Have jitstress_isas_x86_evex set PreferredVectorBitWidth=512 (#88531)

* Have jitstress_isas_x86_evex set PreferredVectorBitWidth=512 * Ensure that IsHardwareAccelerated correctly takes the preferred width into account * Ensure the tests take DOTNET_PreferredVectorBitWidth into account * Ensure PreferredVectorBitWidth is interpreted as a decimal * Fix a build failure where the default value wasn't passed in * Minor whitespace fix to trigger CI
dotnet · Jul 8, 2023 · 42742cd · 42742cd
1 parent b6266a6
commit 42742cd
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Showing 9 changed files with 102 additions and 67 deletions.
diff --git a/eng/pipelines/coreclr/jitstress-isas-avx512.yml b/eng/pipelines/coreclr/jitstress-isas-avx512.yml
@@ -8,6 +8,9 @@ pr:
     - main
   paths:
     include:
+    - src/coreclr/jit/hwintrinsiccodegenxarch.cpp
+    - src/coreclr/jit/hwintrinsiclistxarch.h
+    - src/coreclr/jit/hwintrinsicxarch.cpp
     - src/coreclr/jit/instrsxarch.h
     - src/coreclr/jit/emitxarch.cpp
     - src/coreclr/jit/emitxarch.h

diff --git a/src/coreclr/jit/compiler.cpp b/src/coreclr/jit/compiler.cpp
@@ -2266,7 +2266,7 @@ void Compiler::compSetProcessor()
 // the total sum of flags is still valid.
 #if defined(TARGET_XARCH)
     // Get the preferred vector bitwidth, rounding down to the nearest multiple of 128-bits
-    uint32_t preferredVectorBitWidth   = (JitConfig.PreferredVectorBitWidth() / 128) * 128;
+    uint32_t preferredVectorBitWidth   = (ReinterpretHexAsDecimal(JitConfig.PreferredVectorBitWidth()) / 128) * 128;
     uint32_t preferredVectorByteLength = preferredVectorBitWidth / 8;
 
     if (instructionSetFlags.HasInstructionSet(InstructionSet_SSE))
@@ -2298,7 +2298,7 @@ void Compiler::compSetProcessor()
 
         instructionSetFlags.AddInstructionSet(InstructionSet_Vector512);
 
-        if ((preferredVectorByteLength == 0) && opts.Vector512Throttling())
+        if ((preferredVectorByteLength == 0) && jitFlags.IsSet(JitFlags::JIT_FLAG_VECTOR512_THROTTLING))
         {
             // Some architectures can experience frequency throttling when
             // executing 512-bit width instructions. To account for this we set the

diff --git a/src/coreclr/jit/compiler.h b/src/coreclr/jit/compiler.h
@@ -9526,16 +9526,6 @@ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
             return jitFlags->IsSet(JitFlags::JIT_FLAG_REVERSE_PINVOKE);
         }
 
-        // true if JitFlags::JIT_FLAG_VECTOR512_THROTTLING is set to true
-        bool Vector512Throttling()
-        {
-#if defined(TARGET_XARCH)
-            return jitFlags->IsSet(JitFlags::JIT_FLAG_VECTOR512_THROTTLING);
-#else
-            return false;
-#endif
-        }
-
         bool compScopeInfo; // Generate the LocalVar info ?
         bool compDbgCode;   // Generate debugger-friendly code?
         bool compDbgInfo;   // Gather debugging info?

diff --git a/src/coreclr/jit/hwintrinsic.cpp b/src/coreclr/jit/hwintrinsic.cpp
@@ -511,12 +511,15 @@ NamedIntrinsic HWIntrinsicInfo::lookupId(Compiler*         comp,
         }
         else if (strcmp(className, "Vector256") == 0)
         {
+            if (comp->getPreferredVectorByteLength() < 32)
+            {
+                return NI_IsSupported_False;
+            }
             isa = InstructionSet_AVX2;
         }
         else if (strcmp(className, "Vector512") == 0)
         {
-            // If the JitFlags::JIT_FLAG_VECTOR512_THROTTLING flag is set, we do not need to do any further checks.
-            if (comp->opts.Vector512Throttling())
+            if (comp->getPreferredVectorByteLength() < 64)
             {
                 return NI_IsSupported_False;
             }

