Combine call info and cache to speed up method invocation

To perform a regular method call, the VM needs two structs,
`rb_call_info` and `rb_call_cache`. At the moment, we allocate these two
structures in separate buffers. In the worst case, the CPU needs to read
4 cache lines to complete a method call. Putting the two structures
together reduces the maximum number of cache line reads to 2.

Combining the structures also saves 8 bytes per call site as the current
layout uses separate two pointers for the call info and the call cache.
This saves about 2 MiB on Discourse.

This change improves the Optcarrot benchmark at least 3%. For more
details, see attached bugs.ruby-lang.org ticket.

Complications:
 - A new instruction attribute `comptime_sp_inc` is introduced to
 calculate SP increase at compile time without using call caches. At
 compile time, a `TS_CALLDATA` operand points to a call info struct, but
 at runtime, the same operand points to a call data struct. Instruction
 that explicitly define `sp_inc` also need to define `comptime_sp_inc`.
 - MJIT code for copying call cache becomes slightly more complicated.
 - This changes the bytecode format, which might break existing tools.

[Misc #16258]

1 files changed, 2 insertions, 2 deletions

diff --git a/tool/ruby_vm/views/mjit_compile.inc.erb b/tool/ruby_vm/views/mjit_compile.inc.erb
index d9092a756d..95e71183d9 100644
--- a/tool/ruby_vm/views/mjit_compile.inc.erb
+++ b/tool/ruby_vm/views/mjit_compile.inc.erb
@@ -56,8 +56,8 @@ switch (insn) {
 <%=   render 'mjit_compile_send', locals: { insn: insn } -%>
 %   when *send_compatible_opt_insns
 %     # To avoid cancel, just emit `opt_send_without_block` instead of `opt_*` insn if call cache is populated.
-%     cc_index = insn.opes.index { |o| o.fetch(:type) == 'CALL_CACHE' }
-      if (has_valid_method_type(status->cc_entries + ((CALL_CACHE)operands[<%= cc_index %>] - body->cc_entries))) {
+%     cd_index = insn.opes.index { |o| o.fetch(:type) == 'CALL_DATA' }
+      if (has_valid_method_type(status->cc_entries + call_data_index((CALL_DATA)operands[<%= cd_index %>], body))) {
 <%=       render 'mjit_compile_send', locals: { insn: opt_send_without_block } -%>
 <%=       render 'mjit_compile_insn', locals: { insn: opt_send_without_block } -%>
           break;