extr_x.md

Quick summary

Instruction	General theme	Writemask	Optional special features
extrx	x[i] = y[i]	None

Instruction encoding

Bit	Width	Meaning	Notes
10	22	A64 reserved instruction	Must be 0x201000 >> 10
5	5	Instruction	Must be 8
0	5	5-bit GPR index	See below for the meaning of the 64 bits in the GPR

Operand bitfields

Bit	Width	Meaning	Notes
28	36	Ignored
27	1	Must be 1	Otherwise decodes as extrh
26	1	Must be 0	Otherwise decodes as extrh
23	3	Ignored
20	3	Y register index
19	1	Ignored
16	3	X register index
0	16	Ignored

Description

Copies an entire register from Y to X.

Emulation code

See extr.c.

A representative sample is:

void emulate_AMX_EXTRX(amx_state* state, uint64_t operand) {
    if (operand & EXTR_HV) {
        ...
    } else if (operand & EXTR_BETWEEN_XY) {
        memcpy(state->x + ((operand >> 16) & 7),
               state->y + ((operand >> 20) & 7), 64);
    } else {
        ...
    }
}