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I refer to the document of ISA extensions at <https://software.intel.com/sites/default/files/managed/07/b7/319433-023.pdf>. (page 2-18)
The highest valid sub-leaf index, n, is(POPCNT(CPUID.(EAX=0D, ECX=0):EAX) + POPCNT(CPUID.(EAX=0D, ECX=0):EDX) - 1)
How to obtain this formula of the highest valid sub-leaf index of CPUID.0DH?
I expect that it should be the most-significant bit of CPUID.(EAX=0D,ECX=0).[EAX:EDX] instead, because the sub-leaf index corresponds to bit position of CPUID.(EAX=0D,ECX=0).[EAX:EDX]
- Tags:
- Intel® Advanced Vector Extensions (Intel® AVX)
- Intel® Streaming SIMD Extensions
- Parallel Computing
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Doc bug.
I will ask the doc team to try sync the CPUID stuff up again.
See the latest SDM instead: http://www.intel.com/sdm
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Doc bug.
I will ask the doc team to try sync the CPUID stuff up again.
See the latest SDM instead: http://www.intel.com/sdm
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Thanks for confirmation of the bug

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