Changes between Version 2 and Version 3 of Commentary/Compiler/GeneratedCode

Timestamp:

Oct 29, 2013 5:15:50 AM (3 years ago)

Author:

Tarrasch

Comment:

Fix nested levels of bullets

Commentary/Compiler/GeneratedCode

@@ -110 +110 @@
        practicably stored in actual available processor registers on most
        architectures.
-     * To deal with the lack of processor registers, most of the STG
+     * To deal with the lack of processor registers, most of the STG 
        registers are actually kept on the stack in a block of memory
-       pointed to by a special STG register called the "base register" (or
+       pointed to by a special STG register called the "base register" (or 
        `BaseReg`). To get or set values of registers which are not kept in
        processor registers, the STG machine generates an instruction to
@@ -118 +118 @@
      * The most important four registers are the `BaseReg`, the stack
        pointer (`Sp`), the heap pointer (`Hp`), and the general purpose
-       register `R1` which is used for intermediate values, as well as for
-       returning evaluated values when unwinding the stack. These are the
+       register `R1` which is used for intermediate values, as well as for 
+       returning evaluated values when unwinding the stack. These are the 
        four registers which are assigned actual processor registers when
        implementing the STG machine on x86.
-     * The STG stack:
-        * Stores function arguments and continuations (i.e. the stack
-          frames which are executed when a function returns)
-        * Grows downwards in memory
-        * The top of the stack is pointed to by the STG register `Sp`, and
-          the maximum available stack pointer is stored in `SpLim`. There is
-          no frame pointer.
-
-     * The heap:
-        * Used to store many different sorts of heap object: notably
-          functions, thunks and data constructors
-        * Grows upwards in memory, towards the stack
-        * All allocation occurs using a bump-allocator: the heap pointer is
-          simply incremented by the number of bytes desired (subject to to a
-          check that this does not exhaust available memory). The garbage
-          collector is responsible for moving objects out of the area of the
-          heap managed by the bump allocator and into the care of its
-          generational collector.
-        * The last address in the bump-allocated part of the heap that has
-          been used is pointed to by the STG register `Hp`, with `HpLim`
-          holding the maximum address available for bump-allocation.
-
-
+ 2. The STG stack:
+     * Stores function arguments and continuations (i.e. the stack
+       frames which are executed when a function returns)
+     * Grows downwards in memory
+     * The top of the stack is pointed to by the STG register `Sp`, and 
+       the maximum available stack pointer is stored in `SpLim`. There is
+       no frame pointer.
+
+ 3. The heap:
+    * Used to store many different sorts of heap object: notably
+      functions, thunks and data constructors
+    * Grows upwards in memory, towards the stack
+    * All allocation occurs using a bump-allocator: the heap pointer is
+      simply incremented by the number of bytes desired (subject to to a
+      check that this does not exhaust available memory). The garbage
+      collector is responsible for moving objects out of the area of the 
+      heap managed by the bump allocator and into the care of its 
+      generational collector.
+    * The last address in the bump-allocated part of the heap that has 
+      been used is pointed to by the STG register `Hp`, with `HpLim`
+      holding the maximum address available for bump-allocation.
 
 === Important concepts in the machine ===