Merge branch 'bjorn/erts/improve-beam-ops'

* bjorn/erts/improve-beam-ops:
  Don't allow macros to assign to hard-coded variables
  Annotate try_case_end as cold
  beam_emu.c: Mark initialization code as unlikely
  Try to avoid generating unecessary do/while wrappers
  Eliminate unecessary instruction macro i_move_call_only()

4 files changed, 48 insertions, 25 deletions

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 7ef0772703..3dce16aedd 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -649,7 +649,7 @@ void process_main(Eterm * x_reg_array, FloatDef* f_reg_array)
      * Note: c_p->arity must be set to reflect the number of useful terms in
      * c_p->arg_reg before calling the scheduler.
      */
-    if (!init_done) {
+    if (ERTS_UNLIKELY(!init_done)) {
        /* This should only be reached during the init phase when only the main
         * process is running. I.e. there is no race for init_done.
         */
diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index 9c3e615cea..b79b960fd7 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -110,15 +110,11 @@ i_call_only(CallDest) {
     $DISPATCH($CallDest);
 }
 
-i_move_call_only(CallDest, Src) {
+move_call_only(Src, CallDest) {
     x(0) = $Src;
     $i_call_only($CallDest);
 }
 
-move_call_only(Src, CallDest) {
-    $i_move_call_only($CallDest, $Src);
-}
-
 DISPATCHX(Dest) {
     //| -no_next
     DTRACE_GLOBAL_CALL_FROM_EXPORT(c_p, $Dest);
@@ -156,10 +152,10 @@ i_move_call_ext_last(Dest, StackOffset, Src) {
     $i_call_ext_last($Dest, $StackOffset);
 }
 
-APPLY(I, Deallocate) {
+APPLY(I, Deallocate, Next) {
     //| -no_next
     HEAVY_SWAPOUT;
-    next = apply(c_p, reg, $I, $Deallocate);
+    $Next = apply(c_p, reg, $I, $Deallocate);
     HEAVY_SWAPIN;
 }
 
@@ -170,7 +166,7 @@ HANDLE_APPLY_ERROR() {
 
 i_apply() {
     BeamInstr *next;
-    $APPLY(NULL, 0);
+    $APPLY(NULL, 0, next);
     if (ERTS_LIKELY(next != NULL)) {
         $i_call(next);
     }
@@ -179,7 +175,7 @@ i_apply() {
 
 i_apply_last(Deallocate) {
     BeamInstr *next;
-    $APPLY(I, $Deallocate);
+    $APPLY(I, $Deallocate, next);
     if (ERTS_LIKELY(next != NULL)) {
         $i_call_last(next, $Deallocate);
     }
@@ -188,23 +184,23 @@ i_apply_last(Deallocate) {
 
 i_apply_only() {
     BeamInstr *next;
-    $APPLY(I, 0);
+    $APPLY(I, 0, next);
     if (ERTS_LIKELY(next != NULL)) {
         $i_call_only(next);
     }
     $HANDLE_APPLY_ERROR();
 }
 
-FIXED_APPLY(Arity, I, Deallocate) {
+FIXED_APPLY(Arity, I, Deallocate, Next) {
     //| -no_next
     HEAVY_SWAPOUT;
-    next = fixed_apply(c_p, reg, $Arity, $I, $Deallocate);
+    $Next = fixed_apply(c_p, reg, $Arity, $I, $Deallocate);
     HEAVY_SWAPIN;
 }
 
 apply(Arity) {
     BeamInstr *next;
-    $FIXED_APPLY($Arity, NULL, 0);
+    $FIXED_APPLY($Arity, NULL, 0, next);
     if (ERTS_LIKELY(next != NULL)) {
         $i_call(next);
     }
@@ -213,16 +209,16 @@ apply(Arity) {
 
 apply_last(Arity, Deallocate) {
     BeamInstr *next;
-    $FIXED_APPLY($Arity, I, $Deallocate);
+    $FIXED_APPLY($Arity, I, $Deallocate, next);
     if (ERTS_LIKELY(next != NULL)) {
         $i_call_last(next, $Deallocate);
     }
     $HANDLE_APPLY_ERROR();
 }
 
