BM_iter_as_arrayN() can now take an optional existing array argument, useful to avoid many small malloc's by passing a fixes size stack variable instead.

Will give some speedup to edge-split modifier and bevel.

15 files changed, 70 insertions, 48 deletions

diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index 068059dc29a..fd5af6a20bb 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -3011,7 +3011,7 @@ float BKE_mesh_calc_poly_area(MPoly *mpoly, MLoop *loopstart,
 		MLoop *l_iter = loopstart;
 		float area, polynorm_local[3], (*vertexcos)[3];
 		const float *no = polynormal ? polynormal : polynorm_local;
-		BLI_array_fixedstack_declare(vertexcos, BM_NGON_STACK_SIZE, mpoly->totloop, __func__);
+		BLI_array_fixedstack_declare(vertexcos, BM_DEFAULT_NGON_STACK_SIZE, mpoly->totloop, __func__);
 
 		/* pack vertex cos into an array for area_poly_v3 */
 		for (i = 0; i < mpoly->totloop; i++, l_iter++) {
diff --git a/source/blender/bmesh/bmesh_class.h b/source/blender/bmesh/bmesh_class.h
index cff7da78ef2..32ae7824739 100644
--- a/source/blender/bmesh/bmesh_class.h
+++ b/source/blender/bmesh/bmesh_class.h
@@ -243,10 +243,16 @@ enum {
 #  define BM_FACE_FIRST_LOOP(p) ((p)->l_first)
 #endif
 
-/* size to use for static arrays when dealing with NGons,
+/**
+ * size to use for stack arrays when dealing with NGons,
  * alloc after this limit is reached.
  * this value is rather arbitrary */
-#define BM_NGON_STACK_SIZE 32
+#define BM_DEFAULT_NGON_STACK_SIZE 32
+/**
+ * size to use for stack arrays dealing with connected mesh data
+ * verts of faces, edges of vert - etc.
+ * often used with #BM_iter_as_arrayN() */
+#define BM_DEFAULT_ITER_STACK_SIZE 16
 
 /* avoid inf loop, this value is arbitrary
  * but should not error on valid cases */
diff --git a/source/blender/bmesh/intern/bmesh_construct.c b/source/blender/bmesh/intern/bmesh_construct.c
index eae78c6cc25..81405079a56 100644
--- a/source/blender/bmesh/intern/bmesh_construct.c
+++ b/source/blender/bmesh/intern/bmesh_construct.c
@@ -174,9 +174,9 @@ void BM_face_copy_shared(BMesh *bm, BMFace *f)
 BMFace *BM_face_create_ngon(BMesh *bm, BMVert *v1, BMVert *v2, BMEdge **edges, int len, int nodouble)
 {
 	BMEdge **edges2 = NULL;
-	BLI_array_staticdeclare(edges2, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(edges2, BM_DEFAULT_NGON_STACK_SIZE);
 	BMVert **verts = NULL;
-	BLI_array_staticdeclare(verts, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(verts, BM_DEFAULT_NGON_STACK_SIZE);
 	BMFace *f = NULL;
 	BMEdge *e;
 	BMVert *v, *ev1, *ev2;
diff --git a/source/blender/bmesh/intern/bmesh_core.c b/source/blender/bmesh/intern/bmesh_core.c
index 0910dd82701..c0c550b0def 100644
--- a/source/blender/bmesh/intern/bmesh_core.c
+++ b/source/blender/bmesh/intern/bmesh_core.c
@@ -195,8 +195,8 @@ BMFace *BM_face_copy(BMesh *bm, BMFace *f, const short copyverts, const short co
 {
 	BMVert **verts = NULL;
 	BMEdge **edges = NULL;
-	BLI_array_fixedstack_declare(verts, BM_NGON_STACK_SIZE, f->len, __func__);
-	BLI_array_fixedstack_declare(edges, BM_NGON_STACK_SIZE, f->len, __func__);
+	BLI_array_fixedstack_declare(verts, BM_DEFAULT_NGON_STACK_SIZE, f->len, __func__);
+	BLI_array_fixedstack_declare(edges, BM_DEFAULT_NGON_STACK_SIZE, f->len, __func__);
 	BMLoop *l_iter;
 	BMLoop *l_first;
 	BMLoop *l_copy;
@@ -558,7 +558,7 @@ static void bm_kill_only_loop(BMesh *bm, BMLoop *l)
 void BM_face_edges_kill(BMesh *bm, BMFace *f)
 {
 	BMEdge **edges = NULL;
-	BLI_array_staticdeclare(edges, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(edges, BM_DEFAULT_NGON_STACK_SIZE);
 	BMLoop *l_iter;
 	BMLoop *l_first;
 	int i;
@@ -582,7 +582,7 @@ void BM_face_edges_kill(BMesh *bm, BMFace *f)
 void BM_face_verts_kill(BMesh *bm, BMFace *f)
 {
 	BMVert **verts = NULL;
-	BLI_array_staticdeclare(verts, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(verts, BM_DEFAULT_NGON_STACK_SIZE);
 	BMLoop *l_iter;
 	BMLoop *l_first;
 	int i;
@@ -734,7 +734,7 @@ static int bm_loop_reverse_loop(BMesh *bm, BMFace *f
 	const int do_disps = CustomData_has_layer(&bm->ldata, CD_MDISPS);
 	BMLoop *l_iter, *oldprev, *oldnext;
 	BMEdge **edar = NULL;
-	BLI_array_fixedstack_declare(edar, BM_NGON_STACK_SIZE, len, __func__);
+	BLI_array_fixedstack_declare(edar, BM_DEFAULT_NGON_STACK_SIZE, len, __func__);
 	int i, j, edok;
 
