| 1 | @ (c) 2020 Aaron Taylor <ataylor at subgeniuskitty dot com> |
| 2 | @ See LICENSE.txt file for copyright and license details. |
| 3 | |
| 4 | #ifndef VVS_STDLIB_MATH |
| 5 | #define VVS_STDLIB_MATH |
| 6 | |
| 7 | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
| 8 | @ Name: |
| 9 | @ random (10000) |
| 10 | @ Description: |
| 11 | @ Returns a pseudo-random number. |
| 12 | @ Before using for the first time, seed heap[0] with a non-zero value. |
| 13 | @ This PRNG was taken from: https://en.wikipedia.org/wiki/Xorshift |
| 14 | @ Call Stack: |
| 15 | @ empty |
| 16 | @ Return Stack: |
| 17 | @ random number <-- TOS |
| 18 | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
| 19 | #include <logic.pvvs> |
| 20 | NSSVTSSSSN | Mark: 10000 (random) |
| 21 | |
| 22 | @ Fetch seed from heap[0]. |
| 23 | SSSSN | PUSH 0 (ptr) |
| 24 | TTT | LOAD |
| 25 | |
| 26 | @ Set TOS ^= TOS << 13 |
| 27 | SNS | DUP |
| 28 | SSSTTSTN | PUSH +13 |
| 29 | NSTTSTTSTN | JSR > 101101 (lshift) |
| 30 | NSTTSTSTTN | JSR > 101011 (xor) |
| 31 | |
| 32 | @ Set TOS ^= TOS >> 7 |
| 33 | SNS | DUP |
| 34 | SSSTTTN | PUSH +7 |
| 35 | NSTTSTTSSN | JSR > 101100 (rshift) |
| 36 | NSTTSTSTTN | JSR > 101011 (xor) |
| 37 | |
| 38 | @ Set TOS ^= TOS << 17 |
| 39 | SNS | DUP |
| 40 | SSSTSSSTN | PUSH +17 |
| 41 | NSTTSTTSTN | JSR > 101101 (lshift) |
| 42 | NSTTSTSTTN | JSR > 101011 (xor) |
| 43 | |
| 44 | @ Store a copy of the new seed at heap[0] and return. |
| 45 | SNS | DUP |
| 46 | SSSSN | PUSH 0 (ptr) |
| 47 | SNT | SWAP |
| 48 | TTS | STORE |
| 49 | NTN | RTS |
| 50 | |
| 51 | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
| 52 | @ Name: |
| 53 | @ abs (10001) |
| 54 | @ Description: |
| 55 | @ Returns the absolute value of its argument |
| 56 | @ Call Stack: |
| 57 | @ signed number <-- TOS |
| 58 | @ Return Stack: |
| 59 | @ abs(signed number) <-- TOS |
| 60 | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
| 61 | NSSVTSSSTN | Mark: 10001 (absolute value) |
| 62 | |
| 63 | @ Catch -(2^63) as a special case since its absolute value will overflow |
| 64 | @ a twos-complement 64-bit word. Return zero as though the absolute value |
| 65 | @ overflowed to the bottom of the non-negative integers rather than |
| 66 | @ overflowing back to the most negative integer. |
| 67 | SNS | DUP |
| 68 | SSTTSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSN | -(2^63) |
| 69 | TSST | SUBTRACT |
| 70 | NTSSSSTSSSTSSSSSSTSN | BRZ > 00010001 00000010 |
| 71 | |
| 72 | @ Handle all the other numbers. |
| 73 | SNS | DUP |
| 74 | NTTSSSTSSSTSSSSSSSSN | BMI > 00010001 00000000 |
