Arm® A32/T32 Instruction Set Architecture: Armv8, for Armv8-A architecture profile Documentation | POP (multiple registers): Pop Multiple Registers from Stack: an alias of LDM, LDMIA, LDMFD.

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POP (multiple registers)

Pop Multiple Registers from Stack loads multiple general-purpose registers from the stack, loading from consecutive memory locations starting at the address in SP, and updates SP to point just above the loaded data.

This is an alias of LDM, LDMIA, LDMFD. This means:

The encodings in this description are named to match the encodings of LDM, LDMIA, LDMFD.
The description of LDM, LDMIA, LDMFD gives the operational pseudocode for this instruction.

It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T2 ) .

A1

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
!= 1111				1	0	0	0	1	0	1	1	1	1	0	1	register_list
cond										W		Rn

A1

POP{<c>}{<q>} <registers>

is equivalent to

LDM{<c>}{<q>} SP!, <registers>

and is the preferred disassembly when BitCount(register_list) > 1.

T2

15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
1	1	1	0	1	0	0	0	1	0	1	1	1	1	0	1	P	M	register_list
										W		Rn

T2

POP{<c>}.W <registers> // (All registers in R0-R7, PC)

POP{<c>}{<q>} <registers>

is equivalent to

LDM{<c>}{<q>} SP!, <registers>

and is the preferred disassembly when BitCount(P:M:register_list) > 1.

Assembler Symbols

<c>	See Standard assembler syntax fields.

<q>	See Standard assembler syntax fields.

For encoding A1: is a list of two or more registers to be loaded, separated by commas and surrounded by { and }. The lowest-numbered register is loaded from the lowest memory address, through to the highest-numbered register from the highest memory address. See also Encoding of lists of general-purpose registers and the PC.

If the SP is in the list, the value of the SP after such an instruction is unknown.

The PC can be in the list. If it is, the instruction branches to the address loaded to the PC. This is an interworking branch, see Pseudocode description of operations on the AArch32 general-purpose registers and the PC.

Arm deprecates the use of this instruction with both the LR and the PC in the list.

For encoding T2: is a list of two or more registers to be loaded, separated by commas and surrounded by { and }. The lowest-numbered register is loaded from the lowest memory address, through to the highest-numbered register from the highest memory address. See also Encoding of lists of general-purpose registers and the PC.

The registers in the list must be in the range R0-R12, encoded in the "register_list" field, and can optionally contain one of the LR or the PC. If the LR is in the list, the "M" field is set to 1, otherwise it defaults to 0. If the PC is in the list, the "P" field is set to 1, otherwise it defaults to 0.

The LR must not be in the list.
The instruction must be either outside any IT block, or the last instruction in an IT block.

Operation

The description of LDM, LDMIA, LDMFD gives the operational pseudocode for this instruction.

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