lhz (Load Half and Zero) instruction
Purpose
Loads a halfword of data from a specified location in memory into a general-purpose register and sets the remaining 16 bits to 0.
Syntax
| Bits | Value |
|---|---|
| 0 - 5 | 40 |
| 6 - 10 | RT |
| 11 - 15 | RA |
| 16 - 31 | D |
Description
The lhz instruction loads a halfword of data from a specified location in memory, addressed by the effective address (EA), into bits 16-31 of the target general-purpose register (GPR) RT and sets bits 0-15 of GPR RT to 0.
If GPR RA is not 0, the EA is the sum of the contents of GPR RA and D, a 16-bit, signed two's complement integer sign-extended to 32 bits. If GPR RA is 0, then the EA is D.
The lhz instruction has one syntax form and does not affect the Fixed-Point Exception Register or Condition Register Field 0.
Parameters
| Item | Description |
|---|---|
| RT | Specifies target general-purpose register where result of operation is stored. |
| D | 16-bit, signed two's complement integer sign-extended to 32 bits for EA calculation. |
| RA | Specifies source general-purpose register for EA calculation. |
Examples
The following code loads a halfword of data into bits 16-31 of GPR 6 and sets bits 0-15 of GPR 6 to 0:
.csect data[rw]
storage: .short 0xffff
# Assume GPR 4 holds the address of csect data[rw].
.csect text[pr]
lhz 6,storage(4)
# GPR 6 now holds 0x0000 ffff.