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Implement ctz/popcnt in yulInterpreter

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This commit is contained in:
Alex Beregszaszi 2020-07-08 23:16:43 +01:00
parent 87557896ed
commit 8df4baac42
1 changed files with 50 additions and 0 deletions
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50
test/tools/yulInterpreter/EwasmBuiltinInterpreter.cpp
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@ -67,6 +67,50 @@ uint64_t clz64(uint64_t _v)
return r;
}
/// Count trailing zeros for uint32. Following WebAssembly rules, it returns 32 for @a _v being zero.
/// NOTE: the ctz builtin of the compiler may or may not do this
uint32_t ctz32(uint32_t _v)
{
if (_v == 0)
return 32;
uint32_t r = 0;
while (!(_v & 1))
{
r++;
_v >>= 1;
}
return r;
}
/// Count trailing zeros for uint64. Following WebAssembly rules, it returns 64 for @a _v being zero.
/// NOTE: the ctz builtin of the compiler may or may not do this
uint64_t ctz64(uint64_t _v)
{
if (_v == 0)
return 64;
uint64_t r = 0;
while (!(_v & 1))
{
r++;
_v >>= 1;
}
return r;
}
/// Count number of bits set for uint64
uint64_t popcnt(uint64_t _v)
{
uint64_t r = 0;
while (_v)
{
r += (_v & 1);
_v >>= 1;
}
return r;
}
}
using u512 = boost::multiprecision::number<boost::multiprecision::cpp_int_backend<512, 256, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>>;
@ -139,6 +183,10 @@ u256 EwasmBuiltinInterpreter::evalBuiltin(YulString _fun, vector<u256> const& _a
return clz64(arg[0] & uint32_t(-1)) - 32;
else if (_fun == "i64.clz"_yulstring)
return clz64(arg[0]);
else if (_fun == "i32.ctz"_yulstring)
return ctz32(uint32_t(arg[0] & uint32_t(-1)));
else if (_fun == "i64.ctz"_yulstring)
return ctz64(arg[0]);
string prefix = _fun.str();
string suffix;
@ -207,6 +255,8 @@ u256 EwasmBuiltinInterpreter::evalWasmBuiltin(string const& _fun, vector<Word> c
return arg[0] != arg[1] ? 1 : 0;
else if (_fun == "eqz")
return arg[0] == 0 ? 1 : 0;
else if (_fun == "popcnt")
return popcnt(arg[0]);
else if (_fun == "lt_u")
return arg[0] < arg[1] ? 1 : 0;
else if (_fun == "gt_u")