 	for (i = 0, l_iter = l_first; i < len; i++, l_iter = l_iter->next) {
@@ -937,9 +937,9 @@ BMFace *BM_faces_join(BMesh *bm, BMFace **faces, int totface, const short do_del
 	BMEdge **edges = NULL;
 	BMEdge **deledges = NULL;
 	BMVert **delverts = NULL;
-	BLI_array_staticdeclare(edges,    BM_NGON_STACK_SIZE);
-	BLI_array_staticdeclare(deledges, BM_NGON_STACK_SIZE);
-	BLI_array_staticdeclare(delverts, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(edges,    BM_DEFAULT_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(deledges, BM_DEFAULT_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(delverts, BM_DEFAULT_NGON_STACK_SIZE);
 	BMVert *v1 = NULL, *v2 = NULL;
 	const char *err = NULL;
 	int i, tote = 0;
@@ -1587,7 +1587,7 @@ BMEdge *bmesh_jekv(BMesh *bm, BMEdge *ke, BMVert *kv, const short check_edge_dou
 
 				if (LIKELY(radlen)) {
 					BMLoop **loops = NULL;
-					BLI_array_fixedstack_declare(loops, BM_NGON_STACK_SIZE, radlen, __func__);
+					BLI_array_fixedstack_declare(loops, BM_DEFAULT_NGON_STACK_SIZE, radlen, __func__);
 
 					killoop = ke->l;
 
@@ -1808,23 +1808,28 @@ BMFace *bmesh_jfke(BMesh *bm, BMFace *f1, BMFace *f2, BMEdge *e)
  */
 int BM_vert_splice(BMesh *bm, BMVert *v, BMVert *v_target)
 {
-	BMEdge *e;
-
+	void *loops_stack[BM_DEFAULT_ITER_STACK_SIZE];
 	BMLoop **loops;
 	int i, loops_tot;
 
+	BMEdge *e;
+
 	/* verts already spliced */
 	if (v == v_target) {
 		return FALSE;
 	}
 
 	/* we can't modify the vert while iterating so first allocate an array of loops */
-	loops = BM_iter_as_arrayN(bm, BM_LOOPS_OF_VERT, v, &loops_tot);
-	if (loops) {
+	loops = BM_iter_as_arrayN(bm, BM_LOOPS_OF_VERT, v, &loops_tot,
+	                          (void **)loops_stack, BM_DEFAULT_ITER_STACK_SIZE);
+
+	if (LIKELY(loops != NULL)) {
 		for (i = 0; i < loops_tot; i++) {
 			loops[i]->v = v_target;
 		}
-		MEM_freeN(loops);
+		if (loops != (BMLoop **)loops_stack) {
+			MEM_freeN(loops);
+		}
 	}
 
