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⬅️ Previous capture (2023-01-29)
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Created 2023-01-05
Register Synonym Special Role in the procedure call standard
r15 PC The Program Counter.
r14 LR The Link Register.
r13 SP The Stack Pointer.
r12 IP The Intra-Procedure-call scratch register.
r11 v8 FP ARM-state variable-register 8. ARM-state frame pointer.
r10 v7 SL ARM-state variable-register 7. Stack Limit pointer in stack-checked variants.
r9 v6 SB ARM-state v-register 6. Static Base in PID,/re-entrant/shared-library variants
r8 v5 ARM-state variable-register 5.
r7 v4 WR Variable register (v-register) 4. Thumb-state Work Register.
r6 v3 Variable register (v-register) 3.
r5 v2 Variable register (v-register) 2.
r4 v1 Variable register (v-register) 1.
r3 a4 Argument/result/scratch register 4.
r2 a3 Argument/result/ scratch register 3.
r1 a2 Argument/result/ scratch register 2.
r0 a1 Argument/result/ scratch register 1.
r0-r3 For passing parameters in and out. Can also be used as scratch registers. Caller should assume callee modifies the values.
r4-r11 used to hold values of routine's local variables. Callee must restore thir values before return to caller.
r12-r15 have special roles