microsoft/qdk
Publicmirrored fromhttps://github.com/microsoft/qdkAvailable
library/std/src/Std/InternalHelpers.qs
228lines · modecode
| 1 | // Copyright (c) Microsoft Corporation. |
| 2 | // Licensed under the MIT License. |
| 3 | |
| 4 | |
| 5 | import Std.Arrays.*; |
| 6 | import Std.Core.*; |
| 7 | import Std.Math.*; |
| 8 | import Std.Intrinsic.*; |
| 9 | import QIR.Intrinsic.*; |
| 10 | |
| 11 | internal operation CH(control : Qubit, target : Qubit) : Unit is Adj { |
| 12 | within { |
| 13 | S(target); |
| 14 | H(target); |
| 15 | T(target); |
| 16 | } apply { |
| 17 | CNOT(control, target); |
| 18 | } |
| 19 | } |
| 20 | |
| 21 | internal operation CCH(control1 : Qubit, control2 : Qubit, target : Qubit) : Unit is Adj { |
| 22 | within { |
| 23 | S(target); |
| 24 | H(target); |
| 25 | T(target); |
| 26 | } apply { |
| 27 | CCNOT(control1, control2, target); |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | internal operation ApplyGlobalPhase(theta : Double) : Unit is Ctl + Adj { |
| 32 | body ... { |
| 33 | ControllableGlobalPhase(theta); |
| 34 | } |
| 35 | adjoint ... { |
| 36 | ControllableGlobalPhase(-theta); |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | // Global phase is not relevant for physical systems, but controlled global phase is physical. We use |
| 41 | // the Rz gate to implement controlled global phase physically, and then correct for the extra global phase it |
| 42 | // introduces in simulation using additional calls to the simulation-only global phase intrinsic. |
| 43 | // We use a separate operation for this controlled case to avoid recursive calls to the same operation |
| 44 | // that can interfere with runtime capabilities analysis. |
| 45 | internal operation ControllableGlobalPhase(theta : Double) : Unit is Ctl { |
| 46 | body ... { |
| 47 | GlobalPhase([], theta); |
| 48 | } |
| 49 | controlled (ctls, ...) { |
| 50 | if Length(ctls) == 0 { |
| 51 | GlobalPhase([], theta); |
| 52 | } else { |
| 53 | Controlled Rz(ctls[1...], (theta, ctls[0])); |
| 54 | GlobalPhase(ctls[1...], theta / 2.0); |
| 55 | } |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | // Global phase intrinsic, which only has affect in simulation and is a no-op otherwise. |
| 60 | internal operation GlobalPhase(ctls : Qubit[], theta : Double) : Unit { |
| 61 | body intrinsic; |
| 62 | } |
| 63 | |
| 64 | internal operation CRz(control : Qubit, theta : Double, target : Qubit) : Unit is Adj { |
| 65 | Rz(theta / 2.0, target); |
| 66 | CNOT(control, target); |
| 67 | Rz(-theta / 2.0, target); |
| 68 | CNOT(control, target); |
| 69 | } |
| 70 | |
| 71 | internal operation CS(control : Qubit, target : Qubit) : Unit is Adj + Ctl { |
| 72 | T(control); |
| 73 | T(target); |
| 74 | CNOT(control, target); |
| 75 | Adjoint T(target); |
| 76 | CNOT(control, target); |
| 77 | } |
| 78 | |
| 79 | internal operation CT(control : Qubit, target : Qubit) : Unit is Adj { |
| 80 | let angle = PI() / 8.0; |
| 81 | Rz(angle, control); |
| 82 | Rz(angle, target); |
| 83 | CNOT(control, target); |
| 84 | Adjoint Rz(angle, target); |
| 85 | CNOT(control, target); |
| 86 | // This decomposition for controlled-T introduces a global phase (due to the unmatched call to Rz from above). |
| 87 | // We correct for this global phase in simulation, which is a no-op on hardware. |
| 88 | ApplyGlobalPhase(angle / 2.0); |
| 89 | } |
| 90 | |
| 91 | internal operation EntangleForJointMeasure(basis : Pauli, aux : Qubit, qubit : Qubit) : Unit { |
| 92 | if basis == PauliX { |
| 93 | __quantum__qis__cx__body(aux, qubit); |
| 94 | } elif basis == PauliZ { |
| 95 | __quantum__qis__cz__body(aux, qubit); |
| 96 | } elif basis == PauliY { |
| 97 | __quantum__qis__cy__body(aux, qubit); |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | /// Collects the given list of control qubits into one or two of the given auxiliary qubits, using |
| 102 | /// all but the last qubits in the auxiliary list as scratch qubits. The auxiliary list must be |
| 103 | /// big enough to accommodate the data, so it is usually smaller than controls list by number of |
| 104 | /// qubits needed for the eventual controlled unitary application. The passed adjustment value is |
| 105 | /// used to ensure the right number of auxiliary qubits are processed. |
| 106 | /// |
| 107 | /// For example, if the controls list is 6 qubits, the auxiliary list must be 5 qubits, and the |
| 108 | /// state from the 6 control qubits will be collected into the last qubit of the auxiliary array. |
| 109 | internal operation CollectControls(ctls : Qubit[], aux : Qubit[], adjustment : Int) : Unit is Adj { |
