[fpc-devel] win32 debugging broken in fixes_2_2?

Florian Klaempfl florian at freepascal.org
Wed Jul 11 08:39:41 CEST 2007

Sergei Gorelkin schrieb:
> Wednesday, July 11, 2007, 12:06:51 AM, Florian wrote:
> FK> Vinzent Hoefler schrieb:
>>> On Tuesday 10 July 2007 09:58, Vinzent Hoefler wrote:
>>>> On Tuesday 10 July 2007 12:40, Yury Sidorov wrote:
>>>>> Maybe other way to detect SSE support exists...
>>>> CPUID?
>>> To be more precise, the way recommended by Intel:
>>> "To make this check, execute the CPUID instruction with an argument of 1 
>>> in the EAX register, and check that bit 25 (SSE) and/or bit 26 (SSE2) 
>>> are set to 1."
>>>   -- IA32 Software Developer's Manual,
>>>      Volume 3: System Programming Guide
>> This gives you only the information that the CPU supports it but not if
>> the OS supports it.
> But, if CPU has no SSE2 support, then OS is unable to support it, too?
> And if CPU has SSE2 support, modern OSes probably tend to support it.
> Thus, by checking CPUID before attempting to execute an SSE2
> instruction you'll be able to exclude exceptions in vast majority of
> cases.

That's a point though I thought we could safe this extra check because I
didn't expect that a lot of people are still using PII :)

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