[X86][AARCH64] Improve ISD::ABS support

This patch takes some of the code from D49837 to allow us to enable ISD::ABS support for all SSE vector types.

Differential Revision: https://reviews.llvm.org/D56544

llvm-svn: 350998

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index 753158dc2c3..6e0bc97e92b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -117,6 +117,12 @@ class VectorLegalizer {
   /// the remaining lanes, finally bitcasting to the proper type.
   SDValue ExpandZERO_EXTEND_VECTOR_INREG(SDValue Op);
 
+  /// Implement expand-based legalization of ABS vector operations.
+  /// If following expanding is legal/custom then do it:
+  /// (ABS x) --> (XOR (ADD x, (SRA x, sizeof(x)-1)), (SRA x, sizeof(x)-1))
+  /// else unroll the operation.
+  SDValue ExpandABS(SDValue Op);
+
   /// Expand bswap of vectors into a shuffle if legal.
   SDValue ExpandBSWAP(SDValue Op);
 
@@ -355,6 +361,7 @@ SDValue VectorLegalizer::LegalizeOp(SDValue Op) {
   case ISD::FSHR:
   case ISD::ROTL:
   case ISD::ROTR:
+  case ISD::ABS:
   case ISD::BSWAP:
   case ISD::BITREVERSE:
   case ISD::CTLZ:
@@ -749,6 +756,8 @@ SDValue VectorLegalizer::Expand(SDValue Op) {
     return ExpandFSUB(Op);
   case ISD::SETCC:
     return UnrollVSETCC(Op);
+  case ISD::ABS:
+    return ExpandABS(Op);
   case ISD::BITREVERSE:
     return ExpandBITREVERSE(Op);
   case ISD::CTPOP:
@@ -1064,6 +1073,16 @@ SDValue VectorLegalizer::ExpandVSELECT(SDValue Op) {
   return DAG.getNode(ISD::BITCAST, DL, Op.getValueType(), Val);
 }
 
+SDValue VectorLegalizer::ExpandABS(SDValue Op) {
+  // Attempt to expand using TargetLowering.
+  SDValue Result;
+  if (TLI.expandABS(Op.getNode(), Result, DAG))
+    return Result;
+
+  // Otherwise go ahead and unroll.
+  return DAG.UnrollVectorOp(Op.getNode());
+}
+
 SDValue VectorLegalizer::ExpandFP_TO_UINT(SDValue Op) {
   // Attempt to expand using TargetLowering.
   SDValue Result;