mes/lib/arm-mes/arm.M1

### GNU Mes --- Maxwell Equations of Software
### Copyright © 2017,2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
### Copyright © 2019 Danny Milosavljevic <dannym@scratchpost.org>
###
### This file is part of GNU Mes.
###
### Mes is free software# you can redistribute it and/or modify it
### under the terms of the GNU General Public License as published by
### the Free Software Foundation# either version 3 of the License, or (at
### your option) any later version.
###
### GNU Mes is distributed in the hope that it will be useful, but
### WITHOUT ANY WARRANTY# without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
### GNU General Public License for more details.
###
### You should have received a copy of the GNU General Public License
### along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.

# Note: r9 is used as scratch register and is assumed to not contain anything important!

# FIXME: https://w3challs.com/syscalls/?arch=arm_strong

# reduced instruction set: r0, r1 (some r2 for shift, r3 for mul, div)
# FIXME: count instructions

#DEFINE add____$i32,(%r0) xx
#DEFINE add____$i32,(%r1) xx
#DEFINE add____$i32,0x32(%r0) xx
DEFINE add____$i8,%r0 0090e2 # adds    r0, r0, #xx
DEFINE add____$i8,%r1 1091e2 # adds    r1, r1, #xx
DEFINE add____$i8,%r13 d09de2 # adds    r13, r13, #xx
#DEFINE add____$i8,(%r0) xx
#DEFINE add____$i8,(%r1) xx
#DEFINE add____$i8,0x32 xx
#DEFINE add____$i8,0x32(%r0) xx
#DEFINE add____$i8,0x8(%r0) xx
DEFINE add____%r0,%r0 000090e0 # adds    r0, r0, r0
DEFINE add____%r0,%r1 001091e0 # adds    r1, r1, r0
DEFINE add____%r1,%r0 010090e0 # adds    r0, r0, r1
DEFINE add____%r1,%r1 011091e0 # adds    r1, r1, r1
DEFINE and____%r1,%r0 010010e0 # ands    r0, r0, r1
DEFINE and____$i8,%r0 0000e2
DEFINE and____$i8,%r1 1001e2
#DEFINE call32 xx
DEFINE call___*%r0 00f0a0e1
DEFINE call___*%r1 01f0a0e1
#DEFINE cltd xx
#DEFINE cmp____$0x32,%r0 xx
#DEFINE cmp____$i32,%r0 xx
DEFINE cmp____$i8,%r0 0050e3
DEFINE cmp____$i8,%r1 0051e3
#DEFINE div___%r1 xx
DEFINE hlt 700000e1
#DEFINE idiv___%r1 xx
#DEFINE int xx
DEFINE swi____$0 000000ef
DEFINE ja 8a
DEFINE jae 3a
DEFINE jb 2a
DEFINE jbe 9a
DEFINE je 0a
DEFINE jg ca
DEFINE jge aa
DEFINE jl ba
DEFINE jle da
#DEFINE jmp____*%r1 xx
DEFINE jne 1a
#DEFINE lea____0x32(%ebp),%r0 xx
#DEFINE lea____0x8(%ebp),%r0 xx

# e3a00064        mov     r0, #100
# e3a01064        mov     r1, #100
# e3a02064        mov     r2, #100

#    0:   e3047215        movw    r7, #16917      ; 0x4215

# OK:
DEFINE mov____$i8,%r0 00a0e3
DEFINE mov____$i8,%r1 10a0e3 # mov     r1, #66
DEFINE mov____$i8,%r7 70a0e3
DEFINE mov____$i8,%r9 90a0e3
DEFINE mov____%r0,%r1 0010a0e1
DEFINE mov____%r0,%r2 0020a0e1
DEFINE mov____%r0,(%r1) 000081e5
DEFINE mov____%r1,%r0 0100a0e1
DEFINE mov____%r1,%r2 0120a0e1
#DEFINE mov____%r1,0x32 xx
DEFINE mov____%lr,%r9 0e90a0e1
DEFINE mov____%r9,%pc 09f0a0e1

# fp -> r0
DEFINE mov____%r11,%r0 0b00a0e1

# e52d1004        push    {r1}            ; (str r1, [sp, #-4]!)
# e59f1004        ldr     r1, [pc, #4]    ; 10 <L1>
# e5810000        str     r0, [r1]
# e49d1004        pop     {r1}            ; (ldr r1, [sp], #4)
# ea000000        b L2
# L1: ???
# L2:
DEFINE mov____%r0,0x32 04102de504109fe5000081e504109de4000000ea

