[Beignet] [PATCH 3/3] GBE: Enable CFG printer.

[Ruiling Song]

export OCL_OUTPUT_CFG=1
or export OCL_OUTPUT_CFG_ONLY=1
then it will output .dot file of CFG for the compiled kernels.

The CFG_ONLY means pure cfg without llvm IR.
You can use xdot to view .dot file.

Signed-off-by: Ruiling Song <ruiling.song at intel.com>
---
 backend/src/llvm/llvm_to_gen.cpp |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/backend/src/llvm/llvm_to_gen.cpp b/backend/src/llvm/llvm_to_gen.cpp
index 50b84ce..37a5b2b 100644
--- a/backend/src/llvm/llvm_to_gen.cpp
+++ b/backend/src/llvm/llvm_to_gen.cpp
@@ -55,6 +55,7 @@
 #include "llvm/Assembly/PrintModulePass.h"
 #endif
 
+#include "llvm/Analysis/CFGPrinter.h"
 #include "llvm/llvm_gen_backend.hpp"
 #include "llvm/llvm_to_gen.hpp"
 #include "sys/cvar.hpp"
@@ -68,6 +69,8 @@
 namespace gbe
 {
   BVAR(OCL_OUTPUT_LLVM, false);
+  BVAR(OCL_OUTPUT_CFG, false);
+  BVAR(OCL_OUTPUT_CFG_ONLY, false);
   BVAR(OCL_OUTPUT_LLVM_BEFORE_EXTRA_PASS, false);
   using namespace llvm;
 
@@ -204,6 +207,11 @@ namespace gbe
     passes.add(createDeadInstEliminationPass());  // Remove simplified instructions
     passes.add(createCFGSimplificationPass());     // Merge & remove BBs
     passes.add(createScalarizePass());        // Expand all vector ops
+
+    if(OCL_OUTPUT_CFG)
+      passes.add(createCFGPrinterPass());
+    if(OCL_OUTPUT_CFG_ONLY)
+      passes.add(createCFGOnlyPrinterPass());
     passes.add(createGenPass(unit));
 
     // Print the code extra optimization passes
-- 
1.7.10.4