Optimize scalar conversions with AVX512

src/coreclr/jit/codegenxarch.cpp

@@ -7336,7 +7336,19 @@ void CodeGen::genIntToFloatCast(GenTree* treeNode)
     // Also we don't expect to see uint32 -> float/double and uint64 -> float conversions
     // here since they should have been lowered appropriately.
     noway_assert(srcType != TYP_UINT);
-    noway_assert((srcType != TYP_ULONG) || (dstType != TYP_FLOAT));
+    assert((srcType != TYP_ULONG) || (dstType != TYP_FLOAT) ||
+           compiler->compIsaSupportedDebugOnly(InstructionSet_AVX512F));
+
+    if ((srcType == TYP_ULONG) && varTypeIsFloating(dstType) &&
+        compiler->compOpportunisticallyDependsOn(InstructionSet_AVX512F))
+    {
+        assert(compiler->compIsaSupportedDebugOnly(InstructionSet_AVX512F));
+        genConsumeOperands(treeNode->AsOp());
+        instruction ins = ins_FloatConv(dstType, srcType, emitTypeSize(srcType));
+        GetEmitter()->emitInsBinary(ins, emitTypeSize(srcType), treeNode, op1);
+        genProduceReg(treeNode);
+        return;
+    }
 
     // To convert int to a float/double, cvtsi2ss/sd SSE2 instruction is used
     // which does a partial write to lower 4/8 bytes of xmm register keeping the other
@@ -7450,7 +7462,7 @@ void CodeGen::genFloatToIntCast(GenTree* treeNode)
 
     // We shouldn't be seeing uint64 here as it should have been converted
     // into a helper call by either front-end or lowering phase.
-    noway_assert(!varTypeIsUnsigned(dstType) || (dstSize != EA_ATTR(genTypeSize(TYP_LONG))));
+    assert(!varTypeIsUnsigned(dstType) || (dstSize != EA_ATTR(genTypeSize(TYP_LONG))));
 
     // If the dstType is TYP_UINT, we have 32-bits to encode the
     // float number. Any of 33rd or above bits can be the sign bit.

src/coreclr/jit/emitxarch.cpp

@@ -1399,7 +1399,6 @@ bool emitter::TakesRexWPrefix(const instrDesc* id) const
             case INS_vcvtsd2usi:
             case INS_vcvtss2usi:
             case INS_vcvttsd2usi:
-            case INS_vcvttss2usi:
             {
                 if (attr == EA_8BYTE)
                 {
@@ -2623,7 +2622,8 @@ bool emitter::emitInsCanOnlyWriteSSE2OrAVXReg(instrDesc* id)
         case INS_vcvtsd2usi:
         case INS_vcvtss2usi:
         case INS_vcvttsd2usi:
-        case INS_vcvttss2usi:
+        case INS_vcvttss2usi32:
+        case INS_vcvttss2usi64:
         {
             // These SSE instructions write to a general purpose integer register.
             return false;
@@ -11435,12 +11435,18 @@ void emitter::emitDispIns(
                 case INS_vcvtsd2usi:
                 case INS_vcvtss2usi:
                 case INS_vcvttsd2usi:
-                case INS_vcvttss2usi:
                 {
                     printf(" %s, %s", emitRegName(id->idReg1(), attr), emitRegName(id->idReg2(), EA_16BYTE));
                     break;
                 }
 
+                case INS_vcvttss2usi32:
+                case INS_vcvttss2usi64:
+                {
+                    printf(" %s, %s", emitRegName(id->idReg1(), attr), emitRegName(id->idReg2(), EA_4BYTE));
+                    break;
+                }
+
 #ifdef TARGET_AMD64
                 case INS_movsxd:
                 {
@@ -18595,23 +18601,32 @@ emitter::insExecutionCharacteristics emitter::getInsExecutionCharacteristics(ins
         case INS_cvtsi2sd64:
         case INS_cvtsi2ss64:
         case INS_vcvtsd2usi:
-        case INS_vcvttsd2usi:
-        case INS_vcvtusi2sd32:
-        case INS_vcvtusi2sd64:
         case INS_vcvtusi2ss32:
         case INS_vcvtusi2ss64:
+        case INS_vcvttsd2usi:
+        case INS_vcvttss2usi32:
             result.insThroughput = PERFSCORE_THROUGHPUT_1C;
             result.insLatency += PERFSCORE_LATENCY_7C;
             break;
 
