[AMDGPU] Update subtarget features for new target ID support

Support for XNACK and SRAMECC is not static on some GPUs. We must be able
to differentiate between different scenarios for these dynamic subtarget
features.

The possible settings are:

- Unsupported: The GPU has no support for XNACK/SRAMECC.
- Any: Preference is unspecified. Use conservative settings that can run anywhere.
- Off: Request support for XNACK/SRAMECC Off
- On: Request support for XNACK/SRAMECC On

GCNSubtarget will track the four options based on the following criteria. If
the subtarget does not support XNACK/SRAMECC we say the setting is
"Unsupported". If no subtarget features for XNACK/SRAMECC are requested we
must support "Any" mode. If the subtarget features XNACK/SRAMECC exist in the
feature string when initializing the subtarget, the settings are "On/Off".

The defaults are updated to be conservatively correct, meaning if no setting
for XNACK or SRAMECC is explicitly requested, defaults will be used which
generate code that can be run anywhere. This corresponds to the "Any" setting.

Differential Revision: https://reviews.llvm.org/D85882

llvm/lib/Target/AMDGPU/AMDGPU.td

@@ -129,10 +129,10 @@ def FeatureFmaMixInsts : SubtargetFeature<"fma-mix-insts",
   "Has v_fma_mix_f32, v_fma_mixlo_f16, v_fma_mixhi_f16 instructions"
 >;
 
-def FeatureDoesNotSupportXNACK : SubtargetFeature<"no-xnack-support",
-  "DoesNotSupportXNACK",
+def FeatureSupportsXNACK : SubtargetFeature<"xnack-support",
+  "SupportsXNACK",
   "true",
-  "Hardware does not support XNACK"
+  "Hardware supports XNACK"
 >;
 
 // XNACK is disabled if SH_MEM_CONFIG.ADDRESS_MODE = GPUVM on chips that support
@@ -491,16 +491,16 @@ def FeatureAtomicFaddInsts : SubtargetFeature<"atomic-fadd-insts",
   [FeatureFlatGlobalInsts]
 >;
 
-def FeatureDoesNotSupportSRAMECC : SubtargetFeature<"no-sram-ecc-support",
-  "DoesNotSupportSRAMECC",
+def FeatureSupportsSRAMECC : SubtargetFeature<"sramecc-support",
+  "SupportsSRAMECC",
   "true",
-  "Hardware does not support SRAM ECC"
+  "Hardware supports SRAMECC"
 >;
 
-def FeatureSRAMECC : SubtargetFeature<"sram-ecc",
+def FeatureSRAMECC : SubtargetFeature<"sramecc",
   "EnableSRAMECC",
   "true",
-  "Enable SRAM ECC"
+  "Enable SRAMECC"
 >;
 
 def FeatureNoSdstCMPX : SubtargetFeature<"no-sdst-cmpx",
@@ -675,8 +675,7 @@ def FeatureSouthernIslands : GCNSubtargetFeatureGeneration<"SOUTHERN_ISLANDS",
   [FeatureFP64, FeatureLocalMemorySize32768, FeatureMIMG_R128,
   FeatureWavefrontSize64, FeatureSMemTimeInst, FeatureMadMacF32Insts,
   FeatureDsSrc2Insts, FeatureLDSBankCount32, FeatureMovrel,
-  FeatureTrigReducedRange, FeatureDoesNotSupportSRAMECC,
-  FeatureDoesNotSupportXNACK]
+  FeatureTrigReducedRange]
 >;
 
 def FeatureSeaIslands : GCNSubtargetFeatureGeneration<"SEA_ISLANDS",
@@ -685,8 +684,7 @@ def FeatureSeaIslands : GCNSubtargetFeatureGeneration<"SEA_ISLANDS",
   FeatureWavefrontSize64, FeatureFlatAddressSpace,
   FeatureCIInsts, FeatureMovrel, FeatureTrigReducedRange,
   FeatureGFX7GFX8GFX9Insts, FeatureSMemTimeInst, FeatureMadMacF32Insts,
-  FeatureDsSrc2Insts, FeatureDoesNotSupportSRAMECC,
-  FeatureUnalignedBufferAccess]
+  FeatureDsSrc2Insts, FeatureUnalignedBufferAccess]
 >;
 
