Merge branch 'egil/erts/sub-binary-to-heap-binary/OTP-14149'

* egil/erts/sub-binary-to-heap-binary/OTP-14149:
  observer: Fix crashdump viewer testcase
  erts: Refactor MOVE_CONS to inline function
  erts: Refactor MOVE_BOXED to inline function
  erts: Convert small sub-binaries to heap-binaries

7 files changed, 147 insertions, 86 deletions

diff --git a/erts/emulator/beam/copy.c b/erts/emulator/beam/copy.c
index 85db23393c..e567eabc82 100644
--- a/erts/emulator/beam/copy.c
+++ b/erts/emulator/beam/copy.c
@@ -1990,7 +1990,7 @@ move_one_frag(Eterm** hpp, ErlHeapFragment* frag, ErlOffHeap* off_heap, int lite
 	if (is_header(val)) {
 	    struct erl_off_heap_header* hdr = (struct erl_off_heap_header*)hp;
 	    ASSERT(ptr + header_arity(val) < end);
-	    MOVE_BOXED(ptr, val, hp, &dummy_ref);
+	    move_boxed(&ptr, val, &hp, &dummy_ref);
 	    switch (val & _HEADER_SUBTAG_MASK) {
 	    case REF_SUBTAG:
 		if (is_ordinary_ref_thing(hdr))
@@ -2007,7 +2007,7 @@ move_one_frag(Eterm** hpp, ErlHeapFragment* frag, ErlOffHeap* off_heap, int lite
 	}
 	else { /* must be a cons cell */
 	    ASSERT(ptr+1 < end);
-	    MOVE_CONS(ptr, val, hp, &dummy_ref);
+	    move_cons(&ptr, val, &hp, &dummy_ref);
 	    ptr += 2;
 	}
     }
diff --git a/erts/emulator/beam/erl_binary.h b/erts/emulator/beam/erl_binary.h
index 946d3cfe03..6ff71ec6d1 100644
--- a/erts/emulator/beam/erl_binary.h
+++ b/erts/emulator/beam/erl_binary.h
@@ -156,6 +156,7 @@ typedef union {
 #include "erl_threads.h"
 #include "bif.h"
 #include "erl_bif_unique.h"
+#include "erl_bits.h"
 
 /*
  * Maximum number of bytes to place in a heap binary.
@@ -163,23 +164,6 @@ typedef union {
 
 #define ERL_ONHEAP_BIN_LIMIT 64
 
-/*
- * This structure represents a SUB_BINARY.
- *
- * Note: The last field (orig) is not counted in arityval in the header.
- * This simplifies garbage collection.
- */
-
-typedef struct erl_sub_bin {
-    Eterm thing_word;		/* Subtag SUB_BINARY_SUBTAG. */
-    Uint size;			/* Binary size in bytes. */
-    Uint offs;			/* Offset into original binary. */
-    byte bitsize; 
-    byte bitoffs; 
-    byte is_writable;		/* The underlying binary is writable */
-    Eterm orig;			/* Original binary (REFC or HEAP binary). */
-} ErlSubBin;
-
 #define ERL_SUB_BIN_SIZE (sizeof(ErlSubBin)/sizeof(Eterm))
 #define HEADER_SUB_BIN	_make_header(ERL_SUB_BIN_SIZE-2,_TAG_HEADER_SUB_BIN)
 
diff --git a/erts/emulator/beam/erl_bits.h b/erts/emulator/beam/erl_bits.h
index 4bd5b24157..1b4546722f 100644
--- a/erts/emulator/beam/erl_bits.h
+++ b/erts/emulator/beam/erl_bits.h
@@ -22,6 +22,23 @@
 #define __ERL_BITS_H__
 
 /*
+ * This structure represents a SUB_BINARY.
+ *
+ * Note: The last field (orig) is not counted in arityval in the header.
+ * This simplifies garbage collection.
+ */
+
+typedef struct erl_sub_bin {
+    Eterm thing_word;		/* Subtag SUB_BINARY_SUBTAG. */
+    Uint size;			/* Binary size in bytes. */
+    Uint offs;			/* Offset into original binary. */
+    byte bitsize;
+    byte bitoffs;
+    byte is_writable;		/* The underlying binary is writable */
+    Eterm orig;			/* Original binary (REFC or HEAP binary). */
+} ErlSubBin;
+
+/*
  * This structure represents a binary to be matched.
  */
 