diff --git a/src/coreclr/jit/hwintrinsiclistxarch.h b/src/coreclr/jit/hwintrinsiclistxarch.h
@@ -1292,7 +1292,7 @@ HARDWARE_INTRINSIC(POPCNT_X64,      PopCount,
 //                                                                                                              {TYP_BYTE,              TYP_UBYTE,              TYP_SHORT,              TYP_USHORT,             TYP_INT,                TYP_UINT,               TYP_LONG,               TYP_ULONG,              TYP_FLOAT,              TYP_DOUBLE}
 // ***************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************
 //  X86Serialize Intrinsics
-HARDWARE_INTRINSIC(X86Serialize,   Serialize,                                    0,              0,     false,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid},           HW_Category_Special,                HW_Flag_NoContainment|HW_Flag_NoRMWSemantics|HW_Flag_SpecialSideEffect_Barrier)
+HARDWARE_INTRINSIC(X86Serialize,    Serialize,                                   0,              0,     false,  {INS_invalid,           INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid,            INS_invalid},           HW_Category_Special,                HW_Flag_NoContainment|HW_Flag_NoRMWSemantics|HW_Flag_SpecialSideEffect_Barrier)
 
 
 // ***************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************

diff --git a/src/coreclr/jit/jitconfigvalues.h b/src/coreclr/jit/jitconfigvalues.h
@@ -299,7 +299,7 @@ CONFIG_INTEGER(JitStressEvexEncoding, W("JitStressEvexEncoding"), 0) // Enable E
 
 // clang-format off
 
-CONFIG_INTEGER(PreferredVectorBitWidth,     W("PreferredVectorBitWidth"),   0) // The preferred width, in bits, to use for any implicit vectorization emitted. A value less than 128 is treated as the system default.
+CONFIG_INTEGER(PreferredVectorBitWidth,     W("PreferredVectorBitWidth"),   0) // The preferred decimal width, in bits, to use for any implicit vectorization emitted. A value less than 128 is treated as the system default.
 
 //
 // Hardware Intrinsic ISAs; keep in sync with clrconfigvalues.h

diff --git a/src/tests/Common/testenvironment.proj b/src/tests/Common/testenvironment.proj
@@ -38,6 +38,7 @@
       DOTNET_EnableSSE42;
       DOTNET_EnableSSSE3;
       DOTNET_JitStressEvexEncoding;
+      DOTNET_PreferredVectorBitWidth;
       DOTNET_ForceRelocs;
       DOTNET_GCStress;
       DOTNET_GCName;
@@ -107,7 +108,7 @@
     <TestEnvironment Include="jitstress2_tiered" JitStress="2" TieredCompilation="1" />
     <TestEnvironment Include="jitstress_isas_incompletehwintrinsic" EnableIncompleteISAClass="1"  />
     <TestEnvironment Include="jitstress_isas_nohwintrinsic" EnableHWIntrinsic="0" />
-    <TestEnvironment Include="jitstress_isas_x86_evex" JitStressEvexEncoding="1" />
+    <TestEnvironment Include="jitstress_isas_x86_evex" JitStressEvexEncoding="1" PreferredVectorBitWidth="512" />
     <TestEnvironment Include="jitstress_isas_x86_noaes" EnableAES="0" /> <!-- Depends on SSE2 -->
     <TestEnvironment Include="jitstress_isas_x86_noavx" EnableAVX="0" /> <!-- Depends on SSE42 -->
     <TestEnvironment Include="jitstress_isas_x86_noavx2" EnableAVX2="0" /> <!-- Depends on AVX -->

diff --git a/src/tests/JIT/HardwareIntrinsics/X86/X86Base/CpuId.cs b/src/tests/JIT/HardwareIntrinsics/X86/X86Base/CpuId.cs
@@ -216,36 +216,50 @@ public unsafe static void CpuId()
             }
 
