ARM base instruction -- adcs

Add with Carry, setting flags, adds two register values and the Carry flag value, and writes the result to the destination register. It updates the condition flags based on the result.

带进位加法，设置标志，将两个寄存器值和进位标志值相加，并将结果写入目标寄存器。它根据结果更新条件标志。

32-bit variant

Applies when sf == 0.

ADCS <Wd>, <Wn>, <Wm>

64-bit variant

Applies when sf == 1.

ADCS <Xd>, <Xn>, <Xm>

Decode for all variants of this encoding

integer d = UInt(Rd);

integer n = UInt(Rn);

integer m = UInt(Rm);

integer datasize = if sf == '1' then 64 else 32;

Operation

bits(datasize) result;

bits(datasize) operand1 = X[n];

bits(datasize) operand2 = X[m];

bits(4) nzcv;

(result, nzcv) = AddWithCarry(operand1, operand2, PSTATE.C);

PSTATE.<N,Z,C,V> = nzcv;

X[d] = result;

(bits(N), bits(4)) AddWithCarry(bits(N) x, bits(N) y, bit carry_in)

integer unsigned_sum = UInt(x) + UInt(y) + UInt(carry_in);

integer signed_sum = SInt(x) + SInt(y) + UInt(carry_in);

bits(N) result = unsigned_sum<N-1:0>; // same value as signed_sum<N-1:0>

bit n = result<N-1>;

bit z = if IsZero(result) then '1' else '0';

bit c = if UInt(result) == unsigned_sum then '0' else '1';

bit v = if SInt(result) == signed_sum then '0' else '1';

return (result, n:z:c:v);

ADC指令用于把两个操作数相加，再加上CPSR中的C条件标志位的值，并将结果存放到目的寄存器中

adds r0, r4, r8 // 加低端的字

adcs r1, r5, r9 // 加第二个字,带进位

adcs r2, r6, r10 // 加第三个字,带进位

adc r3, r7, r11 // 加第四个字,带进位