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index 8cc7fc0142..50805d9cd9 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -1173,7 +1173,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
 		    ASSERT(is_boxed(val));
                     *g_ptr++ = val;
 		} else if (ErtsInArea(ptr, area, area_size)) {
-                    MOVE_BOXED(ptr,val,old_htop,g_ptr++);
+                    move_boxed(&ptr,val,&old_htop,g_ptr++);
 		} else {
 		    g_ptr++;
 		}
@@ -1184,7 +1184,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
                 if (IS_MOVED_CONS(val)) { /* Moved */
                     *g_ptr++ = ptr[1];
 		} else if (ErtsInArea(ptr, area, area_size)) {
-                    MOVE_CONS(ptr,val,old_htop,g_ptr++);
+                    move_cons(&ptr,val,&old_htop,g_ptr++);
                 } else {
 		    g_ptr++;
 		}
@@ -1479,9 +1479,9 @@ do_minor(Process *p, ErlHeapFragment *live_hf_end,
 		    ASSERT(is_boxed(val));
                     *g_ptr++ = val;
                 } else if (ErtsInArea(ptr, mature, mature_size)) {
-                    MOVE_BOXED(ptr,val,old_htop,g_ptr++);
+                    move_boxed(&ptr,val,&old_htop,g_ptr++);
                 } else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) {
-                    MOVE_BOXED(ptr,val,n_htop,g_ptr++);
+                    move_boxed(&ptr,val,&n_htop,g_ptr++);
                 } else {
 		    g_ptr++;
 		}
@@ -1494,9 +1494,9 @@ do_minor(Process *p, ErlHeapFragment *live_hf_end,
                 if (IS_MOVED_CONS(val)) { /* Moved */
                     *g_ptr++ = ptr[1];
                 } else if (ErtsInArea(ptr, mature, mature_size)) {
-                    MOVE_CONS(ptr,val,old_htop,g_ptr++);
+                    move_cons(&ptr,val,&old_htop,g_ptr++);
                 } else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) {
-                    MOVE_CONS(ptr,val,n_htop,g_ptr++);
+                    move_cons(&ptr,val,&n_htop,g_ptr++);
                 } else {
 		    g_ptr++;
 		}
@@ -1538,9 +1538,9 @@ do_minor(Process *p, ErlHeapFragment *live_hf_end,
 		    ASSERT(is_boxed(val));
 		    *n_hp++ = val;
 		} else if (ErtsInArea(ptr, mature, mature_size)) {
-		    MOVE_BOXED(ptr,val,old_htop,n_hp++);
+		    move_boxed(&ptr,val,&old_htop,n_hp++);
 		} else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) {
-		    MOVE_BOXED(ptr,val,n_htop,n_hp++);
+		    move_boxed(&ptr,val,&n_htop,n_hp++);
 		} else {
 		    n_hp++;
 		}
@@ -1552,9 +1552,9 @@ do_minor(Process *p, ErlHeapFragment *live_hf_end,
 		if (IS_MOVED_CONS(val)) {
 		    *n_hp++ = ptr[1];
 		} else if (ErtsInArea(ptr, mature, mature_size)) {
-		    MOVE_CONS(ptr,val,old_htop,n_hp++);
+		    move_cons(&ptr,val,&old_htop,n_hp++);
 		} else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) {
-		    MOVE_CONS(ptr,val,n_htop,n_hp++);
+		    move_cons(&ptr,val,&n_htop,n_hp++);
 		} else {
 		    n_hp++;
 		}
@@ -1574,10 +1574,10 @@ do_minor(Process *p, ErlHeapFragment *live_hf_end,
 			    *origptr = val;
 			    mb->base = binary_bytes(val);
 			} else if (ErtsInArea(ptr, mature, mature_size)) {
-			    MOVE_BOXED(ptr,val,old_htop,origptr);
+			    move_boxed(&ptr,val,&old_htop,origptr);
 			    mb->base = binary_bytes(mb->orig);
 			} else if (ErtsInYoungGen(*origptr, ptr, oh, oh_size)) {
-			    MOVE_BOXED(ptr,val,n_htop,origptr);
+			    move_boxed(&ptr,val,&n_htop,origptr);
 			    mb->base = binary_bytes(mb->orig);
 			}
 		    }
@@ -1792,7 +1792,7 @@ full_sweep_heaps(Process *p,
 	    Eterm* ptr;
 	    Eterm val;
 	    Eterm gval = *g_ptr;
-	    
+
 	    switch (primary_tag(gval)) {
 
