[clang] [clang] Lower _BitInt(129+) to a different type in LLVM IR (PR #91364)

[John McCall via cfe-commits]

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@@ -118,6 +124,39 @@ llvm::Type *CodeGenTypes::ConvertTypeForMem(QualType T, bool ForBitField) {
   return R;
 }
 
+bool CodeGenTypes::typeRequiresSplitIntoByteArray(QualType ASTTy,
+                                                  llvm::Type *LLVMTy) {
+  if (!LLVMTy)
+    LLVMTy = ConvertType(ASTTy);
+
+  CharUnits ASTSize = Context.getTypeSizeInChars(ASTTy);
+  CharUnits LLVMSize =
+      CharUnits::fromQuantity(getDataLayout().getTypeAllocSize(LLVMTy));
+  return ASTSize != LLVMSize;
+}
+
+llvm::Type *CodeGenTypes::convertTypeForLoadStore(QualType T,
+                                                  llvm::Type *LLVMTy) {
+  if (!LLVMTy)
+    LLVMTy = ConvertType(T);
+
+  if (!T->isBitIntType() && LLVMTy->isIntegerTy(1))
+    return llvm::IntegerType::get(getLLVMContext(),
+                                  (unsigned)Context.getTypeSize(T));
+
+  if (T->isBitIntType()) {
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rjmccall wrote:

You can avoid a second call to `isBitIntType()` by just putting this block before the one above it.

https://github.com/llvm/llvm-project/pull/91364