2 Commits

Author SHA1 Message Date
Michael Liao
7fdc66bf73 Add boolean simplification support from CMOV
- If a boolean value is generated from CMOV and tested as boolean value,
  simplify the use of test result by referencing the original condition.
  RDRAND intrinisc is one of such cases.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163516 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-10 16:36:16 +00:00
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