Michael Liao 2a33cec66a add X86-specific DAG optimization to simplify boolean test
- if a boolean test (X86ISD::CMP or X86ISD:SUB) checks a boolean value
  generated from X86ISD::SETCC, try to simplify the boolean value
  generation and checking by reusing the original EFLAGS with proper
  condition code
- add hooks to X86 specific SETCC/BRCOND/CMOV, the major 3 places
  consuming EFLAGS

part of patches fixing PR12312



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161687 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-10 19:58:13 +00:00
..
2012-07-23 08:51:15 +00:00