 	    case TAG_PRIMARY_BOXED: {
@@ -1802,7 +1802,7 @@ full_sweep_heaps(Process *p,
 		    ASSERT(is_boxed(val));
 		    *g_ptr++ = val;
 		} else if (!erts_is_literal(gval, ptr)) {
-		    MOVE_BOXED(ptr,val,n_htop,g_ptr++);
+		    move_boxed(&ptr,val,&n_htop,g_ptr++);
 		} else {
 		    g_ptr++;
 		}
@@ -1815,7 +1815,7 @@ full_sweep_heaps(Process *p,
 		if (IS_MOVED_CONS(val)) {
 		    *g_ptr++ = ptr[1];
 		} else if (!erts_is_literal(gval, ptr)) {
-		    MOVE_CONS(ptr,val,n_htop,g_ptr++);
+		    move_cons(&ptr,val,&n_htop,g_ptr++);
 		} else {
 		    g_ptr++;
 		}
@@ -2104,7 +2104,7 @@ sweep(Eterm *n_hp, Eterm *n_htop,
 		ASSERT(is_boxed(val));
 		*n_hp++ = val;
 	    } else if (ERTS_IS_IN_SWEEP_AREA(gval, ptr)) {
-		MOVE_BOXED(ptr,val,n_htop,n_hp++);
+		move_boxed(&ptr,val,&n_htop,n_hp++);
 	    } else {
 		n_hp++;
 	    }
@@ -2116,7 +2116,7 @@ sweep(Eterm *n_hp, Eterm *n_htop,
 	    if (IS_MOVED_CONS(val)) {
 		*n_hp++ = ptr[1];
 	    } else if (ERTS_IS_IN_SWEEP_AREA(gval, ptr)) {
-		MOVE_CONS(ptr,val,n_htop,n_hp++);
+		move_cons(&ptr,val,&n_htop,n_hp++);
 	    } else {
 		n_hp++;
 	    }
@@ -2129,7 +2129,7 @@ sweep(Eterm *n_hp, Eterm *n_htop,
 		if (header_is_bin_matchstate(gval)) {
 		    ErlBinMatchState *ms = (ErlBinMatchState*) n_hp;
 		    ErlBinMatchBuffer *mb = &(ms->mb);
-		    Eterm* origptr;	
+		    Eterm* origptr;
 		    origptr = &(mb->orig);
 		    ptr = boxed_val(*origptr);
 		    val = *ptr;
@@ -2137,7 +2137,7 @@ sweep(Eterm *n_hp, Eterm *n_htop,
 			*origptr = val;
 			mb->base = binary_bytes(*origptr);
 		    } else if (ERTS_IS_IN_SWEEP_AREA(*origptr, ptr)) {
-			MOVE_BOXED(ptr,val,n_htop,origptr); 
+			move_boxed(&ptr,val,&n_htop,origptr);
 			mb->base = binary_bytes(*origptr);
 		    }
 		}
@@ -2200,7 +2200,7 @@ sweep_literals_to_old_heap(Eterm* heap_ptr, Eterm* heap_end, Eterm* htop,
 		ASSERT(is_boxed(val));
 		*heap_ptr++ = val;
 	    } else if (ErtsInArea(ptr, src, src_size)) {
-		MOVE_BOXED(ptr,val,htop,heap_ptr++);
+		move_boxed(&ptr,val,&htop,heap_ptr++);
 	    } else {
 		heap_ptr++;
 	    }
@@ -2212,7 +2212,7 @@ sweep_literals_to_old_heap(Eterm* heap_ptr, Eterm* heap_end, Eterm* htop,
 	    if (IS_MOVED_CONS(val)) {
 		*heap_ptr++ = ptr[1];
 	    } else if (ErtsInArea(ptr, src, src_size)) {
-		MOVE_CONS(ptr,val,htop,heap_ptr++);
+		move_cons(&ptr,val,&htop,heap_ptr++);
 	    } else {
 		heap_ptr++;
 	    }
@@ -2233,7 +2233,7 @@ sweep_literals_to_old_heap(Eterm* heap_ptr, Eterm* heap_end, Eterm* htop,
 			*origptr = val;
 			mb->base = binary_bytes(*origptr);
 		    } else if (ErtsInArea(ptr, src, src_size)) {
-			MOVE_BOXED(ptr,val,htop,origptr);
+			move_boxed(&ptr,val,&htop,origptr);
 			mb->base = binary_bytes(*origptr);
 		    }
 		}
@@ -2266,11 +2266,11 @@ move_one_area(Eterm* n_htop, char* src, Uint src_size)
 	ASSERT(val != ERTS_HOLE_MARKER);
 	if (is_header(val)) {
 	    ASSERT(ptr + header_arity(val) < end);
-	    MOVE_BOXED(ptr, val, n_htop, &dummy_ref);	    
+	    move_boxed(&ptr, val, &n_htop, &dummy_ref);
 	}
 	else { /* must be a cons cell */
 	    ASSERT(ptr+1 < end);
-	    MOVE_CONS(ptr, val, n_htop, &dummy_ref);
+	    move_cons(&ptr, val, &n_htop, &dummy_ref);
 	    ptr += 2;
 	}
     }
@@ -3256,6 +3256,39 @@ reply_gc_info(void *vgcirp)
 	gcireq_free(vgcirp);
 }
 
