From 00a64c9271322e78a9e1c490b5ea3434d840b1e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Lindqvist?= <bjourne@gmail.com>
Date: Mon, 30 May 2016 04:57:14 +0200
Subject: [PATCH] VM: name change no_non_safepoint_words_p -> stack_frame_p

It returns true if the quotation should be wrapped in a stack frame.
---
 vm/quotations.cpp | 29 +++++++++++++----------------
 vm/quotations.hpp |  3 +--
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/vm/quotations.cpp b/vm/quotations.cpp
index 09919adb11..36fa01fbd3 100644
--- a/vm/quotations.cpp
+++ b/vm/quotations.cpp
@@ -84,24 +84,21 @@ bool quotation_jit::mega_lookup_p(cell i, cell length) {
       array_nth(elements.untagged(), i + 3) == parent->special_objects[MEGA_LOOKUP_WORD];
 }
 
+/* Subprimitives should be flagged with whether they require a stack frame.
+   See #295. */
 bool quotation_jit::special_subprimitive_p(cell obj) {
-  // Subprimitives should be flagged with whether they require a stack frame.
-  // See #295.
   return obj == parent->special_objects[SIGNAL_HANDLER_WORD] ||
          obj == parent->special_objects[LEAF_SIGNAL_HANDLER_WORD] ||
          obj == parent->special_objects[UNWIND_NATIVE_FRAMES_WORD];
 }
 
-bool quotation_jit::word_safepoint_p(cell obj) {
-  return !special_subprimitive_p(obj);
-}
-
-/* true if there are no non-safepoint words in the quoation... */
-bool quotation_jit::no_non_safepoint_words_p() {
+/* All quotations wants a stack frame, except those that contain calls
+   to the special subprimitives. See #295. */
+bool quotation_jit::stack_frame_p() {
   cell length = array_capacity(elements.untagged());
   for (cell i = 0; i < length; i++) {
     cell obj = array_nth(elements.untagged(), i);
-    if (TAG(obj) == WORD_TYPE && !word_safepoint_p(obj))
+    if (TAG(obj) == WORD_TYPE && special_subprimitive_p(obj))
       return false;
   }
   return true;
@@ -139,11 +136,11 @@ void quotation_jit::emit_quotation(cell quot_) {
 
 /* Allocates memory (parameter(), literal(), emit_epilog, emit_with_literal)*/
 void quotation_jit::iterate_quotation() {
-  bool no_non_safepoint_words = no_non_safepoint_words_p();
+  bool stack_frame = stack_frame_p();
 
   set_position(0);
 
-  if (no_non_safepoint_words) {
+  if (stack_frame) {
     emit(parent->special_objects[JIT_SAFEPOINT]);
     emit(parent->special_objects[JIT_PROLOG]);
   }
@@ -162,10 +159,10 @@ void quotation_jit::iterate_quotation() {
         if (to_boolean(obj.as<word>()->subprimitive)) {
           tail_call = emit_subprimitive(obj.value(),     /* word */
                                         i == length - 1, /* tail_call_p */
-                                        no_non_safepoint_words);    /* stack_frame_p */
+                                        stack_frame);  /* stack_frame_p */
         }                                                /* Everything else */
         else if (i == length - 1) {
-          emit_epilog(no_non_safepoint_words);
+          emit_epilog(stack_frame);
           tail_call = true;
           word_jump(obj.value());
         } else
@@ -199,7 +196,7 @@ void quotation_jit::iterate_quotation() {
         /* 'if' preceded by two literal quotations (this is why if and ? are
            mutually recursive in the library, but both still work) */
         if (fast_if_p(i, length)) {
-          emit_epilog(no_non_safepoint_words);
+          emit_epilog(stack_frame);
           tail_call = true;
 
           emit_quotation(array_nth(elements.untagged(), i));
@@ -232,7 +229,7 @@ void quotation_jit::iterate_quotation() {
           /* Load the object from the datastack, then remove our stack frame. */
           emit_with_literal(parent->special_objects[PIC_LOAD],
                             tag_fixnum(-index * sizeof(cell)));
-          emit_epilog(no_non_safepoint_words);
+          emit_epilog(stack_frame);
           tail_call = true;
 
           emit_mega_cache_lookup(array_nth(elements.untagged(), i), index,
@@ -252,7 +249,7 @@ void quotation_jit::iterate_quotation() {
 
   if (!tail_call) {
     set_position(length);
-    emit_epilog(no_non_safepoint_words);
+    emit_epilog(stack_frame);
     emit(parent->special_objects[JIT_RETURN]);
   }
 }
diff --git a/vm/quotations.hpp b/vm/quotations.hpp
index 68d0a98720..0f794be1e4 100644
--- a/vm/quotations.hpp
+++ b/vm/quotations.hpp
@@ -25,8 +25,7 @@ struct quotation_jit : public jit {
   bool declare_p(cell i, cell length);
   bool special_subprimitive_p(cell obj);
   cell word_stack_frame_size(cell obj);
-  bool word_safepoint_p(cell obj);
-  bool no_non_safepoint_words_p();
+  bool stack_frame_p();
   void iterate_quotation();
 
   /* Allocates memory */