# Comparing arrays of numbers.
== code
array-equal?: # a: (addr array int), b: (addr array int) -> result/eax: boolean
# pseudocode:
# asize = a->size
# if (asize != b->size) return false
# i = 0
# curra = a->data
# currb = b->data
# while i < asize
# i1 = *curra
# i2 = *currb
# if (c1 != c2) return false
# i+=4, curra+=4, currb+=4
# return true
#
# registers:
# i: ecx
# asize: edx
# curra: esi
# currb: edi
# i1: eax
# i2: ebx
#
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
51/push-ecx
52/push-edx
53/push-ebx
56/push-esi
57/push-edi
# esi = a
8b/-> *(ebp+8) 6/r32/esi
# edi = b
8b/-> *(ebp+0xc) 7/r32/edi
# var asize/edx: int = a->size
8b/-> *esi 2/r32/edx
$array-equal?:sizes:
# if (asize != b->size) return false
39/compare *edi 2/r32/edx
75/jump-if-!= $array-equal?:false/disp8
# var curra/esi: (addr byte) = a->data
81 0/subop/add %esi 4/imm32
# var currb/edi: (addr byte) = b->data
81 0/subop/add %edi 4/imm32
# var i/ecx: int = 0
31/xor-with %ecx 1/r32/ecx
# var vala/eax: int
# var valb/ebx: int
$array-equal?:loop:
# if (i >= asize) return true
39/compare %ecx 2/r32/edx
7d/jump-if->= $array-equal?:true/disp8
# var vala/eax: int = *curra
8b/-> *esi 0/r32/eax
# var valb/ebx: int = *currb
8b/-> *edi 3/r32/ebx
# if (vala != valb) return false
39/compare %eax 3/r32/ebx
75/jump-if-!= $array-equal?:false/disp8
# i += 4
81 0/subop/add %ecx 4/imm32
# currs += 4
81 0/subop/add %esi 4/imm32
# currb += 4
81 0/subop/add %edi 4/imm32
eb/jump $array-equal?:loop/disp8
$array-equal?:true:
b8/copy-to-eax 1/imm32
eb/jump $array-equal?:end/disp8
$array-equal?:false:
b8/copy-to-eax 0/imm32
$array-equal?:end:
# . restore registers
5f/pop-to-edi
5e/pop-to-esi
5b/pop-to-ebx
5a/pop-to-edx
59/pop-to-ecx
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-compare-empty-with-empty-array:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var ecx: (array _) = []
68/push 0/imm32/size
89/<- %ecx 4/r32/esp
# var edx: (array _) = []
68/push 0/imm32/size
89/<- %edx 4/r32/esp
#
(array-equal? %ecx %edx) # => eax
(check-ints-equal %eax 1 "F - test-compare-empty-with-empty-array")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-compare-empty-with-non-empty-array: # also checks size-mismatch code path
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var ecx: (array int) = [1]
68/push 1/imm32
68/push 4/imm32/size
89/<- %ecx 4/r32/esp
# var edx: (array int) = []
68/push 0/imm32/size
89/<- %edx 4/r32/esp
#
(array-equal? %ecx %edx) # => eax
(check-ints-equal %eax 0 "F - test-compare-empty-with-non-empty-array")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-compare-equal-arrays:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var ecx: (array int) = [1, 2, 3]
68/push 3/imm32
68/push 2/imm32
68/push 1/imm32
68/push 0xc/imm32/size
89/<- %ecx 4/r32/esp
# var edx: (array int) = [1, 2, 3]
68/push 3/imm32
68/push 2/imm32
68/push 1/imm32
68/push 0xc/imm32/size
89/<- %edx 4/r32/esp
#
(array-equal? %ecx %edx) # => eax
(check-ints-equal %eax 1 "F - test-compare-equal-arrays")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-compare-inequal-arrays-equal-sizes:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var ecx: (array int) = [1, 4, 3]
68/push 3/imm32
68/push 4/imm32
68/push 1/imm32
68/push 0xc/imm32/size
