Fix digit-formatting calculation for small numbers.

Calling log10() on zero causes a non-sensical value to be calculated. On some
compile options, I've observed yosys crashing with an illegal
instruction (SIGILL).

To make it safe, fix the calculation to do a range check; wrap it a
decimal_digits() function, and use it where the previous ceil(log10(n)) call
was used. As a side, it also improves readability.

Signed-off-by: Henner Zeller <h.zeller@acm.org>
This commit is contained in:
Henner Zeller 2021-01-21 12:20:53 -08:00
parent 1f88a3de74
commit 7d014902ec
1 changed files with 10 additions and 6 deletions

View File

@ -55,6 +55,10 @@ inline int32_t from_big_endian(int32_t i32) {
#define log_debug2(...) ;
//#define log_debug2(...) log_debug(__VA_ARGS__)
static int decimal_digits(unsigned n) {
return n > 1 ? ceil(log10(n)) : 1;
}
struct ConstEvalAig
{
RTLIL::Module *module;
@ -515,7 +519,7 @@ void AigerReader::parse_aiger_ascii()
unsigned l1, l2, l3;
// Parse inputs
int digits = ceil(log10(I));
int digits = decimal_digits(I);
for (unsigned i = 1; i <= I; ++i, ++line_count) {
if (!(f >> l1))
log_error("Line %u cannot be interpreted as an input!\n", line_count);
@ -537,7 +541,7 @@ void AigerReader::parse_aiger_ascii()
clk_wire->port_input = true;
clk_wire->port_output = false;
}
digits = ceil(log10(L));
digits = decimal_digits(L);
for (unsigned i = 0; i < L; ++i, ++line_count) {
if (!(f >> l1 >> l2))
log_error("Line %u cannot be interpreted as a latch!\n", line_count);
@ -575,7 +579,7 @@ void AigerReader::parse_aiger_ascii()
}
// Parse outputs
digits = ceil(log10(O));
digits = decimal_digits(O);
for (unsigned i = 0; i < O; ++i, ++line_count) {
if (!(f >> l1))
log_error("Line %u cannot be interpreted as an output!\n", line_count);
@ -643,7 +647,7 @@ void AigerReader::parse_aiger_binary()
std::string line;
// Parse inputs
int digits = ceil(log10(I));
int digits = decimal_digits(I);
for (unsigned i = 1; i <= I; ++i) {
log_debug2("%d is an input\n", i);
RTLIL::Wire *wire = module->addWire(stringf("$i%0*d", digits, i));
@ -662,7 +666,7 @@ void AigerReader::parse_aiger_binary()
clk_wire->port_input = true;
clk_wire->port_output = false;
}
digits = ceil(log10(L));
digits = decimal_digits(L);
l1 = (I+1) * 2;
for (unsigned i = 0; i < L; ++i, ++line_count, l1 += 2) {
if (!(f >> l2))
@ -700,7 +704,7 @@ void AigerReader::parse_aiger_binary()
}
// Parse outputs
digits = ceil(log10(O));
digits = decimal_digits(O);
for (unsigned i = 0; i < O; ++i, ++line_count) {
if (!(f >> l1))
log_error("Line %u cannot be interpreted as an output!\n", line_count);