microsoft/qdk
Publicmirrored fromhttps://github.com/microsoft/qdkAvailable
library/fixed_point/src/Operations.qs
168lines · modecode
| 1 | // Copyright (c) Microsoft Corporation. All rights reserved. |
| 2 | // Licensed under the MIT License. |
| 3 | |
| 4 | import Types.FixedPoint; |
| 5 | import Init.PrepareFxP; |
| 6 | import Operations.AddFxP; |
| 7 | import Signed.Operations.Invert2sSI, Signed.Operations.MultiplySI, Signed.Operations.SquareSI; |
| 8 | import Facts.AssertPointPositionsIdenticalFxP; |
| 9 | import Std.Arrays.Zipped; |
| 10 | import Std.Arithmetic.RippleCarryTTKIncByLE; |
| 11 | |
| 12 | /// # Summary |
| 13 | /// Adds a classical constant to a quantum fixed-point number. |
| 14 | /// |
| 15 | /// # Input |
| 16 | /// ## constant |
| 17 | /// Constant to add to the quantum fixed-point number. |
| 18 | /// ## fp |
| 19 | /// Fixed-point number to which the constant will |
| 20 | /// be added. |
| 21 | @Config(Unrestricted) |
| 22 | operation AddConstantFxP(constant : Double, fp : FixedPoint) : Unit is Adj + Ctl { |
| 23 | let n = Length(fp::Register); |
| 24 | use ys = Qubit[n]; |
| 25 | let tmpFp = FixedPoint(fp::IntegerBits, ys); |
| 26 | within { |
| 27 | PrepareFxP(constant, tmpFp); |
| 28 | } apply { |
| 29 | AddFxP(tmpFp, fp); |
| 30 | } |
| 31 | } |
| 32 | |
| 33 | /// # Summary |
| 34 | /// Adds two fixed-point numbers stored in quantum registers. |
| 35 | /// |
| 36 | /// # Description |
| 37 | /// Given two fixed-point registers respectively in states $\ket{f_1}$ and $\ket{f_2}$, |
| 38 | /// performs the operation $\ket{f_1} \ket{f_2} \mapsto \ket{f_1} \ket{f_1 + f_2}$. |
| 39 | /// |
| 40 | /// # Input |
| 41 | /// ## fp1 |
| 42 | /// First fixed-point number |
| 43 | /// ## fp2 |
| 44 | /// Second fixed-point number, will be updated to contain the sum of the |
| 45 | /// two inputs. |
| 46 | /// |
| 47 | /// # Remarks |
| 48 | /// The current implementation requires the two fixed-point numbers |
| 49 | /// to have the same point position counting from the least-significant |
| 50 | /// bit, i.e., $n_i$ and $p_i$ must be equal. |
| 51 | @Config(Unrestricted) |
| 52 | operation AddFxP(fp1 : FixedPoint, fp2 : FixedPoint) : Unit is Adj + Ctl { |
| 53 | AssertPointPositionsIdenticalFxP([fp1, fp2]); |
| 54 | |
| 55 | RippleCarryTTKIncByLE(fp1::Register, fp2::Register); |
| 56 | } |
| 57 | |
| 58 | /// # Summary |
| 59 | /// Computes the additive inverse of `fp`. |
| 60 | /// |
| 61 | /// # Input |
| 62 | /// ## fp |
| 63 | /// Fixed-point number to invert. |
| 64 | /// |
| 65 | /// # Remarks |
| 66 | /// Numerical inaccuracies may occur depending on the |
| 67 | /// bit-precision of the fixed-point number. |
| 68 | @Config(Unrestricted) |
| 69 | operation InvertFxP(fp : FixedPoint) : Unit is Adj + Ctl { |
| 70 | let (_, reg) = fp!; |
| 71 | Invert2sSI(reg); |
| 72 | } |
| 73 | |
| 74 | /// # Summary |
| 75 | /// Computes `minuend - subtrahend` and stores the difference in `minuend`. |
| 76 | /// |
| 77 | /// # Input |
| 78 | /// ## subtrahend |
| 79 | /// The subtrahend of the subtraction - the number to be subtracted. |
| 80 | /// ## minuend |