             bool isAvx512HierarchyDisabled = isHierarchyDisabled;
-            if (isGenuineIntel && !isAvx512HierarchyDisabled)
+
+            int preferredVectorBitWidth = (GetDotnetEnvVar("PreferredVectorBitWidth", defaultValue: 0) / 128) * 128;
+            int preferredVectorByteLength = preferredVectorBitWidth / 8;
+
+            if (preferredVectorByteLength == 0)
             {
-                int steppingId = xarchCpuInfo & (int)0b1111;
-                int model = (xarchCpuInfo >> 4) & (int)0b1111;
-                int familyID = (xarchCpuInfo >> 8) & (int)0b1111;
-                int extendedModelID = (xarchCpuInfo >> 16) & (int)0b1111;
-                if (familyID == 0x06)
+                bool isVector512Throttling = false;
+
+                if (isGenuineIntel)
                 {
-                    if (extendedModelID == 0x05)
+                    int steppingId = xarchCpuInfo & 0b1111;
+                    int model = (xarchCpuInfo >> 4) & 0b1111;
+                    int familyID = (xarchCpuInfo >> 8) & 0b1111;
+                    int extendedModelID = (xarchCpuInfo >> 16) & 0b1111;
+
+                    if (familyID == 0x06)
                     {
-                        if (model == 0x05)
+                        if (extendedModelID == 0x05)
                         {
-                            // * Skylake (Server)
-                            // * Cascade Lake
-                            // * Cooper Lake
-
-                            isAvx512HierarchyDisabled = true;
+                            if (model == 0x05)
+                            {
+                                // * Skylake (Server)
+                                // * Cascade Lake
+                                // * Cooper Lake
+
+                                isVector512Throttling = true;
+                            }
                         }
-                    }
-                    else if (extendedModelID == 0x06)
-                    {
-                        if (model == 0x06)
+                        else if (extendedModelID == 0x06)
                         {
-                            // * Cannon Lake
+                            if (model == 0x06)
+                            {
+                                // * Cannon Lake
 
-                            isAvx512HierarchyDisabled = true;
+                                isVector512Throttling = true;
+                            }
                         }
                     }
                 }
 
+                if (isVector512Throttling)
+                {
+                    preferredVectorByteLength = 256 / 8;
+                }
             }
 
             if (IsBitIncorrect(ecx, 1, typeof(Avx512Vbmi), Avx512Vbmi.IsSupported, "AVX512VBMI", ref isHierarchyDisabled))
@@ -305,12 +319,12 @@ public unsafe static void CpuId()
                 testResult = Fail;
             }
 
-            if (IsIncorrect(typeof(Vector256), Vector256.IsHardwareAccelerated, isAvx2HierarchyDisabled))
+            if (IsIncorrect(typeof(Vector256), Vector256.IsHardwareAccelerated, isAvx2HierarchyDisabled || (preferredVectorByteLength < 32)))
             {
                 testResult = Fail;
             }
 
-            if (IsIncorrect(typeof(Vector512), Vector512.IsHardwareAccelerated, isAvx512HierarchyDisabled))
+            if (IsIncorrect(typeof(Vector512), Vector512.IsHardwareAccelerated, isAvx512HierarchyDisabled || (preferredVectorByteLength < 64)))
             {
                 testResult = Fail;
             }
@@ -421,15 +435,20 @@ static bool IsIncorrect(Type isa, bool isHardwareAccelerated, bool isHierarchyDi
 
         static bool GetDotnetEnable(string name)
         {
-            string? stringValue = Environment.GetEnvironmentVariable($"DOTNET_Enable{name}");
+            // Hardware Intrinsic configuration knobs default to true
+            return GetDotnetEnvVar($"Enable{name}", defaultValue: 1) != 0;
+        }
+
+        static int GetDotnetEnvVar(string name, int defaultValue)
+        {
+            string? stringValue = Environment.GetEnvironmentVariable($"DOTNET_{name}");
 
             if ((stringValue is null) || !int.TryParse(stringValue, out int value))
             {
-                // Hardware Intrinsic configuration knobs default to true
-                return true;
+                return defaultValue;
             }
 