 def FeatureVolcanicIslands : GCNSubtargetFeatureGeneration<"VOLCANIC_ISLANDS",
@@ -699,9 +697,7 @@ def FeatureVolcanicIslands : GCNSubtargetFeatureGeneration<"VOLCANIC_ISLANDS",
    FeatureSDWA, FeatureSDWAOutModsVOPC, FeatureSDWAMac, FeatureDPP,
    FeatureIntClamp, FeatureTrigReducedRange, FeatureGFX8Insts,
    FeatureGFX7GFX8GFX9Insts, FeatureSMemTimeInst, FeatureMadMacF32Insts,
-   FeatureDsSrc2Insts, FeatureDoesNotSupportSRAMECC, FeatureFastDenormalF32,
-   FeatureUnalignedBufferAccess
-  ]
+   FeatureDsSrc2Insts, FeatureFastDenormalF32, FeatureUnalignedBufferAccess]
 >;
 
 def FeatureGFX9 : GCNSubtargetFeatureGeneration<"GFX9",
@@ -717,9 +713,8 @@ def FeatureGFX9 : GCNSubtargetFeatureGeneration<"GFX9",
    FeatureAddNoCarryInsts, FeatureGFX8Insts, FeatureGFX7GFX8GFX9Insts,
    FeatureScalarFlatScratchInsts, FeatureScalarAtomics, FeatureR128A16,
    FeatureSMemTimeInst, FeatureMadMacF32Insts, FeatureDsSrc2Insts,
-   FeatureFastDenormalF32, FeatureUnalignedBufferAccess,
-   FeatureUnalignedDSAccess
-  ]
+   FeatureFastDenormalF32, FeatureUnalignedBufferAccess, FeatureUnalignedDSAccess,
+   FeatureSupportsXNACK]
 >;
 
 def FeatureGFX10 : GCNSubtargetFeatureGeneration<"GFX10",
@@ -735,7 +730,7 @@ def FeatureGFX10 : GCNSubtargetFeatureGeneration<"GFX10",
    FeatureAddNoCarryInsts, FeatureFmaMixInsts, FeatureGFX8Insts,
    FeatureNoSdstCMPX, FeatureVscnt, FeatureRegisterBanking,
    FeatureVOP3Literal, FeatureDPP8,
-   FeatureNoDataDepHazard, FeaturePkFmacF16Inst, FeatureDoesNotSupportSRAMECC,
+   FeatureNoDataDepHazard, FeaturePkFmacF16Inst,
    FeatureGFX10A16, FeatureFastDenormalF32, FeatureG16,
    FeatureUnalignedBufferAccess, FeatureUnalignedDSAccess
   ]
@@ -748,109 +743,91 @@ class FeatureSet<list<SubtargetFeature> Features_> {
 def FeatureISAVersion6_0_0 : FeatureSet<[FeatureSouthernIslands,
    FeatureFastFMAF32,
    HalfRate64Ops,
-   FeatureLDSBankCount32,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureLDSBankCount32]>;
 
 def FeatureISAVersion6_0_1 : FeatureSet<
   [FeatureSouthernIslands,
-   FeatureLDSBankCount32,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureLDSBankCount32]>;
 
 def FeatureISAVersion6_0_2 : FeatureSet<
   [FeatureSouthernIslands,
-   FeatureLDSBankCount32,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureLDSBankCount32]>;
 
 def FeatureISAVersion7_0_0 : FeatureSet<
   [FeatureSeaIslands,
-   FeatureLDSBankCount32,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureLDSBankCount32]>;
 
 def FeatureISAVersion7_0_1 : FeatureSet<
   [FeatureSeaIslands,
    HalfRate64Ops,
    FeatureLDSBankCount32,
-   FeatureFastFMAF32,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureFastFMAF32]>;
 
 def FeatureISAVersion7_0_2 : FeatureSet<
   [FeatureSeaIslands,
    FeatureLDSBankCount16,
-   FeatureFastFMAF32,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureFastFMAF32]>;
 
 def FeatureISAVersion7_0_3 : FeatureSet<
   [FeatureSeaIslands,
-   FeatureLDSBankCount16,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureLDSBankCount16]>;
 
 def FeatureISAVersion7_0_4 : FeatureSet<
   [FeatureSeaIslands,
-   FeatureLDSBankCount32,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureLDSBankCount32]>;
 
 def FeatureISAVersion7_0_5 : FeatureSet<
   [FeatureSeaIslands,
-   FeatureLDSBankCount16,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureLDSBankCount16]>;
 