+void erts_sub_binary_to_heap_binary(Eterm **pp, Eterm **hpp, Eterm *orig) {
+    Eterm *ptr = *pp;
+    Eterm *htop = *hpp;
+    Eterm gval;
+    ErlSubBin *sb = (ErlSubBin *)ptr;
+    ErlHeapBin *hb = (ErlHeapBin *)htop;
+    Eterm *real_bin;
+    byte *bs;
+
+    real_bin = binary_val(follow_moved(sb->orig, (Eterm)0));
+
+    if (*real_bin == HEADER_PROC_BIN) {
+        bs = ((ProcBin *) real_bin)->bytes + sb->offs;
+    } else {
+        bs = (byte *)(&(((ErlHeapBin *) real_bin)->data)) + sb->offs;
+    }
+
+    hb->thing_word = header_heap_bin(sb->size);
+    hb->size = sb->size;
+    sys_memcpy((byte *)hb->data, bs, sb->size);
+
+    gval  = make_boxed(htop);
+    *orig = gval;
+    *ptr  = gval;
+
+    ptr  += ERL_SUB_BIN_SIZE;
+    htop += heap_bin_size(sb->size);
+
+    *hpp = htop;
+    *pp  = ptr;
+}
+
+
 Eterm
 erts_gc_info_request(Process *c_p)
 {
diff --git a/erts/emulator/beam/erl_gc.h b/erts/emulator/beam/erl_gc.h
index 1cce426d21..414aff1e06 100644
--- a/erts/emulator/beam/erl_gc.h
+++ b/erts/emulator/beam/erl_gc.h
@@ -28,44 +28,71 @@
 #define ERTS_POTENTIALLY_LONG_GC_HSIZE (128*1024) /* Words */
 
 #include "erl_map.h"
+#include "erl_fun.h"
+#include "erl_bits.h"
 
 #define IS_MOVED_BOXED(x)	(!is_header((x)))
 #define IS_MOVED_CONS(x)	(is_non_value((x)))
+void erts_sub_binary_to_heap_binary(Eterm **pp, Eterm **hpp, Eterm *orig);
 
