[Beignet] [PATCH] GBE: Fix fast-math issue under llvm 3.6.

[Ruiling Song]

"__ocl_math_fastpath_flag" was directly optimized out when compiling libocl under llvm 3.6
And set its initialization value after loading libocl.

Signed-off-by: Ruiling Song <ruiling.song at intel.com>
---
 backend/src/libocl/tmpl/ocl_math.tmpl.cl |    2 +-
 backend/src/llvm/llvm_bitcode_link.cpp   |   10 ++++------
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/backend/src/libocl/tmpl/ocl_math.tmpl.cl b/backend/src/libocl/tmpl/ocl_math.tmpl.cl
index aaa6cc3..2ed7b31 100644
--- a/backend/src/libocl/tmpl/ocl_math.tmpl.cl
+++ b/backend/src/libocl/tmpl/ocl_math.tmpl.cl
@@ -21,7 +21,7 @@
 #include "ocl_common.h"
 #include "ocl_integer.h"
 
-constant int __ocl_math_fastpath_flag = 1;
+extern constant int __ocl_math_fastpath_flag;
 
 PURE CONST float __gen_ocl_fabs(float x);
 CONST float __gen_ocl_sin(float x) __asm("llvm.sin" ".f32");
diff --git a/backend/src/llvm/llvm_bitcode_link.cpp b/backend/src/llvm/llvm_bitcode_link.cpp
index 61e2ea1..96f7781 100644
--- a/backend/src/llvm/llvm_bitcode_link.cpp
+++ b/backend/src/llvm/llvm_bitcode_link.cpp
@@ -73,12 +73,10 @@ namespace gbe
       return NULL;
     }
 
-    if (strictMath) {
-      llvm::GlobalVariable* mathFastFlag = oclLib->getGlobalVariable("__ocl_math_fastpath_flag");
-      assert(mathFastFlag);
-      Type* intTy = IntegerType::get(ctx, 32);
-      mathFastFlag->setInitializer(ConstantInt::get(intTy, 0));
-    }
+    llvm::GlobalVariable* mathFastFlag = oclLib->getGlobalVariable("__ocl_math_fastpath_flag");
+    assert(mathFastFlag);
+    Type* intTy = IntegerType::get(ctx, 32);
+    mathFastFlag->setInitializer(ConstantInt::get(intTy, strictMath ? 0 : 1));
 
     return oclLib;
   }
-- 
1.7.10.4