| #include <sys/auxv.h> |
| |
| void set_sve_registers() { |
| // AArch64 SVE extension ISA adds a new set of vector and predicate registers: |
| // 32 Z registers, 16 P registers, and 1 FFR register. |
| // Code below populates SVE registers to be read back by the debugger via |
| // ptrace interface at runtime. |
| // The P registers are predicate registers and hold one bit for each byte |
| // available in a Z vector register. For example, an SVE implementation with |
| // 1024-bit Z registers has 128-bit predicate registers. |
| // ptrue/pfalse instruction is used to set a predicate lane with a pattern. |
| // pattern is decided based on size specifier, b, h, s and d. if size |
| // specified is b all lanes will be set to 1. which is needed to set all bytes |
| // in a Z registers to the specified value. |
| asm volatile("setffr\n\t"); |
| asm volatile("ptrue p0.b\n\t"); |
| asm volatile("ptrue p1.h\n\t"); |
| asm volatile("ptrue p2.s\n\t"); |
| asm volatile("ptrue p3.d\n\t"); |
| asm volatile("pfalse p4.b\n\t"); |
| asm volatile("ptrue p5.b\n\t"); |
| asm volatile("ptrue p6.h\n\t"); |
| asm volatile("ptrue p7.s\n\t"); |
| asm volatile("ptrue p8.d\n\t"); |
| asm volatile("pfalse p9.b\n\t"); |
| asm volatile("ptrue p10.b\n\t"); |
| asm volatile("ptrue p11.h\n\t"); |
| asm volatile("ptrue p12.s\n\t"); |
| asm volatile("ptrue p13.d\n\t"); |
| asm volatile("pfalse p14.b\n\t"); |
| asm volatile("ptrue p15.b\n\t"); |
| |
| asm volatile("cpy z0.b, p0/z, #1\n\t"); |
| asm volatile("cpy z1.b, p5/z, #2\n\t"); |
| asm volatile("cpy z2.b, p10/z, #3\n\t"); |
| asm volatile("cpy z3.b, p15/z, #4\n\t"); |
| asm volatile("cpy z4.b, p0/z, #5\n\t"); |
| asm volatile("cpy z5.b, p5/z, #6\n\t"); |
| asm volatile("cpy z6.b, p10/z, #7\n\t"); |
| asm volatile("cpy z7.b, p15/z, #8\n\t"); |
| asm volatile("cpy z8.b, p0/z, #9\n\t"); |
| asm volatile("cpy z9.b, p5/z, #10\n\t"); |
| asm volatile("cpy z10.b, p10/z, #11\n\t"); |
| asm volatile("cpy z11.b, p15/z, #12\n\t"); |
| asm volatile("cpy z12.b, p0/z, #13\n\t"); |
| asm volatile("cpy z13.b, p5/z, #14\n\t"); |
| asm volatile("cpy z14.b, p10/z, #15\n\t"); |
| asm volatile("cpy z15.b, p15/z, #16\n\t"); |
| asm volatile("cpy z16.b, p0/z, #17\n\t"); |
| asm volatile("cpy z17.b, p5/z, #18\n\t"); |
| asm volatile("cpy z18.b, p10/z, #19\n\t"); |
| asm volatile("cpy z19.b, p15/z, #20\n\t"); |
| asm volatile("cpy z20.b, p0/z, #21\n\t"); |
| asm volatile("cpy z21.b, p5/z, #22\n\t"); |
| asm volatile("cpy z22.b, p10/z, #23\n\t"); |
| asm volatile("cpy z23.b, p15/z, #24\n\t"); |
| asm volatile("cpy z24.b, p0/z, #25\n\t"); |
| asm volatile("cpy z25.b, p5/z, #26\n\t"); |
| asm volatile("cpy z26.b, p10/z, #27\n\t"); |
| asm volatile("cpy z27.b, p15/z, #28\n\t"); |
| asm volatile("cpy z28.b, p0/z, #29\n\t"); |
| asm volatile("cpy z29.b, p5/z, #30\n\t"); |
| asm volatile("cpy z30.b, p10/z, #31\n\t"); |
| asm volatile("cpy z31.b, p15/z, #32\n\t"); |
| } |
| |
| int main() { |
| if (getauxval(AT_HWCAP) & HWCAP_SVE) // check if SVE is present |
| set_sve_registers(); |
| |
| return 0; // Set a break point here. |
| } |