler supports SSE intrinsics.

--enable-sse results in a definition of FLAC__SSE_OS preprocessor variable.
If it is defined then SSE detection code in src/libFLAC/cpu.c
assumes that OS supports SSE.

Otherwise it tries to perform a runtime check (basically, it executes
an SSE operation and tries to catch invalid opcode exception).

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