114 lines · c
1/// BUILT with2/// xcrun -sdk macosx.internal clang -mcpu=apple-m4 -g sme.c -o sme3 4#include <stdint.h>5#include <stdio.h>6#include <stdlib.h>7 8void write_sve_regs() {9 asm volatile("ptrue p0.b\n\t");10 asm volatile("ptrue p1.h\n\t");11 asm volatile("ptrue p2.s\n\t");12 asm volatile("ptrue p3.d\n\t");13 asm volatile("pfalse p4.b\n\t");14 asm volatile("ptrue p5.b\n\t");15 asm volatile("ptrue p6.h\n\t");16 asm volatile("ptrue p7.s\n\t");17 asm volatile("ptrue p8.d\n\t");18 asm volatile("pfalse p9.b\n\t");19 asm volatile("ptrue p10.b\n\t");20 asm volatile("ptrue p11.h\n\t");21 asm volatile("ptrue p12.s\n\t");22 asm volatile("ptrue p13.d\n\t");23 asm volatile("pfalse p14.b\n\t");24 asm volatile("ptrue p15.b\n\t");25 26 asm volatile("cpy z0.b, p0/z, #1\n\t");27 asm volatile("cpy z1.b, p5/z, #2\n\t");28 asm volatile("cpy z2.b, p10/z, #3\n\t");29 asm volatile("cpy z3.b, p15/z, #4\n\t");30 asm volatile("cpy z4.b, p0/z, #5\n\t");31 asm volatile("cpy z5.b, p5/z, #6\n\t");32 asm volatile("cpy z6.b, p10/z, #7\n\t");33 asm volatile("cpy z7.b, p15/z, #8\n\t");34 asm volatile("cpy z8.b, p0/z, #9\n\t");35 asm volatile("cpy z9.b, p5/z, #10\n\t");36 asm volatile("cpy z10.b, p10/z, #11\n\t");37 asm volatile("cpy z11.b, p15/z, #12\n\t");38 asm volatile("cpy z12.b, p0/z, #13\n\t");39 asm volatile("cpy z13.b, p5/z, #14\n\t");40 asm volatile("cpy z14.b, p10/z, #15\n\t");41 asm volatile("cpy z15.b, p15/z, #16\n\t");42 asm volatile("cpy z16.b, p0/z, #17\n\t");43 asm volatile("cpy z17.b, p5/z, #18\n\t");44 asm volatile("cpy z18.b, p10/z, #19\n\t");45 asm volatile("cpy z19.b, p15/z, #20\n\t");46 asm volatile("cpy z20.b, p0/z, #21\n\t");47 asm volatile("cpy z21.b, p5/z, #22\n\t");48 asm volatile("cpy z22.b, p10/z, #23\n\t");49 asm volatile("cpy z23.b, p15/z, #24\n\t");50 asm volatile("cpy z24.b, p0/z, #25\n\t");51 asm volatile("cpy z25.b, p5/z, #26\n\t");52 asm volatile("cpy z26.b, p10/z, #27\n\t");53 asm volatile("cpy z27.b, p15/z, #28\n\t");54 asm volatile("cpy z28.b, p0/z, #29\n\t");55 asm volatile("cpy z29.b, p5/z, #30\n\t");56 asm volatile("cpy z30.b, p10/z, #31\n\t");57 asm volatile("cpy z31.b, p15/z, #32\n\t");58}59 60#define MAX_VL_BYTES 25661void set_za_register(int svl, int value_offset) {62 uint8_t data[MAX_VL_BYTES];63 64 // ldr za will actually wrap the selected vector row, by the number of rows65 // you have. So setting one that didn't exist would actually set one that did.66 // That's why we need the streaming vector length here.67 for (int i = 0; i < svl; ++i) {68 // This may involve instructions that require the smefa64 extension.69 for (int j = 0; j < MAX_VL_BYTES; j++)70 data[j] = i + value_offset;71 // Each one of these loads a VL sized row of ZA.72 asm volatile("mov w12, %w0\n\t"73 "ldr za[w12, 0], [%1]\n\t" ::"r"(i),74 "r"(&data)75 : "w12");76 }77}78 79static uint16_t arm_sme_svl_b(void) {80 uint64_t ret = 0;81 asm volatile("rdsvl %[ret], #1" : [ret] "=r"(ret));82 return (uint16_t)ret;83}84 85void arm_sme2_set_zt0() {86#define ZTO_LEN (512 / 8)87 uint8_t data[ZTO_LEN];88 for (unsigned i = 0; i < ZTO_LEN; ++i)89 data[i] = i + 0;90 91 asm volatile("ldr zt0, [%0]" ::"r"(&data));92#undef ZT0_LEN93}94 95int main() {96 printf("Enable SME mode\n"); // break before sme97 98 asm volatile("smstart");99 100 write_sve_regs();101 102 set_za_register(arm_sme_svl_b(), 4);103 104 arm_sme2_set_zt0();105 106 int c = 10; // break while sme107 c += 5;108 c += 5;109 110 asm volatile("smstop");111 112 printf("SME mode disabled\n"); // break after sme113}114