Updated plan

docs/plan.txt

@@ -1,7 +1,20 @@
 General:
 - Use custom __builtin_offsetof definition to preserve the call until lower gimple
 
-OLD Approach:
+Approach:
+- Use gcc 16 callback in build_component_ref to replace relevant offfsetofs with __spslr_offsetof(uid) calls
+	- Maintain mapping from uid to type and member information
+- At early RTL, find calls and replace them with UNSPEC RTL mov instructions of constants
+	- Doing it late would most certainly litter rax (return of call)
+	- Doing it late would also cause surrounding code to deal with clobbering caused by call!
+- At very late RTL, find UNSPECs, replace them with constants and add asm labels
+	- To begin with, this causes one move per offsetof
+	- Later, add DIY constant folding -> patcher executes byte code program produced by postprocessor
+		- Patcher program also handles instructions like SET_PERM(RWX, base, page count)
+		- Current operand values and arbitrary number of member offsets can be used in new operand value compuation
+		- Patcher is just a byte code interpreter
+
+OLD Approach 1:
 - At the very last point of gimple (after gimple optimizations), recognize accesses
 	- Build a mapping of statement location (multiple statements share) to a semantic graph (or tree)
 - Right after expansion to RTL, pattern match set of RTL instructions with same location to graph
@@ -9,7 +22,7 @@ OLD Approach:
 - After all RTL optimizations, add assembly labels before relevant RTL instructions (identified by notes)
 - Might need an additional early pass to prevent COMPONENT_REFs to constant/static stuff from being folded early
 
-Approach:
+OLD Approach 2:
 - At the very first point of gimple (before optimizations), replace COMPONENT_REFs of relevant structs
 	- Turn them into calls of __spslr_component_ref(base (new ssa stmt), type uid, member uid)
 	- Make sure the return type is matching that of the COMPONENT_REF (member type)