topic Re: Meaning of Intel Advisor GOPS in Analyzers

Meaning of Intel Advisor GOPS

jgwohlbier — Wed, 17 Feb 2021 17:35:30 GMT

Hi,

I'm wondering specifically what is Advisor is reporting for GFLOPS and GINTOPS. Is it reporting instructions retired and account for vector instructions? I.e., would an 8-way vector fused multiply add instruction be counted as 16 operations?

Thanks!

jgw

Re: Meaning of Intel Advisor GOPS

Ruslan_M_Intel — Thu, 18 Feb 2021 07:53:42 GMT

Hi,

Yes, Advisor takes into account that FMA instruction is not single operation but it's a number of operations. Specifically, for N elements we have N multiplies and N additions (for each of mul result)

Re: Meaning of Intel Advisor GOPS

jgwohlbier — Thu, 18 Feb 2021 15:47:59 GMT

Thanks. Assuming that the count is based on retired instructions, would it be possible to get a list of instructions that result in counts as both GFLOPS and INTOPS?

Thanks.

jgw

Re: Meaning of Intel Advisor GOPS

Ruslan_M_Intel — Thu, 18 Feb 2021 16:16:43 GMT

I'm not sure if FMA contains any instruction which operate on both floating-point and integer data. Could you give an example?

Re: Meaning of Intel Advisor GOPS

jgwohlbier — Thu, 18 Feb 2021 17:14:56 GMT

Sorry, that's not what I meant.

I am interested in a list of instructions that result in GFLOPS counts, and a list of instructions that result in GINTOPS counts. I imagine it is all of the arithmetic instructions and vector variants of those instructions, both for floats and for ints, respectively.

Thanks.

jgw

Re: Meaning of Intel Advisor GOPS

Ruslan_M_Intel — Thu, 18 Feb 2021 17:35:45 GMT

Unfortunately I don't have any list you need but if I remember correctly only IFMA stands for INTOP count. The rest ISAs (or their subsets) stand for FLOP count. So you could compile the list based on data from Intel Intrinsic Guide resource selecting needed ISA. BTW I'm not sure if Advisor supports IFMA yet

Re: Meaning of Intel Advisor GOPS

Zakhar_M_Intel1 — Fri, 19 Feb 2021 10:54:32 GMT

Hi jgw,

For Advisor GINTOPS you can find instructions list at Advisor Integer Roofline article: https://software.intel.com/content/www/us/en/develop/articles/a-brief-overview-of-integer-roofline-modeling-in-intel-advisor.html , quoted:

Currently, ADD, ADC, SUB, MUL, IMUL, DIV, IDIV, INC/DEC, shifts, rotates etc. are counted as INT Operations. For strict integer operation usage, which allows you to exclude the loop counter operations (INC/DEC, shift, rotate) which are not strictly calculations, set the environment variable: ADVIXE_EXPERIMENTAL=intops_strict This will lead to only counting ADD, MUL, IDIV and SUB operations.

FLOPS and GINTOPS are implemented so that for each instruction you multiply by operand SIMD width and taking into account (for AVX-512) mask register values. Also, for FMAs and for VNNI we count them as > 1 op (specifically, 2 for FMA). That's actually why we position Advisor FLOPS/INTOPS collectors as "Precise FLOPS counting" analysis.

Re: Meaning of Intel Advisor GOPS

RaeesaM_Intel — Thu, 25 Feb 2021 04:28:40 GMT

Hi,

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Raeesa

Re: Meaning of Intel Advisor GOPS

Zakhar_M_Intel1 — Fri, 26 Feb 2021 07:39:33 GMT

.. And (in continuation)

For the FLOP/S tool here is a high level list of classes of instructions counted:

ADD, SUB, DIV, DP, MUL, ATAN, FPREM, TAN, SIN, COS, SQRT, SUB, RCP, RSQRT, EXP, VSCALE, MAX, MIN, ABS, IMUL, IDIV, FIDIVR, CMP, VREDUCE, VRND