github.com/afumu/libc@v0.0.6/musl/src/math/x32/fabs.s (about)

     1  .global fabs
     2  .type fabs,@function
     3  fabs:
     4  	xor %eax,%eax
     5  	dec %rax
     6  	shr %rax
     7  	movq %rax,%xmm1
     8  	andpd %xmm1,%xmm0
     9  	ret