minor code cleanup (#672)

which had only the below 4 changes visible to users:
- changed the significant figures from 3 to 4 of reported memory (e.g. `3.23e1 KiB` becomes `32.30 KiB`)
- fixed a README doc link
- renamed to clarify the `setQuregToClone` parameters
- suppressed illegitimate unused-variable compiler warnings

and otherwise merely tidied internal code. See #672 for all changes.

Author: TysonRayJones

README.md

@@ -19,7 +19,7 @@
   [![DOI](https://img.shields.io/badge/DOI-10.1038%2Fs41598--019--47174--9-yellow.svg)](https://doi.org/10.1038/s41598-019-47174-9)
   <br>
   [![GitHub release](https://img.shields.io/github/release/QuEST-Kit/QuEST)](https://GitHub.com/QuEST-Kit/QuEST/releases/) 
-  [![Doc](https://img.shields.io/badge/doc-Github.io-orange.svg)](https://quest-kit.github.io/QuEST/modules.html)
+  [![Doc](https://img.shields.io/badge/doc-Github.io-orange.svg)](https://quest-kit.github.io/QuEST/group__api.html)
   [![MIT license](https://img.shields.io/badge/license-MIT-lightgrey.svg)](LICENCE.txt)
 
 

quest/include/initialisations.h

@@ -113,7 +113,7 @@ void setDensityQuregFlatAmps(Qureg qureg, qindex startInd, qcomp* amps, qindex n
 
 /// @notyetdoced
 /// @notyettested
-void setQuregToClone(Qureg targetQureg, Qureg copyQureg);
+void setQuregToClone(Qureg outQureg, Qureg inQureg);
 
 
 /// @notyetdoced

quest/src/api/initialisations.cpp

@@ -171,17 +171,17 @@ void setDensityQuregFlatAmps(Qureg qureg, qindex startInd, qcomp* amps, qindex n
 }
 
 
-void setQuregToClone(Qureg targetQureg, Qureg copyQureg) {
-    validate_quregFields(targetQureg, __func__);
-    validate_quregFields(copyQureg, __func__);
-    validate_quregsCanBeCloned(targetQureg, copyQureg, __func__);
+void setQuregToClone(Qureg outQureg, Qureg inQureg) {
+    validate_quregFields(outQureg, __func__);
+    validate_quregFields(inQureg, __func__);
+    validate_quregsCanBeCloned(outQureg, inQureg, __func__);
 
     // we invoke mixing/superposing, which involves superfluous
     // floating-point operators but is not expected to cause an
-    // appreciable slowdown since simulation is memory-bound
-    (targetQureg.isDensityMatrix)?
-        localiser_densmatr_mixQureg(0, targetQureg, 1, copyQureg):
-        localiser_statevec_setQuregToClone(targetQureg, copyQureg);
+    // appreciable slowdown since simulation is often memory-bound
+    (outQureg.isDensityMatrix)?
+        localiser_densmatr_mixQureg(0, outQureg, 1, inQureg):
+        localiser_statevec_setQuregToClone(outQureg, inQureg);
 }
 
 

quest/src/api/matrices.cpp

@@ -121,14 +121,14 @@ template <class T>
 bool didAnyLocalAllocsFail(T matr) {
 
     // god help us if these single-integer malloc failed
-    if (!mem_isAllocated(matr.isApproxUnitary))     return true;
-    if (!mem_isAllocated(matr.isApproxHermitian))   return true;
-    if (!mem_isAllocated(matr.wasGpuSynced))  return true;
+    if (!mem_isAllocated(matr.isApproxUnitary))   return true;
+    if (!mem_isAllocated(matr.isApproxHermitian)) return true;
+    if (!mem_isAllocated(matr.wasGpuSynced))      return true;
 
     // only diagonal matrices (which can be raised to
     // exponents) have these addtional fields
     if constexpr (!util_isDenseMatrixType<T>()) {
-        if (!mem_isAllocated(matr.isApproxNonZero))     return true;
+        if (!mem_isAllocated(matr.isApproxNonZero))       return true;
         if (!mem_isAllocated(matr.isStrictlyNonNegative)) return true;
     }
 
@@ -280,7 +280,7 @@ FullStateDiagMatr validateAndCreateCustomFullStateDiagMatr(int numQubits, int us
     // validate parameters before passing them to autodeployer
     validate_newFullStateDiagMatrParams(numQubits, useDistrib, useGpuAccel, useMultithread, caller);
 
-    // overwrite useDistrib and useGpuAccel if they were left as AUTO_FLAG
+    // overwrite all args left as AUTO_FLAG
     autodep_chooseFullStateDiagMatrDeployment(numQubits, useDistrib, useGpuAccel, useMultithread, env);
 
