Add internal utility for zeroing int vectors.

PiperOrigin-RevId: 562608956
Change-Id: I25ff1bbf9abf8fe2a636ed1d728d10ae862e04c9

src/engine/engine_core_smooth.c

@@ -417,7 +417,7 @@ void mj_tendon(const mjModel* m, mjData* d) {
 
   // clear Jacobian: sparse or dense
   if (issparse) {
-    memset(rownnz, 0, nten*sizeof(int));
+    mju_zeroInt(rownnz, nten);
   } else {
     mju_zero(J, nten*nv);
   }

src/engine/engine_derivative_fd.c

@@ -27,6 +27,7 @@
 #include "engine/engine_support.h"
 #include "engine/engine_util_blas.h"
 #include "engine/engine_util_errmem.h"
+#include "engine/engine_util_misc.h"
 
 
 
@@ -202,7 +203,7 @@ void mjd_passive_velFD(const mjModel* m, mjData* d, mjtNum eps) {
   int* cnt = mj_stackAllocInt(d, nv);
 
   // clear row counters
-  memset(cnt, 0, nv*sizeof(int));
+  mju_zeroInt(cnt, nv);
 
   // save qfrc_passive, assume mj_fwdVelocity was called
   mju_copy(qfrc_passive, d->qfrc_passive, nv);
@@ -254,7 +255,7 @@ void mjd_smooth_velFD(const mjModel* m, mjData* d, mjtNum eps) {
   int* cnt = mj_stackAllocInt(d, nv);
 
   // clear row counters
-  memset(cnt, 0, nv*sizeof(int));
+  mju_zeroInt(cnt, nv);
 
   // loop over dofs
   for (int i=0; i < nv; i++) {

src/engine/engine_io.c

@@ -836,7 +836,7 @@ static void makeDSparse(const mjModel* m, mjData* d) {
   int* remaining = mj_stackAllocInt(d, nv);
 
   // compute rownnz
-  memset(rownnz, 0, nv * sizeof(int));
+  mju_zeroInt(rownnz, nv);
   for (int i = nv - 1; i >= 0; i--) {
     // init at diagonal
     int j = i;
@@ -893,7 +893,7 @@ static void makeBSparse(const mjModel* m, mjData* d) {
   int* colind = d->B_colind;
 
   // set rownnz to subtree dofs counts, including self
-  memset(rownnz, 0, sizeof(int) * nbody);
+  mju_zeroInt(rownnz, nbody);
   for (int i = nbody - 1; i > 0; i--) {
     rownnz[i] += m->body_dofnum[i];
     rownnz[m->body_parentid[i]] += rownnz[i];
@@ -927,7 +927,7 @@ static void makeBSparse(const mjModel* m, mjData* d) {
   // allocate and clear incremental row counts
   mjMARKSTACK;
   int* cnt = mj_stackAllocInt(d, nbody);
-  memset(cnt, 0, sizeof(int) * nbody);
+  mju_zeroInt(cnt, nbody);
 
   // add subtree dofs to colind
   for (int i = nbody - 1; i > 0; i--) {

src/engine/engine_island.c

@@ -27,6 +27,7 @@
 #include "engine/engine_io.h"
 #include "engine/engine_support.h"
 #include "engine/engine_util_errmem.h"
+#include "engine/engine_util_misc.h"
 
 #ifdef MEMORY_SANITIZER
   #include <sanitizer/msan_interface.h>
@@ -355,7 +356,7 @@ static int findEdges(const mjModel* m, const mjData* d, int* treenedge, int* edg
   int efc_id = -1;
 
   // clear treenedge
-  memset(treenedge, 0, m->ntree*sizeof(int));
+  mju_zeroInt(treenedge, m->ntree);
 
   int nedge = 0;
   for (int i=0; i < nefc; i++) {
@@ -456,7 +457,7 @@ void mj_island(const mjModel* m, mjData* d) {
 
   // compute dof_island, island_dofnum
   int num_dof_unc = 0;  // number of unconstrained dofs
-  memset(d->island_dofnum, 0, nisland*sizeof(int));
+  mju_zeroInt(d->island_dofnum, nisland);
   for (int i=0; i < nv; i++) {
     // dof_island
     int island = tree_island[m->dof_treeid[i]];
@@ -477,7 +478,7 @@ void mj_island(const mjModel* m, mjData* d) {
   }
 
   // reset island_dofnum
-  memset(d->island_dofnum, 0, nisland*sizeof(int));
+  mju_zeroInt(d->island_dofnum, nisland);
 
   // compute dof_islandind, island_dofind
   int num_dof_island = 0;
@@ -503,7 +504,7 @@ void mj_island(const mjModel* m, mjData* d) {
   }
 
   // compute efc_island, island_efcnum
-  memset(d->island_efcnum, 0, nisland*sizeof(int));
+  mju_zeroInt(d->island_efcnum, nisland);
   for (int i=0; i < nefc; i++) {
     int tree[2];
     treeFirst(m, d, tree, i);
@@ -519,7 +520,7 @@ void mj_island(const mjModel* m, mjData* d) {
   }
 
   // reset island_efcnum
-  memset(d->island_efcnum, 0, nisland*sizeof(int));
+  mju_zeroInt(d->island_efcnum, nisland);
 
   // compute efc_islandind
   for (int i=0; i < nefc; i++) {

src/engine/engine_util_misc.c

@@ -1207,6 +1207,15 @@ int mju_isZero(mjtNum* vec, int n) {
 
 
 
+// set integer vector to 0
+void mju_zeroInt(int* res, int n) {
+  if (n > 0) {
+    memset(res, 0, n*sizeof(int));
+  }
+}
+
+
+
 // standard normal random number generator (optional second number)
 mjtNum mju_standardNormal(mjtNum* num2) {
   const mjtNum scale = 2.0/((mjtNum)RAND_MAX);

src/engine/engine_util_misc.h

@@ -119,6 +119,9 @@ MJAPI int mju_isBad(mjtNum x);
 // return 1 if all elements are 0
 MJAPI int mju_isZero(mjtNum* vec, int n);
 
+// set integer vector to 0
+MJAPI void mju_zeroInt(int* res, int n);
+
 // standard normal random number generator (optional second number)
 MJAPI mjtNum mju_standardNormal(mjtNum* num2);
 

src/engine/engine_util_sparse.c

@@ -22,6 +22,7 @@
 #include <mujoco/mjtnum.h>
 #include "engine/engine_io.h"
 #include "engine/engine_util_blas.h"
+#include "engine/engine_util_misc.h"
 
 
 //------------------------------ sparse operations -------------------------------------------------
@@ -393,7 +394,7 @@ void mju_transposeSparse(mjtNum* res, const mjtNum* mat, int nr, int nc,
                          int* res_rownnz, int* res_rowadr, int* res_colind,
                          const int* rownnz, const int* rowadr, const int* colind) {
   // clear number of non-zeros for each row of transposed
-  memset(res_rownnz, 0, nc*sizeof(int));
+  mju_zeroInt(res_rownnz, nc);
 
   // total number of non-zeros of mat
   int nnz = rowadr[nr-1] + rownnz[nr-1];