-            return value != 0;
+            return value;
         }
     }
 }
diff --git a/src/tests/readytorun/HardwareIntrinsics/X86/CpuId.cs b/src/tests/readytorun/HardwareIntrinsics/X86/CpuId.cs
@@ -211,36 +211,50 @@ public unsafe static int Main()
             }
 
             bool isAvx512HierarchyDisabled = isHierarchyDisabled;
-            if (isGenuineIntel && !isAvx512HierarchyDisabled)
+
+            int preferredVectorBitWidth = (GetDotnetEnvVar("PreferredVectorBitWidth", defaultValue: 0) / 128) * 128;
+            int preferredVectorByteLength = preferredVectorBitWidth / 8;
+
+            if (preferredVectorByteLength == 0)
             {
-                int steppingId = xarchCpuInfo & (int)0b1111;
-                int model = (xarchCpuInfo >> 4) & (int)0b1111;
-                int familyID = (xarchCpuInfo >> 8) & (int)0b1111;
-                int extendedModelID = (xarchCpuInfo >> 16) & (int)0b1111;
-                if (familyID == 0x06)
+                bool isVector512Throttling = false;
+
+                if (isGenuineIntel)
                 {
-                    if (extendedModelID == 0x05)
+                    int steppingId = xarchCpuInfo & 0b1111;
+                    int model = (xarchCpuInfo >> 4) & 0b1111;
+                    int familyID = (xarchCpuInfo >> 8) & 0b1111;
+                    int extendedModelID = (xarchCpuInfo >> 16) & 0b1111;
+
+                    if (familyID == 0x06)
                     {
-                        if (model == 0x05)
+                        if (extendedModelID == 0x05)
                         {
-                            // * Skylake (Server)
-                            // * Cascade Lake
-                            // * Cooper Lake
-
-                            isAvx512HierarchyDisabled = true;
+                            if (model == 0x05)
+                            {
+                                // * Skylake (Server)
+                                // * Cascade Lake
+                                // * Cooper Lake
+
+                                isVector512Throttling = true;
+                            }
                         }
-                    }
-                    else if (extendedModelID == 0x06)
-                    {
-                        if (model == 0x06)
+                        else if (extendedModelID == 0x06)
                         {
-                            // * Cannon Lake
+                            if (model == 0x06)
+                            {
+                                // * Cannon Lake
 
-                            isAvx512HierarchyDisabled = true;
+                                isVector512Throttling = true;
+                            }
                         }
                     }
                 }
 
+                if (isVector512Throttling)
+                {
+                    preferredVectorByteLength = 256 / 8;
+                }
             }
 
             if (IsBitIncorrect(ecx, 1, typeof(Avx512Vbmi), Avx512Vbmi.IsSupported, "AVX512VBMI", ref isHierarchyDisabled))
@@ -299,12 +313,12 @@ public unsafe static int Main()
                 testResult = Fail;
             }
 
-            if (IsIncorrect(typeof(Vector256), Vector256.IsHardwareAccelerated, isAvx2HierarchyDisabled))
+            if (IsIncorrect(typeof(Vector256), Vector256.IsHardwareAccelerated, isAvx2HierarchyDisabled || (preferredVectorByteLength < 32)))
             {
                 testResult = Fail;
             }
 
-            if (IsIncorrect(typeof(Vector512), Vector512.IsHardwareAccelerated, isAvx512HierarchyDisabled))
+            if (IsIncorrect(typeof(Vector512), Vector512.IsHardwareAccelerated, isAvx512HierarchyDisabled || (preferredVectorByteLength < 64)))
             {
                 testResult = Fail;
             }
@@ -414,15 +428,20 @@ static bool IsIncorrect(Type isa, bool isHardwareAccelerated, bool isHierarchyDi
 
         static bool GetDotnetEnable(string name)
         {
-            string? stringValue = Environment.GetEnvironmentVariable($"DOTNET_Enable{name}");
+            // Hardware Intrinsic configuration knobs default to true
+            return GetDotnetEnvVar($"Enable{name}", defaultValue: 1) != 0;
+        }
+
+        static int GetDotnetEnvVar(string name, int defaultValue)
+        {
+            string? stringValue = Environment.GetEnvironmentVariable($"DOTNET_{name}");
 
             if ((stringValue is null) || !int.TryParse(stringValue, out int value))
             {
-                // Hardware Intrinsic configuration knobs default to true
-                return true;
+                return defaultValue;
             }
 
-            return value != 0;
+            return value;
         }
     }
 }