Do ARMv7 and/or ARMv8 instruction set provide an instruction similar to PEXT on x86?
If not, what is the most efficient instructions combination to achieve the same behavior?
Equivalent of PEXT instruction on ARM
Viewed 295
1 Answers
This is my implementation
// w14 = pext(val: w13, mask: w15)
// Used Regs x12-x15
// (w13 & w15 will BROKEN after the loop)
mov w14, wzr;
.loop:
cbz w15, .pext_end; // may accelerate by prepare with (w13 & w15)
clz w12, w15
lsl w13, w13, w12
lsl w15, w15, w12
extr w14, w14, w13, #31
bfc w15, #31, #1
b .loop
.pext_end:
Related