Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.
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# Some helpers for copying non-overlapping regions of memory.
# Really only intended to be called from code generated by mu.subx.
== code
copy-bytes: # src: (addr byte), dest: (addr byte), size: int
# pseudocode:
# curr-src/esi = src
# curr-dest/edi = dest
# i/ecx = 0
# while true
# if (i >= size) break
# *curr-dest = *curr-src
# ++curr-src
# ++curr-dest
# ++i
#
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
56/push-esi
57/push-edi
# curr-src/esi = src
8b/-> *(ebp+8) 6/r32/esi
# curr-dest/edi = dest
8b/-> *(ebp+0xc) 7/r32/edi
# var i/ecx: int = 0
b9/copy-to-ecx 0/imm32
# edx = size
8b/-> *(ebp+0x10) 2/r32/edx
{
# if (i >= size) break
39/compare %ecx 2/r32/edx
7d/jump-if->= break/disp8
# *curr-dest = *curr-src
8a/byte-> *esi 0/r32/AL
88/byte<- *edi 0/r32/AL
# update
46/increment-esi
47/increment-edi
41/increment-ecx
eb/jump loop/disp8
}
$copy-bytes:end:
# . restore registers
5f/pop-to-edi
5e/pop-to-esi
5a/pop-to-edx
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
stream-to-array: # in: (addr stream _), out: (addr handle array _)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
56/push-esi
# esi = s
8b/-> *(ebp+8) 6/r32/esi
# var len/ecx: int = s->write - s->read
8b/-> *esi 1/r32/ecx
2b/subtract *(esi+4) 1/r32/ecx
# allocate
(allocate-array Heap %ecx *(ebp+0xc))
# var in/edx: (addr byte) = s->data + s->read
8b/-> *(esi+4) 2/r32/edx
8d/copy-address *(esi+edx+0xc) 2/r32/edx
# var dest/eax: (addr byte) = data for out
8b/-> *(ebp+0xc) 0/r32/eax
(lookup *eax *(eax+4)) # => eax
8d/copy-address *(eax+4) 0/r32/eax
#
(copy-bytes %edx %eax %ecx)
$stream-to-array:end:
# . restore registers
5e/pop-to-esi
5a/pop-to-edx
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-stream-to-array:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# setup
(clear-stream _test-input-stream)
(write _test-input-stream "abc")
# skip something
(read-byte _test-input-stream) # => eax
8b/-> *$_test-input-stream->read 0/r32/eax
(check-ints-equal %eax 1 "F - test-stream-to-array/pre")
# var out/ecx: (handle array byte)
68/push 0/imm32
68/push 0/imm32
89/<- %ecx 4/r32/esp
#
(stream-to-array _test-input-stream %ecx)
(lookup *ecx *(ecx+4)) # => eax
(check-strings-equal %eax "bc" "F - test-stream-to-array")
8b/-> *$_test-input-stream->read 0/r32/eax
(check-ints-equal %eax 1 "F - test-stream-to-array/read-pointer-not-perturbed")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
# like stream-to-array but ignore surrounding quotes
# we might do other stuff here later
unquote-stream-to-array: # in: (addr stream _), out: (addr handle array _)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
56/push-esi
# esi = s
8b/-> *(ebp+8) 6/r32/esi
# var len/ecx: int = s->write - s->read - 2
8b/-> *esi 1/r32/ecx
2b/subtract *(esi+4) 1/r32/ecx
81 7/subop/compare %ecx 2/imm32
7c/jump-if-< $unquote-stream-to-array:end/disp8
81 5/subop/subtract %ecx 2/imm32
# allocate
(allocate-array Heap %ecx *(ebp+0xc))
# var in/edx: (addr byte) = s->data + s->read + 1
8b/-> *(esi+4) 2/r32/edx
8d/copy-address *(esi+edx+0xd) 2/r32/edx # Stream-data + 1
# var dest/eax: (addr byte) = data for out
8b/-> *(ebp+0xc) 0/r32/eax
(lookup *eax *(eax+4)) # => eax
8d/copy-address *(eax+4) 0/r32/eax
#
(copy-bytes %edx %eax %ecx)
$unquote-stream-to-array:end:
# . restore registers
5e/pop-to-esi
5a/pop-to-edx
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return