[llvm-commits] [llvm-gcc] llvm-gcc patch for PR1373 (review only)

[Zhou Sheng]

Hi All,

Here is the llvm-gcc patch for PR1373. It makes llvm-gcc to emit noalias
parameter attribute as well as noalias intrinsic. Note this patch is just
for review. Please give me some suggestion to improve it. Thanks.


Sheng.

Index: gcc/llvm-convert.cpp
===================================================================
--- gcc/llvm-convert.cpp        (revision 359)
+++ gcc/llvm-convert.cpp        (working copy)
@@ -1400,6 +1400,20 @@
   BranchFixups.push_back(BranchFixup(BI, isExceptionEdge));
 }
 
+// Emits noalias intrinsic if the decl has the restrict qualifier.
+Value *TreeToLLVM::EmitNoAliasIntrinsic(Value *V) {
+  Function *noAliasFun = Intrinsic::getDeclaration(TheModule, 
+                                                   Intrinsic::noalias);
+  PointerType *PT = PointerType::get(IntegerType::Int8Ty);
+  const Type *VTy = V->getType();
+  if (VTy != PT) {
+    V = Builder.CreateBitCast(V, PT, "tmp.be");
+    V = Builder.CreateCall(noAliasFun, V, "tmp.noalias");
+    return Builder.CreateBitCast(V, VTy, "tmp.af.noalias");
+  }
+  return Builder.CreateCall(noAliasFun, V, "tmp.noalias");
+}
+
 // Emits annotate intrinsic if the decl has the annotate attribute set.
 void TreeToLLVM::EmitAnnotateIntrinsic(Value *V, tree decl) {
   
@@ -1561,7 +1575,7 @@
   // Handle annotate attributes
   if (DECL_ATTRIBUTES(decl))
     EmitAnnotateIntrinsic(AI, decl);
-  
+
   if (TheDebugInfo) {
     if (DECL_NAME(decl)) {
       TheDebugInfo->EmitDeclare(decl, llvm::dwarf::DW_TAG_auto_variable,
@@ -2425,7 +2439,10 @@
       // Scalar value: emit a load.
       Value *Ptr = CastToType(Instruction::BitCast, LV.Ptr, 
                               PointerType::get(Ty));
-      return Builder.CreateLoad(Ptr, isVolatile, "tmp");
+      Value *Tmp = Builder.CreateLoad(Ptr, isVolatile, "tmp");
+      if (isa<PointerType>(Tmp->getType()) && TYPE_RESTRICT(TREE_TYPE(exp)))
+        Tmp = EmitNoAliasIntrinsic(Tmp);
+      return Tmp;
     } else {
       EmitAggregateCopy(DestLoc, LV.Ptr, TREE_TYPE(exp), false, isVolatile);
       return 0;
Index: gcc/llvm-internal.h
===================================================================
--- gcc/llvm-internal.h (revision 359)
+++ gcc/llvm-internal.h (working copy)
@@ -453,6 +453,9 @@
   
   /// EmitAnnotateIntrinsic - Emits call to annotate attr intrinsic
   void EmitAnnotateIntrinsic(Value *V, tree_node *decl);
+
+  /// EmitNoAliasIntrinsic - Emits call to noalias intrinsic
+  Value *EmitNoAliasIntrinsic(Value *V);
   
 private:
   /// GatherTypeInfo - Walk through the expression gathering all the
Index: gcc/llvm-types.cpp
===================================================================
--- gcc/llvm-types.cpp  (revision 359)
+++ gcc/llvm-types.cpp  (working copy)
@@ -1006,6 +1006,11 @@
       else
         Attributes |= ParamAttr::SExt;
     }
+
+    // Compute noalias attributes.
+    if (TREE_CODE(ArgTy) == POINTER_TYPE)
+      if (TYPE_RESTRICT(ArgTy))
+        Attributes |= ParamAttr::NoAlias;
     
 #ifdef LLVM_TARGET_ENABLE_REGPARM
     // Allow the target to mark this as inreg.

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