also use sp_inc in vm core

Now that sp_inc attributes are officially provided as inline
functions. Why not use them directly from the vm core, not just
by the compiler. By doing so, it is now possible for us to
optimize stack manipulations. We can now know exactly how many
words of stack space an instruction consumes before it actually
does. This changeset deletes some lines from insns.def because
they are no longer needed.  As a result it reduces the size of
vm_exec_core function from 32,400 bytes to 32,352 bytes on my
machine.

It seems it does not affect performance:

-----------------------------------------------------------
benchmark results:
minimum results in each 3 measurements.
Execution time (sec)
name    before  after
loop_for         1.093  1.061
loop_generator   1.156  1.152
loop_times       0.982  0.974
loop_whileloop   0.549  0.587
loop_whileloop2  0.115  0.121

Speedup ratio: compare with the result of `before' (greater is better)
name    after
loop_for        1.030
loop_generator  1.003
loop_times      1.008
loop_whileloop  0.935
loop_whileloop2 0.949

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62087 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 8 deletions

diff --git a/insns.def b/insns.def
index cd57fbd6b8..69f1795814 100644
--- a/insns.def
+++ b/insns.def
@@ -366,7 +366,6 @@ concatstrings
 // attr rb_snum_t sp_inc = 1 - num;
 {
     val = rb_str_concat_literals(num, STACK_ADDR_FROM_TOP(num));
-    POPN(num);
 }
 
 /* push the result of to_s. */
@@ -403,7 +402,6 @@ toregexp
     VALUE rb_reg_new_ary(VALUE ary, int options);
     VALUE rb_ary_tmp_new_from_values(VALUE, long, const VALUE *);
     const VALUE ary = rb_ary_tmp_new_from_values(0, cnt, STACK_ADDR_FROM_TOP(cnt));
-    POPN(cnt);
     val = rb_reg_new_ary(ary, (int)opt);
     rb_ary_clear(ary);
 }
@@ -427,7 +425,6 @@ newarray
 // attr rb_snum_t sp_inc = 1 - num;
 {
     val = rb_ary_new4(num, STACK_ADDR_FROM_TOP(num));
-    POPN(num);
 }
 
 /* dup array */
@@ -494,7 +491,6 @@ newhash
     if (num) {
         rb_hash_bulk_insert(num, STACK_ADDR_FROM_TOP(num), val);
     }
-    POPN(num);
 }
 
 /* put new Range object.(Range.new(low, high, flag)) */
@@ -545,6 +541,7 @@ dupn
 
     INC_SP(n); /* alloca */
     MEMCPY(dst, src, VALUE, n);
+    DEC_SP(n);
 }
 
 /* swap top 2 vals */
@@ -606,7 +603,7 @@ setn
 (VALUE val)
 // attr rb_snum_t sp_inc = 0;
 {
-    TOPN(n-1) = val;
+    TOPN(n) = val;
 }
 
 /* empty current stack */
@@ -617,7 +614,7 @@ adjuststack
 (...)
 // attr rb_snum_t sp_inc = -(rb_snum_t)n;
 {
-    DEC_SP(n);
+    /* none */
 }
 
 /**********************************************************/
@@ -757,7 +754,6 @@ opt_newarray_max
 // attr rb_snum_t sp_inc = 1 - num;
 {
     val = vm_opt_newarray_max(num, STACK_ADDR_FROM_TOP(num));
-    POPN(num);
 }
 
 DEFINE_INSN
@@ -768,7 +764,6 @@ opt_newarray_min
 // attr rb_snum_t sp_inc = 1 - num;
 {
     val = vm_opt_newarray_min(num, STACK_ADDR_FROM_TOP(num));
-    POPN(num);
 }
 
 /* Invoke method without block */