Created attachment 645945 [details] [diff] [review]
LMathFunctionD always performs a call using callWithABI(), but it uses saveVolatile() and restoreVolatile() to preserve register safety. These functions push and pop, respectively, every single XMM register around each LMathFunctionD callsite. This is very slow.
By instead marking LMathFunctionD as isCall(), regalloc will have already guaranteed register safety around the LMathFunctionD, perhaps even in a more intelligent manner.