Optimize dynamic string interpolation for symbol/true/false/nil/0-9

This provides a significant speedup for symbol, true, false,
nil, and 0-9, class/module, and a small speedup in most other cases.

Speedups (using included benchmarks):
:symbol        :: 60%
0-9            :: 50%
Class/Module   :: 50%
nil/true/false :: 20%
integer        :: 10%
[]             :: 10%
""             :: 3%

One reason this approach is faster is it reduces the number of
VM instructions for each interpolated value.

Initial idea, approach, and benchmarks from Eric Wong. I applied
the same approach against the master branch, updating it to handle
the significant internal changes since this was first proposed 4
years ago (such as CALL_INFO/CALL_CACHE -> CALL_DATA). I also
expanded it to optimize true/false/nil/0-9/class/module, and added
handling of missing methods, refined methods, and RUBY_DEBUG.

This renames the tostring insn to anytostring, and adds an
objtostring insn that implements the optimization. This requires
making a few functions non-static, and adding some non-static
functions.

This disables 4 YJIT tests.  Those tests should be reenabled after
YJIT optimizes the new objtostring insn.

Implements [Feature #13715]

Co-authored-by: Eric Wong <e@80x24.org>
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
Co-authored-by: Yusuke Endoh <mame@ruby-lang.org>
Co-authored-by: Koichi Sasada <ko1@atdot.net>

1 files changed, 30 insertions, 3 deletions

diff --git a/numeric.c b/numeric.c
index 4f6d76c528..64df7fb807 100644
--- a/numeric.c
+++ b/numeric.c
@@ -35,6 +35,7 @@
 #include "internal/numeric.h"
 #include "internal/object.h"
 #include "internal/rational.h"
+#include "internal/string.h"
 #include "internal/util.h"
 #include "internal/variable.h"
 #include "ruby/encoding.h"
@@ -3631,6 +3632,18 @@ rb_fix2str(VALUE x, int base)
     return rb_usascii_str_new(b, e - b);
 }
 
+static VALUE rb_fix_to_s_static[10];
+
+MJIT_FUNC_EXPORTED VALUE
+rb_fix_to_s(VALUE x)
+{
+    long i = FIX2LONG(x);
+    if (i >= 0 && i < 10) {
+        return rb_fix_to_s_static[i];
+    }
+    return rb_fix2str(x, 10);
+}
+
 /*
  *  call-seq:
  *    to_s(base = 10)  ->  string
@@ -3652,8 +3665,8 @@ rb_fix2str(VALUE x, int base)
  *
  */
 
-static VALUE
-int_to_s(int argc, VALUE *argv, VALUE x)
+MJIT_FUNC_EXPORTED VALUE
+rb_int_to_s(int argc, VALUE *argv, VALUE x)
 {
     int base;
 
@@ -5949,7 +5962,7 @@ Init_Numeric(void)
     rb_define_singleton_method(rb_cInteger, "sqrt", rb_int_s_isqrt, 1);
     rb_define_singleton_method(rb_cInteger, "try_convert", int_s_try_convert, 1);
 
-    rb_define_method(rb_cInteger, "to_s", int_to_s, -1);
+    rb_define_method(rb_cInteger, "to_s", rb_int_to_s, -1);
     rb_define_alias(rb_cInteger, "inspect", "to_s");
     rb_define_method(rb_cInteger, "allbits?", int_allbits_p, 1);
     rb_define_method(rb_cInteger, "anybits?", int_anybits_p, 1);
@@ -5999,6 +6012,20 @@ Init_Numeric(void)
 
     rb_define_method(rb_cInteger, "digits", rb_int_digits, -1);
 
+    rb_fix_to_s_static[0] = rb_fstring_literal("0");
+    rb_fix_to_s_static[1] = rb_fstring_literal("1");
+    rb_fix_to_s_static[2] = rb_fstring_literal("2");
+    rb_fix_to_s_static[3] = rb_fstring_literal("3");
+    rb_fix_to_s_static[4] = rb_fstring_literal("4");
+    rb_fix_to_s_static[5] = rb_fstring_literal("5");
+    rb_fix_to_s_static[6] = rb_fstring_literal("6");
+    rb_fix_to_s_static[7] = rb_fstring_literal("7");
+    rb_fix_to_s_static[8] = rb_fstring_literal("8");
+    rb_fix_to_s_static[9] = rb_fstring_literal("9");
+    for(int i = 0; i < 10; i++) {
+        rb_gc_register_mark_object(rb_fix_to_s_static[i]);
+    }
+
     /* An obsolete class, use Integer */
     rb_define_const(rb_cObject, "Fixnum", rb_cInteger);
     rb_deprecate_constant(rb_cObject, "Fixnum");