 def FeatureISAVersion8_0_1 : FeatureSet<
   [FeatureVolcanicIslands,
    FeatureFastFMAF32,
    HalfRate64Ops,
    FeatureLDSBankCount32,
-   FeatureXNACK,
+   FeatureSupportsXNACK,
    FeatureUnpackedD16VMem]>;
 
 def FeatureISAVersion8_0_2 : FeatureSet<
   [FeatureVolcanicIslands,
    FeatureLDSBankCount32,
    FeatureSGPRInitBug,
-   FeatureUnpackedD16VMem,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureUnpackedD16VMem]>;
 
 def FeatureISAVersion8_0_3 : FeatureSet<
   [FeatureVolcanicIslands,
    FeatureLDSBankCount32,
-   FeatureUnpackedD16VMem,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureUnpackedD16VMem]>;
 
 def FeatureISAVersion8_0_5 : FeatureSet<
   [FeatureVolcanicIslands,
    FeatureLDSBankCount32,
    FeatureSGPRInitBug,
-   FeatureUnpackedD16VMem,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureUnpackedD16VMem]>;
 
 def FeatureISAVersion8_1_0 : FeatureSet<
   [FeatureVolcanicIslands,
    FeatureLDSBankCount16,
-   FeatureXNACK,
+   FeatureSupportsXNACK,
    FeatureImageStoreD16Bug,
    FeatureImageGather4D16Bug]>;
 
 def FeatureISAVersion9_0_0 : FeatureSet<
   [FeatureGFX9,
    FeatureMadMixInsts,
    FeatureLDSBankCount32,
-   FeatureDoesNotSupportXNACK,
-   FeatureDoesNotSupportSRAMECC,
    FeatureImageGather4D16Bug]>;
 
 def FeatureISAVersion9_0_2 : FeatureSet<
   [FeatureGFX9,
    FeatureMadMixInsts,
    FeatureLDSBankCount32,
-   FeatureXNACK,
-   FeatureDoesNotSupportSRAMECC,
    FeatureImageGather4D16Bug]>;
 
 def FeatureISAVersion9_0_4 : FeatureSet<
   [FeatureGFX9,
    FeatureLDSBankCount32,
    FeatureFmaMixInsts,
-   FeatureDoesNotSupportXNACK,
-   FeatureDoesNotSupportSRAMECC,
    FeatureImageGather4D16Bug]>;
 
 def FeatureISAVersion9_0_6 : FeatureSet<
@@ -861,7 +838,7 @@ def FeatureISAVersion9_0_6 : FeatureSet<
    FeatureDLInsts,
    FeatureDot1Insts,
    FeatureDot2Insts,
-   FeatureDoesNotSupportXNACK,
+   FeatureSupportsSRAMECC,
    FeatureImageGather4D16Bug]>;
 
 def FeatureISAVersion9_0_8 : FeatureSet<
@@ -879,15 +856,14 @@ def FeatureISAVersion9_0_8 : FeatureSet<
    FeatureMAIInsts,
    FeaturePkFmacF16Inst,
    FeatureAtomicFaddInsts,
-   FeatureSRAMECC,
+   FeatureSupportsSRAMECC,
    FeatureMFMAInlineLiteralBug,
    FeatureImageGather4D16Bug]>;
 
 def FeatureISAVersion9_0_9 : FeatureSet<
   [FeatureGFX9,
    FeatureMadMixInsts,
    FeatureLDSBankCount32,
-   FeatureXNACK,
    FeatureImageGather4D16Bug]>;
 
 def FeatureISAVersion9_0_C : FeatureSet<
@@ -928,7 +904,7 @@ def FeatureISAVersion10_1_0 : FeatureSet<
      FeatureMadMacF32Insts,
      FeatureDsSrc2Insts,
      FeatureLdsMisalignedBug,
-     FeatureDoesNotSupportXNACK])>;
+     FeatureSupportsXNACK])>;
 
 def FeatureISAVersion10_1_1 : FeatureSet<
   !listconcat(FeatureGroup.GFX10_1_Bugs,
@@ -949,7 +925,7 @@ def FeatureISAVersion10_1_1 : FeatureSet<
      FeatureMadMacF32Insts,
      FeatureDsSrc2Insts,
      FeatureLdsMisalignedBug,
-     FeatureDoesNotSupportXNACK])>;
+     FeatureSupportsXNACK])>;
 
 def FeatureISAVersion10_1_2 : FeatureSet<
   !listconcat(FeatureGroup.GFX10_1_Bugs,
@@ -970,7 +946,7 @@ def FeatureISAVersion10_1_2 : FeatureSet<
      FeatureMadMacF32Insts,
      FeatureDsSrc2Insts,
      FeatureLdsMisalignedBug,
-     FeatureDoesNotSupportXNACK])>;
+     FeatureSupportsXNACK])>;
 
 def FeatureISAVersion10_3_0 : FeatureSet<
   [FeatureGFX10,
@@ -983,8 +959,7 @@ def FeatureISAVersion10_3_0 : FeatureSet<
    FeatureDot5Insts,
    FeatureDot6Insts,
    FeatureNSAEncoding,
-   FeatureWavefrontSize32,
-   FeatureDoesNotSupportXNACK]>;
+   FeatureWavefrontSize32]>;
 