89/<- %ecx 4/r32/esp
# var edx: (array int) = [1, 2, 3]
68/push 3/imm32
68/push 2/imm32
68/push 1/imm32
68/push 0xc/imm32/size
89/<- %edx 4/r32/esp
#
(array-equal? %ecx %edx) # => eax
(check-ints-equal %eax 0 "F - test-compare-inequal-arrays-equal-sizes")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
_parse-array-of-ints: # ad: (addr allocation-descriptor), s: (addr array byte), out: (addr handle array int)
# pseudocode
# end = &s->data[s->size]
# curr = s->data
# size = 0
# while true
# if (curr >= end) break
# curr = skip-chars-matching-in-slice(curr, end, ' ')
# if (curr >= end) break
# curr = skip-chars-not-matching-in-slice(curr, end, ' ')
# ++size
# allocate-array(ad, size*4, out)
# var slice: slice = {s->data, 0}
# curr = lookup(out)->data
# while true
# if (slice->start >= end) break
# slice->start = skip-chars-matching-in-slice(slice->start, end, ' ')
# if (slice->start >= end) break
# slice->end = skip-chars-not-matching-in-slice(slice->start, end, ' ')
# *curr = parse-hex-int-from-slice(slice)
# curr += 4
# slice->start = slice->end
# return result
#
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
53/push-ebx
56/push-esi
57/push-edi
# esi = s
8b/-> *(ebp+0xc) 6/r32/esi
# var curr/ecx: (addr byte) = s->data
8d/copy-address *(esi+4) 1/r32/ecx
# var end/edx: (addr byte) = &s->data[s->size]
# . edx = s->size
8b/-> *esi 2/r32/edx
# . edx += curr
01/add-to %edx 1/r32/ecx
# var size/ebx: int = 0
31/xor-with %ebx 3/r32/ebx
$_parse-array-of-ints:loop1:
# if (curr >= end) break
39/compare %ecx 2/r32/edx
73/jump-if-addr>= $_parse-array-of-ints:break1/disp8
# curr = skip-chars-matching-in-slice(curr, end, ' ')
(skip-chars-matching-in-slice %ecx %edx 0x20) # => eax
89/<- %ecx 0/r32/eax
# if (curr >= end) break
39/compare %ecx 2/r32/edx
73/jump-if-addr>= $_parse-array-of-ints:break1/disp8
# curr = skip-chars-not-matching-in-slice(curr, end, ' ')
(skip-chars-not-matching-in-slice %ecx %edx 0x20) # => eax
89/<- %ecx 0/r32/eax
# size += 4
81 0/subop/add %ebx 4/imm32
eb/jump $_parse-array-of-ints:loop1/disp8
$_parse-array-of-ints:break1:
(allocate-array *(ebp+8) %ebx *(ebp+0x10))
$_parse-array-of-ints:pass2:
# var slice/edi: slice = {s->data, 0}
68/push 0/imm32/end
8d/copy-address *(esi+4) 7/r32/edi
57/push-edi
89/<- %edi 4/r32/esp
# curr = lookup(out)->data
8b/-> *(ebp+0x10) 0/r32/eax
(lookup *eax *(eax+4)) # => eax
8d/copy-address *(eax+4) 1/r32/ecx
$_parse-array-of-ints:loop2:
# if (slice->start >= end) break
39/compare *edi 2/r32/edx
73/jump-if-addr>= $_parse-array-of-ints:end/disp8
# slice->start = skip-chars-matching-in-slice(slice->start, end, ' ')
(skip-chars-matching-in-slice *edi %edx 0x20) # => eax
89/<- *edi 0/r32/eax
# if (slice->start >= end) break
39/compare *edi 2/r32/edx
73/jump-if-addr>= $_parse-array-of-ints:end/disp8
# slice->end = skip-chars-not-matching-in-slice(slice->start, end, ' ')
(skip-chars-not-matching-in-slice *edi %edx 0x20) # => eax
89/<- *(edi+4) 0/r32/eax
# *curr = parse-hex-int-from-slice(slice)
(parse-hex-int-from-slice %edi)
89/<- *ecx 0/r32/eax
# curr += 4
81 0/subop/add %ecx 4/imm32
# slice->start = slice->end
8b/-> *(edi+4) 0/r32/eax
89/<- *edi 0/r32/eax
eb/jump $_parse-array-of-ints:loop2/disp8
$_parse-array-of-ints:end:
# . reclaim locals
81 0/subop/add %esp 8/imm32
