[CIR][CIRGen][TBAA] Add support for BitInt

Author: PikachuHyA

clang/include/clang/CIR/MissingFeatures.h

@@ -60,7 +60,6 @@ struct MissingFeatures {
   static bool tbaa() { return false; }
   static bool tbaaStruct() { return false; }
   static bool tbaaTagForStruct() { return false; }
-  static bool tbaaTagForBitInt() { return false; }
   static bool tbaaVTablePtr() { return false; }
   static bool tbaaIncompleteType() { return false; }
   static bool tbaaMergeTBAAInfo() { return false; }

clang/lib/CIR/CodeGen/CIRGenTBAA.cpp

@@ -192,8 +192,13 @@ cir::TBAAAttr CIRGenTBAA::getTypeInfoHelper(clang::QualType qty) {
                                     types.convertType(qty));
   }
   if (const auto *eit = dyn_cast<BitIntType>(ty)) {
-    assert(!cir::MissingFeatures::tbaaTagForBitInt());
-    return tbaa_NYI(mlirContext);
+    SmallString<256> outName;
+    llvm::raw_svector_ostream out(outName);
+    // Don't specify signed/unsigned since integer types can alias despite sign
+    // differences.
+    out << "_BitInt(" << eit->getNumBits() << ')';
+    return cir::TBAAScalarAttr::get(mlirContext, outName,
+                                    types.convertType(qty));
   }
   // For now, handle any other kind of type conservatively.
   return getChar();

clang/test/CIR/CodeGen/tbaa-bitinit.c

@@ -1,13 +1,26 @@
 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir -O1
 // RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-llvm %s -o %t.ll -O1 -disable-llvm-passes
+// RUN: FileCheck --check-prefix=LLVM --input-file=%t.ll %s
 
-
-// CIR: #tbaa[[tbaa_NYI:.*]] = #cir.tbaa
+// CIR: #tbaa[[BitInt33:.*]] = #cir.tbaa_scalar<id = "_BitInt(33)", type = !cir.int<s, 33>>
+// CIR: #tbaa[[BitInt31:.*]] = #cir.tbaa_scalar<id = "_BitInt(31)", type = !cir.int<s, 31>>
 
 _BitInt(33) a;
 _BitInt(31) b;
 void c() {
-  // CIR: %{{.*}} = cir.load %{{.*}} : !cir.ptr<!cir.int<s, 33>>, !cir.int<s, 33> tbaa(#tbaa[[tbaa_NYI]])
-  // CIR: cir.store %{{.*}}, %{{.*}} : !cir.int<s, 31>, !cir.ptr<!cir.int<s, 31>> tbaa(#tbaa[[tbaa_NYI]])
+  // CIR-LABEL: cir.func {{.*}} @c()
+  // CIR: %{{.*}} = cir.load %{{.*}} : !cir.ptr<!cir.int<s, 33>>, !cir.int<s, 33> tbaa(#tbaa[[BitInt33]])
+  // CIR: cir.store %{{.*}}, %{{.*}} : !cir.int<s, 31>, !cir.ptr<!cir.int<s, 31>> tbaa(#tbaa[[BitInt31]])
+
+  // LLVM-LABEL: define {{.*}} void @c()
+  // LLVM: %{{.*}} = load i33, ptr @a, align 8, !tbaa [[tbaa_tag_bitint_33:!.*]]
+  // LLVM: store i31 %{{.*}}, ptr @b, align 4, !tbaa [[tbaa_tag_bitint_31:!.*]]
   b = a;
 }
+// LLVM: [[tbaa_tag_bitint_33]] = !{[[TYPE_bitint_33:!.*]], [[TYPE_bitint_33]], i64 0}
+// LLVM: [[TYPE_bitint_33]] = !{!"_BitInt(33)", [[TYPE_char:!.*]], i64 0}
+// LLVM: [[TYPE_char]] = !{!"omnipotent char", [[TAG_c_tbaa:!.*]], i64 0}
+// LLVM: [[TAG_c_tbaa]] = !{!"Simple C/C++ TBAA"}
+// LLVM: [[tbaa_tag_bitint_31]] = !{[[TYPE_bitint_31:!.*]], [[TYPE_bitint_31]], i64 0}
+// LLVM: [[TYPE_bitint_31]] = !{!"_BitInt(31)", [[TYPE_char:!.*]], i64 0}