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Bug 2404

Summary: CPU detection not working with MSVC on x64
Product: SDL Reporter: Tiemo Jung <maddog.q3a>
Component: *don't know*Assignee: Sam Lantinga <slouken>
Status: RESOLVED FIXED QA Contact: Sam Lantinga <slouken>
Severity: normal    
Priority: P2    
Version: 2.0.1   
Hardware: x86_64   
OS: Windows 8   

Description Tiemo Jung 2014-02-18 19:15:37 UTC
All CPU detection functions SDL_Has* will return false, even if it is supported by the CPU, if SDL is compiled with MSVC and the target is x64.

The reason for this is that 'CPU_haveCPUID' will return 0 and macro 'cpuid' in SDL_cpuinfo.c is the fallback implementation, which sets all params to zero.

It is safe to assume that cpuid is supported on a CPU that runs windows x64, so CPU_haveCPUID can just return 1, and the empty macro can be replaced with a small wrap around the __cpuid intrinsic.
Comment 1 Sam Lantinga 2014-02-23 03:11:27 UTC
Good catch, thanks!
https://hg.libsdl.org/SDL/rev/b6d5a589ce3f