Cleanup and move gather-bench to util folder

util/gather-bench/src/avx2/gather_aos.S

@@ -0,0 +1,71 @@
+.intel_syntax noprefix
+.data
+.align 64
+SCALAR:
+.double 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
+
+# rdi -> a
+# rsi -> idx
+# rdx -> N
+# rcx -> t
+.text
+.globl gather_aos
+.type gather_aos, @function
+gather_aos :
+push rbp
+mov rbp, rsp
+push rbx
+push r9
+push r10
+push r11
+push r12
+push r13
+push r14
+push r15
+
+xor   rax, rax
+vpcmpeqd ymm8, ymm8, ymm8
+.align 16
+1:
+
+vmovups xmm3, XMMWORD PTR [rsi + rax * 4]
+vpaddd xmm4, xmm3, xmm3
+#ifdef PADDING
+vpaddd xmm3, xmm4, xmm4
+#else
+vpaddd xmm3, xmm3, xmm4
+#endif
+vmovdqa ymm5, ymm8
+vmovdqa ymm6, ymm8
+vmovdqa ymm7, ymm8
+vxorpd ymm0, ymm0, ymm0
+vxorpd ymm1, ymm1, ymm1
+vxorpd ymm2, ymm2, ymm2
+vgatherdpd ymm0, [     rdi + xmm3 * 8], ymm5
+vgatherdpd ymm1, [8  + rdi + xmm3 * 8], ymm6
+vgatherdpd ymm2, [16 + rdi + xmm3 * 8], ymm7
+
+#ifdef TEST
+vmovupd  [rcx + rax * 8], ymm0
+lea rbx, [rcx + rdx * 8]
+vmovupd  [rbx + rax * 8], ymm1
+lea r9,  [rbx + rdx * 8]
+vmovupd  [r9  + rax * 8], ymm2
+#endif
+
+addq rax, 4
+cmpq rax, rdx
+jl 1b
+
+pop r15
+pop r14
+pop r13
+pop r12
+pop r11
+pop r10
+pop r9
+pop rbx
+mov  rsp, rbp
+pop rbp
+ret
+.size gather_aos, .-gather_aos