lhia.adoc

th.lhia

Synopsis

Load indexed half-word, increment address after loading.

Mnemonic

th.lhia rd, (rs1), imm5, imm2

Encoding

{reg:[
    { bits:  7, name: 0xb, attr: ['custom-0, 32 bit'] },
    { bits:  5, name: 'rd' },
    { bits:  3, name: 0x4, attr: ['Mem-Load'] },
    { bits:  5, name: 'rs1' },
    { bits:  5, name: 'imm5' },
    { bits:  2, name: 'imm2' },
    { bits:  5, name: 0x07 },
]}

Description

This instruction loads a sign extended 16-bit value into the GP register rd from the address rs1. After the load, this instruction increments the value in rs1 by (sign_extend(imm5) << imm2) and writes the result back to rs1.

The values of rd and rs1 must not be the same.

Operation

rd := sign_extend(mem[rs1+1:rs1])
rs1 := rs1 + (sign_extend(imm5) << imm2)

Permission

This instruction can be executed in all privilege levels.

Exceptions

This instruction triggers the same exceptions that a corresponding LH instruction would trigger.

Included in

Extension
XTheadMemIdx ([xtheadmemidx])