19/10/2021 12:47, Aman Kumar:
> This patch provides rte_memcpy* calls optimized for
> AMD EPYC platforms. Use config/x86/x86_amd_epyc_linux_gcc
> as cross-file with meson to build dpdk for AMD EPYC platforms.
Please split in 2 patches: platform & memcpy.
What optimization is specific to EPYC?
I dislike the asm code below.
What is AMD specific inside?
Can it use compiler intrinsics as it is done elsewhere?
> +static __rte_always_inline void *
> +rte_memcpy_aligned_ntload_tstore16_amdepyc2(void *dst,
> + const void *src,
> + size_t size)
> +{
> + asm volatile goto("movq %0, %%rsi\n\t"
> + "movq %1, %%rdi\n\t"
> + "movq %2, %%rdx\n\t"
> + "cmpq $(128), %%rdx\n\t"
> + "jb 202f\n\t"
> + "201:\n\t"
> + "vmovntdqa (%%rsi), %%ymm0\n\t"
> + "vmovntdqa 32(%%rsi), %%ymm1\n\t"
> + "vmovntdqa 64(%%rsi), %%ymm2\n\t"
> + "vmovntdqa 96(%%rsi), %%ymm3\n\t"
> + "vmovdqu %%ymm0, (%%rdi)\n\t"
> + "vmovdqu %%ymm1, 32(%%rdi)\n\t"
> + "vmovdqu %%ymm2, 64(%%rdi)\n\t"
> + "vmovdqu %%ymm3, 96(%%rdi)\n\t"
> + "addq $128, %%rsi\n\t"
> + "addq $128, %%rdi\n\t"
> + "subq $128, %%rdx\n\t"
> + "jz %l[done]\n\t"
> + "cmpq $128, %%rdx\n\t" /*Vector Size 32B. */
> + "jae 201b\n\t"
> + "202:\n\t"
> + "cmpq $64, %%rdx\n\t"
> + "jb 203f\n\t"
> + "vmovntdqa (%%rsi), %%ymm0\n\t"
> + "vmovntdqa 32(%%rsi), %%ymm1\n\t"
> + "vmovdqu %%ymm0, (%%rdi)\n\t"
> + "vmovdqu %%ymm1, 32(%%rdi)\n\t"
> + "addq $64, %%rsi\n\t"
> + "addq $64, %%rdi\n\t"
> + "subq $64, %%rdx\n\t"
> + "jz %l[done]\n\t"
> + "203:\n\t"
> + "cmpq $32, %%rdx\n\t"
> + "jb 204f\n\t"
> + "vmovntdqa (%%rsi), %%ymm0\n\t"
> + "vmovdqu %%ymm0, (%%rdi)\n\t"
> + "addq $32, %%rsi\n\t"
> + "addq $32, %%rdi\n\t"
> + "subq $32, %%rdx\n\t"
> + "jz %l[done]\n\t"
> + "204:\n\t"
> + "cmpb $16, %%dl\n\t"
> + "jb 205f\n\t"
> + "vmovntdqa (%%rsi), %%xmm0\n\t"
> + "vmovdqu %%xmm0, (%%rdi)\n\t"
> + "addq $16, %%rsi\n\t"
> + "addq $16, %%rdi\n\t"
> + "subq $16, %%rdx\n\t"
> + "jz %l[done]\n\t"
> + "205:\n\t"
> + "cmpb $2, %%dl\n\t"
> + "jb 208f\n\t"
> + "cmpb $4, %%dl\n\t"
> + "jbe 207f\n\t"
> + "cmpb $8, %%dl\n\t"
> + "jbe 206f\n\t"
> + "movq -8(%%rsi,%%rdx), %%rcx\n\t"
> + "movq (%%rsi), %%rsi\n\t"
> + "movq %%rcx, -8(%%rdi,%%rdx)\n\t"
> + "movq %%rsi, (%%rdi)\n\t"
> + "jmp %l[done]\n\t"
> + "206:\n\t"
> + "movl -4(%%rsi,%%rdx), %%ecx\n\t"
> + "movl (%%rsi), %%esi\n\t"
> + "movl %%ecx, -4(%%rdi,%%rdx)\n\t"
> + "movl %%esi, (%%rdi)\n\t"
> + "jmp %l[done]\n\t"
> + "207:\n\t"
> + "movzwl -2(%%rsi,%%rdx), %%ecx\n\t"
> + "movzwl (%%rsi), %%esi\n\t"
> + "movw %%cx, -2(%%rdi,%%rdx)\n\t"
> + "movw %%si, (%%rdi)\n\t"
