Recompile JIT-ed code without optimization

based on inline cache when JIT cancel happens by that.

This feature was in the original MJIT implementation by Vladimir, but on
merging MJIT to Ruby it was removed for simplification. This commit adds
the functionality again for the following benchmark:

https://github.com/benchmark-driver/misc/blob/52f05781f65467baf895bf6ba79d172c9b0826fd/concurrent-map/bench.rb
(shown float is duration seconds. shorter is better)

* Before
```
$ INHERIT=0 ruby -v bench.rb
ruby 2.7.0dev (2019-04-13 trunk 67523) [x86_64-linux]
--
1.6507579649914987

$ INHERIT=0 ruby -v --jit bench.rb
ruby 2.7.0dev (2019-04-13 trunk 67523) +JIT [x86_64-linux]
--
1.5091587850474752

$ INHERIT=1 ruby -v bench.rb
ruby 2.7.0dev (2019-04-13 trunk 67523) [x86_64-linux]
--
1.6124781150138006

$ INHERIT=1 ruby --jit -v bench.rb
ruby 2.7.0dev (2019-04-13 trunk 67523) +JIT [x86_64-linux]
--
1.7495657080435194 # <-- this
```

* After
```
$ INHERIT=0 ruby -v bench.rb
ruby 2.7.0dev (2019-04-13 trunk 67523) [x86_64-linux]
last_commit=Recompile JIT-ed code without optimization
--
1.653559010999743

$ INHERIT=0 ruby --jit -v bench.rb
ruby 2.7.0dev (2019-04-13 trunk 67523) +JIT [x86_64-linux]
last_commit=Recompile JIT-ed code without optimization
--
1.4738391840364784

$ INHERIT=1 ruby -v bench.rb
ruby 2.7.0dev (2019-04-13 trunk 67523) [x86_64-linux]
last_commit=Recompile JIT-ed code without optimization
--
1.645227018976584

$ INHERIT=1 ruby --jit -v bench.rb
ruby 2.7.0dev (2019-04-13 trunk 67523) +JIT [x86_64-linux]
last_commit=Recompile JIT-ed code without optimization
--
1.523708809982054 # <-- this
```

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67530 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/mjit_compile.c b/mjit_compile.c
index 8a3b6b3437..9341970e01 100644
--- a/mjit_compile.c
+++ b/mjit_compile.c
@@ -37,6 +37,8 @@ struct compile_status {
     // Safely-accessible cache entries copied from main thread.
     union iseq_inline_storage_entry *is_entries;
     struct rb_call_cache *cc_entries;
+    // Mutated optimization levels
+    struct rb_mjit_compile_info *compile_info;
 };
 
 /* Storage to keep data which is consistent in each conditional branch.
@@ -213,6 +215,7 @@ mjit_compile(FILE *f, const rb_iseq_t *iseq, const char *funcname)
             alloca(sizeof(struct rb_call_cache) * (body->ci_size + body->ci_kw_size)) : NULL,
         .is_entries = (body->is_size > 0) ?
             alloca(sizeof(union iseq_inline_storage_entry) * body->is_size) : NULL,
+        .compile_info = rb_mjit_iseq_compile_info(body),
     };
     memset(status.stack_size_for_pos, NOT_COMPILED_STACK_SIZE, sizeof(int) * body->iseq_size);
     if ((status.cc_entries != NULL || status.is_entries != NULL)
@@ -235,6 +238,7 @@ mjit_compile(FILE *f, const rb_iseq_t *iseq, const char *funcname)
     else {
         fprintf(f, "    VALUE *stack = reg_cfp->sp;\n");
     }
+    fprintf(f, "    static const rb_iseq_t *original_iseq = 0x%"PRIxVALUE";\n", (VALUE)iseq);
     fprintf(f, "    static const VALUE *const original_body_iseq = (VALUE *)0x%"PRIxVALUE";\n",
             (VALUE)body->iseq_encoded);