From 3e1dbab0f019cdb87b9df360be0ad44ca727d69f Mon Sep 17 00:00:00 2001
From: Joel Dice <git@seibutsu.mailsnare.net>
Date: Thu, 11 Oct 2007 20:52:16 -0600
Subject: [PATCH] move bitmap helper functions to common.h; preserve
 callee-saved registers in vmInvoke()

---
 src/common.h    | 18 ++++++++++++++++++
 src/compile.S   | 24 +++++++++++++++++++++---
 src/compile.cpp | 22 ++--------------------
 src/heap.cpp    |  8 ++++----
 4 files changed, 45 insertions(+), 27 deletions(-)

diff --git a/src/common.h b/src/common.h
index c1011c6cd7..f80c455057 100644
--- a/src/common.h
+++ b/src/common.h
@@ -127,6 +127,24 @@ indexOf(unsigned word, unsigned bit)
   return (word * BitsPerWord) + bit;
 }
 
+inline void
+markBit(uintptr_t* map, unsigned i)
+{
+  map[wordOf(i)] |= static_cast<uintptr_t>(1) << bitOf(i);
+}
+
+inline void
+clearBit(uintptr_t* map, unsigned i)
+{
+  map[wordOf(i)] &= ~(static_cast<uintptr_t>(1) << bitOf(i));
+}
+
+inline unsigned
+getBit(uintptr_t* map, unsigned i)
+{
+  return map[wordOf(i)] & (static_cast<uintptr_t>(1) << bitOf(i));
+}
+
 template <class T>
 inline T&
 cast(void* p, unsigned offset)
diff --git a/src/compile.S b/src/compile.S
index 40f6630e06..328685e374 100644
--- a/src/compile.S
+++ b/src/compile.S
@@ -9,12 +9,16 @@ vmInvoke:
    pushq  %rbp
    movq   %rsp,%rbp
    
+   // rbx is a callee-saved register (so are r12-r15, but we don't use those)
+   pushq  %rbx
+   
    // %rdi: function
    // %rsi: stack
    // %rdx: stackSize
    // %rcx: returnType
 
    // reserve space for arguments
+   pushq  %rdx
    subq   %rdx,%rsp
 
    // copy memory arguments into place
@@ -36,7 +40,12 @@ test:
    
    // call function
    call   *%rdi
+
+   // pop arguments
+   addq   -16(%rbp),%rsp
+   addq   $8,%rsp
    
+   popq   %rbx
    movq   %rbp,%rsp   
    popq   %rbp
    ret
@@ -54,15 +63,18 @@ vmInvoke:
    pushl  %ebp
    movl   %esp,%ebp
 
+   // ebx, esi and edi are callee-saved registers
+   pushl  %ebx
+   pushl  %esi
+   pushl  %edi
+
    //  8(%ebp): function
    // 12(%ebp): stack
    // 16(%ebp): stackSize
    // 20(%ebp): returnType
    
    // reserve space for arguments
-   movl   16(%ebp),%ecx
-   
-   subl   %ecx,%esp
+   subl   16(%ebp),%esp
 
    // copy arguments into place
    movl   $0,%ecx
@@ -84,6 +96,9 @@ test:
    // call function
    call   *8(%ebp)
 
+   // pop arguments
+   addl   16(%ebp),%esp
+
    // handle return value based on expected type
    movl   20(%ebp),%ecx
    
@@ -101,6 +116,9 @@ int32:
    movl   $0,%edx
 
 exit:
+   popl   %edi
+   popl   %esi
+   popl   %ebx
    movl   %ebp,%esp
    popl   %ebp
    ret
diff --git a/src/compile.cpp b/src/compile.cpp
index c944aca14d..7d39109c6b 100644
--- a/src/compile.cpp
+++ b/src/compile.cpp
@@ -28,24 +28,6 @@ const unsigned FrameFootprint = BytesPerWord * 3;
 
 class ArgumentList;
 
-inline void
-markBit(uintptr_t* map, unsigned i)
-{
-  map[wordOf(i)] |= static_cast<uintptr_t>(1) << bitOf(i);
-}
-
-inline void
-clearBit(uintptr_t* map, unsigned i)
-{
-  map[wordOf(i)] &= ~(static_cast<uintptr_t>(1) << bitOf(i));
-}
-
-inline unsigned
-getBit(uintptr_t* map, unsigned i)
-{
-  return map[wordOf(i)] & (static_cast<uintptr_t>(1) << bitOf(i));
-}
-
 class Buffer {
  public:
   Buffer(System* s, unsigned minimumCapacity):
@@ -318,8 +300,8 @@ class StackMapper {
 
       unsigned i = index[ip];
       while (true) {
-        fprintf(stderr, "event %d; ip %d; sp %d; local size %d; map size %d\n",
-                log.get(i), ip, sp, localSize(), mapSize());
+//         fprintf(stderr, "event %d; ip %d; sp %d; local size %d; map size %d\n",
+//                 log.get(i), ip, sp, localSize(), mapSize());
 
         switch (log.get(i++)) {
         case Call: {
diff --git a/src/heap.cpp b/src/heap.cpp
index 73e9a9c42e..409edda161 100644
--- a/src/heap.cpp
+++ b/src/heap.cpp
@@ -206,13 +206,13 @@ class Segment {
     void clearBit(unsigned i) {
       assert(segment->context, wordOf(i) < size());
 
-      data()[wordOf(i)] &= ~(static_cast<uintptr_t>(1) << bitOf(i));
+      vm::clearBit(data(), i);
     }
 
     void setBit(unsigned i) {
       assert(segment->context, wordOf(i) < size());
 
-      data()[wordOf(i)] |= static_cast<uintptr_t>(1) << bitOf(i);
+      vm::markBit(data(), i);
     }
 
     void clearOnlyIndex(unsigned index) {
@@ -738,9 +738,9 @@ bitsetSet(uintptr_t* p, unsigned i, bool v)
   }
 
   if (v) {
-    p[wordOf(i)] |= static_cast<uintptr_t>(1) << bitOf(i);
+    markBit(p, i);
   } else {
-    p[wordOf(i)] &= ~(static_cast<uintptr_t>(1) << bitOf(i));
+    clearBit(p, i);
   }
 }