From 67b453b0d1ed7ab42a9408a6eb00131e160eb421 Mon Sep 17 00:00:00 2001
From: Bob Wilson <bob.wilson@apple.com>
Date: Wed, 4 Aug 2010 00:12:08 +0000
Subject: [PATCH] Combine NEON VABD (absolute difference) intrinsics with ADDs
 to make VABA (absolute difference with accumulate) intrinsics.  Radar
 8228576.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110170 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMISelLowering.cpp | 16 ++++++++++++++++
 test/CodeGen/ARM/vaba.ll           | 24 ++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 08054cbae32..92fb442ac75 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -4248,12 +4248,28 @@ SDValue combineSelectAndUse(SDNode *N, SDValue Slct, SDValue OtherOp,
 /// operands.
 static SDValue PerformADDCombineWithOperands(SDNode *N, SDValue N0, SDValue N1,
                                          TargetLowering::DAGCombinerInfo &DCI) {
+  SelectionDAG &DAG = DCI.DAG;
+
   // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
   if (N0.getOpcode() == ISD::SELECT && N0.getNode()->hasOneUse()) {
     SDValue Result = combineSelectAndUse(N, N0, N1, DCI);
     if (Result.getNode()) return Result;
   }
 
+  // fold (add (arm_neon_vabd a, b) c) -> (arm_neon_vaba c, a, b)
+  EVT VT = N->getValueType(0);
+  if (N0.getOpcode() == ISD::INTRINSIC_WO_CHAIN && VT.isInteger()) {
+    unsigned IntNo = cast<ConstantSDNode>(N0.getOperand(0))->getZExtValue();
+    if (IntNo == Intrinsic::arm_neon_vabds)
+      return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, N->getDebugLoc(), VT,
+                         DAG.getConstant(Intrinsic::arm_neon_vabas, MVT::i32),
+                         N1, N0.getOperand(1), N0.getOperand(2));
+    if (IntNo == Intrinsic::arm_neon_vabdu)
+      return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, N->getDebugLoc(), VT,
+                         DAG.getConstant(Intrinsic::arm_neon_vabau, MVT::i32),
+                         N1, N0.getOperand(1), N0.getOperand(2));
+  }
+
   return SDValue();
 }
 
diff --git a/test/CodeGen/ARM/vaba.ll b/test/CodeGen/ARM/vaba.ll
index e2dca4647bc..e7aa6aecb96 100644
--- a/test/CodeGen/ARM/vaba.ll
+++ b/test/CodeGen/ARM/vaba.ll
@@ -203,3 +203,27 @@ declare <2 x i64> @llvm.arm.neon.vabals.v2i64(<2 x i64>, <2 x i32>, <2 x i32>) n
 declare <8 x i16> @llvm.arm.neon.vabalu.v8i16(<8 x i16>, <8 x i8>, <8 x i8>) nounwind readnone
 declare <4 x i32> @llvm.arm.neon.vabalu.v4i32(<4 x i32>, <4 x i16>, <4 x i16>) nounwind readnone
 declare <2 x i64> @llvm.arm.neon.vabalu.v2i64(<2 x i64>, <2 x i32>, <2 x i32>) nounwind readnone
+
+define <8 x i8> @vabd_combine_s8(<8 x i8>* %A, <8 x i8>* %B) nounwind {
+;CHECK: vabd_combine_s8:
+;CHECK: vaba.s8
+	%tmp1 = load <8 x i8>* %A
+	%tmp2 = load <8 x i8>* %B
+	%tmp3 = call <8 x i8> @llvm.arm.neon.vabds.v8i8(<8 x i8> %tmp1, <8 x i8> %tmp2)
+        %tmp4 = add <8 x i8> %tmp2, %tmp3
+	ret <8 x i8> %tmp4
+}
+
+define <4 x i16> @vabd_combine_u16(<4 x i16>* %A, <4 x i16>* %B) nounwind {
+;CHECK: vabd_combine_u16:
+;CHECK: vaba.u16
+	%tmp1 = load <4 x i16>* %A
+	%tmp2 = load <4 x i16>* %B
+	%tmp3 = call <4 x i16> @llvm.arm.neon.vabdu.v4i16(<4 x i16> %tmp1, <4 x i16> %tmp2)
+        %tmp4 = add <4 x i16> %tmp3, %tmp1
+	ret <4 x i16> %tmp4
+}
+
+declare <8 x i8>  @llvm.arm.neon.vabds.v8i8(<8 x i8>, <8 x i8>) nounwind readnone
+declare <4 x i16> @llvm.arm.neon.vabdu.v4i16(<4 x i16>, <4 x i16>) nounwind readnone
+
-- 
2.34.1