[Clang][AArch64] Inline assembly support for the ACLE type 'data512_t'

In LLVM IR terms the ACLE type 'data512_t' is essentially an aggregate
type { [8 x i64] }. When emitting code for inline assembly operands,
clang tries to scalarize aggregate types to an integer of the equivalent
length, otherwise it passes them by-reference. This patch adds a target
hook to tell whether a given inline assembly operand is scalarizable
so that clang can emit code to pass/return it by-value.

Differential Revision: https://reviews.llvm.org/D94098

1 files changed, 14 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index a2b68a0..d2cc0a6 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -5526,6 +5526,20 @@ public:
     Fn->addFnAttr("branch-target-enforcement",
                   BPI.BranchTargetEnforcement ? "true" : "false");
   }
+
+  bool isScalarizableAsmOperand(CodeGen::CodeGenFunction &CGF,
+                                llvm::Type *Ty) const override {
+    if (CGF.getTarget().hasFeature("ls64")) {
+      auto *ST = dyn_cast<llvm::StructType>(Ty);
+      if (ST && ST->getNumElements() == 1) {
+        auto *AT = dyn_cast<llvm::ArrayType>(ST->getElementType(0));
+        if (AT && AT->getNumElements() == 8 &&
+            AT->getElementType()->isIntegerTy(64))
+          return true;
+      }
+    }
+    return TargetCodeGenInfo::isScalarizableAsmOperand(CGF, Ty);
+  }
 };
 
 class WindowsAArch64TargetCodeGenInfo : public AArch64TargetCodeGenInfo {