diff options
| -rw-r--r-- | kernel/yosys.cc | 23 |
1 files changed, 5 insertions, 18 deletions
diff --git a/kernel/yosys.cc b/kernel/yosys.cc index 8590242d..eba1aef1 100644 --- a/kernel/yosys.cc +++ b/kernel/yosys.cc @@ -129,24 +129,11 @@ int ceil_log2(int x) if (x <= 0) return 0; - int y = (x & (x - 1)); - y = (y | -y) >> 31; - - x |= (x >> 1); - x |= (x >> 2); - x |= (x >> 4); - x |= (x >> 8); - x |= (x >> 16); - - x >>= 1; - x -= ((x >> 1) & 0x55555555); - x = (((x >> 2) & 0x33333333) + (x & 0x33333333)); - x = (((x >> 4) + x) & 0x0f0f0f0f); - x += (x >> 8); - x += (x >> 16); - x = x & 0x0000003f; - - return x - y; + for (int i = 0; i < 32; i++) + if (((x-1) >> i) == 0) + return i; + + log_abort(); } std::string stringf(const char *fmt, ...) |