[llvm-branch-commits] [clang] [llvm] [RISCV] Support __builtin_cpu_is (PR #116231)

[Pengcheng Wang via llvm-branch-commits]

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@@ -22505,6 +22506,47 @@ Value *CodeGenFunction::EmitHexagonBuiltinExpr(unsigned BuiltinID,
   return nullptr;
 }
 
+Value *CodeGenFunction::EmitRISCVCpuIs(const CallExpr *E) {
+  const Expr *CPUExpr = E->getArg(0)->IgnoreParenCasts();
+  StringRef CPUStr = cast<clang::StringLiteral>(CPUExpr)->getString();
+  return EmitRISCVCpuIs(CPUStr);
+}
+
+Value *CodeGenFunction::EmitRISCVCpuIs(StringRef CPUStr) {
+  llvm::Type *Int32Ty = Builder.getInt32Ty();
+  llvm::Type *Int64Ty = Builder.getInt64Ty();
+  llvm::StructType *StructTy = llvm::StructType::get(Int32Ty, Int64Ty, Int64Ty);
+  llvm::Constant *RISCVCPUModel =
+      CGM.CreateRuntimeVariable(StructTy, "__riscv_cpu_model");
+  cast<llvm::GlobalValue>(RISCVCPUModel)->setDSOLocal(true);
+
+  auto loadRISCVCPUID = [&](unsigned Index) {
+    Value *Ptr = Builder.CreateStructGEP(StructTy, RISCVCPUModel, Index);
+    Value *CPUID = Builder.CreateAlignedLoad(StructTy->getTypeAtIndex(Index),
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wangpc-pp wrote:

Tried it, but `CreateLoad` in `CGBuilder` needs `Address` which also needs alignment.

https://github.com/llvm/llvm-project/pull/116231