JIT: Include auxiliary types in hardware intrinsic value numbering

src/coreclr/jit/valuenum.cpp

@@ -2518,9 +2518,17 @@ ValueNum ValueNumStore::VNOneForSimdType(var_types simdType, var_types simdBaseT
     return VNBroadcastForSimdType(simdType, simdBaseType, oneVN);
 }
 
-ValueNum ValueNumStore::VNForSimdType(unsigned simdSize, var_types simdBaseType)
+ValueNum ValueNumStore::VNForSimdType(unsigned simdSize, var_types simdBaseType, var_types auxiliaryType)
 {
-    ValueNum baseTypeVN = VNForIntCon(INT32(simdBaseType));
+    // Both types fit in a byte. Reserve zero in the upper byte for no auxiliary type,
+    // preserving the base-type constant for the common case.
+    unsigned encodedTypes = static_cast<unsigned>(simdBaseType);
+    if (auxiliaryType != TYP_UNKNOWN)
+    {
+        encodedTypes |= (static_cast<unsigned>(auxiliaryType) + 1) << SimdTypeBits;
+    }
+
+    ValueNum baseTypeVN = VNForIntCon(encodedTypes);
     ValueNum sizeVN     = VNForIntCon(simdSize);
     ValueNum simdTypeVN = VNForFunc(TYP_REF, VNF_SimdType, sizeVN, baseTypeVN);
 
@@ -10932,7 +10940,7 @@ uint32_t ValueNumStore::GetVNHWIntrinsicSizeAndBaseType(const VNFuncApp& funcApp
     assert(IsVNConstant(simdType.GetArg(0)));
     assert(IsVNConstant(simdType.GetArg(1)));
 
-    *simdBaseType = static_cast<var_types>(GetConstantInt32(simdType.GetArg(1)));
+    *simdBaseType = static_cast<var_types>(GetConstantInt32(simdType.GetArg(1)) & SimdTypeMask);
     return static_cast<uint32_t>(GetConstantInt32(simdType.GetArg(0)));
 }
 #endif // FEATURE_HW_INTRINSICS
@@ -11422,11 +11430,19 @@ void ValueNumStore::vnDumpSimdType(Compiler* comp, VNFuncApp* simdType)
     assert(IsVNConstant(simdType->GetArg(0)));
     assert(IsVNConstant(simdType->GetArg(1)));
 
-    int       simdSize     = ConstantValue<int>(simdType->GetArg(0));
-    var_types simdBaseType = static_cast<var_types>(ConstantValue<int>(simdType->GetArg(1)));
+    int       simdSize      = ConstantValue<int>(simdType->GetArg(0));
+    unsigned  encodedTypes  = ConstantValue<unsigned>(simdType->GetArg(1));
+    var_types simdBaseType  = static_cast<var_types>(encodedTypes & SimdTypeMask);
+    unsigned  auxiliaryType = encodedTypes >> SimdTypeBits;
 
-    printf("%s(simd%d, %s)", VNFuncName(simdType->GetFunc()), simdSize,
+    printf("%s(simd%d, %s", VNFuncName(simdType->GetFunc()), simdSize,
            (simdBaseType == TYP_UNDEF) ? varTypeName(TYP_UNDEF) : varTypeName(simdBaseType));
+
+    if (auxiliaryType != 0)
+    {
+        printf(", aux %s", varTypeName(static_cast<var_types>(auxiliaryType - 1)));
+    }
+    printf(")");
 }
 #endif // FEATURE_SIMD
 
@@ -14188,8 +14204,10 @@ void Compiler::fgValueNumberHWIntrinsic(GenTreeHWIntrinsic* tree)
     }
     else
     {
-        VNFunc       func       = GetVNFuncForNode(tree);
-        ValueNum     simdTypeVN = vnStore->VNForSimdType(tree->GetSimdSize(), tree->GetSimdBaseType());
+        // The auxiliary type distinguishes overloads with the same operand bits, such as gather index widths.
+        VNFunc   func = GetVNFuncForNode(tree);
+        ValueNum simdTypeVN =
+            vnStore->VNForSimdType(tree->GetSimdSize(), tree->GetSimdBaseType(), tree->GetAuxiliaryType());
         ValueNumPair resultTypeVNPair(simdTypeVN, simdTypeVN);
 
         JITDUMP("    simdTypeVN is ");

src/coreclr/jit/valuenum.h

@@ -396,6 +396,12 @@ class ValueNumStore
         VCA_ReservedBits = 0x01, // i.e. (VCA_UnsignedSrc)
     };
 
+#ifdef FEATURE_SIMD
+    static constexpr unsigned SimdTypeBits = 8;
+    static constexpr unsigned SimdTypeMask = (1 << SimdTypeBits) - 1;
+    static_assert(TYP_COUNT <= SimdTypeMask);
+#endif
+
     // Helpers and an array of length GT_COUNT, mapping genTreeOp values to their VNFOpAttrib.
     static constexpr uint8_t GetOpAttribsForArity(genTreeOps oper, GenTreeOperKind kind);
     static constexpr uint8_t GetOpAttribsForGenTree(genTreeOps      oper,
@@ -792,7 +798,7 @@ class ValueNumStore
     ValueNum VNOneForSimdType(var_types simdType, var_types simdBaseType);
 
     // A helper function for constructing VNF_SimdType VNs.
-    ValueNum VNForSimdType(unsigned simdSize, var_types simdBaseType);
+    ValueNum VNForSimdType(unsigned simdSize, var_types simdBaseType, var_types auxiliaryType);
 
     // Returns if a value number represents NaN in all elements
     bool VNIsVectorNaN(var_types simdType, var_types simdBaseType, ValueNum valVN);

src/tests/JIT/Regression_ro_2/Runtime_134486.cs

@@ -0,0 +1,43 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.Arm;
+using System.Runtime.Intrinsics.X86;
+using Xunit;
+
+public class Runtime_134486
+{
+    [ConditionalFact(typeof(Avx2), nameof(Avx2.IsSupported))]
+    public static unsafe void TestGather()
+    {
+        int* data = stackalloc int[] { 10, 11, 12, 13 };
+        Assert.Equal(2, Gather(data, Vector128.Create(1, 0, 2, 0), Vector128.Create(11, 10, 12, 10)));
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining | MethodImplOptions.AggressiveOptimization)]
+    private static unsafe int Gather(int* data, Vector128<int> indices, Vector128<int> expected)
+    {
+        Vector128<int> a = Avx2.GatherVector128(data, indices, 4);
+        Vector128<int> b = Avx2.GatherVector128(data, indices.AsInt64(), 4);
+
+        if (a == expected)
+        {
+            return b == expected ? 1 : 2;
+        }
+        return 3;
+    }
+
+    [ConditionalFact(typeof(AdvSimd.Arm64), nameof(AdvSimd.Arm64.IsSupported))]
+    public static void TestAddSaturateScalar()
+    {
+        Assert.True(DistinguishAddSaturateScalar(Vector64.CreateScalar(1), Vector64.CreateScalar(-1)));
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining | MethodImplOptions.AggressiveOptimization)]
+    private static bool DistinguishAddSaturateScalar(Vector64<int> left, Vector64<int> right)
+    {
+        return AdvSimd.Arm64.AddSaturateScalar(left, right) != AdvSimd.Arm64.AddSaturateScalar(left, right.AsUInt32());
+    }
+}