Fix for issue #430

builtins.cpp

@@ -597,8 +597,14 @@ lSetInternalFunctions(llvm::Module *module) {
     int count = sizeof(names) / sizeof(names[0]);
     for (int i = 0; i < count; ++i) {
         llvm::Function *f = module->getFunction(names[i]);
-        if (f != NULL && f->empty() == false)
+        if (f != NULL && f->empty() == false) {
             f->setLinkage(llvm::GlobalValue::InternalLinkage);
+#if !defined(LLVM_3_1) && !defined(LLVM_3_2)
+            f->addAttributes(
+                llvm::AttributeSet::FunctionIndex,
+                *g->target.tf_attributes);
+#endif
+        }
     }
 }
 

ispc.cpp

@@ -73,6 +73,7 @@
   #include <llvm/DataLayout.h>
 #else // LLVM 3.3+
   #include <llvm/IR/DataLayout.h>
+  #include <llvm/IR/Attributes.h>
 #endif
 #include <llvm/Support/TargetRegistry.h>
 #include <llvm/Support/TargetSelect.h>
@@ -419,6 +420,19 @@ Target::GetTarget(const char *arch, const char *cpu, const char *isa,
         const llvm::DataLayout *dataLayout = targetMachine->getDataLayout();
         t->is32Bit = (dataLayout->getPointerSize(addressSpace) == 4);
 #endif
+
+#if !defined(LLVM_3_1) && !defined(LLVM_3_2)
+        // This is LLVM 3.3+ feature.
+        // Initialize target-specific "target-feature" attribute.
+        llvm::AttrBuilder attrBuilder;
+        attrBuilder.addAttribute("target-features", t->attributes);
+        t->tf_attributes = new llvm::AttributeSet(
+            llvm::AttributeSet::get(
+                *g->ctx,
+                llvm::AttributeSet::FunctionIndex,
+                attrBuilder));
+#endif
+
         Assert(t->vectorWidth <= ISPC_MAX_NVEC);
     }
 

ispc.h

@@ -68,6 +68,7 @@
 
 // Forward declarations of a number of widely-used LLVM types
 namespace llvm {
+    class AttributeSet;
     class BasicBlock;
     class Constant;
     class ConstantValue;
@@ -224,9 +225,16 @@ struct Target {
     /** Target CPU. (e.g. "corei7", "corei7-avx", ..) */
     std::string cpu;
 
-    /** Target-specific attributes to pass along to the LLVM backend */
+    /** Target-specific attribute string to pass along to the LLVM backend */
     std::string attributes;
 
+#if !defined(LLVM_3_1) && !defined(LLVM_3_2)
+    /** Target-specific LLVM attribute, which has to be attached to every
+        function to ensure that it is generated for correct target architecture.
+        This is requirement was introduced in LLVM 3.3 */
+    llvm::AttributeSet* tf_attributes;
+#endif
+
     /** Native vector width of the vector instruction set.  Note that this
         value is directly derived from the ISA Being used (e.g. it's 4 for
         SSE, 8 for AVX, etc.) */

module.cpp

@@ -785,6 +785,10 @@ Module::AddFunctionDeclaration(const std::string &name,
         function->setDoesNotAlias(1);
 #endif
 
+#if !defined(LLVM_3_1) && !defined(LLVM_3_2)
+    function->addAttributes(llvm::AttributeSet::FunctionIndex, *g->target.tf_attributes);
+#endif
+
     // Make sure that the return type isn't 'varying' or vector typed if
     // the function is 'export'ed.
     if (functionType->isExported &&