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|
# some utilities for converting numbers to/from hex
# lowercase letters only for now
== code
# instruction effective address register displacement immediate
# . op subop mod rm32 base index scale r32
# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes
# main:
e8/call run-tests/disp32 # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.
# syscall(exit, Num-test-failures)
8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/EBX Num-test-failures/disp32 # copy *Num-test-failures to EBX
b8/copy-to-EAX 1/imm32/exit
cd/syscall 0x80/imm8
is-hex-int?: # in : (address slice) -> bool/EAX
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# . save registers
51/push-ECX
52/push-EDX
53/push-EBX
# ECX = s
8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 1/r32/ECX 8/disp8 . # copy *(EBP+8) to ECX
# EDX = s->end
8b/copy 1/mod/*+disp8 1/rm32/ECX . . . 2/r32/EDX 4/disp8 . # copy *(ECX+4) to EDX
# curr/ECX = s->start
8b/copy 0/mod/indirect 1/rm32/ECX . . . 1/r32/ECX . . # copy *ECX to ECX
# if s is empty return false
b8/copy-to-EAX 0/imm32/false
39/compare 3/mod/direct 1/rm32/ECX . . . 2/r32/EDX . . # compare ECX with EDX
7d/jump-if-greater-or-equal $is-hex-int?:end/disp8
# skip past leading '0x'
$is-hex-int?:initial-0:
# . if (*curr != '0') jump to loop
31/xor 3/mod/direct 3/rm32/EBX . . . 3/r32/EBX . . # clear EBX
8a/copy-byte 0/mod/indirect 1/rm32/ECX . . . 3/r32/BL . . # copy byte at *ECX to BL
81 7/subop/compare 3/mod/direct 3/rm32/EBX . . . . . 0x30/imm32/0 # compare EBX
75/jump-if-not-equal $is-hex-int?:loop/disp8
# . ++curr
41/increment-ECX
$is-hex-int?:initial-0x:
# . if (curr >= in->end) return true
39/compare 3/mod/direct 1/rm32/ECX . . . 2/r32/EDX . . # compare ECX with EDX
7d/jump-if-greater-or-equal $is-hex-int?:true/disp8
# . if (*curr != 'x') jump to loop # the previous '0' is still valid so doesn't need to be checked again
31/xor 3/mod/direct 3/rm32/EBX . . . 3/r32/EBX . . # clear EBX
8a/copy-byte 0/mod/indirect 1/rm32/ECX . . . 3/r32/BL . . # copy byte at *ECX to BL
81 7/subop/compare 3/mod/direct 3/rm32/EBX . . . . . 0x78/imm32/x # compare EBX
75/jump-if-not-equal $is-hex-int?:loop/disp8
# . ++curr
41/increment-ECX
$is-hex-int?:loop:
# if (curr >= in->end) return true
39/compare 3/mod/direct 1/rm32/ECX . . . 2/r32/EDX . . # compare ECX with EDX
7d/jump-if-greater-or-equal $is-hex-int?:true/disp8
# EAX = is-hex-digit?(*curr)
# . . push args
8a/copy-byte 0/mod/indirect 1/rm32/ECX . . . 0/r32/AL . . # copy byte at *ECX to AL
50/push-EAX
# . . call
e8/call is-hex-digit?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# if EAX == false return false
3d/compare-with-EAX 0/imm32
74/jump-if-equal $is-hex-int?:end/disp8
# ++curr
41/increment-ECX
# loop
eb/jump $is-hex-int?:loop/disp8
$is-hex-int?:true:
# return true
b8/copy-to-EAX 1/imm32/true
$is-hex-int?:end:
# . restore registers
5b/pop-to-EBX
5a/pop-to-EDX
59/pop-to-ECX
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-is-hex-int:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = "34"
68/push _test-slice-hex-int-end/imm32
68/push _test-slice-hex-int/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = is-hex-int?(slice)
# . . push args
51/push-ECX
# . . call
e8/call is-hex-int?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 1, msg)
# . . push args
68/push "F - test-is-hex-int"/imm32
68/push 1/imm32/true
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-is-hex-int-handles-letters:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = "34a"
68/push _test-slice-hex-int-letters-end/imm32
68/push _test-slice-hex-int-letters/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = is-hex-int?(slice)
# . . push args
51/push-ECX
# . . call
e8/call is-hex-int?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 1, msg)
# . . push args
68/push "F - test-is-hex-int-handles-letters"/imm32
68/push 1/imm32/true
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-is-hex-int-with-trailing-char:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = "34q"
68/push _test-slice-digits-and-char-end/imm32
68/push _test-slice-digits-and-char/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = is-hex-int?(slice)
# . . push args
51/push-ECX
# . . call
e8/call is-hex-int?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0, msg)
# . . push args
68/push "F - test-is-hex-int-with-trailing-char"/imm32
68/push 0/imm32/false
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-is-hex-int-with-leading-char:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = "q34"
68/push _test-slice-char-and-digits-end/imm32
68/push _test-slice-char-and-digits/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = is-hex-int?(slice)
