# Test for add64

.org 0
# Provide program starting address to linker
.global _start

.extern add64
.extern tohex

/* newlib system calls */
.set SYSEXIT,  93
.set SYSWRITE, 64

.section .rodata

inputs:
    .word 0x40000000   # 0.25
    .word 1            # 1
    .word 0x40000000   # 0.25
    .word 2            # 2

    .word 0x40000000   # 0.25
    .word 1            # 1
    .word 0x80000000   # 0.5
    .word 2            # 2

    .word 0x40000000   # 0.25
    .word -1           # -1
    .word 0x80000000   # 0.5
    .word 2            # 2

    .word 0x40000000   # 0.25
    .word 1            # 1
    .word 0x80000000   # 0.5
    .word -2           # -2
inputs_end:
  # llvm doesn't like this: error: expected relocatable expression
  #.set inputs_end, .-inputs
  # turns out it was right. That was calculating a length, which was
  # incorrect for how it was used for looping.

.section .bss

buf: .skip 9

.text

_start:
    li a0, '\n'
    la a1, buf
    sb a0, 8(a1)        # append newline to buf

    la s0, inputs       # init loop variables
    la s1, inputs_end
loop:
    lw a0, 0(s0)        # a0: x lower 32 bits
    lw a1, 4(s0)        # a1: x upper 32 bits
    lw a2, 8(s0)        # a2: y lower 32 bits
    lw a3, 12(s0)       # a3: y upper 32 bits
    jal add64

    # TODO: Format as an actual decimal
    # print the result, hi = a1, lo = a0, a1.a0
    # a0 is value, a1 is buf addr
    addi sp, sp, -4
    sw a0, 0(sp)        # stash a0 for later
    mv a0, a1           # copy a1 to a0
    la a1, buf
    jal tohex

    # print hi word
    li t0, SYSWRITE     # "write" syscall
    li a0, 1            # 1 = standard output (stdout)
    la a1, buf          # load address of output string
    li a2, 8            # length of output string
    ecall               # invoke syscall to print the string

    # print .
    li t0, SYSWRITE     # "write" syscall
    li a0, 1            # 1 = standard output (stdout)
    la a1, buf          # load address of output string
    li a2, '.'
    sb a2, 0(a1)
    li a2, 1            # length of output string
    ecall               # invoke syscall to print the string

    # print lo word
    lw a0, 0(sp)        # restore lo word
    addi sp, sp, 4
    la a1, buf
    jal tohex

    li t0, SYSWRITE     # "write" syscall
    li a0, 1            # 1 = standard output (stdout)
    la a1, buf          # load address of output string
    li a2, 9            # length of output string
    ecall               # invoke syscall to print the string

    addi s0, s0, 16     # increment input pointer to next pair of 64-bit inputs
    bltu s0, s1, loop   # if the input address is less than inputs_end, loop

    li t0, SYSEXIT      # "exit" syscall
    la a0, 0            # Use 0 return code
    ecall               # invoke syscall to terminate the program