#define INSTR and #define NINST 64 #define N edi #define i r8d .intel_syntax noprefix .globl ninst .data ninst: .long NINST .align 32 PI: .long 0xf01b866e, 0x400921f9, 0xf01b866e, 0x400921f9, 0xf01b866e, 0x400921f9, 0xf01b866e, 0x400921f9, 0xf01b866e, 0x400921f9, 0xf01b866e, 0x400921f9, 0xf01b866e, 0x400921f9, 0xf01b866e, 0x400921f9 .text .globl latency .type latency, @function .align 32 latency: push rbp mov rbp, rsp xor i, i test N, N jle done # create DP 1.0 vpcmpeqw xmm0, xmm0, xmm0 # all ones vpsllq xmm0, xmm0, 54 # logical left shift: 11111110..0 (54=64-(10-1)) vpsrlq xmm0, xmm0, 2 # logical right shift: 1 bit for sign; leading mantissa bit is zero push rax push rbx push rcx push rdx push r9 push r10 push r11 push r12 push r13 push r14 push r15 xor rax, rax xor rbx, rbx xor rcx, rcx xor rdx, rdx xor r9, r9 xor r10, r10 xor r11, r11 xor r12, r12 xor r13, r13 xor r14, r14 xor r15, r15 loop: inc i INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 INSTR eax, 1 cmp i, N jl loop pop r15 pop r14 pop r13 pop r12 pop r11 pop r10 pop r9 pop rdx pop rcx pop rbx pop rax done: mov rsp, rbp pop rbp ret .size latency, .-latency