Sawv cev ntawm tus xov tooj nyob rau hauv ib lub computer. Sawv cev ntawm cov zauv thiab cov zauv tiag tiag nyob rau hauv lub computer nco

Leej twg uas tau puas tau xav nyob rau hauv kuv lub neej uas mus ua tus "pros" los yog system administrator, los yog tsuas yog mus txuas cov ntau nrog computer technology, kev txawj ntse txog yuav ua li cas cov sawv cev ntawm tus xov tooj nyob rau hauv lub computer nco, yog tsim nyog kiag li. Tom qab tag nrho, raws li nyob rau hauv no low-level programming hom lus xws li assembler. Yog li ntawd, niaj hnub no peb xav txog cov sawv cev ntawm tus xov tooj nyob rau hauv lub computer thiab muab lawv nyob rau hauv lub cim xeeb hlwb.

cim

Yog hais tias koj nyeem qhov no tsab xov xwm, tej zaum koj twb paub txog nws, tab sis yog tsim nyog rov qab ua dua. Tag nrho cov ntaub ntawv nyob rau hauv ib tug tus kheej lub computer yog muab cia rau hauv lub binary tooj system. Qhov no txhais tau tias tej xov tooj koj yuav tsum xa qhov kev tsim nyog daim ntawv no, uas yog tsim los ntawm cov zeros thiab sawv daws yuav.

Nyob rau hauv thiaj li yuav hloov npaj rau peb decimal xov tooj rau ib daim ntawv to taub computer, koj yuav tsum siv cov algorithm piav hauv qab no. Tseem muaj tshwj xeeb cov cav laij leb.

Yog li ntawd, nyob rau hauv thiaj li yuav muab tso rau lub xov tooj nyob rau hauv lub binary system, koj yuav tau muab peb xaiv tus nqi thiab faib nws los ntawm 2. Tom qab hais tias, peb tau txais lub txiaj ntsim thiab lub seem (0 los yog 1). Tshwm 2 dua faib thiab cim residue. Qhov no txoj kev yuav tsum tau rov qab raws li ntev raws li lub txiaj ntsim kuj yuav tsum yog 0 los yog 1. Ces sau qhov kawg tus nqi thiab cov seem nyob rau hauv lub rov qab txiav txim, raws li peb tau txais lawv.

Uas yog raws nraim li cas yog tshwm sim nyob rau hauv lub computer sawv cev ntawm cov zauv. Tej xov tooj cia rau hauv binary daim ntawv, thiab ces noj lub cim xeeb ntawm tes.

nco

Raws li koj yuav tsum twb paub qhov tsawg kawg nkaus ntaub ntawv chav tsev yog 1 ntsis. Raws li peb tau pom, cov sawv cev ntawm tus xov tooj nyob rau hauv lub computer yuav siv sij hawm qhov chaw nyob rau hauv binary hom. Yog li, txhua me ntsis ntawm lub cim xeeb yog nyob los ntawm ib tug nqi ntawm - 1 los yog 0.

Rau cia ntawm loj tus xov tooj siv cell. Txhua chav tsev muaj 8 khoom ntawm cov ntaub ntawv. Yog li ntawd, peb yuav xaus uas qhov tsawg kawg nkaus tus nqi nyob rau hauv txhua lub cim xeeb ya tej zaum yuav tsum yog 1 los yog ua tau ib tug yim-byte binary tooj.

tag nrho

Thaum kawg peb tau txais mus rau qhov ncaj kev tso kawm ntawm cov ntaub ntawv nyob rau hauv ib lub computer. Raws li hais, tus thawj yam uas tus processor translates cov ntaub ntawv mus rau hauv ib tug binary hom ntawv, thiab xwb ces allocates lub cim xeeb.

Peb mam li pib nrog qhov nyuaj kev xaiv, uas yog tus sawv cev ntawm cov zauv nyob rau hauv lub computer. PC nco tseg rau hauv tus txheej txheem yog ridiculously me me naj npawb ntawm cov hlwb - cia li ib tug. Yog li, ib tug tshaj plaws ntawm ib qhov tej zaum yuav muaj nqis los ntawm 0 mus 11111111. Wb txhais lub siab tshaj plaws pes tsawg tus nkag hauv lub niaj zaus daim ntawv no.
X = 1 × 2 ⁷ + 1 × 2 ⁶ + 1 × 2 ⁵ + 1 × 2 ⁴ + 1 × 2 ³ + 1 × 2 ² + 1 × 2 ¹ + 1 × 2 ⁰ = 1 × 2 ⁸ - 1 = 255 .