> + "jmp %l[done]\n\t"
> + "208:\n\t"
> + "movzbl (%%rsi), %%ecx\n\t"
> + "movb %%cl, (%%rdi)"
> + :
> + : "r"(src), "r"(dst), "r"(size)
> + : "rcx", "rdx", "rsi", "rdi", "ymm0", "ymm1", "ymm2", "ymm3", "memory"
> + : done
> + );
> +done:
> + return dst;
> +}
> +
> +static __rte_always_inline void *
> +rte_memcpy_generic(void *dst, const void *src, size_t len)
> +{
> + asm goto("movq %0, %%rsi\n\t"
> + "movq %1, %%rdi\n\t"
> + "movq %2, %%rdx\n\t"
> + "movq %%rdi, %%rax\n\t"
> + "cmp $32, %%rdx\n\t"
> + "jb 101f\n\t"
> + "cmp $(32 * 2), %%rdx\n\t"
> + "ja 108f\n\t"
> + "vmovdqu (%%rsi), %%ymm0\n\t"
> + "vmovdqu -32(%%rsi,%%rdx), %%ymm1\n\t"
> + "vmovdqu %%ymm0, (%%rdi)\n\t"
> + "vmovdqu %%ymm1, -32(%%rdi,%%rdx)\n\t"
> + "vzeroupper\n\t"
> + "jmp %l[done]\n\t"
> + "101:\n\t"
> + /* Less than 1 VEC. */
> + "cmpb $32, %%dl\n\t"
> + "jae 103f\n\t"
> + "cmpb $16, %%dl\n\t"
> + "jae 104f\n\t"
> + "cmpb $8, %%dl\n\t"
> + "jae 105f\n\t"
> + "cmpb $4, %%dl\n\t"
> + "jae 106f\n\t"
> + "cmpb $1, %%dl\n\t"
> + "ja 107f\n\t"
> + "jb 102f\n\t"
> + "movzbl (%%rsi), %%ecx\n\t"
> + "movb %%cl, (%%rdi)\n\t"
> + "102:\n\t"
> + "jmp %l[done]\n\t"
> + "103:\n\t"
> + /* From 32 to 63. No branch when size == 32. */
> + "vmovdqu (%%rsi), %%ymm0\n\t"
> + "vmovdqu -32(%%rsi,%%rdx), %%ymm1\n\t"
> + "vmovdqu %%ymm0, (%%rdi)\n\t"
> + "vmovdqu %%ymm1, -32(%%rdi,%%rdx)\n\t"
> + "vzeroupper\n\t"
> + "jmp %l[done]\n\t"
> + /* From 16 to 31. No branch when size == 16. */
> + "104:\n\t"
> + "vmovdqu (%%rsi), %%xmm0\n\t"
> + "vmovdqu -16(%%rsi,%%rdx), %%xmm1\n\t"
> + "vmovdqu %%xmm0, (%%rdi)\n\t"
> + "vmovdqu %%xmm1, -16(%%rdi,%%rdx)\n\t"
> + "jmp %l[done]\n\t"
> + "105:\n\t"
> + /* From 8 to 15. No branch when size == 8. */
> + "movq -8(%%rsi,%%rdx), %%rcx\n\t"
> + "movq (%%rsi), %%rsi\n\t"
> + "movq %%rcx, -8(%%rdi,%%rdx)\n\t"
> + "movq %%rsi, (%%rdi)\n\t"
> + "jmp %l[done]\n\t"
> + "106:\n\t"
> + /* From 4 to 7. No branch when size == 4. */
> + "movl -4(%%rsi,%%rdx), %%ecx\n\t"
> + "movl (%%rsi), %%esi\n\t"
> + "movl %%ecx, -4(%%rdi,%%rdx)\n\t"
> + "movl %%esi, (%%rdi)\n\t"
> + "jmp %l[done]\n\t"
> + "107:\n\t"
> + /* From 2 to 3. No branch when size == 2. */
> + "movzwl -2(%%rsi,%%rdx), %%ecx\n\t"
> + "movzwl (%%rsi), %%esi\n\t"
> + "movw %%cx, -2(%%rdi,%%rdx)\n\t"
> + "movw %%si, (%%rdi)\n\t"
> + "jmp %l[done]\n\t"
> + "108:\n\t"
> + /* More than 2 * VEC and there may be overlap between destination */
> + /* and source. */
> + "cmpq $(32 * 8), %%rdx\n\t"
> + "ja 111f\n\t"
> + "cmpq $(32 * 4), %%rdx\n\t"
> + "jb 109f\n\t"