| 81 | /// The minuend of the subtraction - the number from which the other is subtracted. |
| 82 | /// |
| 83 | /// # Remarks |
| 84 | /// Computes the difference by inverting `subtrahend` before and after adding |
| 85 | /// it to `minuend`. Notice that `minuend`, the first argument is updated. |
| 86 | @Config(Unrestricted) |
| 87 | operation SubtractFxP(minuend : FixedPoint, subtrahend : FixedPoint) : Unit is Adj + Ctl { |
| 88 | within { |
| 89 | InvertFxP(subtrahend); |
| 90 | } apply { |
| 91 | AddFxP(subtrahend, minuend); |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | |
| 96 | /// # Summary |
| 97 | /// Multiplies two fixed-point numbers in quantum registers. |
| 98 | /// |
| 99 | /// # Input |
| 100 | /// ## fp1 |
| 101 | /// First fixed-point number. |
| 102 | /// ## fp2 |
| 103 | /// Second fixed-point number. |
| 104 | /// ## result |
| 105 | /// Result fixed-point number, must be in state $\ket{0}$ initially. |
| 106 | /// |
| 107 | /// # Remarks |
| 108 | /// The current implementation requires the three fixed-point numbers |
| 109 | /// to have the same point position and the same number of qubits. |
| 110 | @Config(Unrestricted) |
| 111 | operation MultiplyFxP(fp1 : FixedPoint, fp2 : FixedPoint, result : FixedPoint) : Unit is Adj { |
| 112 | |
| 113 | body (...) { |
| 114 | Controlled MultiplyFxP([], (fp1, fp2, result)); |
| 115 | } |
| 116 | controlled (controls, ...) { |
| 117 | Facts.AssertFormatsAreIdenticalFxP([fp1, fp2, result]); |
| 118 | let n = Length(fp1::Register); |
| 119 | |
| 120 | use tmpResult = Qubit[2 * n]; |
| 121 | let xsInt = ((fp1::Register)); |
| 122 | let ysInt = ((fp2::Register)); |
| 123 | let tmpResultInt = tmpResult; |
| 124 | |
| 125 | within { |
| 126 | MultiplySI(xsInt, ysInt, tmpResultInt); |
| 127 | } apply { |
| 128 | Controlled ApplyToEachCA(controls, (CNOT, Zipped(tmpResult[n - fp1::IntegerBits..2 * n - fp1::IntegerBits - 1], result::Register))); |
| 129 | } |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | /// # Summary |
| 134 | /// Squares a fixed-point number. |
| 135 | /// |
| 136 | /// # Input |
| 137 | /// ## fp |
| 138 | /// Fixed-point number. |
| 139 | /// ## result |
| 140 | /// Result fixed-point number, |
| 141 | /// must be in state $\ket{0}$ initially. |
| 142 | @Config(Unrestricted) |
| 143 | operation SquareFxP(fp : FixedPoint, result : FixedPoint) : Unit is Adj { |
| 144 | body (...) { |
| 145 | Controlled SquareFxP([], (fp, result)); |
| 146 | } |
| 147 | controlled (controls, ...) { |
| 148 | Facts.AssertFormatsAreIdenticalFxP([fp, result]); |
| 149 | let n = Length(fp::Register); |
| 150 | |
| 151 | use tmpResult = Qubit[2 * n]; |
| 152 | let xsInt = fp::Register; |
| 153 | let tmpResultInt = tmpResult; |
| 154 | within { |
| 155 | SquareSI(xsInt, tmpResultInt); |
| 156 | } apply { |
| 157 | Controlled ApplyToEachCA(controls, (CNOT, Zipped(tmpResult[n - fp::IntegerBits..2 * n - fp::IntegerBits - 1], result::Register))); |
| 158 | } |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | export |
| 163 | AddConstantFxP, |
| 164 | AddFxP, |
| 165 | InvertFxP, |
| 166 | SubtractFxP, |
| 167 | MultiplyFxP, |
| 168 | SquareFxP; |
| 169 | |