Add support for the PPC isel instruction.

The isel (integer select) instruction is supported on the 440 and A2
embedded cores and on the POWER7.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159045 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 1 deletions

diff --git a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
index 61d23ce..79af9a7 100644
--- a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
+++ b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
@@ -86,8 +86,33 @@ void PPCInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
 void PPCInstPrinter::printPredicateOperand(const MCInst *MI, unsigned OpNo,
                                            raw_ostream &O, 
                                            const char *Modifier) {
-  assert(Modifier && "Must specify 'cc' or 'reg' as predicate op modifier!");
   unsigned Code = MI->getOperand(OpNo).getImm();
+  if (!Modifier) {
+    unsigned CCReg = MI->getOperand(OpNo+1).getReg();
+    unsigned RegNo;
+    switch (CCReg) {
+    default: llvm_unreachable("Unknown CR register");
+    case PPC::CR0: RegNo = 0; break;
+    case PPC::CR1: RegNo = 1; break;
+    case PPC::CR2: RegNo = 2; break;
+    case PPC::CR3: RegNo = 3; break;
+    case PPC::CR4: RegNo = 4; break;
+    case PPC::CR5: RegNo = 5; break;
+    case PPC::CR6: RegNo = 6; break;
+    case PPC::CR7: RegNo = 7; break;
+    }
+
+    // Print the CR bit number. The Code is ((BI << 5) | BO) for a
+    // BCC, but we must have the positive form here (BO == 12)
+    unsigned BO = Code & 0xF;
+    unsigned BI = Code >> 5;
+    assert(BO == 12 && "BO in predicate bit must have the positive form");
+
+    unsigned Value = 4*RegNo + BI;
+    O << Value;
+    return;
+  }
+
   if (StringRef(Modifier) == "cc") {
     switch ((PPC::Predicate)Code) {
     case PPC::PRED_ALWAYS: return; // Don't print anything for always.