stmw or stm (Store Multiple Word) instruction
Stores the contents of consecutive registers into a specified memory location.
Syntax
| Bits | Value |
|---|---|
| 0 - 5 | 47 |
| 6 - 10 | RT |
| 11 - 15 | RA |
| 16 - 31 | D |
Description
The stmw and stm instructions store N consecutive words from general-purpose register (GPR) RS through GPR 31. Storage starts at the effective address (EA). N is a register number equal to 32 minus RS.
If GPR RA is not 0, the EA is the sum of the contents of GPR RA and D. The sum is a 16-bit signed two's complement integer sign-extended to 32 bits. If GPR RA is 0, then the EA is D.
The stmw instruction has one syntax form. If the EA is not a multiple of 4, the results are boundedly undefined.
The stm instruction has one syntax form and does not affect the Fixed-Point Exception Register or Condition Register Field 0.
Parameters
| Item | Description |
|---|---|
| RS | Specifies source general-purpose register of stored data. |
| D | Specifies a 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 stores the contents of GPR 29 through GPR 31 into a location in memory:
.csect data[rw]
buffer: .long 0,0,0
# Assume GPR 29 contains 0x1000 2200.
# Assume GPR 30 contains 0x1000 3300.
# Assume GPR 31 contains 0x1000 4400.
.csect text[pr]
stmw 29,buffer(4)
# Three consecutive words in storage beginning at the address
# of buffer are now 0x1000 2200 1000 3300 1000 4400.