[llvm-commits] [dragonegg] r132747 - /dragonegg/trunk/src/Convert.cpp

[Duncan Sands]

Author: baldrick
Date: Wed Jun  8 09:06:18 2011
New Revision: 132747

URL: http://llvm.org/viewvc/llvm-project?rev=132747&view=rev
Log:
GCC sometimes generates shifts of vectors where the shift amount
is a scalar.  It seems to want all elements to be shifted by that
scalar, so implement that.

Modified:
    dragonegg/trunk/src/Convert.cpp

Modified: dragonegg/trunk/src/Convert.cpp
URL: http://llvm.org/viewvc/llvm-project/dragonegg/trunk/src/Convert.cpp?rev=132747&r1=132746&r2=132747&view=diff
==============================================================================
--- dragonegg/trunk/src/Convert.cpp (original)
+++ dragonegg/trunk/src/Convert.cpp Wed Jun  8 09:06:18 2011
@@ -6797,9 +6797,31 @@
 Value *TreeToLLVM::EmitReg_ShiftOp(tree op0, tree op1, unsigned Opc) {
   Value *LHS = EmitRegister(op0);
   Value *RHS = EmitRegister(op1);
-  if (RHS->getType() != LHS->getType())
-    RHS = CastToAnyType(RHS, /*isSigned*/false, LHS->getType(),
-                        /*isSigned*/false);
+  // Ensure that the shift amount has the same type as the shiftee.
+  if (RHS->getType() != LHS->getType()) {
+    if (LHS->getType()->isVectorTy() == RHS->getType()->isVectorTy()) {
+      // Scalar shifted by a scalar amount, or a vector shifted by a vector
+      // amount.
+      assert((!LHS->getType()->isVectorTy() ||
+              cast<VectorType>(LHS->getType())->getNumElements() ==
+              cast<VectorType>(RHS->getType())->getNumElements()) &&
+             "Vector length mismatch!");
+      RHS = CastToAnyType(RHS, /*isSigned*/false, LHS->getType(),
+                          /*isSigned*/false);
+    } else {
+      // Vector shifted by a scalar amount.  Turn the shift amount into a vector
+      // with all elements equal.
+      assert(LHS->getType()->isVectorTy() &&
+             "Shifting a scalar by a vector amount!");
+      const VectorType *VecTy = cast<VectorType>(LHS->getType());
+      RHS = CastToAnyType(RHS, /*isSigned*/false, VecTy->getElementType(),
+                          /*isSigned*/false);
+      RHS = Builder.CreateInsertElement(UndefValue::get(VecTy), RHS,
+                                        Builder.getInt32(0));
+      RHS = Builder.CreateShuffleVector(RHS, UndefValue::get(VecTy),
+                                        ConstantInt::get(VecTy, 0));
+    }
+  }
   return Builder.CreateBinOp((Instruction::BinaryOps)Opc, LHS, RHS);
 }