     // validation ensures this never overflows

quest/src/core/errors.cpp

@@ -161,11 +161,6 @@ void error_commButEnvNotDistributed() {
     raiseInternalError("A function attempted to invoke communication despite QuEST being compiled in non-distributed mode.");
 }
 
-void error_commButQuregNotDistributed() {
-
-    raiseInternalError("A function attempted to invoke communication of a Qureg which was not distributed.");
-}
-
 void error_commOutOfBounds() {
 
     raiseInternalError("A function invoked communication which attempted to exchange amplitudes between arrays at invalid bounds.");
@@ -209,7 +204,7 @@ void assert_commPayloadIsPowerOf2(qindex numAmps) {
 void assert_commQuregIsDistributed(Qureg qureg) {
 
     if (!qureg.isDistributed)
-        error_commButQuregNotDistributed();
+        raiseInternalError("A function attempted to invoke communication of a Qureg which was not distributed.");
 }
 
 void assert_commFullStateDiagMatrIsDistributed(FullStateDiagMatr matr) {

quest/src/core/errors.hpp

@@ -77,8 +77,6 @@ void error_commAlreadyInit();
 
 void error_commButEnvNotDistributed();
 
-void error_commButQuregNotDistributed();
-
 void error_commOutOfBounds();
 
 void error_commWithSameRank();

quest/src/core/localiser.cpp

@@ -1232,6 +1232,10 @@ void localiser_statevec_anyCtrlAnyTargAnyMatr(Qureg qureg, vector<int> ctrls, ve
     bool transp = false;
     qcomp expo = 1;
 
+    // suppress warnings since not used by all compile-time expansions below
+    (void) transp;
+    (void) expo;
+
     if constexpr (util_isDiagMatr <T>()) localiser_statevec_anyCtrlAnyTargDiagMatr(qureg,  ctrls, ctrlStates, targs,        matr, expo, conj);
     if constexpr (util_isDiagMatr1<T>()) localiser_statevec_anyCtrlOneTargDiagMatr(qureg,  ctrls, ctrlStates, targs[0],           matr, conj);
     if constexpr (util_isDiagMatr2<T>()) localiser_statevec_anyCtrlTwoTargDiagMatr(qureg,  ctrls, ctrlStates, targs[0], targs[1], matr, conj);

quest/src/core/printer.cpp

@@ -460,10 +460,9 @@ string printer_getMemoryWithUnitStr(size_t numBytes) {
         ind++;
     ind--;
 
-    // express numBytes in terms of new unit, forcefully rounding to 3 sig-figs max,
-    // except when the chosen unit is bytes (then we permit all 4 digits)
+    // express numBytes in terms of new unit, forcefully rounding to 4 sig-figs max
     qreal frac = numBytes / static_cast<qreal>(sizes[ind]);
-    return floatToStr(frac, false, (ind==0)? 4 : 3) + " " + units[ind];
+    return floatToStr(frac, false, 4) + " " + units[ind];
 }
 
 

quest/src/core/validation.cpp

@@ -3994,6 +3994,9 @@ void validate_quregCanBeWorkspace(Qureg qureg, Qureg workspace, const char* call
     assertThat(
         doQuregsHaveIdenticalMemoryLayouts(qureg, workspace),
         report::QUREG_IS_INCOMPATIBLE_WITH_WORKSPACE, caller);
+
+    // @todo
+    // check whether any of their memories overlap, which is forbidden
 }
 
 void validate_numQuregsInSum(int numQuregs, const char* caller) {

quest/src/gpu/gpu_cuquantum.cuh

@@ -260,7 +260,7 @@ void cuquantum_densmatr_oneQubitDephasing_subA(Qureg qureg, int qubit, qreal pro
     cu_qcomp a = {1,        0};
     cu_qcomp b = {1-2*prob, 0};
     cu_qcomp elems[] = {a, b, b, a};
-    vector<int> targs {qubit, qubit + qureg.numQubits};
+    vector<int> targs {qubit, util_getBraQubit(qubit,qureg)};
 
     bool conj = false;
     cuquantum_statevec_anyCtrlAnyTargDiagMatr_sub(qureg, {}, {}, targs, elems, conj);
@@ -297,7 +297,7 @@ void cuquantum_densmatr_twoQubitDephasing_subA(Qureg qureg, int qubitA, int qubi
     cu_qcomp a = {1,          0};
     cu_qcomp b = {1-4*prob/3, 0};
     cu_qcomp elems[] = {a,b,b,b, b,a,b,b, b,b,a,b, b,b,b,a};
-    vector<int> targs {qubitA, qubitB, qubitA + qureg.numQubits, qubitB + qureg.numQubits};
+    vector<int> targs {qubitA, qubitB, util_getBraQubit(qubitA,qureg), util_getBraQubit(qubitB,qureg)};
 
     bool conj = false;
     cuquantum_statevec_anyCtrlAnyTargDiagMatr_sub(qureg, {}, {}, targs, elems, conj);