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kaityo256/cntb.cpp

Created January 6, 2021 07:50
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cntb.cpp
#include <cstdio>
int main(){
int x;
asm __volatile__("cntb %[x]" : [ x ] "=r"(x));
printf("%d\n",x*8);
}
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kaityo256 commented Jan 6, 2021 •
edited 

$ qemu-aarch64 -cpu max,sve128=on ./a.out
128
$ qemu-aarch64 -cpu max,sve256=on ./a.out
256
$ qemu-aarch64 -cpu max,sve512=on ./a.out
512
$ qemu-aarch64 -cpu max,sve=off ./a.out
qemu: uncaught target signal 4 (Illegal instruction) - core dumped
Illegal instruction

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