[llvm] [RISCV][GISel] Sink getOperandsMapping call out of the switch in getInstrMapping. (PR #72326)

[Min-Yih Hsu via llvm-commits]

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@@ -265,76 +283,60 @@ RISCVRegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
   case TargetOpcode::G_GLOBAL_VALUE:
   case TargetOpcode::G_JUMP_TABLE:
   case TargetOpcode::G_BRCOND:
-    OperandsMapping = getOperandsMapping({GPRValueMapping, nullptr});
+    OpdsMapping[0] = GPRValueMapping;
     break;
   case TargetOpcode::G_BR:
-    OperandsMapping = getOperandsMapping({nullptr});
     break;
   case TargetOpcode::G_BRJT:
-    OperandsMapping =
-        getOperandsMapping({GPRValueMapping, nullptr, GPRValueMapping});
+    OpdsMapping[0] = GPRValueMapping;
+    OpdsMapping[2] = GPRValueMapping;
     break;
   case TargetOpcode::G_ICMP:
-    OperandsMapping = getOperandsMapping(
-        {GPRValueMapping, nullptr, GPRValueMapping, GPRValueMapping});
+    OpdsMapping[0] = GPRValueMapping;
+    OpdsMapping[2] = GPRValueMapping;
+    OpdsMapping[3] = GPRValueMapping;
     break;
   case TargetOpcode::G_SEXT_INREG:
-    OperandsMapping =
-        getOperandsMapping({GPRValueMapping, GPRValueMapping, nullptr});
+    OpdsMapping[0] = GPRValueMapping;
+    OpdsMapping[1] = GPRValueMapping;
     break;
   case TargetOpcode::G_SELECT:
-    OperandsMapping = getOperandsMapping(
-        {GPRValueMapping, GPRValueMapping, GPRValueMapping, GPRValueMapping});
+    OpdsMapping[0] = GPRValueMapping;
+    OpdsMapping[1] = GPRValueMapping;
+    OpdsMapping[2] = GPRValueMapping;
+    OpdsMapping[3] = GPRValueMapping;
     break;
-  case TargetOpcode::G_FADD:
-  case TargetOpcode::G_FSUB:
-  case TargetOpcode::G_FMUL:
-  case TargetOpcode::G_FDIV:
-  case TargetOpcode::G_FNEG:
-  case TargetOpcode::G_FABS:
-  case TargetOpcode::G_FSQRT:
-  case TargetOpcode::G_FMAXNUM:
-  case TargetOpcode::G_FMINNUM: {
-    LLT Ty = MRI.getType(MI.getOperand(0).getReg());
-    OperandsMapping = getFPValueMapping(Ty.getSizeInBits());
-    break;
-  }
   case TargetOpcode::G_FMA: {
     LLT Ty = MRI.getType(MI.getOperand(0).getReg());
-    const RegisterBankInfo::ValueMapping *FPValueMapping =
-        getFPValueMapping(Ty.getSizeInBits());
-    OperandsMapping = getOperandsMapping(
-        {FPValueMapping, FPValueMapping, FPValueMapping, FPValueMapping});
+    OpdsMapping[0] = getFPValueMapping(Ty.getSizeInBits());
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mshockwave wrote:

I think it'll probably be more tidy to use `std::fill_n` here

https://github.com/llvm/llvm-project/pull/72326