# . . push args
51/push-ECX
# . . call
e8/call is-hex-int?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0, msg)
# . . push args
68/push "F - test-is-hex-int-with-leading-char"/imm32
68/push 0/imm32/false
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-is-hex-int-empty:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = ""
68/push _test-slice-empty-end/imm32
68/push _test-slice-empty/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = is-hex-int?(slice)
# . . push args
51/push-ECX
# . . call
e8/call is-hex-int?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0, msg)
# . . push args
68/push "F - test-is-hex-int-empty"/imm32
68/push 0/imm32/false
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-is-hex-int-handles-0x-prefix:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = "0x3a"
68/push _test-slice-hex-int-with-0x-prefix-end/imm32
68/push _test-slice-hex-int-with-0x-prefix/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = is-hex-int?(slice)
# . . push args
51/push-ECX
# . . call
e8/call is-hex-int?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 1, msg)
# . . push args
68/push "F - test-is-hex-int-handles-0x-prefix"/imm32
68/push 1/imm32/true
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
parse-hex-int: # in : (address slice) -> result/EAX
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# . save registers
51/push-ECX
52/push-EDX
53/push-EBX
# result/EBX = 0
31/xor 3/mod/direct 3/rm32/EBX . . . 3/r32/EBX . . # clear EBX
# ECX = s
8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 1/r32/ECX 8/disp8 . # copy *(EBP+8) to ECX
# EDX = s->end
8b/copy 1/mod/*+disp8 1/rm32/ECX . . . 2/r32/EDX 4/disp8 . # copy *(ECX+4) to EDX
# curr/ECX = s->start
8b/copy 0/mod/indirect 1/rm32/ECX . . . 1/r32/ECX . . # copy *ECX to ECX
# skip past leading '0x'
$parse-hex-int:initial-0:
# . if (*curr != '0') jump to loop
31/xor 3/mod/direct 0/rm32/EAX . . . 0/r32/EAX . . # clear EAX
8a/copy-byte 0/mod/indirect 1/rm32/ECX . . . 0/r32/AL . . # copy byte at *ECX to AL
81 7/subop/compare 3/mod/direct 0/rm32/EAX . . . . . 0x30/imm32/0 # compare EAX
75/jump-if-not-equal $parse-hex-int:loop/disp8
# . ++curr
41/increment-ECX
$parse-hex-int:initial-0x:
# . if (curr >= in->end) return result
39/compare 3/mod/direct 1/rm32/ECX . . . 2/r32/EDX . . # compare ECX with EDX
7d/jump-if-greater-or-equal $parse-hex-int:end/disp8
# . if (*curr != 'x') jump to loop # the previous '0' is still valid so doesn't need to be checked again
31/xor 3/mod/direct 0/rm32/EAX . . . 0/r32/EAX . . # clear EAX
8a/copy-byte 0/mod/indirect 1/rm32/ECX . . . 0/r32/AL . . # copy byte at *ECX to AL
81 7/subop/compare 3/mod/direct 0/rm32/EAX . . . . . 0x78/imm32/x # compare EAX
75/jump-if-not-equal $parse-hex-int:loop/disp8
# . ++curr
41/increment-ECX
$parse-hex-int:loop:
# if (curr >= in->end) break
39/compare 3/mod/direct 1/rm32/ECX . . . 2/r32/EDX . . # compare ECX with EDX
7d/jump-if-greater-or-equal $parse-hex-int:end/disp8
# EAX = parse-hex-digit(*curr)
# . . push args
8a/copy-byte 0/mod/indirect 1/rm32/ECX . . . 0/r32/AL . . # copy byte at *ECX to AL
50/push-EAX
# . . call
e8/call parse-hex-digit/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# result = result * 16 + EAX
c1/shift 4/subop/left 3/mod/direct 3/rm32/EBX . . . . . 4/imm8 # shift EBX left by 4 bits
01/add 3/mod/direct 3/rm32/EBX . . . 0/r32/EAX . . # add EAX to EBX
# ++curr
41/increment-ECX
# loop
eb/jump $parse-hex-int:loop/disp8
$parse-hex-int:end:
89/copy 3/mod/direct 0/rm32/EAX . . . 3/r32/EBX . . # copy EBX to EAX
# . restore registers
5b/pop-to-EBX
5a/pop-to-EDX
59/pop-to-ECX
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-parse-hex-int-single-digit:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = "a"
68/push _test-slice-hex-int-single-letter-end/imm32
68/push _test-slice-hex-int-single-letter/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = parse-hex-int(slice)
# . . push args
51/push-ECX
# . . call
e8/call parse-hex-int/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0xa, msg)
# . . push args
68/push "F - test-parse-hex-int-single-digit"/imm32
68/push 0xa/imm32
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-parse-hex-int-multi-digit:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = "34a"
68/push _test-slice-hex-int-letters-end/imm32
68/push _test-slice-hex-int-letters/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = parse-hex-int(slice)
# . . push args
51/push-ECX
# . . call
e8/call parse-hex-int/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0x34a, msg)
# . . push args
68/push "F - test-parse-hex-int-multi-digit"/imm32
68/push 0x34a/imm32
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-parse-hex-int-0x-prefix:
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# var slice/ECX = "0x34"
68/push _test-slice-hex-int-with-0x-prefix-end/imm32
68/push _test-slice-hex-int-with-0x-prefix/imm32
89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX
# EAX = parse-hex-int(slice)
# . . push args
51/push-ECX
# . . call
e8/call parse-hex-int/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0x34a, msg)
# . . push args
68/push "F - test-parse-hex-int-0x-prefix"/imm32
68/push 0x34/imm32
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
is-hex-digit?: # c : byte -> bool/EAX
# . prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# . save registers
51/push-ECX
# ECX = c
8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 1/r32/ECX 8/disp8 . # copy *(EBP+8) to ECX
# return false if c < '0'
b8/copy-to-EAX 0/imm32/false
81 7/subop/compare 3/mod/direct 1/rm32/ECX . . . . . 0x30/imm32 # compare ECX
7c/jump-if-lesser $is-hex-digit?:end/disp8
# return false if c > 'f'
81 7/subop/compare 3/mod/direct 1/rm32/ECX . . . . . 0x66/imm32 # compare ECX
7f/jump-if-greater $is-hex-digit?:end/disp8
# return true if c <= '9'
b8/copy-to-EAX 1/imm32/true
81 7/subop/compare 3/mod/direct 1/rm32/ECX . . . . . 0x39/imm32 # compare ECX
7e/jump-if-lesser-or-equal $is-hex-digit?:end/disp8
# return true if c >= 'a'
81 7/subop/compare 3/mod/direct 1/rm32/ECX . . . . . 0x61/imm32 # compare ECX
7d/jump-if-greater-or-equal $is-hex-digit?:end/disp8
# otherwise return false
b8/copy-to-EAX 0/imm32/false
$is-hex-digit?:end:
# . restore registers
59/pop-to-ECX
# . epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-hex-below-0:
# EAX = is-hex-digit?(0x2f)
# . . push args
68/push 0x2f/imm32
# . . call
e8/call is-hex-digit?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0, msg)
# . . push args
68/push "F - test-hex-below-0"/imm32
68/push 0/imm32/false
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
c3/return
test-hex-0-to-9:
# EAX = is-hex-digit?(0x30)
# . . push args
68/push 0x30/imm32
# . . call
e8/call is-hex-digit?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 1, msg)
# . . push args
68/push "F - test-hex-at-0"/imm32
68/push 1/imm32/true
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# EAX = is-hex-digit?(0x39)
# . . push args
68/push 0x39/imm32
# . . call
e8/call is-hex-digit?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 1, msg)
# . . push args
68/push "F - test-hex-at-9"/imm32
68/push 1/imm32/true
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
c3/return
test-hex-above-9-to-a:
# EAX = is-hex-digit?(0x3a)
# . . push args
68/push 0x3a/imm32
# . . call
e8/call is-hex-digit?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0, msg)
# . . push args
68/push "F - test-hex-above-9-to-a"/imm32
68/push 0/imm32/false
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
c3/return
test-hex-a-to-f:
# EAX = is-hex-digit?(0x61)
# . . push args
68/push 0x61/imm32
# . . call
e8/call is-hex-digit?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 1, msg)
# . . push args
68/push "F - test-hex-at-a"/imm32
68/push 1/imm32/true
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# EAX = is-hex-digit?(0x66)
# . . push args
68/push 0x66/imm32
# . . call
e8/call is-hex-digit?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 1, msg)
# . . push args
68/push "F - test-hex-at-f"/imm32
68/push 1/imm32/true
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
c3/return
test-hex-above-f:
# EAX = is-hex-digit?(0x67)
# . . push args
68/push 0x67/imm32
# . . call
e8/call is-hex-digit?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# check-ints-equal(EAX, 0, msg)
# . . push args
68/push "F - test-hex-above-f"/imm32
68/push 0/imm32/false
50/push-EAX
# . . call
e8/call check-ints-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
c3/return
parse-hex-digit: # in/EAX : byte -> out/EAX : num
# no error checking; accepts argument in EAX
# if EAX <= '9' return EAX - '0'
3d/compare-EAX 0x39/imm32/9
7f/jump-if-greater $parse-hex-digit:else/disp8
2d/subtract-from-EAX 0x30/imm32/0
c3/return
$parse-hex-digit:else:
# otherwise return EAX - 'a' + 10
2d/subtract-from-EAX 0x57/imm32/a-10
c3/return
== data
_test-slice-empty:
# nothing
_test-slice-empty-end:
_test-slice-hex-int:
33/3 34/4
_test-slice-hex-int-end:
_test-slice-hex-int-with-0x-prefix:
30/0 78/x 33/3 34/4
_test-slice-hex-int-with-0x-prefix-end:
_test-slice-hex-int-letters:
33/3 34/4 61/a
_test-slice-hex-int-letters-end:
_test-slice-hex-int-single-letter:
61/a
_test-slice-hex-int-single-letter-end:
_test-slice-char-and-digits:
71/q 33/3 34/4
_test-slice-char-and-digits-end:
_test-slice-digits-and-char:
33/3 34/4 71/q
_test-slice-digits-and-char-end:
# . . vim:nowrap:textwidth=0
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