> + /* Copy from 4 * VEC to 8 * VEC, inclusively. */
> + "vmovdqu (%%rsi), %%ymm0\n\t"
> + "vmovdqu 32(%%rsi), %%ymm1\n\t"
> + "vmovdqu (32 * 2)(%%rsi), %%ymm2\n\t"
> + "vmovdqu (32 * 3)(%%rsi), %%ymm3\n\t"
> + "vmovdqu -32(%%rsi,%%rdx), %%ymm4\n\t"
> + "vmovdqu -(32 * 2)(%%rsi,%%rdx), %%ymm5\n\t"
> + "vmovdqu -(32 * 3)(%%rsi,%%rdx), %%ymm6\n\t"
> + "vmovdqu -(32 * 4)(%%rsi,%%rdx), %%ymm7\n\t"
> + "vmovdqu %%ymm0, (%%rdi)\n\t"
> + "vmovdqu %%ymm1, 32(%%rdi)\n\t"
> + "vmovdqu %%ymm2, (32 * 2)(%%rdi)\n\t"
> + "vmovdqu %%ymm3, (32 * 3)(%%rdi)\n\t"
> + "vmovdqu %%ymm4, -32(%%rdi,%%rdx)\n\t"
> + "vmovdqu %%ymm5, -(32 * 2)(%%rdi,%%rdx)\n\t"
> + "vmovdqu %%ymm6, -(32 * 3)(%%rdi,%%rdx)\n\t"
> + "vmovdqu %%ymm7, -(32 * 4)(%%rdi,%%rdx)\n\t"
> + "vzeroupper\n\t"
> + "jmp %l[done]\n\t"
> + "109:\n\t"
> + /* Copy from 2 * VEC to 4 * VEC. */
> + "vmovdqu (%%rsi), %%ymm0\n\t"
> + "vmovdqu 32(%%rsi), %%ymm1\n\t"
> + "vmovdqu -32(%%rsi,%%rdx), %%ymm2\n\t"
> + "vmovdqu -(32 * 2)(%%rsi,%%rdx), %%ymm3\n\t"
> + "vmovdqu %%ymm0, (%%rdi)\n\t"
> + "vmovdqu %%ymm1, 32(%%rdi)\n\t"
> + "vmovdqu %%ymm2, -32(%%rdi,%%rdx)\n\t"
> + "vmovdqu %%ymm3, -(32 * 2)(%%rdi,%%rdx)\n\t"
> + "vzeroupper\n\t"
> + "110:\n\t"
> + "jmp %l[done]\n\t"
> + "111:\n\t"
> + "cmpq %%rsi, %%rdi\n\t"
> + "ja 113f\n\t"
> + /* Source == destination is less common. */
> + "je 110b\n\t"
> + /* Load the first VEC and last 4 * VEC to
> + * support overlapping addresses.
> + */
> + "vmovdqu (%%rsi), %%ymm4\n\t"
> + "vmovdqu -32(%%rsi, %%rdx), %%ymm5\n\t"
> + "vmovdqu -(32 * 2)(%%rsi, %%rdx), %%ymm6\n\t"
> + "vmovdqu -(32 * 3)(%%rsi, %%rdx), %%ymm7\n\t"
> + "vmovdqu -(32 * 4)(%%rsi, %%rdx), %%ymm8\n\t"
> + /* Save start and stop of the destination buffer. */
> + "movq %%rdi, %%r11\n\t"
> + "leaq -32(%%rdi, %%rdx), %%rcx\n\t"
> + /* Align destination for aligned stores in the loop. Compute */
> + /* how much destination is misaligned. */
> + "movq %%rdi, %%r8\n\t"
> + "andq $(32 - 1), %%r8\n\t"
> + /* Get the negative of offset for alignment. */
> + "subq $32, %%r8\n\t"
> + /* Adjust source. */
> + "subq %%r8, %%rsi\n\t"
> + /* Adjust destination which should be aligned now. */
> + "subq %%r8, %%rdi\n\t"
> + /* Adjust length. */
> + "addq %%r8, %%rdx\n\t"
> + /* Check non-temporal store threshold. */
> + "cmpq $(1024*1024), %%rdx\n\t"
> + "ja 115f\n\t"
> + "112:\n\t"
> + /* Copy 4 * VEC a time forward. */
> + "vmovdqu (%%rsi), %%ymm0\n\t"
> + "vmovdqu 32(%%rsi), %%ymm1\n\t"
> + "vmovdqu (32 * 2)(%%rsi), %%ymm2\n\t"
> + "vmovdqu (32 * 3)(%%rsi), %%ymm3\n\t"
> + "addq $(32 * 4), %%rsi\n\t"