 	/* move all the edges from v's disk to vtarget's disk */
diff --git a/source/blender/bmesh/intern/bmesh_decimate_dissolve.c b/source/blender/bmesh/intern/bmesh_decimate_dissolve.c
index d1371a18160..fb78050988d 100644
--- a/source/blender/bmesh/intern/bmesh_decimate_dissolve.c
+++ b/source/blender/bmesh/intern/bmesh_decimate_dissolve.c
@@ -231,8 +231,8 @@ void BM_mesh_decimate_dissolve(BMesh *bm, const float angle_limit, const int do_
 	int vinput_len;
 	int einput_len;
 
-	BMVert **vinput_arr = BM_iter_as_arrayN(bm, BM_VERTS_OF_MESH, NULL, &vinput_len);
-	BMEdge **einput_arr = BM_iter_as_arrayN(bm, BM_EDGES_OF_MESH, NULL, &einput_len);
+	BMVert **vinput_arr = BM_iter_as_arrayN(bm, BM_VERTS_OF_MESH, NULL, &vinput_len, NULL, 0);
+	BMEdge **einput_arr = BM_iter_as_arrayN(bm, BM_EDGES_OF_MESH, NULL, &einput_len, NULL, 0);
 
 	BM_mesh_decimate_dissolve_ex(bm, angle_limit, do_dissolve_boundaries,
 	                             vinput_arr, vinput_len,
diff --git a/source/blender/bmesh/intern/bmesh_interp.c b/source/blender/bmesh/intern/bmesh_interp.c
index 508b3b8fcdf..caf9f3c70d5 100644
--- a/source/blender/bmesh/intern/bmesh_interp.c
+++ b/source/blender/bmesh/intern/bmesh_interp.c
@@ -174,9 +174,9 @@ void BM_face_interp_from_face(BMesh *bm, BMFace *target, BMFace *source)
 
 	void **blocks = NULL;
 	float (*cos)[3] = NULL, *w = NULL;
-	BLI_array_fixedstack_declare(cos,     BM_NGON_STACK_SIZE, source->len, __func__);
-	BLI_array_fixedstack_declare(w,       BM_NGON_STACK_SIZE, source->len, __func__);
-	BLI_array_fixedstack_declare(blocks,  BM_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(cos,     BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(w,       BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(blocks,  BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
 	int i;
 	
 	BM_elem_attrs_copy(bm, bm, source, target);
@@ -613,10 +613,10 @@ void BM_loop_interp_from_face(BMesh *bm, BMLoop *target, BMFace *source,
 	void **vblocks = NULL;
 	float (*cos)[3] = NULL, co[3], *w = NULL;
 	float cent[3] = {0.0f, 0.0f, 0.0f};
-	BLI_array_fixedstack_declare(cos,      BM_NGON_STACK_SIZE, source->len, __func__);
-	BLI_array_fixedstack_declare(w,        BM_NGON_STACK_SIZE, source->len, __func__);
-	BLI_array_fixedstack_declare(blocks,   BM_NGON_STACK_SIZE, source->len, __func__);
-	BLI_array_fixedstack_declare(vblocks,  BM_NGON_STACK_SIZE, do_vertex ? source->len : 0, __func__);
+	BLI_array_fixedstack_declare(cos,      BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(w,        BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(blocks,   BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(vblocks,  BM_DEFAULT_NGON_STACK_SIZE, do_vertex ? source->len : 0, __func__);
 	int i, ax, ay;
 
