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| author | Miguel Sofer <miguel.sofer@gmail.com> | 2002-06-14 19:31:48 (GMT) |
|---|---|---|
| committer | Miguel Sofer <miguel.sofer@gmail.com> | 2002-06-14 19:31:48 (GMT) |
| commit | be3103c4099dfda4a53affe04992f488d7e8a4fe (patch) | |
| tree | 057ce72220d95c29b19129566699ccae913f5117 | |
| parent | 715d823e14591cf3069111aaf5e006e00c23c08d (diff) | |
| download | tcl-be3103c4099dfda4a53affe04992f488d7e8a4fe.zip tcl-be3103c4099dfda4a53affe04992f488d7e8a4fe.tar.gz tcl-be3103c4099dfda4a53affe04992f488d7e8a4fe.tar.bz2 | |
BC-engine: runtime peep-hole optimisation of INST_FOREACH
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | generic/tclExecute.c | 31 |
2 files changed, 27 insertions, 10 deletions
@@ -1,3 +1,9 @@ +2002-06-14 Miguel Sofer <msofer@users.sourceforge.net> + + * generic/tclExecute.c (TclExecuteByteCode): runtime peep-hole + optimisation of INST_FOREACH - relies on peculiarities of the code + produced by the bytecode compiler. + 2002-06-14 David Gravereaux <davygrvy@pobox.com> * win/rules.vc: The test for compiler optimizations was in error. diff --git a/generic/tclExecute.c b/generic/tclExecute.c index 9c29d41..37ebc4b 100644 --- a/generic/tclExecute.c +++ b/generic/tclExecute.c @@ -11,7 +11,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclExecute.c,v 1.65 2002/06/13 23:10:12 msofer Exp $ + * RCS: @(#) $Id: tclExecute.c,v 1.66 2002/06/14 19:31:48 msofer Exp $ */ #include "tclInt.h" @@ -3685,7 +3685,13 @@ TclExecuteByteCode(interp, codePtr) TRACE(("%u => loop iter count temp %d\n", opnd, iterTmpIndex)); } - ADJUST_PC(5); + + /* + * Remark that the compiler ALWAYS sets INST_FOREACH_STEP4 immediately + * after INST_FOREACH_START4 - let us just fall through instead of + * ADJUST_PC(5); + */ + pc += 5; case INST_FOREACH_STEP4: opnd = TclGetUInt4AtPtr(pc+1); @@ -3789,18 +3795,23 @@ TclExecuteByteCode(interp, codePtr) listTmpIndex++; } } - - /* - * Push 1 if at least one value list had a remaining element - * and the loop should continue. Otherwise push 0. - */ - - PUSH_OBJECT(Tcl_NewLongObj(continueLoop)); TRACE(("%u => %d lists, iter %d, %s loop\n", opnd, numLists, iterNum, (continueLoop? "continue" : "exit"))); + + /* + * Run-time peep-hole optimisation: the compiler ALWAYS follows + * INST_FOREACH_STEP4 with an INST_JUMP_FALSE. We just skip that + * instruction and jump direct from here. + */ + + pc += 5; + if (*pc == INST_JUMP_FALSE1) { + ADJUST_PC(continueLoop? 2 : TclGetUInt1AtPtr(pc+1)); + } else { + ADJUST_PC(continueLoop? 5 : TclGetUInt4AtPtr(pc+1)); + } } - ADJUST_PC(5); case INST_BEGIN_CATCH4: /* |