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ruby--ruby/vm_exec.c
ko1 745c23b2d9 * vm_core.h: remove VM_FRAME_MAGIC_FINISH (finish frame type).
Before this commit:
  `finish frame' was place holder which indicates that VM loop
  needs to return function.
  If a C method calls a Ruby methods (a method written by Ruby),
  then VM loop will be (re-)invoked.  When the Ruby method returns,
  then also VM loop should be escaped.  `finish frame' has only
  one instruction `finish', which returns VM loop function.
  VM loop function executes `finish' instruction, then VM loop
  function returns itself.
  With such mechanism, `leave' instruction (which returns one
  frame from current scope) doesn't need to check that this `leave'
  should also return from VM loop function.
  Strictly, one branch can be removed from `leave' instructon.
  Consideration:
  However, pushing the `finish frame' needs costs because
  it needs several memory accesses.  The number of pushing
  `finish frame' is greater than I had assumed.  Of course,
  pushing `finish frame' consumes additional control frame.
  Moreover, recent processors has good branch prediction,
  with which we can ignore such trivial checking.
  After this commit:
  Finally, I decide to remove `finish frame' and `finish'
  instruction.  Some parts of VM depend on `finish frame',
  so the new frame flag VM_FRAME_FLAG_FINISH is introduced.
  If this frame should escape from VM function loop, then
  the result of VM_FRAME_TYPE_FINISH_P(cfp) is true.
  `leave' instruction checks this flag every time.
  I measured performance on it.  However on my environments,
  it improves some benchmarks and slows some benchmarks down.
  Maybe it is because of C compiler optimization parameters.
  I'll re-visit here if this cause problems.
* insns.def (leave, finish): remove finish instruction.
* vm.c, vm_eval.c, vm_exec.c, vm_backtrace.c, vm_dump.c:
  apply above changes.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36099 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2012-06-15 10:22:34 +00:00

143 lines
2.7 KiB
C

/* -*-c-*- */
/**********************************************************************
vm_exec.c -
$Author$
Copyright (C) 2004-2007 Koichi Sasada
**********************************************************************/
#include <math.h>
#if VMDEBUG > 0
#define DECL_SC_REG(type, r, reg) register type reg_##r
#elif __GNUC__ && __x86_64__
#define DECL_SC_REG(type, r, reg) register type reg_##r __asm__("r" reg)
#elif __GNUC__ && __i386__
#define DECL_SC_REG(type, r, reg) register type reg_##r __asm__("e" reg)
#else
#define DECL_SC_REG(type, r, reg) register type reg_##r
#endif
/* #define DECL_SC_REG(r, reg) VALUE reg_##r */
#if !OPT_CALL_THREADED_CODE
static VALUE
vm_exec_core(rb_thread_t *th, VALUE initial)
{
#if OPT_STACK_CACHING
#if 0
#elif __GNUC__ && __x86_64__
DECL_SC_REG(VALUE, a, "12");
DECL_SC_REG(VALUE, b, "13");
#else
register VALUE reg_a;
register VALUE reg_b;
#endif
#endif
#if __GNUC__ && __i386__
DECL_SC_REG(VALUE *, pc, "di");
DECL_SC_REG(rb_control_frame_t *, cfp, "si");
#define USE_MACHINE_REGS 1
#elif __GNUC__ && __x86_64__
DECL_SC_REG(VALUE *, pc, "14");
DECL_SC_REG(rb_control_frame_t *, cfp, "15");
#define USE_MACHINE_REGS 1
#else
register rb_control_frame_t *reg_cfp;
VALUE *reg_pc;
#endif
#if USE_MACHINE_REGS
#undef RESTORE_REGS
#define RESTORE_REGS() \
{ \
REG_CFP = th->cfp; \
reg_pc = reg_cfp->pc; \
}
#undef REG_PC
#define REG_PC reg_pc
#undef GET_PC
#define GET_PC() (reg_pc)
#undef SET_PC
#define SET_PC(x) (reg_cfp->pc = REG_PC = (x))
#endif
#if OPT_TOKEN_THREADED_CODE || OPT_DIRECT_THREADED_CODE
#include "vmtc.inc"
if (UNLIKELY(th == 0)) {
return (VALUE)insns_address_table;
}
#endif
reg_cfp = th->cfp;
reg_pc = reg_cfp->pc;
#if OPT_STACK_CACHING
reg_a = initial;
reg_b = 0;
#endif
first:
INSN_DISPATCH();
/*****************/
#include "vm.inc"
/*****************/
END_INSNS_DISPATCH();
/* unreachable */
rb_bug("vm_eval: unreachable");
goto first;
}
const void **
rb_vm_get_insns_address_table(void)
{
return (const void **)vm_exec_core(0, 0);
}
#else
#include "vm.inc"
#include "vmtc.inc"
const void *const *
rb_vm_get_insns_address_table(void)
{
return insns_address_table;
}
static VALUE
vm_exec_core(rb_thread_t *th, VALUE initial)
{
register rb_control_frame_t *reg_cfp = th->cfp;
VALUE ret;
while (*GET_PC()) {
reg_cfp = ((rb_insn_func_t) (*GET_PC()))(th, reg_cfp);
if (reg_cfp == 0) {
VALUE err = th->errinfo;
th->errinfo = Qnil;
return err;
}
}
if (VM_FRAME_TYPE_FINISH_P(th->cfp)) {
rb_bug("cfp consistency error");
}
ret = *(th->cfp->sp-1); /* pop */
th->cfp++; /* pop cf */
return ret;
}
#endif