diff options
Diffstat (limited to 'src/passes/OptimizeInstructions.cpp')
| -rw-r--r-- | src/passes/OptimizeInstructions.cpp | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp index 36d92e81f..55af9a34d 100644 --- a/src/passes/OptimizeInstructions.cpp +++ b/src/passes/OptimizeInstructions.cpp @@ -161,7 +161,10 @@ struct OptimizeInstructions #endif } + bool fastMath; + void doWalkFunction(Function* func) { + fastMath = getPassOptions().fastMath; // first, scan locals { LocalScanner scanner(localInfo, getPassOptions()); @@ -1414,14 +1417,15 @@ private: } { double value; - if (matches(curr, binary(Abstract::Sub, any(), fval(&value))) && + if (fastMath && + matches(curr, binary(Abstract::Sub, any(), fval(&value))) && value == 0.0) { // x - (-0.0) ==> x + 0.0 if (std::signbit(value)) { curr->op = Abstract::getBinary(type, Abstract::Add); right->value = right->value.neg(); return curr; - } else { + } else if (fastMath) { // x - 0.0 ==> x return curr->left; } @@ -1430,19 +1434,18 @@ private: { // x + (-0.0) ==> x double value; - if (matches(curr, binary(Abstract::Add, any(), fval(&value))) && + if (fastMath && + matches(curr, binary(Abstract::Add, any(), fval(&value))) && value == 0.0 && std::signbit(value)) { return curr->left; } } - // Note that this is correct even on floats with a NaN on the left, - // as a NaN would skip the computation and just return the NaN, - // and that is precisely what we do here. but, the same with -1 - // (change to a negation) would be incorrect for that reason. if (matches(curr, binary(Abstract::Mul, any(&left), constant(1))) || matches(curr, binary(Abstract::DivS, any(&left), constant(1))) || matches(curr, binary(Abstract::DivU, any(&left), constant(1)))) { - return left; + if (curr->type.isInteger() || fastMath) { + return left; + } } return nullptr; } |