| 75 | NSNSSSTSSSTSSSSSSSTN | JMP > 00010001 00000001 |
| 76 | NSSVSSSTSSSTSSSSSSSSN | Mark: 00010001 00000000 |
| 77 | SSTTN | PUSH -1 |
| 78 | TSSN | MULTIPLY |
| 79 | NSSVSSSTSSSTSSSSSSSTN | Mark: 00010001 00000001 |
| 80 | NTN | RTS |
| 81 | |
| 82 | @ Special case: Push 0 and return. |
| 83 | NSSVSSSTSSSTSSSSSSTSN | Mark: 00010001 00000010 |
| 84 | SNN | DROP |
| 85 | SSSSN | PUSH 0 |
| 86 | NTN | RTS |
| 87 | |
| 88 | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
| 89 | @ Name: |
| 90 | @ gcd (10010) |
| 91 | @ Description: |
| 92 | @ Returns greatest common divisor of X and Y. |
| 93 | @ Call Stack: |
| 94 | @ Y |
| 95 | @ X <-- TOS |
| 96 | @ Return Stack: |
| 97 | @ gcd(X,Y) <-- TOS |
| 98 | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
| 99 | #include <stack.pvvs> |
| 100 | NSSVTSSTSN | Mark: 10010 (gcd) |
| 101 | |
| 102 | @ Since 1 > -1, transform problem into gcd(abs(X),abs(Y)). |
| 103 | SNT | SWAP |
| 104 | NSTTSSSTN | JSR > 10001 (abs) |
| 105 | SNT | SWAP |
| 106 | NSTTSSSTN | JSR > 10001 (abs) |
| 107 | |
| 108 | @ Verify neither operand is zero. |
| 109 | SNT | SWAP |
| 110 | SNS | DUP |
| 111 | NTSSSSTSSTSSSSSSSSSN | BRZ > 00010010 00000000 (gcd:zero input) |
| 112 | SNT | SWAP |
| 113 | SNS | DUP |
| 114 | NTSSSSTSSTSSSSSSSSSN | BRZ > 00010010 00000000 (gcd:zero input) |
| 115 | |
| 116 | @ Verify X != Y and sort X,Y so the smaller is TOS. |
| 117 | SNS | DUP |
| 118 | SSSTTN | PUSH 3 |
| 119 | NSTTTSSN | JSR > 1100 (deepdup) |
| 120 | SNT | SWAP |
| 121 | TSST | SUBTRACT |
| 122 | @ TOS> Y-X, X, Y |
| 123 | NTTSSSTSSTSSSSSSSSTN | BMI > 00010010 00000001 (gcd:swap inputs) |
| 124 | NSNSSSTSSTSSSSSSSTSN | JMP > 00010010 00000010 (gcd:main loop) |
| 125 | NSSVSSSTSSTSSSSSSSSTN | MARK: 00010010 00000001 (gcd:swap inputs) |
| 126 | SNT | SWAP |
| 127 | |
| 128 | @ Main gcd loop. |
| 129 | @ Euclidean algorithm. |
| 130 | NSSVSSSTSSTSSSSSSSTSN | MARK: 00010010 00000010 (gcd:main loop) |
| 131 | SNS | DUP |
| 132 | SSSTTN | PUSH 3 |
| 133 | NSTTSTSN | JSR > 1010 (stackrotate) |
| 134 | TSTT | MODULO |
| 135 | SNS | DUP |
| 136 | NTSSSSTSSTSSSSSSSTTN | BRZ > 00010010 00000011 (gcd:loop termination) |
| 137 | NSNSSSTSSTSSSSSSSTSN | JMP > 00010010 00000010 (gcd:main loop) |
| 138 | NSSVSSSTSSTSSSSSSSTTN | MARK: 00010010 00000011 (gcd:loop termination) |
| 139 | SNN | DROP |
| 140 | NTN | RTS |
| 141 | |
| 142 | @ At least one operand was zero. |
| 143 | @ Since we define gcd(a,0) = a, return the other operand. |
| 144 | NSSVSSSTSSTSSSSSSSSSN | MARK: 00010010 00000000 (gcd:zero input) |
| 145 | SNN | DROP |
| 146 | NTN | RTS |
| 147 | |
| 148 | #endif |