Differences

This shows you the differences between two versions of the page.

--- dev:crosscompiler:backend_ppc:code_generator [2018/11/06 15:58] – [Stackframe] ursgraf
+++ dev:crosscompiler:backend_ppc:code_generator [2022/12/20 15:52] (current) – [Accessing the Hardware] ursgraf
@@ Line 36: / Line 36: @@
 ===== Accessing the Hardware =====
-Java does not allow direct access and manipulation of absolute memory locations. Nevertheless this is essential for embedded programming. We therefore include this possibility by using a special class //ch.ntb.inf.deep.unsafe.ppc.US.java// (US stand for unsafe). Wenn methods of this class are used the code generator has to insert machine code directly. The register allocator does not have to allocate registers for this instructions. //US.java// therefore serves as simple stubs.
+Java does not allow direct access and manipulation of absolute memory locations. Nevertheless this is essential for embedded programming. We therefore include this possibility by using a special class //org.deepjava.unsafe.ppc.US.java// (US stand for unsafe). Wenn methods of this class are used the code generator has to insert machine code directly. The register allocator does not have to allocate registers for this instructions. //US.java// therefore serves as simple stubs.
 ===== Low Level Classes =====
@@ Line 48: / Line 48: @@
   * Delegation of interface methods: address of this method inserted into the type descriptor by the linker
   * Exception handling: call to this methods inserted by the code generator
+==== Practical Implementation of Searching the Correct Interface Method ====
+//imDelegIiMm// needs 3 auxiliary registers. At compile time we cannot reserve such auxiliary registers as these registers must always be the same. Therefore, we use parameter registers. They are volatile and can be freely used though this means, that interface methods can pass less parameters, which is generally true. If not true, the compiler will report.\\
+R10 holds the necessary information for the delegate method. The first two bytes are the ID of the sought-after interface, tho last to bytes contain the method offset. Loading of R10 should happen after parameter copying as R10 might be used there.

deep

User Tools

Site Tools

Differences

Page Tools