PTX: Add basic register spilling code

The current implementation generates stack loads/stores, which are
really just mov instructions from/to "special" registers.  This may
not be the most efficient implementation, compared to an approach where
the stack registers are directly folded into instructions, but this is
easier to implement and I have yet to see a case where ptxas is unable
to see through this kind of register usage and know what is really
going on.

llvm-svn: 133443

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/Target/PTX/PTXAsmPrinter.cpp b/llvm/lib/Target/PTX/PTXAsmPrinter.cpp
index df973fdeb76..6f6fc29673e 100644
--- a/llvm/lib/Target/PTX/PTXAsmPrinter.cpp
+++ b/llvm/lib/Target/PTX/PTXAsmPrinter.cpp
@@ -23,6 +23,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/MC/MCStreamer.h"
@@ -194,6 +195,18 @@ void PTXAsmPrinter::EmitFunctionBodyStart() {
     def += ';';
     OutStreamer.EmitRawText(Twine(def));
   }
+
+  const MachineFrameInfo* FrameInfo = MF->getFrameInfo();
+  DEBUG(dbgs() << "Have " << FrameInfo->getNumObjects() << " frame object(s)\n");
+  for (unsigned i = 0, e = FrameInfo->getNumObjects(); i != e; ++i) {
+    DEBUG(dbgs() << "Size of object: " << FrameInfo->getObjectSize(i) << "\n");
+    std::string def = "\t.reg .b";
+    def += utostr(FrameInfo->getObjectSize(i)*8); // Convert to bits
+    def += " s";
+    def += utostr(i);
+    def += ";";
+    OutStreamer.EmitRawText(Twine(def));
+  }
 }
 
 void PTXAsmPrinter::EmitInstruction(const MachineInstr *MI) {