[clang] [clang] Return larger CXX records in memory (PR #120670)

[Eli Friedman via cfe-commits]

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@@ -1334,6 +1334,16 @@ class X86_64ABIInfo : public ABIInfo {
     return T.isOSLinux() || T.isOSNetBSD();
   }
 
+  bool returnCXXRecordGreaterThan128InMem() const {
+    // Clang <= 20.0 did not do this.
+    if (getContext().getLangOpts().getClangABICompat() <=
+        LangOptions::ClangABI::Ver20)
+      return false;
+
+    const llvm::Triple &T = getTarget().getTriple();
+    return T.isOSLinux() || T.isOSNetBSD();
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efriedma-quic wrote:

Please make this apply to all targets by default. Almost all targets will want to be consistent with the spec and gcc.  If you think you need to exclude some target for some reason, please list it explicitly.

https://github.com/llvm/llvm-project/pull/120670