Add LoadCombine pass.

[oota-llvm.git] / include / llvm / IR / IRBuilder.h

diff --git a/include/llvm/IR/IRBuilder.h b/include/llvm/IR/IRBuilder.h
index 580d333683376b35d4c2b429bea1f32ce41559e9..cedb87cdb7ccf819a3bf8790b37b0d4e26916ca8 100644 (file)
--- a/include/llvm/IR/IRBuilder.h
+++ b/include/llvm/IR/IRBuilder.h
@@ -1464,6 +1464,30 @@ public:
     Value *Zeros = ConstantAggregateZero::get(VectorType::get(I32Ty, NumElts));
     return CreateShuffleVector(V, Undef, Zeros, Name + ".splat");
   }
+
+  /// \brief Return a value that has been extracted from a larger integer type.
+  Value *CreateExtractInteger(const DataLayout &DL, Value *From,
+                              IntegerType *ExtractedTy, uint64_t Offset,
+                              const Twine &Name) {
+    IntegerType *IntTy = cast<IntegerType>(From->getType());
+    assert(DL.getTypeStoreSize(ExtractedTy) + Offset <=
+               DL.getTypeStoreSize(IntTy) &&
+           "Element extends past full value");
+    uint64_t ShAmt = 8 * Offset;
+    Value *V = From;
+    if (DL.isBigEndian())
+      ShAmt = 8 * (DL.getTypeStoreSize(IntTy) -
+                   DL.getTypeStoreSize(ExtractedTy) - Offset);
+    if (ShAmt) {
+      V = CreateLShr(V, ShAmt, Name + ".shift");
+    }
+    assert(ExtractedTy->getBitWidth() <= IntTy->getBitWidth() &&
+           "Cannot extract to a larger integer!");
+    if (ExtractedTy != IntTy) {
+      V = CreateTrunc(V, ExtractedTy, Name + ".trunc");
+    }
+    return V;
+  }
 };
 
 // Create wrappers for C Binding types (see CBindingWrapping.h).