3
0
Fork 0
mirror of https://github.com/YosysHQ/yosys synced 2025-04-24 01:25:33 +00:00

cxxrtl: Fix value::sshr

This commit is contained in:
Merry 2023-12-13 12:11:57 +00:00
parent ff53f3d2b6
commit ded63bedd5
2 changed files with 30 additions and 5 deletions

View file

@ -430,12 +430,12 @@ struct value : public expr_base<value<Bits>> {
// Detect shifts definitely large than Bits early.
for (size_t n = 1; n < amount.chunks; n++)
if (amount.data[n] != 0)
return {};
return (Signed && is_neg()) ? value<Bits>().bit_not() : value<Bits>();
// Past this point we can use the least significant chunk as the shift size.
size_t shift_chunks = amount.data[0] / chunk::bits;
size_t shift_bits = amount.data[0] % chunk::bits;
if (shift_chunks >= chunks)
return {};
return (Signed && is_neg()) ? value<Bits>().bit_not() : value<Bits>();
value<Bits> result;
chunk::type carry = 0;
for (size_t n = 0; n < chunks - shift_chunks; n++) {
@ -444,12 +444,13 @@ struct value : public expr_base<value<Bits>> {
: data[chunks - 1 - n] << (chunk::bits - shift_bits);
}
if (Signed && is_neg()) {
size_t top_chunk_idx = (Bits - shift_bits) / chunk::bits;
size_t top_chunk_bits = (Bits - shift_bits) % chunk::bits;
size_t top_chunk_idx = amount.data[0] > Bits ? 0 : (Bits - amount.data[0]) / chunk::bits;
size_t top_chunk_bits = amount.data[0] > Bits ? 0 : (Bits - amount.data[0]) % chunk::bits;
for (size_t n = top_chunk_idx + 1; n < chunks; n++)
result.data[n] = chunk::mask;
if (shift_bits != 0)
if (amount.data[0] != 0)
result.data[top_chunk_idx] |= chunk::mask << top_chunk_bits;
result.data[result.chunks - 1] &= result.msb_mask;
}
return result;
}