Future/bison
1
0
Fork 0
mirror of https://git.savannah.gnu.org/git/bison.git synced 2026-03-09 12:23:04 +00:00
Code Issues Packages Projects Releases Wiki Activity

yacc.c: clarify the computation of yystate

Browse Source 
The yacc.c skeleton is old, and was using many tricks to save
registers.  Today's register allocators can do this themselves.  Let's
keep the code simpler to read and let compilers do their job.

* data/yacc.c: Avoid using yystate for different types of content.
An inline function would be better, but doing this portably will be
a problem.
This commit is contained in:
Akim Demaille
2018-10-22 12:01:56 +02:00
parent ba9db64745
commit ae1e65a285
1 changed files with 12 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
data/yacc.c
View File

@@ -972,13 +972,11 @@ yy_lac (yytype_int16 *yyesa, yytype_int16 **yyes,
{
int yystate;
{
int yylhs = yyr1[yyrule] - YYNTOKENS;
yystate = yypgoto[yylhs] + *yyesp;
if (yystate < 0 || YYLAST < yystate
|| yycheck[yystate] != *yyesp)
yystate = yydefgoto[yylhs];
else
yystate = yytable[yystate];
const int yylhs = yyr1[yyrule] - YYNTOKENS;
const int yyi = yypgoto[yylhs] + *yyesp;
yystate = (0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyesp
? yytable[yyi]
: yydefgoto[yylhs]);
}
if (yyesp == yyes_prev)
{
@@ -1683,14 +1681,13 @@ yyreduce:
/* Now 'shift' the result of the reduction. Determine what state
that goes to, based on the state we popped back to and the rule
number reduced by. */
yyn = yyr1[yyn];
yystate = yypgoto[yyn - YYNTOKENS] + *yyssp;
if (0 <= yystate && yystate <= YYLAST && yycheck[yystate] == *yyssp)
yystate = yytable[yystate];
else
yystate = yydefgoto[yyn - YYNTOKENS];
{
const int yylhs = yyr1[yyn] - YYNTOKENS;
const int yyi = yypgoto[yylhs] + *yyssp;
yystate = (0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyssp
? yytable[yyi]
: yydefgoto[yylhs]);
}
goto yynewstate;