- mono_metadata_row_col
- mono_g_hash_table_lookup
- mono_domain_get
-* the managed/unmanaged boundary is quite slow:
- - it calls mono_get_lmf_addr, which calls TlsGetValue, which calls
- pthread_getspecific (). This means that 3 function calls are needed for
- each native function call.
* if a function which involves locking is called from another function which
acquires the same lock, it might be useful to create a separate _inner
version of the function which does not re-acquire the lock. This is a perf
win only if the function is called a lot of times, like mono_get_method.
-* the frame_state_for function in glibc 2.3.2 can't correctly decipher the
- unwind tables generated by gcc 3.3. It allways tells the runtime that not all
- callee saved registers are saved, even when the icall is marked with
- MONO_ARCH_SAVE_REGS. This forces the runtime to generate wrapper functions
- for all icalls, slowing things down greatly.
-
* we can avoid calls to class init trampolines if the are multiple calls to the
same trampoline in the same basic block. See:
* Remove the various graph options, have a separate --help-graph for
that list.
+Cleanup
+-------
+
+Clean up the usage of the various CEE_/OP_ constants inside the JIT.
+
+Currently, there are the 5 variants for each opcode:
+- CEE_...
+- OP_...
+- OP_I...
+- OP_L...
+- OP_P...
+
+Some opcodes have some variants, while others don't.
+
+They are used as follows:
+- In method_to_ir, CEE_ means the IL opcode ie. without operand size information
+- In the rules inside the .brg files CEE_ means the same as OP_I..., since
+ long opcodes were transformed into OP_L.... by method_to_ir.
+- In the IR emitted by the rules inside the .brg files, CEE_ means the same as
+ OP_P..., since it is usually generated for pointer manipulation.
+- In mono_arch_emit_opcode, CEE_ means OP_P....
+
+As can be seen above, this is a mess. A proposed solution would be the
+following:
+
+- In method_to_ir, transform CEE_ opcodes into the appropriate OP_I/OP_L
+ opcodes.
+- Get rid of the OP_P opcodes, and use the OP_... opcodes instead, since the
+ two usually means the same.
+- In the IR emitted by the burg rules, use the OP_... opcodes instead of the
+ CEE and OP_P opcodes.
+
+Using these rules would ensure that the same opcode means the same thing in
+all parts of the JIT.
+
+