From 9e256c085149afef4bf0991d1fc75a8f50238403 Mon Sep 17 00:00:00 2001
From: inglorion <voodoo@inglorion.net>
Date: Fri, 19 Aug 2011 10:13:22 +0200
Subject: [PATCH] arm_gas_generator: Emit constants at every goto and every
 return to top level

---
 lib/voodoo/generators/arm_gas_generator.rb | 33 ++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/lib/voodoo/generators/arm_gas_generator.rb b/lib/voodoo/generators/arm_gas_generator.rb
index 9f54f8d..bef7e2a 100644
--- a/lib/voodoo/generators/arm_gas_generator.rb
+++ b/lib/voodoo/generators/arm_gas_generator.rb
@@ -271,6 +271,16 @@ module Voodoo
        count
     end
 
+    # Writes any constants that need to be written to the instruction
+    # stream, and clears the list of constants that need to be written.
+    def emit_constants
+      @constants.each do |x|
+        label x[0]
+        word x[1]
+      end
+      @constants = []
+    end
+
     # Emit function prologue.
     def emit_function_prologue formals = [], nlocals = 0
       # Calculate the number of arguments we were passed in
@@ -295,7 +305,7 @@ module Voodoo
       # If we are returning to top level, restore stack pointer
       # and saved registers.
       if @environment.parent == @top_level
-        offset = @frame_size - @saved_registers * @WORDSIZE
+        offset = @frame_size - @saved_registers.length * @WORDSIZE
         if offset > 0
           emit "add sp, sp, \##{offset}\n"
         end
@@ -303,6 +313,13 @@ module Voodoo
         @frame_size = 0
         @frame_offset = 0
         @saved_registers = []
+
+        # If we need to emit constants, do so now
+        unless @constants.empty?
+          lbl = gensym
+          goto lbl
+          label lbl
+        end
       end
 
       # Restore old value of @environment
@@ -334,12 +351,7 @@ module Voodoo
       @frame_offset = 0
       @saved_registers = []
 
-      # Emit constants
-      @constants.each do |x|
-        label x[0]
-        word x[1]
-      end
-      @constants = []
+      emit_constants
 
       emit "# end function\n\n"
 
@@ -464,6 +476,9 @@ module Voodoo
     # Jump to a label.
     def goto label
       emit "b #{label}\n"
+
+      # If we have constants that need to be emitted, do so now
+      emit_constants
     end
 
     # Grows the current frame by n words, plus padding to
@@ -601,8 +616,8 @@ module Voodoo
           end
         else
           # Assume global
-          label = add_constant x
-          emit "ldr #{register}, #{label}\n"
+          lbl = add_constant x
+          emit "ldr #{register}, #{lbl}\n"
           return register
         end
       elsif at_expr? x
-- 
2.11.4.GIT