[PowerPC] Add handling for conversions to fast-isel.

Yet another chunk of fast-isel code.  This one handles various
conversions involving floating-point.  (It also includes some
miscellaneous handling throughout the back end for LWA_32 and LWAX_32
that should have been part of the load-store patch.)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189677 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp

@@ -19,6 +19,7 @@
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetOpcodes.h"
 using namespace llvm;
 
 #include "PPCGenAsmWriter.inc"
@@ -78,6 +79,17 @@ void PPCInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
     }
   }
   
+  // For fast-isel, a COPY_TO_REGCLASS may survive this long.  This is
+  // used when converting a 32-bit float to a 64-bit float as part of
+  // conversion to an integer (see PPCFastISel.cpp:SelectFPToI()),
+  // as otherwise we have problems with incorrect register classes
+  // in machine instruction verification.  For now, just avoid trying
+  // to print it as such an instruction has no effect (a 32-bit float
+  // in a register is already in 64-bit form, just with lower
+  // precision).  FIXME: Is there a better solution?
+  if (MI->getOpcode() == TargetOpcode::COPY_TO_REGCLASS)
+    return;
+  
   printInstruction(MI, O);
   printAnnotation(O, Annot);
 }