[RISCV] Move tuning features below non-tuning features. Put CPU family in their own section. NFC

llvm/lib/Target/RISCV/RISCVFeatures.td

@@ -1791,6 +1791,45 @@ def FeatureUnalignedVectorMem
                       "true", "Has reasonably performant unaligned vector "
                       "loads and stores">;
 
+// Assume that lock-free native-width atomics are available, even if the target
+// and operating system combination would not usually provide them. The user
+// is responsible for providing any necessary __sync implementations. Code
+// built with this feature is not ABI-compatible with code built without this
+// feature, if atomic variables are exposed across the ABI boundary.
+def FeatureForcedAtomics : SubtargetFeature<
+    "forced-atomics", "HasForcedAtomics", "true",
+    "Assume that lock-free native-width atomics are available">;
+def HasAtomicLdSt
+    : Predicate<"Subtarget->hasStdExtZalrsc() || Subtarget->hasForcedAtomics()">;
+
+// The RISC-V Unprivileged Architecture - ISA Volume 1 (Version: 20250508)
+// [https://docs.riscv.org/reference/isa/_attachments/riscv-unprivileged.pdf]
+// in section 13.3. Eventual Success of Store-Conditional Instructions, defines
+// _constrained_ LR/SC loops:
+//   The dynamic code executed between the LR and SC instructions can only
+//   contain instructions from the base ''I'' instruction set, excluding loads,
+//   stores, backward jumps, taken backward branches, JALR, FENCE, and SYSTEM
+//   instructions. Compressed forms of the aforementioned ''I'' instructions in
+//   the Zca and Zcb extensions are also permitted.
+// LR/SC loops that do not adhere to the above are _unconstrained_ LR/SC loops,
+// and success is implementation specific. For implementations which know that
+// non-base instructions (such as the ''B'' extension) will not violate any
+// forward progress guarantees, using these instructions to reduce the LR/SC
+// sequence length is desirable.
+def FeaturePermissiveZalrsc
+    : SubtargetFeature<
+          "permissive-zalrsc", "HasPermissiveZalrsc", "true",
+          "Implementation permits non-base instructions between LR/SC pairs">;
+
+def FeatureTaggedGlobals : SubtargetFeature<"tagged-globals",
+    "AllowTaggedGlobals",
+    "true", "Use an instruction sequence for taking the address of a global "
+    "that allows a memory tag in the upper address bits">;
+
+//===----------------------------------------------------------------------===//
+// Tuning features
+//===----------------------------------------------------------------------===//
+
 def TuneNLogNVRGather
    : SubtargetFeature<"log-vrgather", "RISCVVRGatherCostModel", "NLog2N",
                       "Has vrgather.vv with LMUL*log2(LMUL) latency">;
@@ -1911,19 +1950,6 @@ def TuneHasSingleElementVecFP64
                        "Certain vector FP64 operations produce a single result "
                        "element per cycle">;
 
-def TuneMIPSP8700
-    : SubtargetFeature<"mips-p8700", "RISCVProcFamily", "MIPSP8700",
-                       "MIPS p8700 processor">;
-
-def TuneSiFive7 : SubtargetFeature<"sifive7", "RISCVProcFamily", "SiFive7",
-                                   "SiFive 7-Series processors">;
-
-def TuneVentanaVeyron : SubtargetFeature<"ventana-veyron", "RISCVProcFamily", "VentanaVeyron",
-                                         "Ventana Veyron-Series processors">;
-
-def TuneAndes45 : SubtargetFeature<"andes45", "RISCVProcFamily", "Andes45",
-                                   "Andes 45-Series processors">;
-
 def TuneVXRMPipelineFlush : SubtargetFeature<"vxrm-pipeline-flush", "HasVXRMPipelineFlush",
                                              "true", "VXRM writes causes pipeline flush">;
 
@@ -1933,37 +1959,20 @@ def TunePreferVsetvliOverReadVLENB
                        "true",
                        "Prefer vsetvli over read vlenb CSR to calculate VLEN">;
 
-// Assume that lock-free native-width atomics are available, even if the target
-// and operating system combination would not usually provide them. The user
-// is responsible for providing any necessary __sync implementations. Code
-// built with this feature is not ABI-compatible with code built without this
-// feature, if atomic variables are exposed across the ABI boundary.
-def FeatureForcedAtomics : SubtargetFeature<
-    "forced-atomics", "HasForcedAtomics", "true",
-    "Assume that lock-free native-width atomics are available">;
-def HasAtomicLdSt
-    : Predicate<"Subtarget->hasStdExtZalrsc() || Subtarget->hasForcedAtomics()">;
+//===----------------------------------------------------------------------===//
+// CPU Families (alphabetized by vendor).
+//===----------------------------------------------------------------------===//
 
-// The RISC-V Unprivileged Architecture - ISA Volume 1 (Version: 20250508)
-// [https://docs.riscv.org/reference/isa/_attachments/riscv-unprivileged.pdf]
-// in section 13.3. Eventual Success of Store-Conditional Instructions, defines
-// _constrained_ LR/SC loops:
-//   The dynamic code executed between the LR and SC instructions can only
-//   contain instructions from the base ''I'' instruction set, excluding loads,
-//   stores, backward jumps, taken backward branches, JALR, FENCE, and SYSTEM
-//   instructions. Compressed forms of the aforementioned ''I'' instructions in
-//   the Zca and Zcb extensions are also permitted.
-// LR/SC loops that do not adhere to the above are _unconstrained_ LR/SC loops,
-// and success is implementation specific. For implementations which know that
-// non-base instructions (such as the ''B'' extension) will not violate any
-// forward progress guarantees, using these instructions to reduce the LR/SC
-// sequence length is desirable.
-def FeaturePermissiveZalrsc
-    : SubtargetFeature<
-          "permissive-zalrsc", "HasPermissiveZalrsc", "true",
-          "Implementation permits non-base instructions between LR/SC pairs">;
+def TuneAndes45 : SubtargetFeature<"andes45", "RISCVProcFamily", "Andes45",
+                                   "Andes 45-Series processors">;
+
+def TuneMIPSP8700
+    : SubtargetFeature<"mips-p8700", "RISCVProcFamily", "MIPSP8700",
+                       "MIPS p8700 processor">;
+
+def TuneSiFive7 : SubtargetFeature<"sifive7", "RISCVProcFamily", "SiFive7",
+                                   "SiFive 7-Series processors">;
+
+def TuneVentanaVeyron : SubtargetFeature<"ventana-veyron", "RISCVProcFamily", "VentanaVeyron",
+                                         "Ventana Veyron-Series processors">;
 
-def FeatureTaggedGlobals : SubtargetFeature<"tagged-globals",
-    "AllowTaggedGlobals",
-    "true", "Use an instruction sequence for taking the address of a global "
-    "that allows a memory tag in the upper address bits">;