# e92d0005        push    {r0, r2}
# e5910000        ldr     r0, [r1]
# e59f200c        ldr     r2, [pc, #12]   ; 1c <X2>
# e0800002        add     r0, r0, r2
# e5810000        str     r0, [r1]
# e8bd0005        pop     {r0, r2}
# ea000000        b       20 <Y2>
# X2: ???
# Y2:
DEFINE add____$i32,(%r1) 05002de9000091e50c209fe5020080e0000081e50500bde8000000ea

# e59f0000        ldr     r0, [pc]
# ea000000        b       c <R>
# nop
# R:
DEFINE mov____$i32,%r0 00009fe5000000ea
DEFINE mov____$i32,%r1 00109fe5000000ea
DEFINE mov____$i32,%r2 00209fe5000000ea
#DEFINE mov____%r1,0x32(%ebp) xx
#DEFINE mov____%r1,0x8(%ebp) xx
DEFINE mov____%r2,(%r1) 002081e5
DEFINE mov____%r3,%r0 0300a0e1
DEFINE mov____%r3,%r1 0e10a0e1
#DEFINE mov____%r13,%ebp xx
DEFINE mov____(%r0),%r0 000090e5
DEFINE mov____(%r0),%r2 002090e5
DEFINE mov____(%r1),%r1 001091e5

DEFINE nop 0000a0e1
DEFINE not____%r0 0000e0e1
DEFINE not____%r1 0110e0e1
DEFINE or_____%r1,%r0 010090e1 # orrs    r0, r0, r1
DEFINE pop____%r0 04009de4
DEFINE pop____%r1 04109de4
DEFINE pop____%r3 04309de4
DEFINE pop____%lr 04e09de4

# e59f9004        ldr     r9, [pc, #4]    ; c <L1x>
# e52d9004        push    {r9}            ; (str r9, [sp, #-4]!)
# ea000000        b       10 <L1y>
# L1x: data
# L1y:

DEFINE push___$i32 04909fe504902de5000000ea

DEFINE push___%r0 04002de5 # str r0, [sp, #-4]!
DEFINE push___%r1 04102de5 # str r1, [sp, #-4]!
DEFINE push___%r2 04202de5 # str r2, [sp, #-4]!
DEFINE push___%r3 04302de5 # str r3, [sp, #-4]!
DEFINE push___%lr 04e02de5 # str lr, [sp, #-4]!

#DEFINE push___(%r0) xx
#DEFINE push___0x32(%ebp) xx
#DEFINE push___0x8(%ebp) xx
#DEFINE shl____$i8,%r0 xx # complicated encoding
#DEFINE shl____$i8,%r1 xx # complicated encoding
#DEFINE sub____$8,%r13 xx
#DEFINE sub____$i32,%r13 xx
DEFINE sub____%r1,%r0 e0500001 # subs    r0, r0, r1
#DEFINE test___%al,%al xx
DEFINE test___%r0,%r0 000010e1
DEFINE test___%r1,%r1 010011e1
#DEFINE xchg___%r0,%r1 xx
#DEFINE xchg___%r0,(%r13) xx
#DEFINE xchg___%r1,(%r13) xx
DEFINE xor____$i8,%r0 0030e2 # eors    r0, r0, #xx
DEFINE xor____%r0,%r0 000030e0 # eors    r0, r0, r0
DEFINE xor____%r1,%r0 010030e0 # eors    r0, r0, r1
DEFINE xor____%r1,%r1 011031e0 # eors    r1, r1, r1
DEFINE xor____%r3,%r3 033033e0 # eors    r3, r3, r3

