comment

[Jonas Paulsson via llvm-commits]

Hi,

I find the comment in TargetFrameLoweringImpl.cpp slightly confusing.

My interpretation here is that generally IPRA reduces save/restore in 
callee whenever it can, and instead does this in caller. "Callee saved 
registers" is however also a set of specific registers, which makes me 
think of concerns about the allocation order.

Am I understanding things correctly, and if so does this comment change 
look good?

-  // When interprocedural register allocation is enabled caller saved 
registers
-  // are preferred over callee saved registers.
+  // When interprocedural register allocation is enabled it is preferred
+  // to save/restore registers in caller instead of callee.
    if (MF.getTarget().Options.EnableIPRA && 
isSafeForNoCSROpt(MF.getFunction()))
      return;

/Jonas