 	BM_elem_attrs_copy(bm, bm, source, target->f);
@@ -689,9 +689,9 @@ void BM_vert_interp_from_face(BMesh *bm, BMVert *v, BMFace *source)
 	void **blocks = NULL;
 	float (*cos)[3] = NULL, *w = NULL;
 	float cent[3] = {0.0f, 0.0f, 0.0f};
-	BLI_array_fixedstack_declare(cos,      BM_NGON_STACK_SIZE, source->len, __func__);
-	BLI_array_fixedstack_declare(w,        BM_NGON_STACK_SIZE, source->len, __func__);
-	BLI_array_fixedstack_declare(blocks,   BM_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(cos,      BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(w,        BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
+	BLI_array_fixedstack_declare(blocks,   BM_DEFAULT_NGON_STACK_SIZE, source->len, __func__);
 	int i;
 
 	i = 0;
diff --git a/source/blender/bmesh/intern/bmesh_iterators.c b/source/blender/bmesh/intern/bmesh_iterators.c
index 1cb95d94e9b..51a3776c21d 100644
--- a/source/blender/bmesh/intern/bmesh_iterators.c
+++ b/source/blender/bmesh/intern/bmesh_iterators.c
@@ -116,10 +116,14 @@ int BM_iter_as_array(BMesh *bm, const char itype, void *data, void **array, cons
  *
  * Caller needs to free the array.
  */
-void *BM_iter_as_arrayN(BMesh *bm, const char itype, void *data, int *r_len)
+void *BM_iter_as_arrayN(BMesh *bm, const char itype, void *data, int *r_len,
+                        /* optional static vars to avoid an alloc */
+                        void **stack_array, int stack_array_size)
 {
 	BMIter iter;
 
+	BLI_assert(stack_array_size == 0 || (stack_array_size && stack_array));
+
 	/* we can't rely on coun't being set */
 	switch (itype) {
 		case BM_VERTS_OF_MESH:
@@ -137,7 +141,9 @@ void *BM_iter_as_arrayN(BMesh *bm, const char itype, void *data, int *r_len)
 
 	if (BM_iter_init(&iter, bm, itype, data) && iter.count > 0) {
 		BMElem *ele;
-		BMElem **array = MEM_mallocN(sizeof(ele) * iter.count, __func__);
+		BMElem **array = iter.count > stack_array_size ?
+		                 MEM_mallocN(sizeof(ele) * iter.count, __func__) :
+		                 stack_array;
 		int i = 0;
 
 		*r_len = iter.count;  /* set before iterating */
diff --git a/source/blender/bmesh/intern/bmesh_iterators.h b/source/blender/bmesh/intern/bmesh_iterators.h
index 3c42b3d610c..c0eefc2a3aa 100644
--- a/source/blender/bmesh/intern/bmesh_iterators.h
+++ b/source/blender/bmesh/intern/bmesh_iterators.h
@@ -125,7 +125,8 @@ __attribute__((warn_unused_result))
 #endif
 ;
 int     BM_iter_as_array(BMesh *bm, const char itype, void *data, void **array, const int len);
-void   *BM_iter_as_arrayN(BMesh *bm, const char itype, void *data, int *r_len)
+void   *BM_iter_as_arrayN(BMesh *bm, const char itype, void *data, int *r_len,
+                          void **stack_array, int stack_array_size)
 #ifdef __GNUC__
 __attribute__((warn_unused_result))
 #endif
diff --git a/source/blender/bmesh/intern/bmesh_polygon.c b/source/blender/bmesh/intern/bmesh_polygon.c
index 98edceb30a2..35213c83097 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.c
+++ b/source/blender/bmesh/intern/bmesh_polygon.c
@@ -162,7 +162,7 @@ float BM_face_calc_area(BMFace *f)
 	float area;
 	int i;
 
-	BLI_array_fixedstack_declare(verts, BM_NGON_STACK_SIZE, f->len, __func__);
+	BLI_array_fixedstack_declare(verts, BM_DEFAULT_NGON_STACK_SIZE, f->len, __func__);
 
 	BM_ITER_ELEM_INDEX (l, &iter, f, BM_LOOPS_OF_FACE, i) {
 		copy_v3_v3(verts[i], l->v->co);
@@ -965,8 +965,8 @@ void BM_face_legal_splits(BMesh *bm, BMFace *f, BMLoop *(*loops)[2], int len)
 	float fac1 = 1.0000001f, fac2 = 0.9f; //9999f; //0.999f;
 	int i, j, a = 0, clen;
 
