Reverse Subtract with Carry.
is an optional suffix. If S is specified, the condition flags are updated on the result of the operation.
is an optional condition code.
is the destination register.
is the register holding the first operand.
is a flexible second operand.
RSC instruction subtracts thevalue in
Rn from the value of
Operand2.If the carry flag is clear, the result is reduced by one.
You can use
RSC to synthesize multiwordarithmetic.
In certain circumstances, the assembler can substitute oneinstruction for another. Be aware of this when reading disassemblylistings.
RSC is not available in T32 code.
Use of PC and SP
Use of PC and SP is deprecated.
You cannot use PC for
Rd orany operand in an
RSC instruction thathas a register-controlled shift.
If you use PC (
Rm,the value used is the address of the instruction plus 8.
If you use PC as
- Execution branches to the address corresponding to the result.
- If you use the S suffix, see the
If S is specified, the
RSC instructionupdates the N, Z, C and V flags according to the result.
RSCSLE r0,r5,r0,LSL r4 ; conditional, flags set
RSCSLE r0,pc,r0,LSL r4 ; PC not permitted with register ; controlled shift