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, 16 insertions, 0 deletions

diff --git a/vm_insnhelper.h b/vm_insnhelper.h
index 71ca408bf2..0fc31d2cea 100644
--- a/vm_insnhelper.h
+++ b/vm_insnhelper.h
@@ -101,6 +101,22 @@ enum vm_regan_acttype {
 #define DEC_SP(x)  (VM_REG_SP -= (COLLECT_USAGE_REGISTER_HELPER(SP, SET, (x))))
 #define SET_SV(x)  (*GET_SP() = (x))
   /* set current stack value as x */
+#ifdef _MSC_VER
+/* Workaround needed for adding negative number to a pointer */
+#define ADJ_SP(x)  do { \
+    rb_snum_t adj = (x); \
+    if (adj >= 0) { \
+        INC_SP(adj); \
+    } \
+    else { \
+        SIGNED_VALUE dec = -1; \
+        dec *= adj; \
+        DEC_SP(dec); \
+    } \
+} while (0)
+#else
+#define ADJ_SP(x)  INC_SP(x)
+#endif
 
 /* instruction sequence C struct */
 #define GET_ISEQ() (GET_CFP()->iseq)