| 110 | // First collect the controls into the first part of the auxiliary list. |
| 111 | for i in 0..2..(Length(ctls) - 2) { |
| 112 | CCNOT(ctls[i], ctls[i + 1], aux[i / 2]); |
| 113 | } |
| 114 | // Then collect the auxiliary qubits in the first part of the list forward into the last |
| 115 | // qubit of the auxiliary list. The adjustment is used to allow the caller to reduce or increase |
| 116 | // the number of times this is run based on the eventual number of control qubits needed. |
| 117 | for i in 0..((Length(ctls) / 2) - 2 - adjustment) { |
| 118 | CCNOT(aux[i * 2], aux[(i * 2) + 1], aux[i + Length(ctls) / 2]); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | /// When collecting controls, if there is an uneven number of original control qubits then the |
| 123 | /// last control and the second to last auxiliary will be collected into the last auxiliary. |
| 124 | internal operation AdjustForSingleControl(ctls : Qubit[], aux : Qubit[]) : Unit is Adj { |
| 125 | if Length(ctls) % 2 != 0 { |
| 126 | CCNOT(ctls[Length(ctls) - 1], aux[Length(ctls) - 3], aux[Length(ctls) - 2]); |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | internal operation PhaseCCX(control1 : Qubit, control2 : Qubit, target : Qubit) : Unit is Adj { |
| 131 | // https://arxiv.org/pdf/1210.0974.pdf#page=2 |
| 132 | H(target); |
| 133 | CNOT(target, control1); |
| 134 | CNOT(control1, control2); |
| 135 | T(control2); |
| 136 | Adjoint T(control1); |
| 137 | T(target); |
| 138 | CNOT(target, control1); |
| 139 | CNOT(control1, control2); |
| 140 | Adjoint T(control2); |
| 141 | CNOT(target, control2); |
| 142 | H(target); |
| 143 | } |
| 144 | |
| 145 | internal operation CCZ(control1 : Qubit, control2 : Qubit, target : Qubit) : Unit is Adj { |
| 146 | within { |
| 147 | MapPauliAxis(PauliX, PauliZ, target); |
| 148 | } apply { |
| 149 | CCNOT(control1, control2, target); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | internal operation CCY(control1 : Qubit, control2 : Qubit, target : Qubit) : Unit is Adj { |
| 154 | within { |
| 155 | MapPauliAxis(PauliX, PauliY, target); |
| 156 | } apply { |
| 157 | CCNOT(control1, control2, target); |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | internal operation CRxx(control : Qubit, theta : Double, qubit0 : Qubit, qubit1 : Qubit) : Unit { |
| 162 | within { |
| 163 | MapPauliAxis(PauliZ, PauliX, qubit0); |
| 164 | MapPauliAxis(PauliZ, PauliX, qubit1); |
| 165 | } apply { |
| 166 | CRzz(control, theta, qubit0, qubit1); |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | internal operation CRyy(control : Qubit, theta : Double, qubit0 : Qubit, qubit1 : Qubit) : Unit { |
| 171 | within { |
| 172 | MapPauliAxis(PauliZ, PauliY, qubit0); |
| 173 | MapPauliAxis(PauliZ, PauliY, qubit1); |
| 174 | } apply { |
| 175 | CRzz(control, theta, qubit0, qubit1); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | internal operation CRzz(control : Qubit, theta : Double, qubit0 : Qubit, qubit1 : Qubit) : Unit { |
| 180 | within { |
| 181 | CNOT(qubit1, qubit0); |
| 182 | } apply { |
| 183 | Controlled Rz([control], (theta, qubit0)); |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | internal function IndicesOfNonIdentity(paulies : Pauli[]) : Int[] { |
| 188 | mutable indices = []; |
| 189 | for i in 0..Length(paulies) - 1 { |
| 190 | if (paulies[i] != PauliI) { |
| 191 | set indices += [i]; |
| 192 | } |
| 193 | } |
| 194 | indices |
| 195 | } |
| 196 | |
| 197 | internal function RemovePauliI(paulis : Pauli[], qubits : Qubit[]) : (Pauli[], Qubit[]) { |
| 198 | let indices = IndicesOfNonIdentity(paulis); |
| 199 | let newPaulis = Subarray(indices, paulis); |
| 200 | let newQubits = Subarray(indices, qubits); |
| 201 | return (newPaulis, newQubits); |
| 202 | } |
| 203 | |
| 204 | internal operation SpreadZ(from : Qubit, to : Qubit[]) : Unit is Adj { |
| 205 | let targets = GetSpread(from, to); |
| 206 | for (ctl, tgt) in targets { |
| 207 | CNOT(ctl, tgt); |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | internal function GetSpread(from : Qubit, to : Qubit[]) : (Qubit, Qubit)[] { |
| 212 | mutable queue = [(from, to)]; |
| 213 | mutable targets = []; |
| 214 | while Length(queue) > 0 { |
| 215 | mutable (next, rest) = (queue[0], queue[1...]); |
| 216 | set queue = rest; |
| 217 | let (next_from, next_to) = next; |
| 218 | if Length(next_to) > 0 { |
| 219 | set targets = [(next_to[0], next_from)] + targets; |
| 220 | if Length(next_to) > 1 { |
| 221 | let half = Length(next_to) / 2; |
| 222 | set queue = [(next_from, next_to[1..half]), (next_to[0], next_to[(half + 1)...])] + rest; |
| 223 | } |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | targets |
| 228 | } |
| 229 | |