Generate something sensible for an [SU]ADDO op when the overflow/carry flag is

the conditional for the BRCOND statement. For instance, it will generate:

    addl %eax, %ecx
    jo LOF

instead of

    addl %eax, %ecx
    ; About 10 instructions to compare the signs of LHS, RHS, and sum.
    jl LOF

llvm-svn: 60123

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 2e449b99316..ba73f49f883 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -1382,6 +1382,8 @@ static X86::CondCode GetCondFromBranchOpc(unsigned BrOpc) {
   case X86::JNP: return X86::COND_NP;
   case X86::JO:  return X86::COND_O;
   case X86::JNO: return X86::COND_NO;
+  case X86::JC:  return X86::COND_C;
+  case X86::JNC: return X86::COND_NC;
   }
 }
 
@@ -1404,6 +1406,8 @@ unsigned X86::GetCondBranchFromCond(X86::CondCode CC) {
   case X86::COND_NP: return X86::JNP;
   case X86::COND_O:  return X86::JO;
   case X86::COND_NO: return X86::JNO;
+  case X86::COND_C:  return X86::JC;
+  case X86::COND_NC: return X86::JNC;
   }
 }
 
@@ -1428,6 +1432,8 @@ X86::CondCode X86::GetOppositeBranchCondition(X86::CondCode CC) {
   case X86::COND_NP: return X86::COND_P;
   case X86::COND_O:  return X86::COND_NO;
   case X86::COND_NO: return X86::COND_O;
+  case X86::COND_C:  return X86::COND_NC;
+  case X86::COND_NC: return X86::COND_C;
   }
 }