assembly.md

NOTE: Parenthesis () indicates a required argument. brackets [] indicate an optional argument.

values

there are several types of literals:

• standard int literals, like 10.
• floating point literals, like 10.0f. They must be postfixed with h, f, or d for half-, single-, and double-precision literals.
• character literals, like 'A'. Their value is the ASCII value of the character. common escape sequences are supported.
• string literals, like "Hello". They can only be used with directives or pseudo-instructions that accept them.

labels

labels are defined like so:

label:

the label must have a newline after it. if the label is prefixed with ., it is a local label. it will internally be prefixed with with the name of the last non-local label. for example:

some_function:
    li ra, 0
    .loop:          ; internally "some_function.loop:"
        add ra, ra, 1
        cmp ra, 10
        bne .loop;  ; internally "bne some_function.loop"
    ret

directives

symbol data

• define (symbol), (int) - declare a symbol and set it to a specific value.

pseudo-instructions

In addition to ISA-defined pseudo-instructions, these are supplied:

• loc (int), [fill] - set the address cursor to (int), filling the empty space will [fill]. Empty space is not overwritten if [fill] is not present OR if loc sets the address cursor backwards.

• align (int), [fill] - Insert byte [fill] until the cursor position is aligned to a multiple of (int). An error will be generated if the argument is not a power of two. If [fill] is not present, empty space will not be overwritten.

• byte (val), [count] - Alias for d8.

• d8 (val), [count] - Repeat an 8-bit value (val), [count](default to 1) # of times.

• d16 (val), [count] - Repeat a 16-bit value (val), [count](default to 1) # of times. Errors if not aligned to multiple of 2.

• d32 (val), [count] - Repeat a 32-bit value (val), [count](default to 1) # of times. Errors if not aligned to multiple of 4.

• d64 (val), [count] - Repeat a 64-bit value (val), [count](default to 1) # of times. Errors if not aligned to multiple of 8.

• skip (val) - equivalent to d8 0, (val).

• utf8 (string) - Inserts a UTF-8 encoded string. Does not automatically null-terminate.