+        case INS_vcvtusi2sd64:
+        case INS_vcvtusi2sd32:
+            result.insThroughput = PERFSCORE_THROUGHPUT_1C;
+            result.insLatency += PERFSCORE_LATENCY_5C;
+            break;
+
         case INS_cvttss2si:
         case INS_cvtss2si:
         case INS_vcvtss2usi:
-        case INS_vcvttss2usi:
             result.insThroughput = PERFSCORE_THROUGHPUT_1C;
             result.insLatency += opSize == EA_8BYTE ? PERFSCORE_LATENCY_8C : PERFSCORE_LATENCY_7C;
             break;
 
+        case INS_vcvttss2usi64:
+            result.insThroughput = PERFSCORE_THROUGHPUT_1C;
+            result.insLatency += PERFSCORE_LATENCY_8C;
+            break;
+
         case INS_cvtss2sd:
             result.insThroughput = PERFSCORE_THROUGHPUT_1C;
             result.insLatency += PERFSCORE_LATENCY_5C;

src/coreclr/jit/hwintrinsiclistxarch.h

@@ -845,7 +845,7 @@ HARDWARE_INTRINSIC(AVX512F,         CompareNotEqual,
 HARDWARE_INTRINSIC(AVX512F,         ConvertScalarToVector128Double,             16,              2,     false,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvtusi2sd32,       INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid},           HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromSecondArg|HW_Flag_CopyUpperBits)
 HARDWARE_INTRINSIC(AVX512F,         ConvertScalarToVector128Single,             16,              2,     false,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvtusi2ss32,       INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid},           HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromSecondArg|HW_Flag_CopyUpperBits)
 HARDWARE_INTRINSIC(AVX512F,         ConvertToUInt32,                            16,              1,      true,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvtss2usi,         INS_vcvtsd2usi},        HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
-HARDWARE_INTRINSIC(AVX512F,         ConvertToUInt32WithTruncation,              16,              1,      true,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvttss2usi,        INS_vcvttsd2usi},       HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
+HARDWARE_INTRINSIC(AVX512F,         ConvertToUInt32WithTruncation,              16,              1,      true,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvttss2usi32,      INS_vcvttsd2usi},       HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
 HARDWARE_INTRINSIC(AVX512F,         ConvertToVector128Byte,                     64,              1,      true,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_vpmovdb,            INS_vpmovdb,            INS_vpmovqb,            INS_vpmovqb,            INS_invalid,            INS_invalid},           HW_Category_SimpleSIMD,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
 HARDWARE_INTRINSIC(AVX512F,         ConvertToVector128ByteWithSaturation,       64,              1,      true,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vpmovusdb,          INS_invalid,            INS_vpmovusqb,          INS_invalid,            INS_invalid},           HW_Category_SimpleSIMD,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
 HARDWARE_INTRINSIC(AVX512F,         ConvertToVector128Int16,                    64,              1,     false,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vpmovqw,            INS_vpmovqw,            INS_invalid,            INS_invalid},           HW_Category_SimpleSIMD,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
@@ -1002,7 +1002,7 @@ HARDWARE_INTRINSIC(AVX512F_VL,      TernaryLogic,
 HARDWARE_INTRINSIC(AVX512F_X64,     ConvertScalarToVector128Double,             16,              2,     false,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvtusi2sd64,       INS_invalid,            INS_invalid},           HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromSecondArg|HW_Flag_CopyUpperBits|HW_Flag_SpecialCodeGen)
 HARDWARE_INTRINSIC(AVX512F_X64,     ConvertScalarToVector128Single,             16,              2,     false,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvtusi2ss64,       INS_invalid,            INS_invalid},           HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromSecondArg|HW_Flag_CopyUpperBits|HW_Flag_SpecialCodeGen)
 HARDWARE_INTRINSIC(AVX512F_X64,     ConvertToUInt64,                            16,              1,      true,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvtss2usi,         INS_vcvtsd2usi},        HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
-HARDWARE_INTRINSIC(AVX512F_X64,     ConvertToUInt64WithTruncation,              16,              1,      true,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvttss2usi,        INS_vcvttsd2usi},       HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
+HARDWARE_INTRINSIC(AVX512F_X64,     ConvertToUInt64WithTruncation,              16,              1,      true,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_vcvttss2usi64,      INS_vcvttsd2usi},       HW_Category_SIMDScalar,             HW_Flag_BaseTypeFromFirstArg|HW_Flag_SpecialCodeGen)
 