-#define MOVE_CONS(PTR,CAR,HTOP,ORIG)					\
-do {									\
-    Eterm gval;								\
-									\
-    HTOP[0] = CAR;		/* copy car */				\
-    HTOP[1] = PTR[1];		/* copy cdr */				\
-    gval = make_list(HTOP);	/* new location */			\
-    *ORIG = gval;		/* redirect original reference */	\
-    PTR[0] = THE_NON_VALUE;	/* store forwarding indicator */	\
-    PTR[1] = gval;		/* store forwarding address */		\
-    HTOP += 2;			/* update tospace htop */		\
-} while(0)
-
-#define MOVE_BOXED(PTR,HDR,HTOP,ORIG)                                   \
-do {                                                                    \
-    Eterm gval;                                                         \
-    Sint nelts;                                                         \
-                                                                        \
-    ASSERT(is_header(HDR));                                             \
-    nelts = header_arity(HDR);                                          \
-    switch ((HDR) & _HEADER_SUBTAG_MASK) {                              \
-    case SUB_BINARY_SUBTAG: nelts++; break;                             \
-    case MAP_SUBTAG:                                                    \
-        if (is_flatmap_header(HDR)) nelts+=flatmap_get_size(PTR) + 1;   \
-        else nelts += hashmap_bitcount(MAP_HEADER_VAL(HDR));            \
-    break;                                                              \
-    case FUN_SUBTAG: nelts+=((ErlFunThing*)(PTR))->num_free+1; break;   \
-    }                                                                   \
-    gval    = make_boxed(HTOP);                                         \
-    *ORIG   = gval;                                                     \
-    *HTOP++ = HDR;                                                      \
-    *PTR++  = gval;                                                     \
-    while (nelts--) *HTOP++ = *PTR++;                                   \
-} while(0)
+ERTS_GLB_INLINE void move_cons(Eterm **pp, Eterm car, Eterm **hpp, Eterm *orig);
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE void move_cons(Eterm **pp, Eterm car, Eterm **hpp, Eterm *orig)
+{
+    Eterm *ptr  = *pp;
+    Eterm *htop = *hpp;
+    Eterm gval;
+
+    htop[0] = car;               /* copy car */
+    htop[1] = ptr[1];            /* copy cdr */
+    gval    = make_list(htop);   /* new location */
+    *orig   = gval;              /* redirect original reference */
+    ptr[0]  = THE_NON_VALUE;     /* store forwarding indicator */
+    ptr[1]  = gval;              /* store forwarding address */
+    *hpp   += 2;                 /* update tospace htop */
+}
+#endif
+
+ERTS_GLB_INLINE void move_boxed(Eterm **pp, Eterm hdr, Eterm **hpp, Eterm *orig);
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE void move_boxed(Eterm **pp, Eterm hdr, Eterm **hpp, Eterm *orig)
+{
+    Eterm gval;
+    Sint nelts;
+    Eterm *ptr = *pp;
+    Eterm *htop = *hpp;
+
+    ASSERT(is_header(hdr));
+    nelts = header_arity(hdr);
+    switch ((hdr) & _HEADER_SUBTAG_MASK) {
+    case SUB_BINARY_SUBTAG:
+        {
+            ErlSubBin *sb = (ErlSubBin *)ptr;
+            /* convert sub-binary to heap-binary if applicable */
+            if (sb->bitsize == 0 && sb->bitoffs == 0 &&
+                sb->is_writable == 0 && sb->size <= sizeof(Eterm) * 3) {
+                erts_sub_binary_to_heap_binary(pp, hpp, orig);
+                return;
+            }
+        }
+        nelts++;
+        break;
+    case MAP_SUBTAG:
+        if (is_flatmap_header(hdr)) nelts+=flatmap_get_size(ptr) + 1;
+        else nelts += hashmap_bitcount(MAP_HEADER_VAL(hdr));
+    break;
+    case FUN_SUBTAG: nelts+=((ErlFunThing*)(ptr))->num_free+1; break;
+    }
+    gval    = make_boxed(htop);
+    *orig   = gval;
+    *htop++ = hdr;
+    *ptr++  = gval;
+    while (nelts--) *htop++ = *ptr++;
+
+    *hpp = htop;
+    *pp  = ptr;
+}
+#endif
 
