[PATCH] D31077: Improve DAGTypeLegalizer::PromoteIntRes_TRUNCATE() to handle widening.

[Jonas Paulsson via Phabricator via llvm-commits]

jonpa updated this revision to Diff 92151.
jonpa added a comment.

Test case reduced. Thanks Simon.


https://reviews.llvm.org/D31077

Files:
  lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
  test/CodeGen/SystemZ/vec-trunc-to-i1.ll


Index: test/CodeGen/SystemZ/vec-trunc-to-i1.ll
===================================================================
--- /dev/null
+++ test/CodeGen/SystemZ/vec-trunc-to-i1.ll
@@ -0,0 +1,20 @@
+; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z13 | FileCheck %s
+;
+; Check that a widening truncate to a vector of i1 elements can be handled.
+
+
+define void @autogen_SD29574() {
+; CHECK: .text
+BB:
+  %B15 = sub <4 x i8> undef, zeroinitializer
+  br label %CF34
+
+CF34:                                             ; preds = %CF34, %BB
+  %Tr24 = trunc <4 x i8> %B15 to <4 x i1>
+  %Cmp26 = icmp slt <4 x i1> %Tr24, undef
+  %E28 = extractelement <4 x i1> %Cmp26, i32 3
+  br i1 %E28, label %CF34, label %CF36
+
+CF36:                                             ; preds = %CF34
+  ret void
+}
Index: lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -690,7 +690,7 @@
   case TargetLowering::TypePromoteInteger:
     Res = GetPromotedInteger(InOp);
     break;
-  case TargetLowering::TypeSplitVector:
+  case TargetLowering::TypeSplitVector: {
     EVT InVT = InOp.getValueType();
     assert(InVT.isVector() && "Cannot split scalar types");
     unsigned NumElts = InVT.getVectorNumElements();
@@ -709,6 +709,26 @@
 
     return DAG.getNode(ISD::CONCAT_VECTORS, dl, NVT, EOp1, EOp2);
   }
+  case TargetLowering::TypeWidenVector: {
+    SDValue WideInOp = GetWidenedVector(InOp);
+
+    // Truncate widened InOp.
+    unsigned NumElem = WideInOp.getValueType().getVectorNumElements();
+    EVT TruncVT = EVT::getVectorVT(*DAG.getContext(),
+                                   N->getValueType(0).getScalarType(), NumElem);
+    SDValue WideTrunc = DAG.getNode(ISD::TRUNCATE, dl, TruncVT, WideInOp);
+
+    // Zero extend so that the elements are of same type as those of NVT
+    EVT ExtVT = EVT::getVectorVT(*DAG.getContext(), NVT.getVectorElementType(),
+                                 NumElem);
+    SDValue WideExt = DAG.getNode(ISD::ZERO_EXTEND, dl, ExtVT, WideTrunc);
+
+    // Extract the low NVT subvector.
+    MVT IdxTy = TLI.getVectorIdxTy(DAG.getDataLayout());
+    SDValue ZeroIdx = DAG.getConstant(0, dl, IdxTy);
+    return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, NVT, WideExt, ZeroIdx);
+  }
+  }
 
   // Truncate to NVT instead of VT
   return DAG.getNode(ISD::TRUNCATE, dl, NVT, Res);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D31077.92151.patch
Type: text/x-patch
Size: 2483 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170317/4b781e84/attachment.bin>