[llvm] [RISCV] Use templates to reduce duplicated code for assembler operand predicates. (PR #133351)

[Craig Topper via llvm-commits]

================
@@ -1107,64 +933,16 @@ struct RISCVOperand final : public MCParsedAsmOperand {
   bool isSImm21Lsb0JAL() const { return isBareSimmNLsb0<21>(); }
 
   bool isImmZero() const {
-    if (!isImm())
-      return false;
-    int64_t Imm;
-    RISCVMCExpr::Specifier VK = RISCVMCExpr::VK_None;
-    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
-    return IsConstantImm && (Imm == 0) && VK == RISCVMCExpr::VK_None;
+    return isUImmPred([](int64_t Imm) { return 0 == Imm; });
   }
 
   bool isSImm5Plus1() const {
-    if (!isImm())
-      return false;
-    RISCVMCExpr::Specifier VK = RISCVMCExpr::VK_None;
-    int64_t Imm;
-    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
-    return IsConstantImm &&
-           isInt<5>(fixImmediateForRV32(Imm, isRV64Imm()) - 1) &&
-           VK == RISCVMCExpr::VK_None;
-  }
-
-  bool isSImm20() const {
-    if (!isImm())
-      return false;
-    RISCVMCExpr::Specifier VK = RISCVMCExpr::VK_None;
-    int64_t Imm;
-    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
-    return IsConstantImm && (VK == RISCVMCExpr::VK_None) &&
-           isInt<20>(fixImmediateForRV32(Imm, isRV64Imm()));
-  }
-
-  bool isSImm26() const {
-    if (!isImm())
-      return false;
-    RISCVMCExpr::Specifier VK = RISCVMCExpr::VK_None;
-    int64_t Imm;
-    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
-    return IsConstantImm && (VK == RISCVMCExpr::VK_None) &&
-           isInt<26>(fixImmediateForRV32(Imm, isRV64Imm()));
-  }
-
-  bool isSImm32() const {
-    int64_t Imm;
-    RISCVMCExpr::Specifier VK = RISCVMCExpr::VK_None;
-    if (!isImm())
-      return false;
-    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
-    return IsConstantImm && isInt<32>(fixImmediateForRV32(Imm, isRV64Imm())) &&
-           VK == RISCVMCExpr::VK_None;
+    return isSImmPred(
+        [](int64_t Imm) { return Imm != INT64_MIN && isInt<5>(Imm - 1); });
----------------
topperc wrote:

I added the INT64_MIN check to guard undefined behavior on the Imm-1. The code wasn't optimizable, but could fail if someone build llvm with UBSAN.

https://github.com/llvm/llvm-project/pull/133351