vm_core.h (struct rb_iseq_struct): reduce to 296 bytes on 64-bit

Most iseq do not have a catch_table, so avoid needlessly adding
4-8 bytes to the struct for the common case.

Changes from v2:
- iseq_catch_table_size removed, use if (...) for (;...;)

Changes from v1:
- renamed iseq->_catch_table to iseq->catch_table
- iseq_catch_table_bytes: made a static inline function
- iseq_catch_table_size: new function replaces the
  iseq_catch_table_each iterator macro

* iseq.h (struct iseq_catch_table): new flexible array struct
         (iseq_catch_table_bytes): allocated size function
* vm_core.h (struct rb_iseq_struct): uupdate catch_table member
* compile.c (iseq_set_exception_table): update for struct changes
* iseq.c (iseq_free): ditto
* iseq.c (iseq_memsize): ditto
* iseq.c (rb_iseq_disasm): ditto
* iseq.c (iseq_data_to_ary): ditto
* iseq.c (rb_iseq_build_for_ruby2cext): ditto (untested)
* vm.c (vm_exec): ditto
* vm_core.h (struct rb_iseq_struct): ditto
* vm_insnhelper.c (vm_throw): ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46811 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

7 files changed, 72 insertions, 27 deletions

diff --git a/ChangeLog b/ChangeLog
index 53b777f3b7..4cb65763cf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+Mon Jul 14 16:04:41 2014  Eric Wong  <e@80x24.org>
+
+	* iseq.h (struct iseq_catch_table): new flexible array struct
+		 (iseq_catch_table_bytes): allocated size function
+	* vm_core.h (struct rb_iseq_struct): update catch_table member
+	* compile.c (iseq_set_exception_table): update for struct changes
+	* iseq.c (iseq_free): ditto
+	* iseq.c (iseq_memsize): ditto
+	* iseq.c (rb_iseq_disasm): ditto
+	* iseq.c (iseq_data_to_ary): ditto
+	* iseq.c (rb_iseq_build_for_ruby2cext): ditto (untested)
+	* vm.c (vm_exec): ditto
+	* vm_core.h (struct rb_iseq_struct): ditto
+	* vm_insnhelper.c (vm_throw): ditto
+
 Sun Jul 13 17:49:52 2014  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* ext/openssl/ossl_cipher.c: Fix call to ciphers class method and
diff --git a/compile.c b/compile.c
index 6c71a8586f..637e112b05 100644
--- a/compile.c
+++ b/compile.c
@@ -1681,12 +1681,15 @@ iseq_set_exception_table(rb_iseq_t *iseq)
     tlen = (int)RARRAY_LEN(iseq->compile_data->catch_table_ary);
     tptr = RARRAY_CONST_PTR(iseq->compile_data->catch_table_ary);
 
-    iseq->catch_table = tlen ? ALLOC_N(struct iseq_catch_table_entry, tlen) : 0;
-    iseq->catch_table_size = tlen;
+    iseq->catch_table = 0;
+    if (tlen > 0) {
+	iseq->catch_table = xmalloc(iseq_catch_table_bytes(tlen));
+	iseq->catch_table->size = tlen;
+    }
 
-    for (i = 0; i < tlen; i++) {
+    if (iseq->catch_table) for (i = 0; i < iseq->catch_table->size; i++) {
 	ptr = RARRAY_CONST_PTR(tptr[i]);
-	entry = &iseq->catch_table[i];
+	entry = &iseq->catch_table->entries[i];
 	entry->type = (enum catch_type)(ptr[0] & 0xffff);
 	entry->start = label_get_position((LABEL *)(ptr[1] & ~1));
 	entry->end = label_get_position((LABEL *)(ptr[2] & ~1));
diff --git a/iseq.c b/iseq.c
index 77507d83cf..a7e40ea86c 100644
--- a/iseq.c
+++ b/iseq.c
@@ -141,7 +141,9 @@ iseq_memsize(const void *ptr)
 	    size += iseq->iseq_size * sizeof(VALUE);
 	    size += iseq->line_info_size * sizeof(struct iseq_line_info_entry);
 	    size += iseq->local_table_size * sizeof(ID);
-	    size += iseq->catch_table_size * sizeof(struct iseq_catch_table_entry);
+	    if (iseq->catch_table) {
+		size += iseq_catch_table_bytes(iseq->catch_table->size);
+	    }
 	    size += iseq->arg_opts * sizeof(VALUE);
 	    size += iseq->is_size * sizeof(union iseq_inline_storage_entry);
 	    size += iseq->callinfo_size * sizeof(rb_call_info_t);
@@ -1400,11 +1402,11 @@ rb_iseq_disasm(VALUE self)
     rb_str_cat2(str, "\n");
 
