5.2.1. Return stack predictions

The return stack stores the address and the ARM or Thumb state of the instruction after a function-call type branch instruction. This address is equal to the link register value stored in r14.

The following instructions cause a return stack push if predicted:

The following instructions cause a return stack pop if predicted:

The LDR instruction can use any of the addressing modes, as long as r13 is the base register. Additionally, in ThumbEE state you can also use r9 as a stack pointer so the LDR and LDM instructions with pc as a destination and r9 as a base register are also treated as a return stack pop.

Because return-from-exception instructions can change processor privilege mode and security state, they are not predicted. This includes the LDM(3) instruction, and the MOVS pc, r14 instruction.

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