notes about portability

1 files changed, 33 insertions, 0 deletions

diff --git a/portability b/portability
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+- op_t exists on all architectures, but may have different contents;
+  it is always passable by value.
+
+- pixman-assembler.h:
+
+    - declaration of general assembler methods:
+
+          pixman_assembler_t *pixman_asm_create (
+	  	inst_t *instructions, patch_function_t patch, emit_function_t *emit);
+          pixman_asm (pixman_asm_t *a, const char *instruction, ...);
+	  pixman_asm_label (pixman_asm_t *a, const char *label_name);
+	  pixman_asm_lookup_label (pixman_asm_t *as, const char *label);
+
+- pixman-<arch>-assembler.h contains:
+
+    - definition of op_t for the architecture in question
+    - constructors of op_t for the architecture in question
+    - declaration of pixman_assembler_create_<arch>
+    - declaration of table of inst_t for architecture
+
+- pixman-assembler.c:
+
+    - includes pixman-<arch>-assembler.h
+    - includes pixman-assembler.h
+
+    - has code to:
+
+          lookup functions by name and addressing-modes ie., op_t must
+      	  contain a mask indicating which addressing modes it matches.
+      	  
+	  locate labels based on their names
+
+	  fix up jumps by calling out to 'patch'