> + "subq $(32 * 4), %%rdx\n\t"
> + "vmovdqa %%ymm0, (%%rdi)\n\t"
> + "vmovdqa %%ymm1, 32(%%rdi)\n\t"
> + "vmovdqa %%ymm2, (32 * 2)(%%rdi)\n\t"
> + "vmovdqa %%ymm3, (32 * 3)(%%rdi)\n\t"
> + "addq $(32 * 4), %%rdi\n\t"
> + "cmpq $(32 * 4), %%rdx\n\t"
> + "ja 112b\n\t"
> + /* Store the last 4 * VEC. */
> + "vmovdqu %%ymm5, (%%rcx)\n\t"
> + "vmovdqu %%ymm6, -32(%%rcx)\n\t"
> + "vmovdqu %%ymm7, -(32 * 2)(%%rcx)\n\t"
> + "vmovdqu %%ymm8, -(32 * 3)(%%rcx)\n\t"
> + /* Store the first VEC. */
> + "vmovdqu %%ymm4, (%%r11)\n\t"
> + "vzeroupper\n\t"
> + "jmp %l[done]\n\t"
> + "113:\n\t"
> + /* Load the first 4*VEC and last VEC to support overlapping addresses.*/
> + "vmovdqu (%%rsi), %%ymm4\n\t"
> + "vmovdqu 32(%%rsi), %%ymm5\n\t"
> + "vmovdqu (32 * 2)(%%rsi), %%ymm6\n\t"
> + "vmovdqu (32 * 3)(%%rsi), %%ymm7\n\t"
> + "vmovdqu -32(%%rsi,%%rdx), %%ymm8\n\t"
> + /* Save stop of the destination buffer. */
> + "leaq -32(%%rdi, %%rdx), %%r11\n\t"
> + /* Align destination end for aligned stores in the loop. Compute */
> + /* how much destination end is misaligned. */
> + "leaq -32(%%rsi, %%rdx), %%rcx\n\t"
> + "movq %%r11, %%r9\n\t"
> + "movq %%r11, %%r8\n\t"
> + "andq $(32 - 1), %%r8\n\t"
> + /* Adjust source. */
> + "subq %%r8, %%rcx\n\t"
> + /* Adjust the end of destination which should be aligned now. */
> + "subq %%r8, %%r9\n\t"
> + /* Adjust length. */
> + "subq %%r8, %%rdx\n\t"
> + /* Check non-temporal store threshold. */
> + "cmpq $(1024*1024), %%rdx\n\t"
> + "ja 117f\n\t"
> + "114:\n\t"
> + /* Copy 4 * VEC a time backward. */
> + "vmovdqu (%%rcx), %%ymm0\n\t"
> + "vmovdqu -32(%%rcx), %%ymm1\n\t"
> + "vmovdqu -(32 * 2)(%%rcx), %%ymm2\n\t"
> + "vmovdqu -(32 * 3)(%%rcx), %%ymm3\n\t"
> + "subq $(32 * 4), %%rcx\n\t"
> + "subq $(32 * 4), %%rdx\n\t"
> + "vmovdqa %%ymm0, (%%r9)\n\t"
> + "vmovdqa %%ymm1, -32(%%r9)\n\t"
> + "vmovdqa %%ymm2, -(32 * 2)(%%r9)\n\t"
> + "vmovdqa %%ymm3, -(32 * 3)(%%r9)\n\t"
> + "subq $(32 * 4), %%r9\n\t"
> + "cmpq $(32 * 4), %%rdx\n\t"
> + "ja 114b\n\t"
> + /* Store the first 4 * VEC. */
> + "vmovdqu %%ymm4, (%%rdi)\n\t"
> + "vmovdqu %%ymm5, 32(%%rdi)\n\t"
> + "vmovdqu %%ymm6, (32 * 2)(%%rdi)\n\t"
> + "vmovdqu %%ymm7, (32 * 3)(%%rdi)\n\t"
> + /* Store the last VEC. */
> + "vmovdqu %%ymm8, (%%r11)\n\t"
> + "vzeroupper\n\t"
> + "jmp %l[done]\n\t"
> +
> + "115:\n\t"
> + /* Don't use non-temporal store if there is overlap between */
> + /* destination and source since destination may be in cache */
> + /* when source is loaded. */
> + "leaq (%%rdi, %%rdx), %%r10\n\t"
> + "cmpq %%r10, %%rsi\n\t"
