bug report

[roberto@... (Roberto Ierusalimschy)]

Thierry Grellier reported a bug in Lua 5.1.1.  The bug only happens in
functions with more than 255 names/constants.  Then, the interaction
between contants and table accesses (e.g., "2*a.x") may produce weird
results. Bellow is an example (all results should be 2).

We already tracked the bug to a problem in the register-allocation
algorithm, but we have no patch available yet. (That is, we know what is
the problem, but we do not know a nice and simple solution.)

(Thanks to Thierry for his patience to isolate the bug.)

-- Roberto


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v1=1; v2=1; v3=1; v4=1; v5=1; v6=1; v7=1; v8=1; v9=1;
v10=1; v11=1; v12=1; v13=1; v14=1; v15=1; v16=1; v17=1;
v18=1; v19=1; v20=1; v21=1; v22=1; v23=1; v24=1; v25=1;
v26=1; v27=1; v28=1; v29=1; v30=1; v31=1; v32=1; v33=1;
v34=1; v35=1; v36=1; v37=1; v38=1; v39=1; v40=1; v41=1;
v42=1; v43=1; v44=1; v45=1; v46=1; v47=1; v48=1; v49=1;
v50=1; v51=1; v52=1; v53=1; v54=1; v55=1; v56=1; v57=1;
v58=1; v59=1; v60=1; v61=1; v62=1; v63=1; v64=1; v65=1;
v66=1; v67=1; v68=1; v69=1; v70=1; v71=1; v72=1; v73=1;
v74=1; v75=1; v76=1; v77=1; v78=1; v79=1; v80=1; v81=1;
v82=1; v83=1; v84=1; v85=1; v86=1; v87=1; v88=1; v89=1;
v90=1; v91=1; v92=1; v93=1; v94=1; v95=1; v96=1; v97=1;
v98=1; v99=1; v100=1; v101=1; v102=1; v103=1; v104=1; v105=1;
v106=1; v107=1; v108=1; v109=1; v110=1; v111=1; v112=1; v113=1;
v114=1; v115=1; v116=1; v117=1; v118=1; v119=1; v120=1; v121=1;
v122=1; v123=1; v124=1; v125=1; v126=1; v127=1; v128=1; v129=1;
v130=1; v131=1; v132=1; v133=1; v134=1; v135=1; v136=1; v137=1;
v138=1; v139=1; v140=1; v141=1; v142=1; v143=1; v144=1; v145=1;
v146=1; v147=1; v148=1; v149=1; v150=1; v151=1; v152=1; v153=1;
v154=1; v155=1; v156=1; v157=1; v158=1; v159=1; v160=1; v161=1;
v162=1; v163=1; v164=1; v165=1; v166=1; v167=1; v168=1; v169=1;
v170=1; v171=1; v172=1; v173=1; v174=1; v175=1; v176=1; v177=1;
v178=1; v179=1; v180=1; v181=1; v182=1; v183=1; v184=1; v185=1;
v186=1; v187=1; v188=1; v189=1; v190=1; v191=1; v192=1; v193=1;
v194=1; v195=1; v196=1; v197=1; v198=1; v199=1; v200=1; v201=1;
v202=1; v203=1; v204=1; v205=1; v206=1; v207=1; v208=1; v209=1;
v210=1; v211=1; v212=1; v213=1; v214=1; v215=1; v216=1; v217=1;
v218=1; v219=1; v220=1; v221=1; v222=1; v223=1; v224=1; v225=1;
v226=1; v227=1; v228=1; v229=1; v230=1; v231=1; v232=1; v233=1;
v234=1; v235=1; v236=1; v237=1; v238=1; v239=1; v240=1; v241=1;
v242=1; v243=1; v244=1; v245=1; v246=1; v247=1; v248=1; v249=1;
v250=1;
v251={k1 = 1};
v252=1;
print(2 * v251.k1, v251.k1 * 2);
v253=1;
print(2 * v251.k1, v251.k1 * 2);
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