XeLabs/asm_book
2
0
Fork 0
mirror of https://github.com/pkivolowitz/asm_book.git synced 2026-06-23 07:28:04 +08:00
Code Issues Projects Releases Packages Wiki Activity

Update ldr.md

Browse source
This commit is contained in:
pkivolowitz 2022-06-08 04:16:49 -05:00 committed by GitHub
parent 1cdc7f4c92
commit 0b4d55f0e3
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 1 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
section_1/regs/ldr.md
View file

@ -163,7 +163,7 @@ is implemented as:
add x1, x0, x1, lsl 3 add x1, x0, x1, lsl 3
``` ```
We are performing address arithmetic on `longs`. Each `long` is 8 bytes wide. `x1, lsl 3` means "before adding the value of `x1` to `x0`, multiple `x1` by 8." Eight is 2 raised to the power of 3. `lsl 3` means shift left by 3 bits ... shifting is a fast way of integer multiplication (and division) by powers of 2. We are performing address arithmetic on `longs`. Each `long` is 8 bytes wide. `x1, lsl 3` means "before adding the value of `x1` to `x0`, multiply `x1` by 8." Eight is 2 raised to the power of 3. `lsl 3` means shift left by 3 bits ... shifting is a fast way of integer multiplication (and division) by powers of 2.
`Line 13` is the branch to the *bottom* of the loop where the decision code is written. We saw how this can save an instruction [here](../for/README.md). `Line 13` is the branch to the *bottom* of the loop where the decision code is written. We saw how this can save an instruction [here](../for/README.md).