> + "jb 112b\n\t"
> + "116:\n\t"
> + /* Copy 4 * VEC a time forward with non-temporal stores. */
> + "prefetcht0 (32*4*2)(%%rsi)\n\t"
> + "prefetcht0 (32*4*2 + 64)(%%rsi)\n\t"
> + "prefetcht0 (32*4*3)(%%rsi)\n\t"
> + "prefetcht0 (32*4*3 + 64)(%%rsi)\n\t"
> + "vmovdqu (%%rsi), %%ymm0\n\t"
> + "vmovdqu 32(%%rsi), %%ymm1\n\t"
> + "vmovdqu (32 * 2)(%%rsi), %%ymm2\n\t"
> + "vmovdqu (32 * 3)(%%rsi), %%ymm3\n\t"
> + "addq $(32*4), %%rsi\n\t"
> + "subq $(32*4), %%rdx\n\t"
> + "vmovntdq %%ymm0, (%%rdi)\n\t"
> + "vmovntdq %%ymm1, 32(%%rdi)\n\t"
> + "vmovntdq %%ymm2, (32 * 2)(%%rdi)\n\t"
> + "vmovntdq %%ymm3, (32 * 3)(%%rdi)\n\t"
> + "addq $(32*4), %%rdi\n\t"
> + "cmpq $(32*4), %%rdx\n\t"
> + "ja 116b\n\t"
> + "sfence\n\t"
> + /* Store the last 4 * VEC. */
> + "vmovdqu %%ymm5, (%%rcx)\n\t"
> + "vmovdqu %%ymm6, -32(%%rcx)\n\t"
> + "vmovdqu %%ymm7, -(32 * 2)(%%rcx)\n\t"
> + "vmovdqu %%ymm8, -(32 * 3)(%%rcx)\n\t"
> + /* Store the first VEC. */
> + "vmovdqu %%ymm4, (%%r11)\n\t"
> + "vzeroupper\n\t"
> + "jmp %l[done]\n\t"
> + "117:\n\t"
> + /* Don't use non-temporal store if there is overlap between */
> + /* destination and source since destination may be in cache */
> + /* when source is loaded. */
> + "leaq (%%rcx, %%rdx), %%r10\n\t"
> + "cmpq %%r10, %%r9\n\t"
> + "jb 114b\n\t"
> + "118:\n\t"
> + /* Copy 4 * VEC a time backward with non-temporal stores. */
> + "prefetcht0 (-32 * 4 * 2)(%%rcx)\n\t"
> + "prefetcht0 (-32 * 4 * 2 - 64)(%%rcx)\n\t"
> + "prefetcht0 (-32 * 4 * 3)(%%rcx)\n\t"
> + "prefetcht0 (-32 * 4 * 3 - 64)(%%rcx)\n\t"
> + "vmovdqu (%%rcx), %%ymm0\n\t"
> + "vmovdqu -32(%%rcx), %%ymm1\n\t"
> + "vmovdqu -(32 * 2)(%%rcx), %%ymm2\n\t"
> + "vmovdqu -(32 * 3)(%%rcx), %%ymm3\n\t"
> + "subq $(32*4), %%rcx\n\t"
> + "subq $(32*4), %%rdx\n\t"
> + "vmovntdq %%ymm0, (%%r9)\n\t"
> + "vmovntdq %%ymm1, -32(%%r9)\n\t"
> + "vmovntdq %%ymm2, -(32 * 2)(%%r9)\n\t"
> + "vmovntdq %%ymm3, -(32 * 3)(%%r9)\n\t"
> + "subq $(32 * 4), %%r9\n\t"
> + "cmpq $(32 * 4), %%rdx\n\t"
> + "ja 118b\n\t"
> + "sfence\n\t"
> + /* Store the first 4 * VEC. */
> + "vmovdqu %%ymm4, (%%rdi)\n\t"
> + "vmovdqu %%ymm5, 32(%%rdi)\n\t"
> + "vmovdqu %%ymm6, (32 * 2)(%%rdi)\n\t"
> + "vmovdqu %%ymm7, (32 * 3)(%%rdi)\n\t"
> + /* Store the last VEC. */
> + "vmovdqu %%ymm8, (%%r11)\n\t"
> + "vzeroupper\n\t"
> + "jmp %l[done]"
> + :
> + : "r"(src), "r"(dst), "r"(len)
> + : "rax", "rcx", "rdx", "rdi", "rsi", "r8", "r9", "r10", "r11", "r12",
> "ymm0",
> + "ymm1", "ymm2", "ymm3", "ymm4", "ymm5", "ymm6", "ymm7", "ymm8", "memory"
> + : done
> + );
> +done:
> + return dst;
> +}
