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DateWed, 12 Dec 2007 00:23:04 -0500
FromKyle McMartin <>
SubjectRe: [RFT] Port 0x80 I/O speed
On Wed, Dec 12, 2007 at 12:31:18AM +0100, Rene Herman wrote:
> 	asm volatile ("rdtsc": "=A" (tsc));

rdtsc returns a 64-bit value in two 32-bit regs, you need to do

inline unsigned long long rdtsc(void)
{
	unsigned int lo, hi;
	asm volatile ("rdtsc": "=a" (lo), "=d" (hi));
	return (unsigned long long)hi << 32 | lo;
}
as in msr.h, otherwise you'll only be looking at the value in %rax.

cheers,
	Kyle


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