diff options
| author | Kartik K. Agaram <vc@akkartik.com> | 2021-07-16 08:09:42 -0700 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2021-07-16 08:28:56 -0700 |
| commit | 44d26b77c45668c9b0c99894a4294cec004361fe (patch) | |
| tree | 68a5dcd4971873efd4ce184e9bf9a531c2161813 /linux/apps/ex14.subx | |
| parent | ac45f097153afd3a89f43886e4124c5b2c26b98a (diff) | |
| download | mu-44d26b77c45668c9b0c99894a4294cec004361fe.tar.gz | |
.
Diffstat (limited to 'linux/apps/ex14.subx')
| -rw-r--r-- | linux/apps/ex14.subx | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/linux/apps/ex14.subx b/linux/apps/ex14.subx new file mode 100644 index 00000000..70aa8629 --- /dev/null +++ b/linux/apps/ex14.subx @@ -0,0 +1,26 @@ +# Multiply 2 numbers. +# +# To run: +# $ bootstrap/bootstrap translate apps/ex14.subx -o ex14 +# $ bootstrap/bootstrap run ex14 +# Expected result: +# $ echo $? +# 6 + +== code +# instruction effective address register displacement immediate +# . op subop mod rm32 base index scale r32 +# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes + +Entry: + b8/copy-to-eax 1/imm32 + b9/copy-to-ecx 2/imm32 + bb/copy-to-ebx 3/imm32 + + 69/multiply 3/mod/direct 1/rm32/ecx . . . 3/r32/ebx 3/imm32 # ebx = ecx * 3 + +$exit: + # exit(ebx) + e8/call syscall_exit/disp32 + +# . . vim:nowrap:textwidth=0 |