[llvm-dev] basic blocks with input and output parameters instead of phis

[Henning Thielemann via llvm-dev]

I always found the phi instruction pretty unintuitive, because

  1. I thought that due to the SSA form the register uniquely determines the 
basic block and thus the phi instruction should not need the information of a 
"predecessor block".

  2. I remember to have seen valid LL files where the predecessor block in a phi 
instruction was not an immediate predecessor.


I thought that it would be more intuitive to have input and output parameters 
in basic blocks like so:

start:  param (i32 %0, i1 %1)
    ...
    br i1 %1, label start (%2, %3), label stop (%4)

stop: param (i16 %5)
    ...


Has anybody thought about such a structure, yet?