     /* show catch table information */
-    if (iseqdat->catch_table_size != 0) {
+    if (iseqdat->catch_table) {
 	rb_str_cat2(str, "== catch table\n");
     }
-    for (i = 0; i < iseqdat->catch_table_size; i++) {
-	struct iseq_catch_table_entry *entry = &iseqdat->catch_table[i];
+    if (iseqdat->catch_table) for (i = 0; i < iseqdat->catch_table->size; i++) {
+	struct iseq_catch_table_entry *entry = &iseqdat->catch_table->entries[i];
 	rb_str_catf(str,
 		    "| catch type: %-6s st: %04d ed: %04d sp: %04d cont: %04d\n",
 		    catch_type((int)entry->type), (int)entry->start,
@@ -1413,7 +1415,7 @@ rb_iseq_disasm(VALUE self)
 	    rb_str_concat(str, rb_iseq_disasm(entry->iseq));
 	}
     }
-    if (iseqdat->catch_table_size != 0) {
+    if (iseqdat->catch_table) {
 	rb_str_cat2(str, "|-------------------------------------"
 		    "-----------------------------------\n");
     }
@@ -1845,9 +1847,9 @@ iseq_data_to_ary(rb_iseq_t *iseq)
     nbody = body;
 
     /* exception */
-    for (i=0; i<iseq->catch_table_size; i++) {
+    if (iseq->catch_table) for (i=0; i<iseq->catch_table->size; i++) {
 	VALUE ary = rb_ary_new();
-	struct iseq_catch_table_entry *entry = &iseq->catch_table[i];
+	struct iseq_catch_table_entry *entry = &iseq->catch_table->entries[i];
 	rb_ary_push(ary, exception_type2symbol(entry->type));
 	if (entry->iseq) {
 	    rb_iseq_t *eiseq;
@@ -2117,8 +2119,14 @@ rb_iseq_build_for_ruby2cext(
     ALLOC_AND_COPY(iseq->line_info_table, line_info_table,
 		   struct iseq_line_info_entry, iseq->line_info_size);
 
-    ALLOC_AND_COPY(iseq->catch_table, catch_table,
-		   struct iseq_catch_table_entry, iseq->catch_table_size);
+    /*
+     * FIXME: probably broken, but this function is probably unused
+     * and should be removed
+     */
+    if (iseq->catch_table) {
+	MEMCPY(&iseq->catch_table->entries, catch_table,
+	    struct iseq_catch_table_entry, iseq->catch_table->size);
+    }
 
     ALLOC_AND_COPY(iseq->arg_opt_table, arg_opt_table,
 		   VALUE, iseq->arg_opts);
diff --git a/iseq.h b/iseq.h
index 5487d86f7b..be7d8efd9d 100644
--- a/iseq.h
+++ b/iseq.h
@@ -68,6 +68,18 @@ struct iseq_catch_table_entry {
     unsigned long sp;
 };
 
+PACKED_STRUCT_UNALIGNED(struct iseq_catch_table {
+    int size;
+    struct iseq_catch_table_entry entries[1]; /* flexible array */
+});
+
+static inline int
+iseq_catch_table_bytes(int n)
+{
+    return sizeof(struct iseq_catch_table) +
+           (n - 1) * sizeof(struct iseq_catch_table_entry);
+}
+
 #define INITIAL_ISEQ_COMPILE_DATA_STORAGE_BUFF_SIZE (512)
 
