From 3fe180ab7acd3c2b18e1ad4d7db825126bc32229 Mon Sep 17 00:00:00 2001
From: Tim Besard <tim.besard@gmail.com>
Date: Mon, 27 Sep 2021 10:24:33 +0200
Subject: [PATCH] Strip address information from byval type parameters.

---
 src/llvm-remove-addrspaces.cpp       | 20 +++++++++++++++++++-
 test/llvmpasses/remove-addrspaces.ll |  7 +++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/llvm-remove-addrspaces.cpp b/src/llvm-remove-addrspaces.cpp
index 7c6ef093fbcea..67e2f0a974520 100644
--- a/src/llvm-remove-addrspaces.cpp
+++ b/src/llvm-remove-addrspaces.cpp
@@ -325,7 +325,8 @@ bool RemoveAddrspacesPass::runOnModule(Module &M)
 
         Function *NF = Function::Create(
                 NFTy, F->getLinkage(), F->getAddressSpace(), Name, &M);
-        NF->copyAttributesFrom(F);
+
+        // no need to copy attributes here, that's done by CloneFunctionInto
         VMap[F] = NF;
     }
 
@@ -387,6 +388,23 @@ bool RemoveAddrspacesPass::runOnModule(Module &M)
                 &TypeRemapper,
                 &Materializer);
 
+        // CloneFunctionInto unconditionally copies the attributes from F to NF,
+        // without considering e.g. the byval attribute type.
+        AttributeList Attrs = F->getAttributes();
+        LLVMContext &C = F->getContext();
+        for (unsigned i = 0; i < Attrs.getNumAttrSets(); ++i) {
+            if (Attrs.hasAttribute(i, Attribute::ByVal)) {
+                Type *Ty = Attrs.getAttribute(i, Attribute::ByVal).getValueAsType();
+                if (!Ty)
+                    continue;
+
+                Attrs = Attrs.removeAttribute(C, i, Attribute::ByVal);
+                Attrs = Attrs.addAttribute(
+                    C, i, Attribute::getWithByValType(C, TypeRemapper.remapType(Ty)));
+            }
+        }
+        NF->setAttributes(Attrs);
+
         if (F->hasPersonalityFn())
             NF->setPersonalityFn(MapValue(F->getPersonalityFn(), VMap));
 
diff --git a/test/llvmpasses/remove-addrspaces.ll b/test/llvmpasses/remove-addrspaces.ll
index 2f34cf55ffc08..f8b6de024bfdd 100644
--- a/test/llvmpasses/remove-addrspaces.ll
+++ b/test/llvmpasses/remove-addrspaces.ll
@@ -101,3 +101,10 @@ loop:
 exit:
   ret i64 %sum
 }
+
+
+; COM: check that address spaces in byval types are processed correctly
+define void @byval_type([1 x {} addrspace(10)*] addrspace(11)* byval([1 x {} addrspace(10)*]) %0) {
+; CHECK: define void @byval_type([1 x {}*]* byval([1 x {}*]) %0)
+  ret void
+}