# Note: These are the native ARM instructions.
# Note: Loads INTO register r0 (ARM original operand order)
DEFINE ldrsb__%r0,(%r0) d000d0e1  # ldrsb   r0, [r0]
DEFINE ldrsb__%r1,(%r1) d010d1e1  # ldrsb   r1, [r1]
DEFINE ldrsb__%r2,(%r2) d020d2e1  # ldrsb   r2, [r2]
DEFINE ldrsb__%r3,(%r3) d030d3e1  # ldrsb   r3, [r3]
DEFINE ldrsb__%r4,(%r4) d040d4e1  # ldrsb   r4, [r4]
DEFINE ldrsb__%r5,(%r5) d050d5e1  # ldrsb   r5, [r5]
DEFINE strb___%r0,(%r0) 0000c0e5  # strb    r0, [r0]
DEFINE strb___%r0,(%r1) 0000c1e5  # strb    r0, [r1]
DEFINE strb___%r1,(%r1) 0010c1e5  # strb    r1, [r1]
DEFINE strb___%r2,(%r2) 0020c2e5  # strb    r2, [r2]
DEFINE strb___%r3,(%r3) 0030c3e5  # strb    r3, [r3]
DEFINE strb___%r4,(%r4) 0040c4e5  # strb    r4, [r4]
DEFINE strh___%r0,(%r0) b000c0e1  # strh    r0, [r0]
DEFINE strh___%r1,(%r1) b010c1e1  # strh    r1, [r1]
DEFINE strh___%r2,(%r2) b020c2e1  # strh    r2, [r2]
DEFINE strh___%r3,(%r3) b030c3e1  # strh    r3, [r3]
DEFINE strh___%r4,(%r4) b040c4e1  # strh    r4, [r4]
DEFINE movle__%r0,$i8   00a0d3    # movle  r0, #xx
DEFINE movlt__%r0,$i8   00a0b3    # movlt  r0, #xx
DEFINE movge__%r0,$i8   00a0a3    # movge  r0, #xx
DEFINE movgt__%r0,$i8   00a0c3    # movgt  r0, #xx
DEFINE movcs__%r0,$i8   00a023    # movcs  r0, #xx
DEFINE movcc__%r0,$i8   00a033    # movcc   r0, #xx
DEFINE movhi__%r0,$i8   00a083    # movhi   r0, #xx
DEFINE moveq__%r0,$i8   00a003    # moveq   r0, #xx
DEFINE movle__%r1,$i8   10a0d3    # movle   r1, #xx
DEFINE movlt__%r1,$i8   10a0b3    # movlt   r1, #xx
DEFINE movge__%r1,$i8   10a0a3    # movge   r1, #xx
DEFINE movgt__%r1,$i8   10a0c3    # movgt   r1, #xx
DEFINE movcs__%r1,$i8   10a023    # movcs   r1, #xx
DEFINE movcc__%r1,$i8   10a033    # movcc   r1, #xx
DEFINE movhi__%r1,$i8   10a083    # movhi   r1, #xx
DEFINE moveq__%r1,$i8   10a003    # moveq   r1, #xx

#DEFINE movseq_%r0,$i8   00b003    # movseq  r0, #xx
#DEFINE movs___%r0,$i8   00b0e3    # movs    r0, #xx
#DEFINE teq____%r0,%r0   000030e1  # teq     r0, r0
#DEFINE teq____%r1,$i8   420031e3  # teq     r1, #xx
DEFINE asr____%r0,%r0,%r1 5001a0e1  # asr %r0, %r0, %r1
DEFINE lsl____%r0,%r0,%r1 1001a0e1  # lsl %r0, %r0, %r1
DEFINE lsl____%r0,%r0,$i8 90a0e31009a0e1 # mov     r9, #xx; lsl %r0, %r0, %r9
DEFINE lsl____%r1,%r1,$i8 90a0e31119a0e1 # mov     r9, #xx; lsl %r1, %r1, %r9
DEFINE lsr____%r0,%r0,%r1 3001a0e1  # lsr %r0, %r0, %r1
DEFINE ldr____%r0,(%sp,#$i8) 009de5  # ldr r0, [r13+xx]
DEFINE ldr____%r1,(%sp,#$i8) 109de5  # ldr r1, [r13+xx]
DEFINE add____%r2,%r0,%r1,lsl#4 012280e0
DEFINE add____%r2,$i8 2082e2
DEFINE bl ba
DEFINE b ea
DEFINE sxtb__%r0,%r0 7000afe6
DEFINE sxtb__%r1,%r1 7110afe6
DEFINE sxth__%r0,%r0 7000bfe6
DEFINE uxtb__%r0,%r0 7000efe6
DEFINE uxth__%r0,%r0 7000ffe6

# deprecated, remove after 0.18
#DEFINE sub____%r13,$i32 ec81
#DEFINE sub____%r13,$i8 ec83

DEFINE SYS_exit   010090
DEFINE SYS_fork   020090
DEFINE SYS_read   030090
DEFINE SYS_rmdir  280090
DEFINE SYS_write  040090
DEFINE SYS_open   050090
DEFINE SYS_close  060090
# DEFINE SYS_waitpid does_not_exist
DEFINE SYS_wait4  720090
# waitid: 900118
#__waitpid (__pid_t pid, int *stat_loc, int options)
#  return SYSCALL_CANCEL (wait4, pid, stat_loc, options, NULL); # the NULL is more!

