arm64: Add support for bitwise NOT (#111904)

* Contributes to #68028

Author: jonathandavies-arm

src/coreclr/jit/codegenarm64.cpp

@@ -3490,13 +3490,15 @@ void CodeGen::genCodeForNegNot(GenTree* tree)
 
     GenTree* operand = tree->gtGetOp1();
     // The src must be a register.
-    if (tree->OperIs(GT_NEG) && operand->isContained())
+    if (tree->OperIs(GT_NEG, GT_NOT) && operand->isContained())
     {
         genTreeOps oper = operand->OperGet();
         switch (oper)
         {
             case GT_MUL:
             {
+                assert(tree->OperIs(GT_NEG));
+
                 ins          = INS_mneg;
                 GenTree* op1 = tree->gtGetOp1();
                 GenTree* a   = op1->gtGetOp1();
@@ -3510,7 +3512,7 @@ void CodeGen::genCodeForNegNot(GenTree* tree)
             case GT_RSH:
             case GT_RSZ:
             {
-                assert(ins == INS_neg || ins == INS_negs);
+                assert(ins == INS_neg || ins == INS_negs || ins == INS_mvn);
                 assert(operand->gtGetOp2()->IsCnsIntOrI());
                 assert(operand->gtGetOp2()->isContained());
 

src/coreclr/jit/lower.cpp

@@ -511,6 +511,11 @@ GenTree* Lowering::LowerNode(GenTree* node)
         }
 #endif
         break;
+        case GT_NOT:
+#ifdef TARGET_ARM64
+            ContainCheckNot(node->AsOp());
+#endif
+            break;
         case GT_SELECT:
             return LowerSelect(node->AsConditional());
 

src/coreclr/jit/lower.h

@@ -94,6 +94,7 @@ class Lowering final : public Phase
     insCflags TruthifyingFlags(GenCondition cond);
     void      ContainCheckConditionalCompare(GenTreeCCMP* ccmp);
     void      ContainCheckNeg(GenTreeOp* neg);
+    void      ContainCheckNot(GenTreeOp* notOp);
     void      TryLowerCnsIntCselToCinc(GenTreeOp* select, GenTree* cond);
     void      TryLowerCselToCSOp(GenTreeOp* select, GenTree* cond);
     bool      TryLowerAddSubToMulLongOp(GenTreeOp* op, GenTree** next);

src/coreclr/jit/lowerarmarch.cpp

@@ -304,7 +304,7 @@ bool Lowering::IsContainableUnaryOrBinaryOp(GenTree* parentNode, GenTree* childN
             }
         }
 
-        if (childNode->OperIs(GT_LSH, GT_RSH, GT_RSZ) && parentNode->OperIs(GT_AND_NOT))
+        if (childNode->OperIs(GT_LSH, GT_RSH, GT_RSZ) && parentNode->OperIs(GT_NOT, GT_AND_NOT))
         {
             return true;
         }
@@ -3290,6 +3290,31 @@ void Lowering::ContainCheckNeg(GenTreeOp* neg)
     }
 }
 
+//------------------------------------------------------------------------
+// ContainCheckNot : determine whether the source of a not should be contained.
+//
+// Arguments:
+//    notOp - pointer to the node
+//
+void Lowering::ContainCheckNot(GenTreeOp* notOp)
+{
+    if (notOp->isContained())
+        return;
+
+    if (!varTypeIsIntegral(notOp))
+        return;
+
+    if ((notOp->gtFlags & GTF_SET_FLAGS))
+        return;
+
+    GenTree* childNode = notOp->gtGetOp1();
+    if (comp->opts.OptimizationEnabled() && childNode->OperIs(GT_LSH, GT_RSH, GT_RSZ) &&
+        IsContainableUnaryOrBinaryOp(notOp, childNode))
+    {
+        MakeSrcContained(notOp, childNode);
+    }
+}
+
 //----------------------------------------------------------------------------------------------
 // TryLowerCselToCSOp: Try converting SELECT/SELECTCC to SELECT_?/SELECT_?CC. Conversion is possible only if
 // one of the operands of the select node is one of GT_NEG, GT_NOT or GT_ADD.

src/tests/JIT/opt/InstructionCombining/Mvn.cs

@@ -0,0 +1,97 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.CompilerServices;
+using Xunit;
+
+namespace TestMvn
+{
+    public class Program
+    {
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        [Fact]
+        public static int CheckMvn()
+        {
+            bool fail = false;
+
+            if (Mvn(5) != 0xFFFFFFFA)
+            {
+                fail = true;
+            }
+
+            if (MvnLSL(10) != 0xFFFAFFFF)
+            {
+                fail = true;
+            }
+
+            if (MvnLSR(0x76543210) != 0xFFFFFF89)
+            {
+                fail = true;
+            }
+
+            if (MvnASR(0xACE1234) != -0x5670A)
+            {
+                fail = true;
+            }
+
+            if (MvnLargeShift(0x1A1A) != 0x5FFFFFFf)
+            {
+                fail = true;
+            }
+
+            if (MvnLargeShift64Bit(0x2B3C2B3C2B3C2B3C) != 0xFFFFFFFFD4C3D4C3)
+            {
+                fail = true;
+            }
+
+            if (fail)
+            {
+                return 101;
+            }
+            return 100;
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static uint Mvn(uint a)
+        {
+            //ARM64-FULL-LINE: mvn {{w[0-9]+}}, {{w[0-9]+}}
+            return ~a;
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static uint MvnLSL(uint a)
+        {
+            //ARM64-FULL-LINE: mvn {{w[0-9]+}}, {{w[0-9]+}}, LSL #15
+            return ~(a<<15);
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static uint MvnLSR(uint a)
+        {
+            //ARM64-FULL-LINE: mvn {{w[0-9]+}}, {{w[0-9]+}}, LSR #24
+            return ~(a>>24);
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static int MvnASR(int a)
+        {
+            //ARM64-FULL-LINE: mvn {{w[0-9]+}}, {{w[0-9]+}}, ASR #9
+            return ~(a>>9);
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static uint MvnLargeShift(uint a)
+        {
+            //ARM64-FULL-LINE: mvn {{w[0-9]+}}, {{w[0-9]+}}, LSL #28
+            return ~(a<<60);
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        static ulong MvnLargeShift64Bit(ulong a)
+        {
+            //ARM64-FULL-LINE: mvn {{x[0-9]+}}, {{x[0-9]+}}, LSR #32
+            return ~(a>>160);
+        }
+    }
+}

src/tests/JIT/opt/InstructionCombining/Mvn.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <!-- Needed for CLRTestEnvironmentVariable -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+  </PropertyGroup>
+  <PropertyGroup>
+    <DebugType>None</DebugType>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="Mvn.cs">
+      <HasDisasmCheck>true</HasDisasmCheck>
+    </Compile>
+    <CLRTestEnvironmentVariable Include="DOTNET_TieredCompilation" Value="0" />
+    <CLRTestEnvironmentVariable Include="DOTNET_JITMinOpts" Value="0" />
+  </ItemGroup>
+</Project>