 // ***************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************
 //                 ISA              Function name                               SIMD size       NumArg  EncodesExtraTypeArg                                                                                                       Instructions                                                                                                                  Category                            Flags

src/coreclr/jit/instr.cpp

@@ -2280,7 +2280,10 @@ instruction CodeGen::ins_MathOp(genTreeOps oper, var_types type)
 //
 instruction CodeGen::ins_FloatConv(var_types to, var_types from, emitAttr attr)
 {
-    // AVX: For now we support only conversion from Int/Long -> float
+    // AVX: Supports following conversions
+    //   srcType = int16/int64                     castToType = float
+    // AVX512: Supports following conversions
+    //   srcType = ulong                           castToType = double/float
 
     switch (from)
     {
@@ -2350,6 +2353,17 @@ instruction CodeGen::ins_FloatConv(var_types to, var_types from, emitAttr attr)
             }
             break;
 
+        case TYP_ULONG:
+            switch (to)
+            {
+                case TYP_DOUBLE:
+                    return INS_vcvtusi2sd64;
+                case TYP_FLOAT:
+                    return INS_vcvtusi2ss64;
+                default:
+                    unreached();
+            }
+
         default:
             unreached();
     }

src/coreclr/jit/instrsxarch.h

@@ -637,7 +637,8 @@ INST3(vcvtss2usi,       "cvtss2usi",        IUM_WR, BAD_CODE,               BAD_
 INST3(vcvttpd2udq,      "cvttpd2udq",       IUM_WR, BAD_CODE,               BAD_CODE,     PCKFLT(0x78),                  INS_TT_FULL,                         Input_64Bit    | REX_W1                       | Encoding_EVEX)                                                                                                                                  // cvt w/ truncation packed doubles to unsigned DWORDs
 INST3(vcvttps2udq,      "cvttps2udq",       IUM_WR, BAD_CODE,               BAD_CODE,     PCKFLT(0x78),                  INS_TT_FULL,                         Input_32Bit    | REX_W0                       | Encoding_EVEX)                                                                                                                                  // cvt w/ truncation packed singles to unsigned DWORDs
 INST3(vcvttsd2usi,      "cvttsd2usi",       IUM_WR, BAD_CODE,               BAD_CODE,     SSEDBL(0x78),                  INS_TT_TUPLE1_FIXED,                 Input_64Bit    | REX_WX                       | Encoding_EVEX)                                                                                                                                  // cvt w/ truncation scalar double to unsigned DWORD/QWORD
-INST3(vcvttss2usi,      "cvttss2usi",       IUM_WR, BAD_CODE,               BAD_CODE,     SSEFLT(0x78),                  INS_TT_TUPLE1_FIXED,                 Input_32Bit    | REX_WX                       | Encoding_EVEX)                                                                                                                                  // cvt w/ truncation scalar single to unsigned DWORD/QWORD
+INST3(vcvttss2usi32,    "cvttss2usi",       IUM_WR, BAD_CODE,               BAD_CODE,     SSEFLT(0x78),                  INS_TT_TUPLE1_FIXED,                 Input_32Bit    | REX_W0                       | Encoding_EVEX)                                                                                                                                  // cvt w/ truncation scalar single to unsigned DWORD/QWORD
+INST3(vcvttss2usi64,    "cvttss2usi",       IUM_WR, BAD_CODE,               BAD_CODE,     SSEFLT(0x78),                  INS_TT_TUPLE1_FIXED,                 Input_32Bit    | REX_W1                       | Encoding_EVEX)                                                                                                                                  // cvt w/ truncation scalar single to unsigned DWORD/QWORD
 INST3(vcvtudq2pd,       "cvtudq2pd",        IUM_WR, BAD_CODE,               BAD_CODE,     SSEFLT(0x7A),                  INS_TT_HALF,                         Input_32Bit    | REX_W0                       | Encoding_EVEX)                                                                                                                                  // cvt packed unsigned DWORDs to doubles
 INST3(vcvtudq2ps,       "cvtudq2ps",        IUM_WR, BAD_CODE,               BAD_CODE,     SSEDBL(0x7A),                  INS_TT_FULL,                         Input_32Bit    | REX_W0                       | Encoding_EVEX)                                                                                                                                  // cvt packed unsigned DWORDs to singles
 INST3(vcvtusi2sd32,     "cvtusi2sd",        IUM_WR, BAD_CODE,               BAD_CODE,     SSEDBL(0x7B),                  INS_TT_TUPLE1_SCALAR,                Input_32Bit    | REX_W0                       | Encoding_EVEX  | INS_Flags_IsDstDstSrcAVXInstruction)                                                                                           // cvt scalar unsigned DWORD to double

