P4
The new flag "InitArrayShortSize" was set to 8 on PPC64. However, this leads to bad code. PPC64's C2 compiler currently does not have dedicated match rules to store 0.
Unfortunately, loading of the constant 0 got rematerialized many times in some cases consuming more registers and code space than needed.
An attempt to improve initialization was
8170094: PPC64: Keep immediate value 0 cached into a register to improve performance
but this approach has disadvantages and we had decided against it.
It is possibly to implement special ClearArray nodes to improve the initialization of arrays only.
We decided not to decrease InitArrayShortSize, but to generate better code for constant length arrays.
Unfortunately, loading of the constant 0 got rematerialized many times in some cases consuming more registers and code space than needed.
An attempt to improve initialization was
8170094: PPC64: Keep immediate value 0 cached into a register to improve performance
but this approach has disadvantages and we had decided against it.
It is possibly to implement special ClearArray nodes to improve the initialization of arrays only.
We decided not to decrease InitArrayShortSize, but to generate better code for constant length arrays.