Tam sim no peb pom tau tias nyob rau hauv ib tug nco cell yuav positioned ntawm 0 mus 255. Txawm li cas los, qhov no tsuas yog siv rau cov uas tsis-zoo integer. Yog hais tias lub computer yuav tsum tau sau ib tug tsis zoo nqi, txhua yam mus ib me ntsis txawv.

cov zauv negative

Tam sim no cia saib yuav ua li cas cov sawv cev ntawm tus xov tooj nyob rau hauv lub computer, yog hais tias lawv yog tsis zoo. Rau kev sau ntawv ib tug nqi uas yog tsawg tshaj li pes tsawg, muab ob lub cim xeeb hlwb, los yog 16 me me ntawm cov ntaub ntawv. Yog li 15 mus nyob rau hauv lub xov tooj xwb, thiab cov thawj (leftmost) me ntsis yog muab los ntawm cov coj kos.

Yog hais tias lub cev yog tsis zoo, nws yog kaw, "1", yog zoo, ces "0". Rau yooj yim ntawm kev cim, koj yuav kos cov piv txwv nram qab: yog hais tias tus kos npe rau yog, ces muab tso rau 1 yog hais tias nws tsis yog, ces tsis muaj dab tsi (0).

Qhov seem 15 me me ntawm cov ntaub ntawv muab ib tug xov tooj. Ib yam li ntawd mus rau lub yav dhau los cov ntaub ntawv, koj yuav muab tso rau ib tug tshaj plaws ntawm kaum tsib units nyob rau hauv lawv. Nws yuav tsum tau muab sau tseg tias nkag teb chaws ntawm tsis zoo thiab zoo tus xov tooj yog ho txawv los ntawm txhua lwm yam.

Nyob rau hauv thiaj li yuav haum raws li lub 2 nco hlwb yog ntau tshaj pes tsawg los yog sib npaug zos rau, ib tug thiaj li hu ua ncaj code. Qhov no lub lag luam yog ua nyob rau hauv tib yam raws li tau piav saum toj no, thiab lub siab tshaj plaws A = 32766, thaum uas siv cov zauv cim. Cia li xav kom nco ntsoov tias nyob rau hauv cov ntaub ntawv no, "0" yog hais txog qhov zoo.

piv txwv

Sawv cev ntawm cov zauv nyob rau hauv computer nco tsis yog xws li ib tug yooj yim ua hauj lwm. Txawm hais tias nws yog ib tug me ntsis ntau tham thaum nws los txog rau ib tug tsis zoo nqi. Yuav kom sau cov xov tooj ntawm cov uas yog tsawg tshaj li xoom, siv ib tug ntxiv code.

Yuav kom tau txais nws, lub tshuab ua ib tug xov tooj ntawm koom haum pab kev ua hauj lwm.

1. Thawj kaw modulus ntawm ib tug tsis zoo pes tsawg nyob rau hauv binary cim. Hais tias yog, tus computer nco ib tug zoo li tab sis zoo.
2. Ces, ib tug nco inverting txhua me ntsis. Rau lub hom phiaj no, tag nrho cov chav yuav hloov los ntawm zeros thiab vice versa.
3. Peb ntxiv ib tug "1" rau cov kev tshwm sim. Qhov no yuav tsum yog tus ntxiv code.

Ntawm no yog ib tug tiag tiag li piv txwv. Piv txwv peb muaj ib tug xov tooj ntawm X = - 131. Ua ntej, muab tau cov modulus | X | = 131 yog ces hloov dua siab tshiab rau hauv ib lub binary system thiab ib cov ntaub ntawv ntawm 16 hlwb. Peb tau X = 0000000010000011. Tom qab inverting X = 1111111101111100. Ntxiv thereto "1" thiab muab tau cov ntxeev code X = 1111111101111101. Rau cov ntaubntawv povthawj siv ib tug 16-ntsis nco cell yog qhov tsawg kawg nkaus naj npawb ntawm cov X = - (2 ¹⁵⁾ = - 32767.

longs

Raws li koj tau pom, cov sawv cev ntawm cov zauv tiag tiag nyob rau hauv ib tug computer tsis yog hais tias tsis yooj yim. Txawm li cas los, kev sib tham ntawm cov ntau yam tej zaum yuav tsis muaj txaus rau feem ntau ua hauj lwm. Yog li ntawd, nyob rau hauv kev txiav txim kom haum raws li cov coob ntawm computer allocates nco cell 4, los yog 32 me me.

Qhov txias txheej txheem tsis txawv los ntawm hais tias hais saum toj no. Yog li ntawd peb cia li muab ib tug ntau ntawm cov zauv uas yuav tsum tau muab cia rau hauv no hom.

X _max = 2.147.483.647.

X _min = - 2147483648.

Cov ntaub ntawv tseem ceeb nyob rau hauv feem ntau txaus los sau thiab ua hauj lwm nyob rau hauv cov ntaub ntawv.

