Editing DEC Alpha (section)

===Byte-Word Extensions (BWX)===
Later Alphas include byte-word extensions, a set of instructions to manipulate 8-bit and 16-bit data types. These instructions were first introduced in the [[Alpha 21164#Alpha 21164 (EV56)|21164A]] (EV56) microprocessor and are present in all subsequent implementations. These instructions perform operations that formerly required multiple instructions to implement, which improves code density and the performance of certain applications. BWX also makes the emulation of x86 machine code and the writing of [[device driver]]s easier.<ref>{{Cite journal |doi=10.1109/JSSC.1996.542313 |bibcode=1996IJSSC..31.1687G |title=A 433-MHz 64-b quad-issue RISC microprocessor |journal=IEEE Journal of Solid-State Circuits |volume=31 |issue=11 |pages=1687–1696 |year=1996 |last1=Gronowski |first1=P. E. |last2=Bowhill |first2=W. J. |last3=Donchin |first3=D. R. |last4=Blake-Campos |first4=R. P. |last5=Carlson |first5=D. A. |last6=Equi |first6=E. R. |last7=Loughlin |first7=B. J. |last8=Mehta |first8=S. |last9=Mueller |first9=R. O. |last10=Olesin |first10=A. |last11=Noorlag |first11=D. J. W. |last12=Preston |first12=R. P. |s2cid=39280205}}</ref>

{| class="wikitable"
|-
! width="120" | Mnemonic
! width="360" | Instruction
|-
| <code>LDBU</code>
| Load Zero-Extended Byte from Memory to Register
|-
| <code>LDWU</code>
| Load Zero-Extended Word from Memory to Register
|-
| <code>SEXTB</code>
| Sign Extend Byte
|-
| <code>SEXTW</code>
| Sign Extend Word
|-
| <code>STB</code>
| Store Byte from Register to Memory
|-
| <code>STW</code>
| Store Word from Register to Memory
|-
|}