-	BLI_array_fixedstack_declare(projverts, BM_NGON_STACK_SIZE, f->len,      "projvertsb");
-	BLI_array_fixedstack_declare(edgeverts, BM_NGON_STACK_SIZE * 2, len * 2, "edgevertsb");
+	BLI_array_fixedstack_declare(projverts, BM_DEFAULT_NGON_STACK_SIZE, f->len,      "projvertsb");
+	BLI_array_fixedstack_declare(edgeverts, BM_DEFAULT_NGON_STACK_SIZE * 2, len * 2, "edgevertsb");
 	
 	i = 0;
 	l = BM_iter_new(&iter, bm, BM_LOOPS_OF_FACE, f);
diff --git a/source/blender/bmesh/intern/bmesh_queries.c b/source/blender/bmesh/intern/bmesh_queries.c
index 205108395e6..cae9b5b3b83 100644
--- a/source/blender/bmesh/intern/bmesh_queries.c
+++ b/source/blender/bmesh/intern/bmesh_queries.c
@@ -1393,7 +1393,7 @@ int BM_face_exists_multi(BMVert **varr, BMEdge **earr, int len)
 int BM_face_exists_multi_edge(BMEdge **earr, int len)
 {
 	BMVert **varr;
-	BLI_array_fixedstack_declare(varr, BM_NGON_STACK_SIZE, len, __func__);
+	BLI_array_fixedstack_declare(varr, BM_DEFAULT_NGON_STACK_SIZE, len, __func__);
 
 	int ok;
 	int i, i_next;
diff --git a/source/blender/bmesh/operators/bmo_bevel.c b/source/blender/bmesh/operators/bmo_bevel.c
index 7fededd0635..e18920fc98e 100644
--- a/source/blender/bmesh/operators/bmo_bevel.c
+++ b/source/blender/bmesh/operators/bmo_bevel.c
@@ -1265,8 +1265,10 @@ static void rebuild_polygon(BMesh *bm, BevelParams *bp, BMFace *f)
 /* All polygons touching v need rebuilding because beveling v has made new vertices */
 static void bevel_rebuild_existing_polygons(BMesh *bm, BevelParams *bp, BMVert *v)
 {
+	void    *faces_stack[BM_DEFAULT_ITER_STACK_SIZE];
 	int      faces_len, f_index;
-	BMFace **faces = BM_iter_as_arrayN(bm, BM_FACES_OF_VERT, v, &faces_len);
+	BMFace **faces = BM_iter_as_arrayN(bm, BM_FACES_OF_VERT, v, &faces_len,
+	                                   faces_stack, BM_DEFAULT_ITER_STACK_SIZE);
 
 	if (LIKELY(faces != NULL)) {
 		for (f_index = 0; f_index < faces_len; f_index++) {
@@ -1275,7 +1277,9 @@ static void bevel_rebuild_existing_polygons(BMesh *bm, BevelParams *bp, BMVert *
 			BM_face_kill(bm, f);
 		}
 
-		MEM_freeN(faces);
+		if (faces != (BMFace **)faces_stack) {
+			MEM_freeN(faces);
+		}
 	}
 }
 
diff --git a/source/blender/bmesh/operators/bmo_create.c b/source/blender/bmesh/operators/bmo_create.c
index 093f567d995..49a2f959063 100644
--- a/source/blender/bmesh/operators/bmo_create.c
+++ b/source/blender/bmesh/operators/bmo_create.c
@@ -168,7 +168,7 @@ static void rotsys_reverse(BMEdge *UNUSED(e), BMVert *v, EdgeData *edata, VertDa
 	BMEdge **edges = NULL;
 	BMEdge *e_first;
 	BMEdge *e;
-	BLI_array_staticdeclare(edges, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(edges, BM_DEFAULT_NGON_STACK_SIZE);
 	int i, totedge;
 	
