stfdx (Store Floating-Point Double Indexed) instruction
Purpose
Stores a doubleword of data in a specified location in memory.
Syntax
Bits | Value |
---|---|
0 - 5 | 31 |
6 - 10 | FRS |
11 - 15 | RA |
16 - 20 | RB |
21 - 30 | 727 |
31 | / |
Description
The stfdx instruction stores the contents of floating-point register (FPR) FRS into the doubleword storage addressed by the effective address (EA).
If general-purpose register (GPR) RA is not 0, the EA is the sum of the contents of GPRs RA and RB. If GPR RA is 0, then the EA is the contents of GPR RB.
The stfdx instruction has one syntax form and does not affect the Floating-Point Status and Control Register or Condition Register Field 0.
Parameters
Item | Description |
---|---|
FRS | Specifies source floating-point register of stored data. |
RA | Specifies source general-purpose register for EA calculation. |
RB | Specifies source general-purpose register for EA calculation. |
Examples
The following code stores the contents of FPR 6 into a location in memory addressed by GPR 5 and GPR 4:
.csect data[rw]
buffer: .long 0,0,0,0
# Assume FPR 6 contains 0x4865 6C6C 6F20 776F.
# Assume GPR 4 contains 0x0000 0008.
# Assume GPR 5 contains the address of buffer.
.csect text[pr]
stfdx 6,4,5
# 0x4865 6C6C 6F20 776F is now stored at the
# address buffer+8.