# Linux note: sys_waitpid() remains for compatibility. waitpid() should be implemented by calling sys_wait4() from libc.a.
DEFINE SYS_unlink 0a0090
DEFINE SYS_execve 0b0090
DEFINE SYS_chmod  0f0090
DEFINE SYS_lseek  130090
DEFINE SYS_access 210090
DEFINE SYS_brk    2d0090
DEFINE SYS_ioctl  360090
DEFINE SYS_stat   6a0090
DEFINE SYS_fsync  760090
DEFINE SYS_getcwd b70090

# These are x86 ABI remnants:

DEFINE mul____%r1,%r0 910089e0 # umull   r0, r9, r1, r0
DEFINE mul____%r0,%r1 910089e0 # umull   r0, r9, r1, r0
DEFINE mov____%ebp,%r0 0b00a0e1
DEFINE mov____%ebp,%r1 0b10a0e1
DEFINE push___%ebp 04b02de5 # str fp, [sp, #-4]!
DEFINE pop____%ebp 04b09de4 # ldr fp, [sp], #4
DEFINE mov____%esp,%ebp 0db0a0e1 # mov     fp, sp
DEFINE mov____%ebp,%esp 0bd0a0e1 # mov sp, fp
DEFINE sub____$i8,%esp d04de2 # sub     sp, sp, #xx

# Note: i8 immediate
DEFINE mov____%r0,0x8(%ebp) 008be5
DEFINE mov____%r1,0x8(%ebp) 108be5
DEFINE mov____%r2,0x8(%ebp) 208be5
DEFINE mov____%r3,0x8(%ebp) 308be5
DEFINE mov____%r4,0x8(%ebp) 408be5
DEFINE mov____%r5,0x8(%ebp) 508be5
DEFINE mov____%r7,0x8(%ebp) 908be5
# Note: i8 immediate
DEFINE mov____0x8(%ebp),%r0 009be5
DEFINE mov____0x8(%ebp),%r1 109be5
DEFINE mov____0x8(%ebp),%r2 209be5
DEFINE mov____0x8(%ebp),%r3 309be5
DEFINE mov____0x8(%ebp),%r4 409be5
DEFINE mov____0x8(%ebp),%r5 509be5
DEFINE mov____0x8(%ebp),%r7 909be5

# e59f9008        ldr     r9, [pc, #8]    ; 10 <LX1>
# e089900b        add     r9, r9, fp
# e5890000        str     r0, [r9]
# ea000000        b       14 <LX2>
# 00000010 <LX1>: data
# 00000014 <LX2>:
DEFINE mov____%r0,0x32(%ebp) 08909fe50b9089e0000089e5000000ea
DEFINE mov____%r1,0x32(%ebp) 08909fe50b9089e0001089e5000000ea
DEFINE mov____%r2,0x32(%ebp) 08909fe50b9089e0002089e5000000ea

# e59f9004        ldr     r9, [pc, #4]    ; c <LX1>
# e5990000        ldr     r0, [r9]
# ea000000        b       10 <LX2>
DEFINE mov____0x32,%r0 04909fe5000099e5000000ea
DEFINE mov____0x32,%r1 04909fe5001099e5000000ea
DEFINE mov____0x32,%r2 04909fe5002099e5000000ea

# e1a09000        mov     r9, r0
# e1a00001        mov     r0, r1
# e1a01009        mov     r1, r9
DEFINE xchg___%r0,%r1 0090a0e10100a0e10910a0e1

# e1a0900e        mov     r9, lr
# e49de004        pop     {lr}            ; (ldr lr, [sp], #4)
# e1a0f009        mov     pc, r9
DEFINE ret 0e90a0e104e09de409f0a0e1

# The flags are also updated, but that's probably useless.
DEFINE add____$i8,%esp d09de2
#DEFINE add____$i32,0x32(%ebp) xx
#DEFINE add____$i8,0x32(%ebp) xx
#DEFINE add____$i8,0x8(%ebp) xx
#DEFINE add____%ebp,%r0 xx

# e24ddeff        sub     sp, sp, #4080
# e24dd064        sub     sp, sp, #100
DEFINE allocate_stack_4180 ffde4de264d04de2

# e59f9014        ldr     r9, [pc, #20]
# e089900b        add     r9, r9, fp
# e5991000        ldr     r1, [r9]
DEFINE mov____0x32(%ebp),%r1 14909fe50b9089e0001099e5

# e1a09000        mov     r9, r0
# e59d0000        ldr     r0, [sp]
# e58d9000        str     r9, [sp]
DEFINE xchg___%r0,(%esp) 0090a0e100009de500908de5

# e52d1004        push    {r1}            ; (str r1, [sp, #-4]!)
# e59f1010        ldr     r1, [pc, #16]   ; 1c <WERT>
# e5909000        ldr     r9, [r0]
# e0811009        add     r1, r1, r9
# e5809000        str     r9, [r0]
# e49d1004        pop     {r1}            ; (ldr r1, [sp], #4)
# ea000000        b       20 <VD>
# V: ...
# VD:
DEFINE add____$i32,(%r0) 04102de510109fe5009090e5091081e0009080e504109de4000000ea