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compile.c: Emit send for === calls in when statements

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The checkmatch instruction with VM_CHECKMATCH_TYPE_CASE calls
=== without a call cache. Emit a send instruction to make the call
instead. It includes a call cache.

The call cache improves throughput of using when statements to check the
class of a given object. This is useful for say, JSON serialization.

Use of a regular send instead of checkmatch also avoids taking the VM
lock every time, which is good for multi-ractor workloads.

    Calculating -------------------------------------
                             master        post
         vm_case_classes    11.013M     16.172M i/s -      6.000M times in 0.544795s 0.371009s
             vm_case_lit      2.296       2.263 i/s -       1.000 times in 0.435606s 0.441826s
                 vm_case    74.098M     64.338M i/s -      6.000M times in 0.080974s 0.093257s

    Comparison:
                      vm_case_classes
                    post:  16172114.4 i/s
                  master:  11013316.9 i/s - 1.47x  slower

                          vm_case_lit
                  master:         2.3 i/s
                    post:         2.3 i/s - 1.01x  slower

                              vm_case
                  master:  74097858.6 i/s
                    post:  64338333.9 i/s - 1.15x  slower

The vm_case benchmark is a bit slower post patch, possibily due to the
larger instruction sequence. The benchmark dispatches using
opt_case_dispatch so was not running checkmatch and does not make the
=== call post patch.
This commit is contained in:
Alan Wu 2021-05-26 11:50:37 -04:00
parent 788d30a8b3
commit 5ada23ac12
Notes: git 2021-05-29 01:34:38 +09:00 
Merged: https://github.com/ruby/ruby/pull/4468
3 changed files with 13 additions and 4 deletions
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9
benchmark/vm_case_classes.yml Normal file
View File

@ -0,0 +1,9 @@
benchmark:
vm_case_classes: |
case :foo
when Hash
raise
when Array
raise
end
loop_count: 6000000

6
compile.c
View File

@ -4572,8 +4572,6 @@ when_vals(rb_iseq_t *iseq, LINK_ANCHOR *const cond_seq, const NODE *vals,
rb_hash_aset(literals, lit, (VALUE)(l1) | 1); rb_hash_aset(literals, lit, (VALUE)(l1) | 1);
} }
ADD_INSN(cond_seq, val, dup); /* dup target */
if (nd_type(val) == NODE_STR) { if (nd_type(val) == NODE_STR) {
debugp_param("nd_lit", val->nd_lit); debugp_param("nd_lit", val->nd_lit);
lit = rb_fstring(val->nd_lit); lit = rb_fstring(val->nd_lit);
@ -4584,7 +4582,9 @@ when_vals(rb_iseq_t *iseq, LINK_ANCHOR *const cond_seq, const NODE *vals,
if (!COMPILE(cond_seq, "when cond", val)) return -1; if (!COMPILE(cond_seq, "when cond", val)) return -1;
} }
ADD_INSN1(cond_seq, vals, checkmatch, INT2FIX(VM_CHECKMATCH_TYPE_CASE)); // Emit patern === target
ADD_INSN1(cond_seq, vals, topn, INT2FIX(1));
ADD_CALL(cond_seq, vals, idEqq, INT2FIX(1));
ADD_INSNL(cond_seq, val, branchif, l1); ADD_INSNL(cond_seq, val, branchif, l1);
vals = vals->nd_next; vals = vals->nd_next;
} }

2
test/ruby/test_jit.rb
View File

@ -497,7 +497,7 @@ class TestJIT < Test::Unit::TestCase
end end
def test_compile_insn_checkmatch_opt_case_dispatch def test_compile_insn_checkmatch_opt_case_dispatch
assert_compile_once("#{<<~"begin;"}\n#{<<~"end;"}", result_inspect: '"world"', insns: %i[checkmatch opt_case_dispatch]) assert_compile_once("#{<<~"begin;"}\n#{<<~"end;"}", result_inspect: '"world"', insns: %i[opt_case_dispatch])
begin; begin;
case 'hello' case 'hello'
when 'hello' when 'hello'