 struct iseq_compile_data_storage {
diff --git a/vm.c b/vm.c
index 0fd5e3fd9c..c33f16a0bd 100644
--- a/vm.c
+++ b/vm.c
@@ -1383,6 +1383,7 @@ vm_exec(rb_thread_t *th)
     else {
 	int i;
 	struct iseq_catch_table_entry *entry;
+	struct iseq_catch_table *ct;
 	unsigned long epc, cont_pc, cont_sp;
 	VALUE catch_iseqval;
 	rb_control_frame_t *cfp;
@@ -1417,8 +1418,9 @@ vm_exec(rb_thread_t *th)
 			SET_THROWOBJ_STATE(err, state = TAG_BREAK);
 		    }
 		    else {
-			for (i = 0; i < cfp->iseq->catch_table_size; i++) {
-			    entry = &cfp->iseq->catch_table[i];
+			ct = cfp->iseq->catch_table;
+			if (ct) for (i = 0; i < ct->size; i++) {
+			    entry = &ct->entries[i];
 			    if (entry->start < epc && entry->end >= epc) {
 				if (entry->type == CATCH_TYPE_ENSURE) {
 				    catch_iseqval = entry->iseq;
@@ -1458,8 +1460,9 @@ vm_exec(rb_thread_t *th)
 	}
 
 	if (state == TAG_RAISE) {
-	    for (i = 0; i < cfp->iseq->catch_table_size; i++) {
-		entry = &cfp->iseq->catch_table[i];
+	    ct = cfp->iseq->catch_table;
+	    if (ct) for (i = 0; i < ct->size; i++) {
+		entry = &ct->entries[i];
 		if (entry->start < epc && entry->end >= epc) {
 
 		    if (entry->type == CATCH_TYPE_RESCUE ||
@@ -1473,8 +1476,9 @@ vm_exec(rb_thread_t *th)
 	    }
 	}
 	else if (state == TAG_RETRY) {
-	    for (i = 0; i < cfp->iseq->catch_table_size; i++) {
-		entry = &cfp->iseq->catch_table[i];
+	    ct = cfp->iseq->catch_table;
+	    if (ct) for (i = 0; i < ct->size; i++) {
+		entry = &ct->entries[i];
 		if (entry->start < epc && entry->end >= epc) {
 
 		    if (entry->type == CATCH_TYPE_ENSURE) {
@@ -1499,8 +1503,9 @@ vm_exec(rb_thread_t *th)
 	    type = CATCH_TYPE_BREAK;
 
 	  search_restart_point:
-	    for (i = 0; i < cfp->iseq->catch_table_size; i++) {
-		entry = &cfp->iseq->catch_table[i];
+	    ct = cfp->iseq->catch_table;
+	    if (ct) for (i = 0; i < ct->size; i++) {
+		entry = &ct->entries[i];
 
 		if (entry->start < epc && entry->end >= epc) {
 		    if (entry->type == CATCH_TYPE_ENSURE) {
@@ -1536,8 +1541,9 @@ vm_exec(rb_thread_t *th)
 	    goto search_restart_point;
 	}
 	else {
-	    for (i = 0; i < cfp->iseq->catch_table_size; i++) {
-		entry = &cfp->iseq->catch_table[i];
+	    ct = cfp->iseq->catch_table;
+	    if (ct) for (i = 0; i < ct->size; i++) {
+		entry = &ct->entries[i];
 		if (entry->start < epc && entry->end >= epc) {
 
 		    if (entry->type == CATCH_TYPE_ENSURE) {
diff --git a/vm_core.h b/vm_core.h
index 8a8ceeb981..510a4ad4cd 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -274,8 +274,7 @@ struct rb_iseq_struct {
     ID *arg_keyword_table;
 
     /* catch table */
-    struct iseq_catch_table_entry *catch_table;
-    int catch_table_size;
+    struct iseq_catch_table *catch_table;
 
     /* for child iseq */
     struct rb_iseq_struct *parent_iseq;
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 9d77b01a0f..0f9eab1610 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -646,10 +646,12 @@ vm_throw(rb_thread_t *th, rb_control_frame_t *reg_cfp,
 			if (cfp->ep == ep) {
 			    VALUE epc = cfp->pc - cfp->iseq->iseq_encoded;
 			    rb_iseq_t *iseq = cfp->iseq;
+			    struct iseq_catch_table *ct = iseq->catch_table;
+			    struct iseq_catch_table_entry *entry;
 			    int i;
 
-			    for (i=0; i<iseq->catch_table_size; i++) {
-				struct iseq_catch_table_entry *entry = &iseq->catch_table[i];
+			    for (i=0; i<ct->size; i++) {
+				entry = &ct->entries[i];
 
 				if (entry->type == CATCH_TYPE_BREAK &&
 				    entry->start < epc && entry->end >= epc) {