Native support for sx and csx gates in qasm and qiskit

Author: perak

lib/quantum-circuit.js

@@ -325,18 +325,10 @@ var QuantumCircuit = function(numQubits) {
 						[["-1/sqrt(2)", "0"],["1/sqrt(2)", "0"]]]
 				},
 				qasm: {
-					replacement: [
-						{ name: "h", params: { }},
-						{ name: "rx", params: { theta: "-1*pi/2" }},
-						{ name: "u1", params: { lambda: "-1*pi/2" }}
-				   ]
+					name: "sx"
 				},
 				qiskit: {
-					replacement: [
-						{ name: "h", params: { }},
-						{ name: "rx", params: { theta: "-1*pi/2" }},
-						{ name: "u1", params: { lambda: "-1*pi/2" }}
-				   ]
+					name: "sx"
 				},
 				braket: {
 					name: "v"
@@ -1413,42 +1405,10 @@ var QuantumCircuit = function(numQubits) {
 					defgate: "DEFGATE csrn:\n    1, 0, 0, 0\n    0, 1, 0, 0\n    0, 0, 0.5+0.5i, 0.5-0.5i\n    0, 0, 0.5-0.5i, 0.5+0.5i"
 				},
 				qasm: {
-					equivalent: [
-						{ name: "rz", params: { phi: "-1*pi/4"}, wires: [0] },
-						{ name: "rx", params: { theta: "pi/2"}, wires: [0] },
-						{ name: "rz", params: { phi: "-1*pi/2"}, wires: [1] },
-						{ name: "rx", params: { theta: "pi/2"}, wires: [1] },
-						{ name: "rz", params: { phi: "3*pi/4"}, wires: [1] },
-						{ name: "rx", params: { theta: "pi"}, wires: [1] },
-						{ name: "cz", wires: [0, 1] },
-						{ name: "rx", params: { theta: "pi/2"}, wires: [0] },
-						{ name: "rz", params: { phi: "pi/4"}, wires: [0] },
-						{ name: "rx", params: { theta: "-1*pi/2"}, wires: [0] },
-						{ name: "cz", wires: [0, 1] },
-						{ name: "rx", params: { theta: "-1*pi/2"}, wires: [0] },
-						{ name: "rz", params: { phi: "pi/2"}, wires: [0] },
-						{ name: "rx", params: { theta: "-1*pi/2"}, wires: [1] },
-						{ name: "rz", params: { phi: "-1*pi/2"}, wires: [1] }
-				   ]
+					name: "csx"
 				},
 				qiskit: {
-					equivalent: [
-						{ name: "rz", params: { phi: "-1*pi/4"}, wires: [0] },
-						{ name: "rx", params: { theta: "pi/2"}, wires: [0] },
-						{ name: "rz", params: { phi: "-1*pi/2"}, wires: [1] },
-						{ name: "rx", params: { theta: "pi/2"}, wires: [1] },
-						{ name: "rz", params: { phi: "3*pi/4"}, wires: [1] },
-						{ name: "rx", params: { theta: "pi"}, wires: [1] },
-						{ name: "cz", wires: [0, 1] },
-						{ name: "rx", params: { theta: "pi/2"}, wires: [0] },
-						{ name: "rz", params: { phi: "pi/4"}, wires: [0] },
-						{ name: "rx", params: { theta: "-1*pi/2"}, wires: [0] },
-						{ name: "cz", wires: [0, 1] },
-						{ name: "rx", params: { theta: "-1*pi/2"}, wires: [0] },
-						{ name: "rz", params: { phi: "pi/2"}, wires: [0] },
-						{ name: "rx", params: { theta: "-1*pi/2"}, wires: [1] },
-						{ name: "rz", params: { phi: "-1*pi/2"}, wires: [1] }
-				   ]
+					name: "csx"
 				},
 				pyquil: {
 					name: "csrn",
@@ -7979,11 +7939,14 @@ QuantumCircuit.prototype.exportToQASM = function(options, exportAsGateName, circ
 			var qasmEquivalent = null;
 
 			if(gate && gate.connector == 0) {
+				var qasmName = gate.name;
 				if(!compatibilityMode) {
 					var gateDef = circuit.getGateDef(gate.name);
 					if(gateDef){
 						if(gateDef.exportInfo){
-							if(gateDef.exportInfo.qasm && gateDef.exportInfo.qasm.replacement) {
+							if(gateDef.exportInfo.qasm && gateDef.exportInfo.qasm.name) {
+								qasmName = gateDef.exportInfo.qasm.name;
+							} else if(gateDef.exportInfo.qasm && gateDef.exportInfo.qasm.replacement) {
 								qasmReplacement = gateDef.exportInfo.qasm.replacement;
 								qasmReplacement.map(function(replacement){
 									var replacementCircuit = new QuantumCircuit();
@@ -8061,7 +8024,8 @@ QuantumCircuit.prototype.exportToQASM = function(options, exportAsGateName, circ
 				}
 
 				if((!qasmReplacement && !qasmEquivalent) || compatibilityMode) {
-					var gateName = gate.name;
+					var gateName = compatibilityMode ? gate.name : qasmName;
+
 					var gateParams = gate.options && gate.options.params ? gate.options.params : {};
 					qasm += gateName;
 					if(gateParams) {