luke
/
iverilog
mirror of https://github.com/steveicarus/iverilog.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Add support for scaled real numbers. 

Verilog-AMS supports scaled real numbers, where the "e<N>" (scientific
notation) is replaced with engineering scales from "a" (atto-) to
m (milli-) and "K" (kilo-) to "T" (tera-). This syntax can be handled
way down in the lexor.
This commit is contained in:
Stephen Williams 2008-05-07 22:11:19 -07:00
parent dea1161c7e
commit 2d068ca89f
1 changed files with 43 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
lexor.lex
View File

@ -97,9 +97,12 @@ static int comment_enter;
%x PPDEFAULT_NETTYPE
%x PPBEGIN_KEYWORDS
%s EDGES
%x REAL_SCALE
W [ \t\b\f\r]+
S [afpnumkKMGT]
%%
^"#line"[ ]+\"[^\"]*\"[ ]+[0-9]+.* { line_directive(); }
@ -272,6 +275,46 @@ W [ \t\b\f\r]+
based_size = yylval.number->as_ulong();
return DEC_NUMBER; }
/* These rules handle the scaled real literals from Verilog-AMS. The
value is a number with a single letter scale factor. If
verilog-ams is not enabled, then reject this rule. If it is
enabled, then collect the scale and use it to scale the value. */
[0-9][0-9_]*\.[0-9][0-9_]*/{S} {
if (!gn_verilog_ams_flag) REJECT;
BEGIN(REAL_SCALE);
yymore(); }
[0-9][0-9_]*/{S} {
if (!gn_verilog_ams_flag) REJECT;
BEGIN(REAL_SCALE);
yymore(); }
<REAL_SCALE>{S} {
size_t token_len = strlen(yytext);
char*tmp = new char[token_len + 5];
int scale = 0;
strcpy(tmp, yytext);
switch (tmp[token_len-1]) {
case 'a': scale = -18; break; /* atto- */
case 'f': scale = -15; break; /* femto- */
case 'p': scale = -12; break; /* pico- */
case 'n': scale = -9; break; /* nano- */
case 'u': scale = -6; break; /* micro- */
case 'm': scale = -3; break; /* milli- */
case 'k': scale = 3; break; /* kilo- */
case 'K': scale = 3; break; /* kilo- */
case 'M': scale = 6; break; /* mega- */
case 'G': scale = 9; break; /* giga- */
case 'T': scale = 12; break; /* tera- */
default: assert(0); break;
}
snprintf(tmp+token_len-1, 5, "e%d", scale);
yylval.realtime = new verireal(tmp);
delete[]tmp;
BEGIN(0);
return REALTIME; }
[0-9][0-9_]*\.[0-9][0-9_]*([Ee][+-]?[0-9][0-9_]*)? {
yylval.realtime = new verireal(yytext);
return REALTIME; }