Sawv cev ntawm cov zauv tiag tiag nyob rau hauv ib tug computer nws muaj nws qhov zoo thiab qhov tsis zoo. Nyob rau hauv ib tes, qhov no txoj kev ua rau nws yooj yim rau kev khiav hauj lwm ntawm lub integer qhov tseem ceeb, uas zoo heev speeds cov processor. Nyob rau lwm cov tes, qhov no ntau yam yog tsis txaus yuav daws tau feem ntau teeb meem nyob rau hauv kev lag luam, physics, xam thiab lwm yam sciences. Yog li ntawd tam sim no peb saib lwm txoj kev rau sverhvelichin.

floating taw tes

Qhov no yog qhov kawg uas koj yuav tsum paub txog cov sawv cev ntawm tus xov tooj nyob rau hauv ib lub computer. Txij li thaum muaj ib qho teeb meem kev txiav txim rau txoj hauj lwm ntawm ib tug tsis nco qab nyob rau hauv lawv, kom haum raws li tej xov tooj nyob rau hauv ib tug computer siv los ntawm lub exponential daim ntawv thaum uas sau ntawv cov zauv feem.

Tej xov tooj yuav tsum muaj tuaj nyob rau hauv cov nram qab no daim ntawv X p = m * ^n. Qhov twg m - yog tus naj npawb ntawm mantissa, p - Radix thiab n - qhov kev txiav txim tus naj npawb.

Yuav kom standardize rau cov ntaubntawv povthawj floating taw tes tus xov tooj siv li nram qab no mob, raws li uas tus mantissa module yuav tsum ntau dua los yog sib npaug zos rau 1 / n thiab tsawg tshaj li 1.

Cia peb tus xov tooj 666,66 yog muab. Cia peb muab nws mus rau lub exponential daim ntawv. Nyob rau hauv x = 0.66666 * ¹⁰ Lub peb hlis ntuj. P = 10 thiab n = 3.

Nyob rau cia ntawm floating taw tes qhov tseem ceeb feem ntau faib 4 los yog 8 bytes (32 khoom los yog 64). Nyob rau hauv thawj rooj plaub no nws yog hu ua tus naj npawb ntawm cov single-precision, thaum lub sij hawm thib ob - ib tug muab ob npaug rau precision.

Ntawm 4 bytes faib rau cov cia ntawm tus xov tooj, 1 (8 khoom) muab rau hauv qab no nyob rau hauv cov txheej txheem cov ntaub ntawv thiab nws cov kos npe rau, thiab 3 bytes (24 khoom) rau khaws cia rau hauv lub mantissa tawm nws cov cim thiab nyob rau tib lub hauv paus ntsiab lus raws li rau qhov integer qhov tseem ceeb. Peb paub li no, peb yuav ua tau tej yam yooj yim suav.

Cov nqi siab tshaj plaws ntawm n = ^{2 1111111} 127 = ^10. Raws li nws, peb yuav tau txais qhov ntau tshaj ntawm cov zauv uas yuav tsum tau muab cia rau hauv computer nco. X = ^2127. Tam sim no peb yuav tau xam lub siab tshaj plaws tau mantissa. Nws yuav ua tau sib npaug zos rau 2 ²³ - 1 ≥ 2 ²³ = 2 ^{(10 × 2,3)} ≥ 1000 ^2.3 = 10 ^{(3 × 2,3)} ≥ 10 ^7. Raws li ib tug tshwm sim, peb tau txais ib approximate nqi.

Tam sim no, yog hais tias peb muab ob lub xam, peb tau txais tus nqi uas yuav tsum tau muab cia tsis poob ntawm 4 bytes ntawm lub cim xeeb. Nws yuav ua tau sib npaug zos rau X = 1.701411 * 10 ^38. Qhov seem tug lej tom qab yog muab pov tseg, vim hais tias nws tso cai rau koj kom muaj ib tug precision ntawm cov qauv ntawm cov ntaubntawv povthawj siv.

ob precision

Txij li thaum tag nrho cov suav tau pleev xim rau thiab piav qhia nyob rau hauv lub yav dhau los cov pawg lus, ntawm no peb qhia rau koj tag nrho cov heev sai. Rau ob chav precision tus xov tooj yog feem ntau faib 11 khoom rau qhov kev txiav txim thiab nws kos npe rau raws li zoo raws li 53 khoom rau lub mantissa.

1111111111 n = ² 1023 = ^10.

M = ^{2 52 -1 = 2 (10 *} 5.2) = 1000 5.2 = 10 15.6 . Sib npaug thiab tau lub siab tshaj plaws pes tsawg tus = 2 X ¹⁰²³ mus txog "m".

Peb cia siab tias cov lus qhia txog cov sawv cev ntawm cov zauv thiab cov zauv tiag tiag nyob rau hauv lub computer, peb tau muab, nws yog pab tau rau koj nyob rau hauv kev kawm thiab yuav tsum muaj ib tug me ntsis dlaim phaj tshaj yog dab tsi yog feem ntau sau ib daim ntawv nyob rau hauv cov phau ntawv.