[PATCH] D147236: [AArch64][Combine]: combine <2xi64> Mul-Add.

[hassnaaHamdi via Phabricator via llvm-commits]

hassnaa-arm updated this revision to Diff 509691.
hassnaa-arm added a comment.

Improve code readability, Add comments.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D147236/new/

https://reviews.llvm.org/D147236

Files:
  llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
  llvm/test/CodeGen/AArch64/aarch64-combine-mul-add.ll


Index: llvm/test/CodeGen/AArch64/aarch64-combine-mul-add.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AArch64/aarch64-combine-mul-add.ll
@@ -0,0 +1,32 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=aarch64-none-linux-gnu -mattr=+sve | FileCheck %s
+
+define <2 x i64> @test_add_mull_2x64(<2 x i64> %a, <2 x i64> %b, <2 x i64> %c) {
+; CHECK-LABEL: test_add_mull_2x64:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    // kill: def $q0 killed $q0 def $z0
+; CHECK-NEXT:    ptrue p0.d, vl2
+; CHECK-NEXT:    // kill: def $q2 killed $q2 def $z2
+; CHECK-NEXT:    // kill: def $q1 killed $q1 def $z1
+; CHECK-NEXT:    mla z0.d, p0/m, z1.d, z2.d
+; CHECK-NEXT:    // kill: def $q0 killed $q0 killed $z0
+; CHECK-NEXT:    ret
+  %mul = mul <2 x i64> %b, %c
+  %add = add <2 x i64> %a, %mul
+  ret <2 x i64> %add
+}
+
+define <1 x i64> @test_add_mull_1x64(<1 x i64> %a, <1 x i64> %b, <1 x i64> %c) {
+; CHECK-LABEL: test_add_mull_1x64:
+; CHECK:       // %bb.0:
+; CHECK-NEXT:    // kill: def $d0 killed $d0 def $z0
+; CHECK-NEXT:    ptrue p0.d, vl1
+; CHECK-NEXT:    // kill: def $d2 killed $d2 def $z2
+; CHECK-NEXT:    // kill: def $d1 killed $d1 def $z1
+; CHECK-NEXT:    mla z0.d, p0/m, z1.d, z2.d
+; CHECK-NEXT:    // kill: def $d0 killed $d0 killed $z0
+; CHECK-NEXT:    ret
+  %mul = mul <1 x i64> %b, %c
+  %add = add <1 x i64> %mul, %a
+  ret <1 x i64> %add
+}
Index: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -17812,9 +17812,37 @@
   return DAG.getNode(ISD::SUB, SDLoc(N), VT, Sub, M2);
 }
 
+// This works on the pattern of: add v1 , ( mul v2, v3 ),
+// It will transform the add to scalable version, so that
+// we can make use of SVE's MLA that will be generated for that pattern.
+// Given that the mul is already sclable, as NEON doesn't support i64 mul.
+static SDValue performAddMulCombine(SDNode *N, SelectionDAG &DAG) {
+  if (N->getOpcode() != ISD::ADD)
+    return SDValue();
+
+  SDValue MulValue, ConstValue;
+  if (N->getOperand(0)->getOpcode() == ISD::EXTRACT_SUBVECTOR) {
+    MulValue = N->getOperand(0).getOperand(0);
+    ConstValue = N->getOperand(1);
+  } else if (N->getOperand(1)->getOpcode() == ISD::EXTRACT_SUBVECTOR) {
+    MulValue = N->getOperand(1).getOperand(0);
+    ConstValue = N->getOperand(0);
+  } else
+    return SDValue();
+
+  EVT ContainerVT = getContainerForFixedLengthVector(DAG, N->getValueType(0));
+  SDValue ScaledConstValue =
+      convertToScalableVector(DAG, ContainerVT, ConstValue);
+  SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N), ContainerVT,
+                            {ScaledConstValue, MulValue});
+  return convertFromScalableVector(DAG, N->getValueType(0), Add);
+}
+
 static SDValue performAddSubCombine(SDNode *N,
                                     TargetLowering::DAGCombinerInfo &DCI,
                                     SelectionDAG &DAG) {
+  if (SDValue Val = performAddMulCombine(N, DAG))
+    return Val;
   // Try to change sum of two reductions.
   if (SDValue Val = performAddUADDVCombine(N, DAG))
     return Val;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D147236.509691.patch
Type: text/x-patch
Size: 3294 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230330/20ed9209/attachment.bin>