[clang] [CIR] Upstream support for record packing and padding (PR #136036)

[Andy Kaylor via cfe-commits]

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@@ -225,17 +235,88 @@ void RecordType::complete(ArrayRef<Type> members, bool packed, bool padded) {
 //===----------------------------------------------------------------------===//
 
 llvm::TypeSize
-RecordType::getTypeSizeInBits(const ::mlir::DataLayout &dataLayout,
-                              ::mlir::DataLayoutEntryListRef params) const {
-  assert(!cir::MissingFeatures::recordTypeLayoutInfo());
-  return llvm::TypeSize::getFixed(8);
+RecordType::getTypeSizeInBits(const mlir::DataLayout &dataLayout,
+                              mlir::DataLayoutEntryListRef params) const {
+  if (isUnion()) {
+    // TODO(CIR): Implement union layout.
+    return llvm::TypeSize::getFixed(8);
+  }
+
+  unsigned recordSize = computeStructSize(dataLayout);
+  return llvm::TypeSize::getFixed(recordSize * 8);
 }
 
 uint64_t
 RecordType::getABIAlignment(const ::mlir::DataLayout &dataLayout,
                             ::mlir::DataLayoutEntryListRef params) const {
-  assert(!cir::MissingFeatures::recordTypeLayoutInfo());
-  return 4;
+  if (isUnion()) {
+    // TODO(CIR): Implement union layout.
+    return 8;
+  }
+
+  // Packed structures always have an ABI alignment of 1.
+  if (getPacked())
+    return 1;
+  return computeStructAlignment(dataLayout);
+}
+
+unsigned
+RecordType::computeStructSize(const mlir::DataLayout &dataLayout) const {
----------------
andykaylor wrote:

This matches what the LLVM dialect does for `LLVMStructType::getTypeSizeInBits` except for the asserts about things already being aligned. I'm going to try this in the incubator. If the asserts do hold, I think I can remove the alignment calculations from this function.

https://github.com/llvm/llvm-project/pull/136036