# . restore registers
5f/pop-to-edi
5e/pop-to-esi
5b/pop-to-ebx
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-parse-array-of-ints:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var h/esi: (handle array int)
68/push 0/imm32
68/push 0/imm32
89/<- %esi 4/r32/esp
# var ecx: (array int) = [1, 2, 3]
68/push 3/imm32
68/push 2/imm32
68/push 1/imm32
68/push 0xc/imm32/size
89/<- %ecx 4/r32/esp
#
(_parse-array-of-ints Heap "1 2 3" %esi)
(lookup *esi *(esi+4)) # => eax
(array-equal? %ecx %eax) # => eax
(check-ints-equal %eax 1 "F - test-parse-array-of-ints")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-parse-array-of-ints-empty:
# - empty string = empty array
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var h/esi: handle
68/push 0/imm32
68/push 0/imm32
89/<- %esi 4/r32/esp
#
(_parse-array-of-ints Heap "" %esi)
(lookup *esi *(esi+4)) # => eax
(check-ints-equal *eax 0 "F - test-parse-array-of-ints-empty")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-parse-array-of-ints-just-whitespace:
# - just whitespace = empty array
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var h/esi: handle
68/push 0/imm32
68/push 0/imm32
89/<- %esi 4/r32/esp
#
(_parse-array-of-ints Heap Space %esi)
(lookup *esi *(esi+4)) # => eax
(check-ints-equal *eax 0 "F - test-parse-array-of-ints-just-whitespace")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-parse-array-of-ints-extra-whitespace:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var h/esi: handle
68/push 0/imm32
68/push 0/imm32
89/<- %esi 4/r32/esp
# var ecx: (array int) = [1, 2, 3]
68/push 3/imm32
68/push 2/imm32
68/push 1/imm32
68/push 0xc/imm32/size
89/<- %ecx 4/r32/esp
#
(_parse-array-of-ints Heap " 1 2 3 " %esi)
(lookup *esi *(esi+4)) # => eax
(array-equal? %ecx %eax) # => eax
(check-ints-equal %eax 1 "F - test-parse-array-of-ints-extra-whitespace")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
parse-array-of-ints: # s: (addr array byte), out: (addr handle array int)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
#
(_parse-array-of-ints Heap *(ebp+8) *(ebp+0xc))
$parse-array-of-ints:end:
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
# helper for later tests
# compare an array with a string representation of an array literal
check-array-equal: # a: (addr array int), expected: (addr string), msg: (addr string)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
56/push-esi
# var h/esi: handle
68/push 0/imm32
68/push 0/imm32
89/<- %esi 4/r32/esp
# var b/eax: (addr array int) = parse-array-of-ints(Heap, expected)
(parse-array-of-ints *(ebp+0xc) %esi)
(lookup *esi *(esi+4)) # => eax
#
(array-equal? *(ebp+8) %eax)
(check-ints-equal %eax 1 *(ebp+0x10))
$check-array-equal:end:
# . restore registers
5e/pop-to-esi
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-check-array-equal:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# var ecx: (array int) = [1, 2, 3]
68/push 3/imm32
68/push 2/imm32
68/push 1/imm32
68/push 0xc/imm32/size
89/<- %ecx 4/r32/esp
#
(check-array-equal %ecx "1 2 3" "F - test-check-array-equal")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
== data
# length-prefixed string containing just a single space
Space: # (array byte)
# size: int
1/imm32
# data
20/space