锟斤拷锟斤拷位锟矫ｏ拷锟斤拷页 > 锟斤拷锟斤拷锟教筹拷 > 锟教筹拷 > ARM64锟斤拷锟斤拷械锟紸DD指锟斤拷锟斤拷锟�

ARM64锟斤拷锟斤拷械锟紸DD指锟斤拷锟斤拷锟�

锟斤拷源锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷|锟斤拷时锟戒：2024-11-15 09:57:19 |锟斤拷锟侥讹拷锟斤拷72锟斤拷|锟斤拷锟斤拷签锟斤拷 a 系 AR ARM 锟斤拷 |锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷戏

锟斤拷锟斤拷校锟斤拷臃锟街革拷锟斤拷锟斤拷要锟斤拷锟斤拷为锟斤拷锟斤拷执锟斤拷锟斤拷锟斤拷锟杰讹拷指锟斤拷幕锟斤拷锟斤拷锟� 同时锟斤拷锟接凤拷指锟斤拷也锟斤拷影锟斤拷NZCV锟斤拷志锟斤拷锟叫癸拷NZCV锟侥斤拷锟杰ｏ拷锟斤拷锟皆参匡拷锟斤拷一锟侥搞懂 ARM 64 系锟斤拷: ADC锟斤拷锟斤拷 ARM64锟斤拷锟斤拷校锟紸DD指锟斤拷锟斤拷3锟斤拷锟斤拷式锟斤拷锟斤拷锟斤拷锟斤拷艿锟揭伙拷锟斤拷锟绞斤拷锟揭诧拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟接★拷 1 指锟斤拷锟斤法 ADD <Xd|SP>,

锟节伙拷锟斤拷锟斤拷锟斤拷校锟斤拷臃锟街革拷锟斤拷欠浅锟斤拷锟揭拷模锟斤拷锟轿拷锟斤拷锟街达拷锟斤拷锟斤拷锟斤拷锟斤拷锟街革拷锟侥伙拷锟斤拷锟斤拷

同时锟斤拷锟接凤拷指锟斤拷也锟斤拷影锟斤拷NZCV锟斤拷志锟斤拷锟叫癸拷NZCV锟侥斤拷锟杰ｏ拷锟斤拷锟皆参匡拷锟斤拷一锟侥搞懂 ARM 64 系锟斤拷: ADC锟斤拷锟斤拷

ARM64锟斤拷锟斤拷校锟紸DD指锟斤拷锟斤拷3锟斤拷锟斤拷式锟斤拷锟斤拷锟斤拷锟斤拷艿锟揭伙拷锟斤拷锟绞斤拷锟揭诧拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟接★拷

1 指锟斤拷锟斤法

ADD , , #imm{, shift}

{ }锟斤拷锟斤拷锟斤拷荼锟绞撅拷强锟窖★拷摹锟�

shift锟斤拷示LSL(锟竭硷拷锟斤拷锟斤拷)锟斤拷位锟斤拷锟斤拷锟斤拷2锟斤拷取值锟斤拷一锟斤拷锟斤拷0锟斤拷一锟斤拷锟斤拷12锟斤拷0锟斤拷锟斤拷默锟斤拷值锟斤拷

锟斤拷谓LSL(锟竭硷拷锟斤拷锟斤拷)锟斤拷锟斤拷指锟斤拷锟斤拷值锟斤拷锟斤拷锟斤拷锟斤拷锟狡讹拷锟斤拷锟斤拷位锟斤拷0锟斤拷锟斤拷锟斤拷锟轿伙拷锟斤拷瞥锟饺ワ拷锟街憋拷佣锟斤拷锟斤拷锟�

ARM64汇编中的ADD指令详解

2 指锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷指锟斤拷锟斤拷墙锟皆达拷拇锟斤拷锟�锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷imm(锟斤拷锟斤拷斜锟揭拷锟斤拷锟揭拷锟斤拷锟絃SL)锟斤拷樱锟斤拷锟斤拷锟斤拷写锟斤拷目锟侥寄达拷锟斤拷锟斤拷

注锟斤拷 锟斤拷锟斤拷锟斤拷指锟筋不影锟斤拷NZCV锟斤拷志锟斤拷

(, _) =  + imm << shift

3 NZCV 锟斤拷锟斤拷锟接帮拷锟�

锟斤拷然锟斤拷锟斤拷指锟斤拷锟斤拷锟秸诧拷影锟斤拷NZCV锟斤拷志锟斤拷锟斤拷锟角革拷锟斤拷锟絅ZCV锟斤拷锟斤拷锟接帮拷欤拷锟斤拷呛锟斤拷斜锟揭拷摹锟�

1. 锟斤拷源锟侥达拷锟斤拷锟斤拷值锟斤拷imm << shift锟斤拷锟斤拷锟斤拷锟睫凤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷樱锟斤拷玫锟揭伙拷锟斤拷薹锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷慕锟斤拷锟斤拷锟斤拷锟斤拷u_result锟斤拷锟斤拷时锟斤拷锟斤拷时锟斤拷锟斤拷锟斤拷锟斤拷锟�:

 = 0xffffffffffffffff // 64 bit 全 1
(imm << shift) = 1
u_result = 0xffffffffffffffff + 1 = 0x10000000000000000 // 2^64锟斤拷锟斤拷锟斤拷锟斤拷 0

2. 锟斤拷源锟侥达拷锟斤拷锟斤拷值锟斤拷imm << shift锟斤拷锟斤拷锟斤拷锟叫凤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷樱锟斤拷玫锟揭伙拷锟斤拷蟹锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷慕锟斤拷锟斤拷锟斤拷锟斤拷s_result锟斤拷锟斤拷时锟斤拷锟斤拷时锟斤拷锟斤拷锟斤拷锟斤拷锟�:

 = 0xffffffffffffffff // 64 bit 全 1锟斤拷锟斤拷时锟斤拷锟斤拷 -1 锟斤拷锟斤拷
(imm << shift) = 0x8000000000000000 // 64 bit 锟斤拷小锟斤拷锟斤拷锟斤拷 -9223372036854775808
s_result = -1 + (-9223372036854775808) = -9223372036854775809 // 锟斤拷锟斤拷锟斤拷 0x7fffffffffffffff

3. 锟斤拷u_result锟斤拷取(63~0)锟斤拷64bit锟斤拷锟斤拷锟斤拷result;

4. 锟斤拷锟絩esult锟斤拷锟斤拷锟轿伙拷锟�1锟斤拷锟斤拷么N = 1;

5. 锟斤拷锟絩esult = 0锟斤拷锟斤拷么Z = 1;

6. 锟斤拷锟斤拷锟絩esult锟斤拷锟斤拷锟睫凤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷值锟斤拷锟斤拷u_result锟斤拷锟斤拷么C = 0锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷冢锟斤拷锟矫碈 = 1锟斤拷也锟斤拷锟斤拷锟节斤拷锟叫加凤拷锟斤拷锟斤拷时锟斤拷锟斤拷锟斤拷锟剿斤拷位锟斤拷

7. 锟斤拷锟斤拷锟絩esult锟斤拷锟斤拷锟叫凤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷值锟斤拷锟斤拷s_result锟斤拷锟斤拷么V = 0锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷冢锟斤拷锟矫碫 = 1锟斤拷也锟斤拷锟斤拷说锟节斤拷锟叫加凤拷锟斤拷锟姐，锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�

小锟斤拷锟狡硷拷锟侥讹拷

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锟斤拷戏锟斤拷频

锟斤拷戏锟斤拷锟斤拷

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