src/coreclr/jit/lowerxarch.cpp

@@ -811,7 +811,7 @@ void Lowering::LowerCast(GenTree* tree)
     }
     else if (srcType == TYP_ULONG)
     {
-        noway_assert(castToType != TYP_FLOAT);
+        assert(castToType != TYP_FLOAT || comp->compIsaSupportedDebugOnly(InstructionSet_AVX512F));
     }
 
     // Case of src is a small type and dst is a floating point type.

src/coreclr/jit/morph.cpp

@@ -293,6 +293,39 @@ GenTree* Compiler::fgMorphExpandCast(GenTreeCast* tree)
     var_types dstType = tree->CastToType();
     unsigned  dstSize = genTypeSize(dstType);
 
+#if defined(TARGET_AMD64)
+    // If AVX512 is present, we have intrinsic available to convert
+    // ulong directly to float. Hence, we need to combine the 2 nodes
+    // GT_CAST(GT_CAST(TYP_ULONG, TYP_DOUBLE), TYP_FLOAT) into a single
+    // node i.e. GT_CAST(TYP_ULONG, TYP_FLOAT). At this point, we already
+    // have the 2 GT_CAST nodes in the tree and we are combining them below.
+    if (oper->OperIs(GT_CAST))
+    {
+        GenTreeCast* innerCast = oper->AsCast();
+
+        if (innerCast->IsUnsigned())
+        {
+            GenTree*  innerOper    = innerCast->CastOp();
+            var_types innerSrcType = genActualType(innerOper);
+            var_types innerDstType = innerCast->CastToType();
+            unsigned  innerDstSize = genTypeSize(innerDstType);
+            innerSrcType           = varTypeToUnsigned(innerSrcType);
+
+            // Check if we are going from ulong->double->float
+            if (innerSrcType == TYP_ULONG && innerDstType == TYP_DOUBLE && dstType == TYP_FLOAT)
+            {
+                if (compOpportunisticallyDependsOn(InstructionSet_AVX512F))
+                {
+                    // One optimized (combined) cast here
+                    tree         = gtNewCastNode(TYP_ULONG, innerOper, true, TYP_FLOAT);
+                    tree->gtType = TYP_FLOAT;
+                    return fgMorphTree(tree);
+                }
+            }
+        }
+    }
+#endif // TARGET_AMD64
+
     // See if the cast has to be done in two steps.  R -> I
     if (varTypeIsFloating(srcType) && varTypeIsIntegral(dstType))
     {
@@ -449,7 +482,7 @@ GenTree* Compiler::fgMorphExpandCast(GenTreeCast* tree)
     {
         srcType = varTypeToUnsigned(srcType);
 
-        if (srcType == TYP_ULONG)
+        if (srcType == TYP_ULONG && !compOpportunisticallyDependsOn(InstructionSet_AVX512F))
         {
             if (dstType == TYP_FLOAT)
             {