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  • Status: Solved
  • Priority: Medium
  • Security: Public
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special assembly instruction missing in C-compiler

I have tried to use the Intel Pentium instructions
CPUID, RDPMC and RDTSC together with a C-program
in a _asm{} in-line subroutine. These are however,
reported as errors by the Microsoft 5.0 C++ compiler
(it seems like it will not give the privilege to use
these hardware-close instructions).
Any suggestions?
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poulsen
Asked:
poulsen
  • 2
1 Solution
 
nietodCommented:
Did you indicate that the target processor is a pentium?  These instructions are available only on a pentium or later processor.

If that still doesn't help you can use the "emit" instruction to "create" the instructions you need.


Let me know if you have questions.
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nietodCommented:
I just tried the CPUID instruction in VC 6 and it was recognized
I tried it with VC 5 and had no luck getting it recognized.  I don't think it is supported directly.  I was ablt to make it work using _emit, however, like

__asm _emit 0x0F
__asm _emit 0xA2;

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poulsenAuthor Commented:
Question solved by Nietod (I was also able to get around it myself by
selfmodifying code, which was not so elegant as NIetod's answer).
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