Fix this xform: (sra (shl X, m), result_size) -> (sign_extend (trunc (shl X, result_size - n - m)))


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48578 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index f33946c..f631849 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2400,7 +2400,9 @@
 
       // If the shift wouldn't be a noop, the truncated type is an actual type,
       // and the truncate is free, then proceed with the transform.
-      if (ShiftAmt != 0 && TLI.isTruncateFree(VT, TruncVT)) {
+      if (ShiftAmt != 0 &&
+          TLI.isTypeLegal(TruncVT) &&
+          TLI.isTruncateFree(VT, TruncVT)) {
         SDOperand Amt = DAG.getConstant(ShiftAmt, TLI.getShiftAmountTy());
         SDOperand Shift = DAG.getNode(ISD::SRL, VT, N0.getOperand(0), Amt);
         SDOperand Trunc = DAG.getNode(ISD::TRUNCATE, TruncVT, Shift);
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 93fb802..5a05aba 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -5662,7 +5662,7 @@
     return false;
   unsigned NumBits1 = Ty1->getPrimitiveSizeInBits();
   unsigned NumBits2 = Ty2->getPrimitiveSizeInBits();
-  if (NumBits1 <= NumBits2 || NumBits2 < 8)
+  if (NumBits1 <= NumBits2)
     return false;
   return Subtarget->is64Bit() || NumBits1 < 64;
 }
@@ -5673,7 +5673,7 @@
     return false;
   unsigned NumBits1 = MVT::getSizeInBits(VT1);
   unsigned NumBits2 = MVT::getSizeInBits(VT2);
-  if (NumBits1 <= NumBits2 || NumBits2 < 8)
+  if (NumBits1 <= NumBits2)
     return false;
   return Subtarget->is64Bit() || NumBits1 < 64;
 }