portability

1 files changed, 43 insertions, 19 deletions

diff --git a/portability b/portability
index 092e150..ba5e883 100644
--- a/portability
+++ b/portability
@@ -1,32 +1,46 @@
-- op_t exists on all architectures, but may have different contents;
-  it is always passable by value.
+- optype_t exists on all architectures, but is arch specific. There
+  must be fewer than 32 values in it. (This may be bumped to 64 
+  on all arches if 32 is not enough).
+- op_t exists on all architectures. It is always a 64 bit integer,
+  where the low 8 bits contain an op_type. The rest of the integer
+  is machine specific
+- inst_t is a struct that has three mandatory fields:
+  - name
+  - number of ops
+  - for each op, a bit field describing which optypes are acceptable
+    (remember there are only 32 different optypes).
+  It will typically have additional fields describing the encoding of 
+  the instruction.
+
+
+Files:
 
 - pixman-assembler.h:
 
+    - includes pixman-arch-assembler.h
+
     - declaration of machine_spec_t, which is a struct that describes the
       machine in question.
 
     - declaration of general assembler methods:
 
-          pixman_assembler_t *pixman_assembler_create (const machine_spec_t *machine);
-          uint8_t *pixman_assembler_link (pixman_assembler_t *assembler,
-                                          pixman_fragment_t *fragment,
-                                          ...);
-          pixman_fragment_t *pixman_fragment_new (const machine_spec_t *machine);
-          void               pixman_fragment_assemble (fragment_t *fragment,
-                                                       ...);
-- pixman-<arch>-assembler.h contains:
-
-    - definition of op_type_t for the arch in question
-    - definition of op_t for the architecture in question
-    - constructors of op_t for the architecture in question
-    - declaration of pixman_assembler_create_<arch>
+          pixman_assembler_t *_pixman_assembler_create (const machine_spec_t *machine);
+          uint8_t *_pixman_assembler_link (pixman_assembler_t *assembler,
+                                           pixman_fragment_t *fragment,
+                                           ...);
+          pixman_fragment_t *_pixman_fragment_new (const machine_spec_t *machine);
+          void                pixman_fragment_assemble (fragment_t *fragment,
+                                                        ...);
 
     - declaration of stack manager and register allocator
 
+          void pixman_reg_alloc_init (reg_alloc_t *alloc,
+                                      stack_man_t *stack_man,
+                                      const machine_spec *spec,
+                                      const reg_pool_t *pool);
+
 - pixman-assembler.c:
 
-    - includes pixman-<arch>-assembler.h
     - includes pixman-assembler.h
 
     - has code to:
@@ -42,20 +56,30 @@
 
     - implementation of register allcoator and stack manager.
 
+- pixman-<arch>-assembler.h contains:
+
+    - definition of op_type_t, inst_t for the arch in question
+    - definition of op_t for the architecture in question
+    - macros to construct op_t for the architecture in question
+    - declaration of pixman_assembler_create_<arch>
+
 - pixman-arch-assembler.c contains
 
      - definition of inst_t table
      - definition of pixman_assembler_<arch>_create()
-     - definition of machine_spec_t for the architecture, including
+     - definition of machine_spec_t for the architecture, with methods for
        - how to spill to the stack
        - how to patch up jumps
+       - definition of register pools
 
 - user code will
 
-  - include pixman-<arch>-assembler.h
   - include pixman-assembler.h
-
+  - define pixman_reg_pools as it sees fit
   - call pixman_assembler_create_<arch>
+  - call pixman_reg_alloc_init_<arch>
+
+  Should all the machine_spec stuff go in the user code? Is there any real difference?
 
 Where should the current code-manager.c go? This is platform specific,
 not machine specific. pixman-assembler.c is tempting.