From 4a23f0695a40e735a2215ea9fbf7e388e384f051 Mon Sep 17 00:00:00 2001 From: nobu Date: Wed, 18 Nov 2015 02:32:17 +0000 Subject: compile.c: optimize useless branches * compile.c (iseq_peephole_optimize): eliminate always/never branches after a literal object. this sequence typically appears by defined? operator for a method call on a local variable. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52633 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- compile.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'compile.c') diff --git a/compile.c b/compile.c index f66f12e94b..ae900fbf31 100644 --- a/compile.c +++ b/compile.c @@ -2031,6 +2031,33 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal */ replace_destination(iobj, nobj); } + else if (pobj) { + int cond; + if (pobj->insn_id == BIN(putobject)) { + cond = (iobj->insn_id == BIN(branchif) ? + OPERAND_AT(pobj, 0) != Qfalse : + iobj->insn_id == BIN(branchunless) ? + OPERAND_AT(pobj, 0) == Qfalse : + FALSE); + } + else if (pobj->insn_id == BIN(putstring)) { + cond = iobj->insn_id == BIN(branchif); + } + else if (pobj->insn_id == BIN(putnil)) { + cond = iobj->insn_id != BIN(branchif); + } + else break; + REMOVE_ELEM(&pobj->link); + if (cond) { + iobj->insn_id = BIN(jump); + goto again; + } + else { + unref_destination(iobj); + REMOVE_ELEM(&iobj->link); + } + break; + } else break; nobj = (INSN *)get_destination_insn(nobj); } -- cgit v1.2.3