-APPLY_FUN() {
+APPLY_FUN(Next) {
     HEAVY_SWAPOUT;
-    next = apply_fun(c_p, r(0), x(1), reg);
+    $Next = apply_fun(c_p, r(0), x(1), reg);
     HEAVY_SWAPIN;
 }
 
@@ -237,7 +233,7 @@ DISPATCH_FUN(I) {
 
 i_apply_fun() {
     BeamInstr *next;
-    $APPLY_FUN();
+    $APPLY_FUN(next);
     if (ERTS_LIKELY(next != NULL)) {
         SET_CP(c_p, $NEXT_INSTRUCTION);
         $DISPATCH_FUN(next);
@@ -247,7 +243,7 @@ i_apply_fun() {
 
 i_apply_fun_last(Deallocate) {
     BeamInstr *next;
-    $APPLY_FUN();
+    $APPLY_FUN(next);
     if (ERTS_LIKELY(next != NULL)) {
         $deallocate($Deallocate);
         $DISPATCH_FUN(next);
@@ -257,23 +253,23 @@ i_apply_fun_last(Deallocate) {
 
 i_apply_fun_only() {
     BeamInstr *next;
-    $APPLY_FUN();
+    $APPLY_FUN(next);
     if (ERTS_LIKELY(next != NULL)) {
         $DISPATCH_FUN(next);
     }
     $HANDLE_APPLY_FUN_ERROR();
 }
 
-CALL_FUN(Fun) {
+CALL_FUN(Fun, Next) {
     //| -no_next
     HEAVY_SWAPOUT;
-    next = call_fun(c_p, $Fun, reg, THE_NON_VALUE);
+    $Next = call_fun(c_p, $Fun, reg, THE_NON_VALUE);
     HEAVY_SWAPIN;
 }
 
 i_call_fun(Fun) {
     BeamInstr *next;
-    $CALL_FUN($Fun);
+    $CALL_FUN($Fun, next);
     if (ERTS_LIKELY(next != NULL)) {
         SET_CP(c_p, $NEXT_INSTRUCTION);
         $DISPATCH_FUN(next);
@@ -283,7 +279,7 @@ i_call_fun(Fun) {
 
 i_call_fun_last(Fun, Deallocate) {
     BeamInstr *next;
-    $CALL_FUN($Fun);
+    $CALL_FUN($Fun, next);
     if (ERTS_LIKELY(next != NULL)) {
         $deallocate($Deallocate);
         $DISPATCH_FUN(next);
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index d848c1cceb..d64f6f2cfc 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -190,7 +190,9 @@ try Y F => catch Y F
 try_case Y => try_end Y
 try_end y
 
+%cold
 try_case_end s
+%hot
 
 # Destructive set tuple element
 
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops
index bcc92472d4..38754e67a1 100755
--- a/erts/emulator/utils/beam_makeops
+++ b/erts/emulator/utils/beam_makeops
@@ -1451,7 +1451,32 @@ sub expand_macro {
         warn $@;
         die "... from the body of $name at $where\n";
     }
-    ("do {\n$body\n} while (0)",$rest);
+    $body = "do {\n$body\n} while (0)"
+        if needs_do_wrapper($body);
+    ($body,$rest);
+}
+
+# Conservative heuristic to determine whether a do { ... } while(0)
+# wrapper is needed.
+sub needs_do_wrapper {
+    local $_ = shift;
+
+    s@^//[|][^\n]*\n@@;
+    s@^\s*@@s;
+    s@^/[*].*[*]/\s*@@s;
+    return 1 if /^(Eterm|Uint|Sint|int|unsigned)/; # Definitely needed.
+    return 0 if /^do/;
+    return 0 if /^SET_I/;
+    return 0 if /^SET_CP/;
+    return 0 if /^ERTS_NO_FPE_CHECK_INIT/;
+    return 0 if /^ASSERT/;
+    return 0 if /^DTRACE/;
+    return 0 if /^[A-Za-z_]*\s*=/;
+    return 0 if /^c_p->/;
+    return 0 if /^[A-Z_]*SWAPOUT/;
+    return 0 if /^if\s*[(]/;
+    return 0 if /^goto\b/;
+    return 1;                   # Not sure, say that it is needed.
 }
 
 sub do_pack {