[clang] [llvm] [AIX] support builtin_cpu_is() for aix (PR #80069)

[Amy Kwan via llvm-commits]

================
@@ -16542,22 +16542,75 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
 
   Intrinsic::ID ID = Intrinsic::not_intrinsic;
 
+#include "llvm/TargetParser/PPCTargetParser.def"
+  auto GetOpRes = [&](Value *FieldValue, unsigned Mask, unsigned Op,
+                      unsigned Op_Value) -> Value * {
+    Value *Value1 = FieldValue;
+    if (Mask)
+      Value1 = Builder.CreateAnd(Value1, Mask);
+    assert((Op == OP_EQ) && "Only support equal comparision");
+    return Builder.CreateICmp(ICmpInst::ICMP_EQ, FieldValue,
+                              ConstantInt::get(Int32Ty, Op_Value));
+  };
+
+  auto ConvBuiltinCpu = [&](unsigned SupportOP, unsigned FieldIdx,
+                            unsigned Op_Mask, unsigned Op,
+                            unsigned Op_Value) -> Value * {
+    if (SupportOP == AIX_BUILTIN_PPC_FALSE)
+      return llvm::ConstantInt::getFalse(ConvertType(E->getType()));
+
+    if (SupportOP == AIX_BUILTIN_PPC_TRUE)
+      return llvm::ConstantInt::getTrue(ConvertType(E->getType()));
+
+    assert(SupportOP <= COMP_OP && "Invalid value for SupportOP.");
+    llvm::Type *STy = llvm::StructType::get(PPC_SYSTEMCONFIG_TYPE);
+
+    llvm::Constant *SysConf =
+        CGM.CreateRuntimeVariable(STy, "_system_configuration");
+
+    // Grab the appropriate field from _system_configuration.
+    llvm::Value *Idxs[] = {ConstantInt::get(Int32Ty, 0),
+                           ConstantInt::get(Int32Ty, FieldIdx)};
+
+    llvm::Value *FieldValue = Builder.CreateGEP(STy, SysConf, Idxs);
+    FieldValue = Builder.CreateAlignedLoad(Int32Ty, FieldValue,
+                                           CharUnits::fromQuantity(4));
+
+    return GetOpRes(FieldValue, Op_Mask, Op, Op_Value);
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amy-kwan wrote:

We should rename `Op` since `Op` seems overloaded and misleading in this context.

https://github.com/llvm/llvm-project/pull/80069