From 53e841b4e09f2c715fe459a1e4a84e4de5c161fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 25 Aug 2017 10:15:25 +0200
Subject: Add annotations for likely/unlikely

In a correct Erlang programs, we can expect that:

* A GC test instruction (such as test_heap) is more likely
  not to do the GC.
* A BIF is more likely to succeed than to fail.
* A BIF is more likely to fail in a guard than in a body.
* An apply or fun call is likely to succeed.

Annotate conditions accordingly.
---
 erts/emulator/beam/instrs.tab | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

(limited to 'erts/emulator/beam/instrs.tab')

diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index 1af01e53bd..58432cbbb4 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -171,7 +171,7 @@ HANDLE_APPLY_ERROR() {
 i_apply() {
     BeamInstr *next;
     $APPLY(NULL, 0);
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         $i_call(next);
     }
     $HANDLE_APPLY_ERROR();
@@ -180,7 +180,7 @@ i_apply() {
 i_apply_last(Deallocate) {
     BeamInstr *next;
     $APPLY(I, $Deallocate);
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         $i_call_last(next, $Deallocate);
     }
     $HANDLE_APPLY_ERROR();
@@ -189,7 +189,7 @@ i_apply_last(Deallocate) {
 i_apply_only() {
     BeamInstr *next;
     $APPLY(I, 0);
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         $i_call_only(next);
     }
     $HANDLE_APPLY_ERROR();
@@ -205,7 +205,7 @@ FIXED_APPLY(Arity, I, Deallocate) {
 apply(Arity) {
     BeamInstr *next;
     $FIXED_APPLY($Arity, NULL, 0);
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         $i_call(next);
     }
     $HANDLE_APPLY_ERROR();
@@ -214,7 +214,7 @@ apply(Arity) {
 apply_last(Arity, Deallocate) {
     BeamInstr *next;
     $FIXED_APPLY($Arity, I, $Deallocate);
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         $i_call_last(next, $Deallocate);
     }
     $HANDLE_APPLY_ERROR();
@@ -238,7 +238,7 @@ DISPATCH_FUN(I) {
 i_apply_fun() {
     BeamInstr *next;
     $APPLY_FUN();
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         SET_CP(c_p, $NEXT_INSTRUCTION);
         $DISPATCH_FUN(next);
     }
@@ -248,7 +248,7 @@ i_apply_fun() {
 i_apply_fun_last(Deallocate) {
     BeamInstr *next;
     $APPLY_FUN();
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         $deallocate($Deallocate);
         $DISPATCH_FUN(next);
     }
@@ -258,7 +258,7 @@ i_apply_fun_last(Deallocate) {
 i_apply_fun_only() {
     BeamInstr *next;
     $APPLY_FUN();
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         $DISPATCH_FUN(next);
     }
     $HANDLE_APPLY_FUN_ERROR();
@@ -274,7 +274,7 @@ CALL_FUN(Fun) {
 i_call_fun(Fun) {
     BeamInstr *next;
     $CALL_FUN($Fun);
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         SET_CP(c_p, $NEXT_INSTRUCTION);
         $DISPATCH_FUN(next);
     }
@@ -284,7 +284,7 @@ i_call_fun(Fun) {
 i_call_fun_last(Fun, Deallocate) {
     BeamInstr *next;
     $CALL_FUN($Fun);
-    if (next != NULL) {
+    if (ERTS_LIKELY(next != NULL)) {
         $deallocate($Deallocate);
         $DISPATCH_FUN(next);
     }
@@ -378,7 +378,7 @@ element_group.fetch(Src) {
 
 element_group.execute(Fail, Index, Dst) {
     element_index = $Index;
-    if (is_small(element_index) && is_tuple(element_tuple)) {
+    if (ERTS_LIKELY(is_small(element_index) && is_tuple(element_tuple))) {
         Eterm* tp = tuple_val(element_tuple);
 
         if ((signed_val(element_index) >= 1) &&
@@ -402,7 +402,7 @@ fast_element_group.fetch(Src) {
 }
 
 fast_element_group.execute(Fail, Index, Dst) {
-    if (is_tuple(fast_element_tuple)) {
+    if (ERTS_LIKELY(is_tuple(fast_element_tuple))) {
         Eterm* tp = tuple_val(fast_element_tuple);
         Eterm pos = $Index;	/* Untagged integer >= 1 */
         if (pos <= arityval(*tp)) {
-- 
cgit v1.2.3


From 50da607331bc2de990828c3c74bbf4ee7efa27f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 25 Aug 2017 14:40:50 +0200
Subject: Eliminate three arguments for the apply() helper

We don't need to pass x(0), x(1), and x(2) because they
can already be found in the register array.
---
 erts/emulator/beam/instrs.tab | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'erts/emulator/beam/instrs.tab')

diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index 58432cbbb4..19219d34bd 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -159,7 +159,7 @@ i_move_call_ext_last(Dest, StackOffset, Src) {
 APPLY(I, Deallocate) {
     //| -no_next
     HEAVY_SWAPOUT;
-    next = apply(c_p, r(0), x(1), x(2), reg, $I, $Deallocate);
+    next = apply(c_p, reg, $I, $Deallocate);
     HEAVY_SWAPIN;
 }
 
-- 
cgit v1.2.3


From c3b8fa5742b5fbcd262552fa1d6cad0706fa6a94 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Thu, 31 Aug 2017 12:48:34 +0200
Subject: Add missing -no_next directives

---
 erts/emulator/beam/instrs.tab | 1 +
 1 file changed, 1 insertion(+)

(limited to 'erts/emulator/beam/instrs.tab')

diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index 19219d34bd..9c3e615cea 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -906,5 +906,6 @@ i_raise() {
         c_p->freason = PRIMARY_EXCEPTION(s->freason);
     }
     goto find_func_info;
+    //| -no_next
 }
 
-- 
cgit v1.2.3