 #define ErtsInYoungGen(TPtr, Ptr, OldHeap, OldHeapSz)			\
     (!erts_is_literal((TPtr), (Ptr))					\
diff --git a/erts/emulator/hipe/hipe_gc.c b/erts/emulator/hipe/hipe_gc.c
index cf0435adc9..2311beb34a 100644
--- a/erts/emulator/hipe/hipe_gc.c
+++ b/erts/emulator/hipe/hipe_gc.c
@@ -91,7 +91,7 @@ Eterm *fullsweep_nstack(Process *p, Eterm *n_htop)
 			ASSERT(is_boxed(val));
 			*nsp_i = val;
 		    } else if (!erts_is_literal(gval, ptr)) {
-			MOVE_BOXED(ptr, val, n_htop, nsp_i);
+			move_boxed(&ptr, val, &n_htop, nsp_i);
 		    }
 		} else if (is_list(gval)) {
 		    Eterm *ptr = list_val(gval);
@@ -100,7 +100,7 @@ Eterm *fullsweep_nstack(Process *p, Eterm *n_htop)
 			*nsp_i = ptr[1];
 		    } else if (!erts_is_literal(gval, ptr)) {
 			ASSERT(erts_dbg_within_proc(ptr, p, NULL));
-			MOVE_CONS(ptr, val, n_htop, nsp_i);
+			move_cons(&ptr, val, &n_htop, nsp_i);
 		    }
 		}
 	    }
@@ -206,10 +206,10 @@ void gensweep_nstack(Process *p, Eterm **ptr_old_htop, Eterm **ptr_n_htop)
 			ASSERT(is_boxed(val));
 			*nsp_i = val;
 		    } else if (ErtsInArea(ptr, mature, mature_size)) {
-			MOVE_BOXED(ptr, val, old_htop, nsp_i);
+			move_boxed(&ptr, val, &old_htop, nsp_i);
 		    } else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) {
 			ASSERT(erts_dbg_within_proc(ptr, p, NULL));
-			MOVE_BOXED(ptr, val, n_htop, nsp_i);
+			move_boxed(&ptr, val, &n_htop, nsp_i);
 		    }
 		} else if (is_list(gval)) {
 		    Eterm *ptr = list_val(gval);
@@ -217,10 +217,10 @@ void gensweep_nstack(Process *p, Eterm **ptr_old_htop, Eterm **ptr_n_htop)
 		    if (IS_MOVED_CONS(val)) {
 			*nsp_i = ptr[1];
 		    } else if (ErtsInArea(ptr, mature, mature_size)) {
-			MOVE_CONS(ptr, val, old_htop, nsp_i);
+			move_cons(&ptr, val, &old_htop, nsp_i);
 		    } else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) {
 			ASSERT(erts_dbg_within_proc(ptr, p, NULL));
-			MOVE_CONS(ptr, val, n_htop, nsp_i);
+			move_cons(&ptr, val, &n_htop, nsp_i);
 		    }
 		}
 	    }
@@ -278,7 +278,7 @@ Eterm *sweep_literals_nstack(Process *p, Eterm *old_htop, char *area,
 			ASSERT(is_boxed(val));
 			*nsp_i = val;
 		    } else if (ErtsInArea(ptr, area, area_size)) {
-			MOVE_BOXED(ptr, val, old_htop, nsp_i);
+			move_boxed(&ptr, val, &old_htop, nsp_i);
 		    }
 		} else if (is_list(gval)) {
 		    Eterm *ptr = list_val(gval);
@@ -286,7 +286,7 @@ Eterm *sweep_literals_nstack(Process *p, Eterm *old_htop, char *area,
 		    if (IS_MOVED_CONS(val)) {
 			*nsp_i = ptr[1];
 		    } else if (ErtsInArea(ptr, area, area_size)) {
-			MOVE_CONS(ptr, val, old_htop, nsp_i);
+			move_cons(&ptr, val, &old_htop, nsp_i);
 		    }
 		}
 	    }
diff --git a/lib/observer/test/crashdump_helper.erl b/lib/observer/test/crashdump_helper.erl
index 4239a3d0d1..e57c8162e4 100644
--- a/lib/observer/test/crashdump_helper.erl
+++ b/lib/observer/test/crashdump_helper.erl
@@ -44,7 +44,7 @@ n1_proc(Creator,_N2,Pid2,Port2,_L) ->
     Ref = make_ref(),
     Pid = self(),
     Bin = list_to_binary(lists:seq(1, 255)),
-    SubBin = element(1, split_binary(element(2, split_binary(Bin, 8)), 17)),
+    <<_:2,SubBin:17/binary,_/bits>> = Bin,
 
     register(named_port,Port),