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Unify style of checked integer division for sol->yul code generation.

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Daniel Kirchner 2019-06-12 13:19:38 +02:00 committed by chriseth
parent 5f6af8b374
commit e4c884ae13
1 changed files with 5 additions and 7 deletions
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12
libsolidity/codegen/YulUtilFunctions.cpp
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@ -439,8 +439,6 @@ string YulUtilFunctions::overflowCheckedUIntMulFunction(size_t _bits)
string YulUtilFunctions::overflowCheckedIntDivFunction(IntegerType const& _type) string YulUtilFunctions::overflowCheckedIntDivFunction(IntegerType const& _type)
{ {
unsigned bits = _type.numBits();
solAssert(0 < bits && bits <= 256 && bits % 8 == 0, "");
string functionName = "checked_div_" + _type.identifier(); string functionName = "checked_div_" + _type.identifier();
return m_functionCollector->createFunction(functionName, [&]() { return m_functionCollector->createFunction(functionName, [&]() {
return return
@ -448,7 +446,7 @@ string YulUtilFunctions::overflowCheckedIntDivFunction(IntegerType const& _type)
function <functionName>(x, y) -> r { function <functionName>(x, y) -> r {
if iszero(y) { revert(0, 0) } if iszero(y) { revert(0, 0) }
<?signed> <?signed>
// x / -1 == x // overflow for minVal / -1
if and( if and(
eq(x, <minVal>), eq(x, <minVal>),
eq(y, sub(0, 1)) eq(y, sub(0, 1))
@ -457,10 +455,10 @@ string YulUtilFunctions::overflowCheckedIntDivFunction(IntegerType const& _type)
r := <?signed>s</signed>div(x, y) r := <?signed>s</signed>div(x, y)
} }
)") )")
("functionName", functionName) ("functionName", functionName)
("signed", _type.isSigned()) ("signed", _type.isSigned())
("minVal", (0 - (u256(1) << (bits - 1))).str()) ("minVal", toCompactHexWithPrefix(u256(_type.minValue())))
.render(); .render();
}); });
} }