path: root/linux/ex14.subx

# Multiply 2 numbers.
#
# To run:
#   $ ./bootstrap translate init.linux apps/ex14.subx -o apps/ex14
#   $ ./bootstrap run apps/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

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