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| author | Kartik Agaram <vc@akkartik.com> | 2019-05-25 00:43:19 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-05-25 00:43:19 -0700 |
| commit | 6c03f2edab211d90405187eafa9a0243bbd64c39 (patch) | |
| tree | 91d39f253b3ff5b1c080f3591ec448d9be32e3b0 /subx/075array-equal.subx | |
| parent | 0b2d2d97284c41ad095e9dbbe6657b857af1c7b9 (diff) | |
| download | mu-6c03f2edab211d90405187eafa9a0243bbd64c39.tar.gz | |
new primitive: array-equal?
Diffstat (limited to 'subx/075array-equal.subx')
| -rw-r--r-- | subx/075array-equal.subx | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/subx/075array-equal.subx b/subx/075array-equal.subx new file mode 100644 index 00000000..ebc446d8 --- /dev/null +++ b/subx/075array-equal.subx @@ -0,0 +1,247 @@ +# Comparing arrays of numbers. + +== 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 + +Entry: + + # for debugging: run a single test +#? e8/call test-compare-inequal-arrays-equal-lengths/disp32 +#? 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/EBX Num-test-failures/disp32 # copy *Num-test-failures to EBX +#? eb/jump $array-equal-main:end/disp8 + + e8/call run-tests/disp32 # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'. +$array-equal-main:end: + # 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 + +array-equal?: # a : (address array int), b : (address array int) -> EAX : boolean + # pseudocode: + # lena = a->length + # if (lena != b->length) return false + # i = 0 + # curra = a->data + # currb = b->data + # while i < lena + # i1 = *curra + # i2 = *currb + # if (c1 != c2) return false + # i+=4, curra+=4, currb+=4 + # return true + # + # registers: + # i: ECX + # lena: EDX + # curra: ESI + # currb: EDI + # i1: EAX + # i2: EBX + # + # . 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 + 56/push-ESI + 57/push-EDI + # ESI = a + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 6/r32/ESI 8/disp8 . # copy *(EBP+8) to ESI + # EDI = b + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 7/r32/EDI 0xc/disp8 . # copy *(EBP+12) to EDI + # lena/EDX = a->length + 8b/copy 0/mod/indirect 6/rm32/ESI . . . 2/r32/EDX . . # copy *ESI to EDX +$array-equal?:lengths: + # if (lena != b->length) return false + 39/compare 0/mod/indirect 7/rm32/EDI . . . 2/r32/EDX . . # compare *EDI and EDX + 75/jump-if-not-equal $array-equal?:false/disp8 + # curra/ESI = a->data + 81 0/subop/add 3/mod/direct 6/rm32/ESI . . . . . 4/imm32 # add to ESI + # currb/EDI = b->data + 81 0/subop/add 3/mod/direct 7/rm32/EDI . . . . . 4/imm32 # add to EDI + # i/ECX = i1/EAX = i2/EBX = 0 + 31/xor 3/mod/direct 1/rm32/ECX . . . 1/r32/ECX . . # clear ECX +$array-equal?:loop: + # if (i >= lena) return true + 39/compare 3/mod/direct 1/rm32/ECX . . . 2/r32/EDX . . # compare ECX with EDX + 7d/jump-if-greater-or-equal $array-equal?:true/disp8 + # i1 = *curra + 8b/copy 0/mod/indirect 6/rm32/ESI . . . 0/r32/EAX . . # copy *ESI to EAX + # i2 = *currb + 8b/copy 0/mod/indirect 7/rm32/EDI . . . 3/r32/EBX . . # copy *EDI to EBX + # if (i1 != i2) return false + 39/compare 3/mod/direct 0/rm32/EAX . . . 3/r32/EBX . . # compare EAX and EBX + 75/jump-if-not-equal $array-equal?:false/disp8 + # i += 4 + 81 0/subop/add 3/mod/direct 1/rm32/ECX . . . . . 4/imm32 # add to ECX + # currs += 4 + 81 0/subop/add 3/mod/direct 6/rm32/ESI . . . . . 4/imm32 # add to ESI + # currb += 4 + 81 0/subop/add 3/mod/direct 7/rm32/EDI . . . . . 4/imm32 # add to EDI + 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 + # . epilog + 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP + 5d/pop-to-EBP + c3/return + +# - tests + +test-compare-empty-with-empty-array: + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # var ECX = [] + 68/push 0/imm32/size + 89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX + # var EDX = [] + 68/push 0/imm32/size + 89/copy 3/mod/direct 2/rm32/EDX . . . 4/r32/ESP . . # copy ESP to EDX + # EAX = array-equal?(ECX, EDX) + # . . push args + 52/push-EDX + 51/push-ECX + # . . call + e8/call array-equal?/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # check-ints-equal(EAX, 1, msg) + # . . push args + 68/push "F - test-compare-empty-with-empty-array"/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-compare-empty-with-non-empty-array: # also checks length-mismatch code path + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # var ECX = [1] + 68/push 1/imm32 + 68/push 4/imm32/size + 89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX + # var EDX = [] + 68/push 0/imm32/size + 89/copy 3/mod/direct 2/rm32/EDX . . . 4/r32/ESP . . # copy ESP to EDX + # EAX = array-equal?(ECX, EDX) + # . . push args + 52/push-EDX + 51/push-ECX + # . . call + e8/call array-equal?/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # check-ints-equal(EAX, 0, msg) + # . . push args + 68/push "F - test-compare-empty-with-non-empty-array"/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-compare-equal-arrays: + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # var ECX = [1, 2, 3] + 68/push 3/imm32 + 68/push 2/imm32 + 68/push 1/imm32 + 68/push 0xc/imm32/size + 89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX + # var EDX = [1, 2, 3] + 68/push 3/imm32 + 68/push 2/imm32 + 68/push 1/imm32 + 68/push 0xc/imm32/size + 89/copy 3/mod/direct 2/rm32/EDX . . . 4/r32/ESP . . # copy ESP to EDX + # EAX = array-equal?(ECX, EDX) + # . . push args + 52/push-EDX + 51/push-ECX + # . . call + e8/call array-equal?/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # check-ints-equal(EAX, 1, msg) + # . . push args + 68/push "F - test-compare-equal-arrays"/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-compare-inequal-arrays-equal-lengths: + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # var ECX = [1, 4, 3] + 68/push 3/imm32 + 68/push 4/imm32 + 68/push 1/imm32 + 68/push 0xc/imm32/size + 89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX + # var EDX = [1, 2, 3] + 68/push 3/imm32 + 68/push 2/imm32 + 68/push 1/imm32 + 68/push 0xc/imm32/size + 89/copy 3/mod/direct 2/rm32/EDX . . . 4/r32/ESP . . # copy ESP to EDX + # EAX = array-equal?(ECX, EDX) + # . . push args + 52/push-EDX + 51/push-ECX + # . . call + e8/call array-equal?/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # check-ints-equal(EAX, 0, msg) + # . . push args + 68/push "F - test-compare-inequal-arrays-equal-lengths"/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 + +# . . vim:nowrap:textwidth=0 |