diff options
Diffstat (limited to '311parse-decimal-int.subx')
-rw-r--r-- | 311parse-decimal-int.subx | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/311parse-decimal-int.subx b/311parse-decimal-int.subx new file mode 100644 index 00000000..538f3e87 --- /dev/null +++ b/311parse-decimal-int.subx @@ -0,0 +1,233 @@ +# Helpers for parsing decimal ints. + +parse-decimal-int-from-slice: # in: (addr slice) -> out/eax: int # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # . save registers + 51/push-ecx + # ecx = in + 8b/-> *(ebp+8) 1/r32/ecx + # + (parse-decimal-int-helper *ecx *(ecx+4)) # => eax +$parse-decimal-int-from-slice:end: + # . restore registers + 59/pop-to-ecx + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return + +parse-decimal-int-helper: # start: (addr byte), end: (addr byte) -> result/eax: int + # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # . save registers + 51/push-ecx + 52/push-edx + 53/push-ebx + 56/push-esi + 57/push-edi + # var curr/esi: (addr byte) = start + 8b/-> *(ebp+8) 6/r32/esi + # edi = end + 8b/-> *(ebp+0xc) 7/r32/edi + # var negate?/edx: boolean = false + ba/copy-to-edx 0/imm32/false + # if (*curr == '-') ++curr, negate = true + { +$parse-decimal-int-helper:negative: + b8/copy-to-eax 0/imm32 + 8a/copy-byte *esi 0/r32/AL + 3d/compare-eax-and 0x2d/imm32/- + 75/jump-if-!= break/disp8 + # . ++curr + 46/increment-esi + # . negate = true + ba/copy-to-edx 1/imm32/true + } + # spill negate? + 52/push-edx + # var result/eax: int = 0 + b8/copy-to-eax 0/imm32 + # var digit/ecx: int = 0 + b9/copy-to-ecx 0/imm32 + # const TEN/ebx: int = 10 + bb/copy-to-ebx 0xa/imm32 + { +$parse-decimal-int-helper:loop: + # if (curr >= in->end) break + 39/compare %esi 7/r32/edi + 73/jump-if-addr>= break/disp8 + # digit = from-decimal-char(*curr) + 8a/copy-byte *esi 1/r32/CL + 81 5/subop/subtract %ecx 0x30/imm32/zero + # TODO: error checking + # result = result * 10 + digit + ba/copy-to-edx 0/imm32 + f7 4/subop/multiply-into-edx-eax %ebx + # TODO: check edx for overflow + 01/add %eax 1/r32/ecx + # ++curr + 46/increment-esi + # + eb/jump loop/disp8 + } +$parse-decimal-int-helper:negate: + # if (negate?) result = -result + 5a/pop-to-edx + { + 81 7/subop/compare %edx 0/imm32/false + 74/jump-if-= break/disp8 + f7 3/subop/negate %eax + } +$parse-decimal-int-helper:end: + # . restore registers + 5f/pop-to-edi + 5e/pop-to-esi + 5b/pop-to-ebx + 5a/pop-to-edx + 59/pop-to-ecx + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return + +test-parse-decimal-int-from-slice-single-digit: + # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # . save registers + 50/push-eax + 51/push-ecx + # (eax..ecx) = "3" + b8/copy-to-eax "3"/imm32 + 8b/-> *eax 1/r32/ecx + 8d/copy-address *(eax+ecx+4) 1/r32/ecx + 05/add-to-eax 4/imm32 + # var slice/ecx: slice = {eax, ecx} + 51/push-ecx + 50/push-eax + 89/<- %ecx 4/r32/esp + # + (parse-decimal-int-from-slice %ecx) # => eax + (check-ints-equal %eax 3 "F - test-parse-decimal-int-from-slice-single-digit") +$test-parse-decimal-int-helper-single-digit:end: + # . restore registers + 59/pop-to-ecx + 58/pop-to-eax + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return + +test-parse-decimal-int-from-slice-multi-digit: + # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # . save registers + 50/push-eax + 51/push-ecx + # (eax..ecx) = "34" + b8/copy-to-eax "34"/imm32 + 8b/-> *eax 1/r32/ecx + 8d/copy-address *(eax+ecx+4) 1/r32/ecx + 05/add-to-eax 4/imm32 + # var slice/ecx: slice = {eax, ecx} + 51/push-ecx + 50/push-eax + 89/<- %ecx 4/r32/esp + # + (parse-decimal-int-from-slice %ecx) # => eax + (check-ints-equal %eax 0x22 "F - test-parse-decimal-int-from-slice-multi-digit") # 34 in hex +$test-parse-decimal-int-helper-multi-digit:end: + # . restore registers + 59/pop-to-ecx + 58/pop-to-eax + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return + +test-parse-decimal-int-from-slice-zero: + # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # . save registers + 50/push-eax + 51/push-ecx + # (eax..ecx) = "00" + b8/copy-to-eax "00"/imm32 + 8b/-> *eax 1/r32/ecx + 8d/copy-address *(eax+ecx+4) 1/r32/ecx + 05/add-to-eax 4/imm32 + # var slice/ecx: slice = {eax, ecx} + 51/push-ecx + 50/push-eax + 89/<- %ecx 4/r32/esp + # + (parse-decimal-int-from-slice %ecx) # => eax + (check-ints-equal %eax 0 "F - test-parse-decimal-int-from-slice-zero") +$test-parse-decimal-int-helper-zero:end: + # . restore registers + 59/pop-to-ecx + 58/pop-to-eax + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return + +test-parse-decimal-int-from-slice-negative: + # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # . save registers + 50/push-eax + 51/push-ecx + # (eax..ecx) = "-3" + b8/copy-to-eax "-3"/imm32 + 8b/-> *eax 1/r32/ecx + 8d/copy-address *(eax+ecx+4) 1/r32/ecx + 05/add-to-eax 4/imm32 + # var slice/ecx: slice = {eax, ecx} + 51/push-ecx + 50/push-eax + 89/<- %ecx 4/r32/esp + # + (parse-decimal-int-from-slice %ecx) # => eax + (check-ints-equal %eax -3 "F - test-parse-decimal-int-from-slice-negative") +$test-parse-decimal-int-helper-negative:end: + # . restore registers + 59/pop-to-ecx + 58/pop-to-eax + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return + +test-parse-decimal-int-from-slice-multi-digit-negative: + # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # . save registers + 50/push-eax + 51/push-ecx + # (eax..ecx) = "-32" + b8/copy-to-eax "-32"/imm32 + 8b/-> *eax 1/r32/ecx + 8d/copy-address *(eax+ecx+4) 1/r32/ecx + 05/add-to-eax 4/imm32 + # var slice/ecx: slice = {eax, ecx} + 51/push-ecx + 50/push-eax + 89/<- %ecx 4/r32/esp + # + (parse-decimal-int-from-slice %ecx) # => eax + (check-ints-equal %eax -0x20 "F - test-parse-decimal-int-from-slice-multi-digit-negative") # -32 in hex +$test-parse-decimal-int-helper-multi-digit-negative:end: + # . restore registers + 59/pop-to-ecx + 58/pop-to-eax + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return |