- Exclude SSE2 code paths. Normally SSE2 extension is
- detected at run-time, but the decision whether or not the
- machine code will be executed is taken solely on CPU
- capability vector. This means that if you happen to run OS
- kernel which does not support SSE2 extension on Intel P4
- processor, then your application might be exposed to
- "illegal instruction" exception. There might be a way
- to enable support in kernel, e.g. FreeBSD kernel can be
- compiled with CPU_ENABLE_SSE, and there is a way to
- disengage SSE2 code paths upon application start-up,
- but if you aim for wider "audience" running such kernel,
- consider no-sse2. Both the 386 and no-asm options imply
- no-sse2.
+ Exclude SSE2 code paths from 32-bit x86 assembly modules.
+ Normally SSE2 extension is detected at run-time, but the
+ decision whether or not the machine code will be executed
+ is taken solely on CPU capability vector. This means that
+ if you happen to run OS kernel which does not support SSE2
+ extension on Intel P4 processor, then your application
+ might be exposed to "illegal instruction" exception.
+ There might be a way to enable support in kernel, e.g.
+ FreeBSD kernel can be compiled with CPU_ENABLE_SSE, and
+ there is a way to disengage SSE2 code paths upon application
+ start-up, but if you aim for wider "audience" running
+ such kernel, consider no-sse2. Both the 386 and
+ no-asm options imply no-sse2.