From cef09a18ae9b1a55404db45ade312b06880c0f65 Mon Sep 17 00:00:00 2001 From: sebres Date: Wed, 31 May 2017 08:24:42 +0000 Subject: performance of INST_STR_CONCAT1: closes [716b427f76f8f97a8d9a06043903c53bb2b592c2]: minor optimization in simplest cases, fixed performance regression of TclStringCatObjv usage from [fc9ed1e751180816384d569101950c1f8c4582ad], optimizes patterns like "$v[unset v]", "$v[set v {}]" etc. --- generic/tclExecute.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/generic/tclExecute.c b/generic/tclExecute.c index cfcdd26..2d1c07f 100644 --- a/generic/tclExecute.c +++ b/generic/tclExecute.c @@ -2685,11 +2685,34 @@ TEBCresume( opnd = TclGetUInt1AtPtr(pc+1); + objv = &OBJ_AT_DEPTH(opnd-1); + /* minor optimization in simplest cases */ + switch (opnd) { + case 1: /* only one object */ + objResultPtr = *objv; + goto endINST_STR_CONCAT1; + case 2: /* two objects - check empty */ + if (objv[0]->bytes == &tclEmptyString) { + objResultPtr = objv[1]; + goto endINST_STR_CONCAT1; + } + else + if (objv[1]->bytes == &tclEmptyString) { + objResultPtr = objv[0]; + goto endINST_STR_CONCAT1; + } + break; + case 0: /* no objects - use new empty */ + TclNewObj(objResultPtr); + goto endINST_STR_CONCAT1; + } + /* do concat */ if (TCL_OK != TclStringCatObjv(interp, /* inPlace */ 1, - opnd, &OBJ_AT_DEPTH(opnd-1), &objResultPtr)) { + opnd, objv, &objResultPtr)) { TRACE_ERROR(interp); goto gotError; } + endINST_STR_CONCAT1: TRACE_WITH_OBJ(("%u => ", opnd), objResultPtr); NEXT_INST_V(2, opnd, 1); -- cgit v0.12