It is possible that we have different constants in different slots
of second vector double (float) of pow function. So, in this case
Exp->getSplatValue() will return nullptr. Here, I handle it properly.
Reviewed By: steven.zhang, PowerPC
Differential Revision: https://reviews.llvm.org/D91729
Here, I am proposing to add an special case for massv powf4/powd2 function (SIMD counterpart of powf/pow function in MASSV library) in MASSV pass to get later optimizations like conversion from pow(x,0.75) and pow(x,0.25) for double and single precision to sequence of sqrt's in the DAGCombiner in vector float case. My reason for doing this is: the optimized pow(x,0.75) and pow(x,0.25) for double and single precision to sequence of sqrt's is faster than powf4/powd2 on P8 and P9.
In case MASSV functions is called, and if the exponent of pow is 0.75 or 0.25, we will get the sequence of sqrt's and if exponent is not 0.75 or 0.25 we will get the appropriate MASSV function.
Reviewed By: steven.zhang
Tags: #LLVM #PowerPC
Differential Revision: https://reviews.llvm.org/D80744