 //===----------------------------------------------------------------------===//
 

llvm/lib/Target/AMDGPU/AMDGPUSubtarget.cpp

@@ -19,6 +19,7 @@
 #include "AMDGPURegisterBankInfo.h"
 #include "AMDGPUTargetMachine.h"
 #include "SIMachineFunctionInfo.h"
+#include "Utils/AMDGPUBaseInfo.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/CodeGen/GlobalISel/InlineAsmLowering.h"
 #include "llvm/CodeGen/MachineScheduler.h"
@@ -88,8 +89,7 @@ GCNSubtarget::initializeSubtargetDependencies(const Triple &TT,
   // Similarly we want enable-prt-strict-null to be on by default and not to
   // unset everything else if it is disabled
 
-  // Assuming ECC is enabled is the conservative default.
-  SmallString<256> FullFS("+promote-alloca,+load-store-opt,+enable-ds128,+sram-ecc,+xnack,");
+  SmallString<256> FullFS("+promote-alloca,+load-store-opt,+enable-ds128,");
 
   // Turn on features that HSA ABI requires. Also turn on FlatForGlobal by default
   if (isAmdHsaOS())
@@ -164,20 +164,12 @@ GCNSubtarget::initializeSubtargetDependencies(const Triple &TT,
 
   HasFminFmaxLegacy = getGeneration() < AMDGPUSubtarget::VOLCANIC_ISLANDS;
 
-  // Disable XNACK on targets where it is not enabled by default unless it is
-  // explicitly requested.
-  if (!FS.contains("+xnack") && DoesNotSupportXNACK && EnableXNACK) {
-    ToggleFeature(AMDGPU::FeatureXNACK);
-    EnableXNACK = false;
-  }
+  TargetID.setTargetIDFromFeaturesString(FS);
 
-  // ECC is on by default, but turn it off if the hardware doesn't support it
-  // anyway. This matters for the gfx9 targets with d16 loads, but don't support
-  // ECC.
-  if (DoesNotSupportSRAMECC && EnableSRAMECC) {
-    ToggleFeature(AMDGPU::FeatureSRAMECC);
-    EnableSRAMECC = false;
-  }
+  LLVM_DEBUG(dbgs() << "xnack setting for subtarget: "
+                    << TargetID.getXnackSetting() << '\n');
+  LLVM_DEBUG(dbgs() << "sramecc setting for subtarget: "
+                    << TargetID.getSramEccSetting() << '\n');
 
   return *this;
 }
@@ -206,6 +198,7 @@ GCNSubtarget::GCNSubtarget(const Triple &TT, StringRef GPU, StringRef FS,
     AMDGPUGenSubtargetInfo(TT, GPU, /*TuneCPU*/ GPU, FS),
     AMDGPUSubtarget(TT),
     TargetTriple(TT),
+    TargetID(*this),
     Gen(INVALID),
     InstrItins(getInstrItineraryForCPU(GPU)),
     LDSBankCount(0),
@@ -221,8 +214,8 @@ GCNSubtarget::GCNSubtarget(const Triple &TT, StringRef GPU, StringRef FS,
     UnalignedAccessMode(false),
 
     HasApertureRegs(false),
+    SupportsXNACK(false),
     EnableXNACK(false),
-    DoesNotSupportXNACK(false),
     EnableCuMode(false),
     TrapHandler(false),
 
@@ -271,8 +264,8 @@ GCNSubtarget::GCNSubtarget(const Triple &TT, StringRef GPU, StringRef FS,
     HasMAIInsts(false),
     HasPkFmacF16Inst(false),
     HasAtomicFaddInsts(false),
+    SupportsSRAMECC(false),
     EnableSRAMECC(false),
-    DoesNotSupportSRAMECC(false),
     HasNoSdstCMPX(false),
     HasVscnt(false),
     HasGetWaveIdInst(false),