[llvm] r287553 - [CodeGenPrep] Skip merging empty case blocks

[Joerg Sonnenberger via llvm-commits]

On Mon, Nov 21, 2016 at 04:47:28PM -0000, Jun Bum Lim via llvm-commits wrote:
> Author: junbuml
> Date: Mon Nov 21 10:47:28 2016
> New Revision: 287553
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=287553&view=rev
> Log:
> [CodeGenPrep] Skip merging empty case blocks

This breaks loop info. Try compilating the following test case with -O2:

*a;
b;
fn1() {
  switch (b) {
  case 6:
    while (a && a != ' ' && a[1])
      ;
    while (a)
      fn2();
  }
}

Joerg