 	e = e_first = vdata[BM_elem_index_get(v)].e;
@@ -359,10 +359,10 @@ static void init_rotsys(BMesh *bm, EdgeData *edata, VertData *vdata)
 	BMIter iter;
 	BMEdge *e;
 	BMEdge **edges = NULL;
-	BLI_array_staticdeclare(edges, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(edges, BM_DEFAULT_NGON_STACK_SIZE);
 	BMVert *v;
 	/* BMVert **verts = NULL; */
-	/* BLI_array_staticdeclare(verts, BM_NGON_STACK_SIZE); */ /* UNUSE */
+	/* BLI_array_staticdeclare(verts, BM_DEFAULT_NGON_STACK_SIZE); */ /* UNUSE */
 	int i;
 	
 	BM_ITER_MESH (v, &iter, bm, BM_VERTS_OF_MESH) {
diff --git a/source/blender/bmesh/operators/bmo_extrude.c b/source/blender/bmesh/operators/bmo_extrude.c
index 627351ead11..71048e18335 100644
--- a/source/blender/bmesh/operators/bmo_extrude.c
+++ b/source/blender/bmesh/operators/bmo_extrude.c
@@ -595,10 +595,10 @@ static void solidify_add_thickness(BMesh *bm, const float dist)
 
 	/* array for passing verts to angle_poly_v3 */
 	float **verts = NULL;
-	BLI_array_staticdeclare(verts, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(verts, BM_DEFAULT_NGON_STACK_SIZE);
 	/* array for receiving angles from angle_poly_v3 */
 	float *face_angles = NULL;
-	BLI_array_staticdeclare(face_angles, BM_NGON_STACK_SIZE);
+	BLI_array_staticdeclare(face_angles, BM_DEFAULT_NGON_STACK_SIZE);
 
 	BM_mesh_elem_index_ensure(bm, BM_VERT);
 
diff --git a/source/blender/editors/mesh/editmesh_knife.c b/source/blender/editors/mesh/editmesh_knife.c
index 82447cc0168..5ba85115b2f 100644
--- a/source/blender/editors/mesh/editmesh_knife.c
+++ b/source/blender/editors/mesh/editmesh_knife.c
@@ -2573,8 +2573,8 @@ static void knife_make_chain_cut(KnifeTool_OpData *kcd, BMFace *f, ListBase *cha
 	int nco = BLI_countlist(chain) - 1;
 	float (*cos)[3] = NULL;
 	KnifeVert **kverts;
-	BLI_array_fixedstack_declare(cos, BM_NGON_STACK_SIZE, nco, __func__);
-	BLI_array_fixedstack_declare(kverts, BM_NGON_STACK_SIZE, nco, __func__);
+	BLI_array_fixedstack_declare(cos, BM_DEFAULT_NGON_STACK_SIZE, nco, __func__);
+	BLI_array_fixedstack_declare(kverts, BM_DEFAULT_NGON_STACK_SIZE, nco, __func__);
 
 	kfe = ((Ref *)chain->first)->ref;
 	v1 = kfe->v1->v ? kfe->v1->v : kfe->v2->v;
diff --git a/source/blender/editors/uvedit/uvedit_unwrap_ops.c b/source/blender/editors/uvedit/uvedit_unwrap_ops.c
index f615902eedf..fc60c5a3a0f 100644
--- a/source/blender/editors/uvedit/uvedit_unwrap_ops.c
+++ b/source/blender/editors/uvedit/uvedit_unwrap_ops.c
@@ -1414,7 +1414,7 @@ static void uv_map_mirror(BMEditMesh *em, BMFace *efa, MTexPoly *UNUSED(tf))
 	BMIter liter;
 	MLoopUV *luv;
 	float **uvs = NULL;
-	BLI_array_fixedstack_declare(uvs, BM_NGON_STACK_SIZE, efa->len, __func__);
+	BLI_array_fixedstack_declare(uvs, BM_DEFAULT_NGON_STACK_SIZE, efa->len, __func__);
 	float dx;
 	int i, mi;