| Regression check for optimizing simplify instruction pass. | |
| A pair (sub, neg) should not be transforemd to (sub) for | |
| fp calculation because we can lose the sign of zero for | |
| the following expression: | |
| - ( A - B ) != B - A ; if B == A | |
| Addition or subtraction with fp zero should not be eliminated | |
| because: | |
| -0.0 + 0.0 = 0.0 | |
| -0.0 - -0.0 = 0.0 |