From a223354161104c25f9c6663b66222bd5e1d532cd Mon Sep 17 00:00:00 2001
From: Yuanfang Chen <yuanfang.chen@sony.com>
Date: Fri, 13 Nov 2020 09:27:10 -0800
Subject: [PATCH] [CGProfile] allows bitcast in metadata node storing function
 pointers

For example,  during RAUW in IRMover, the `Function` ValueAsMetadata in "CG Profile" could become bitcast.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D88433
---
 .../CodeGen/TargetLoweringObjectFileImpl.cpp  |  2 +-
 llvm/lib/IR/Verifier.cpp                      |  4 +--
 .../FunctionImport/Inputs/cg_profile.ll       | 12 +++++++
 .../Transforms/FunctionImport/cg_profile.ll   | 32 +++++++++++++++++++
 4 files changed, 47 insertions(+), 3 deletions(-)
 create mode 100644 llvm/test/Transforms/FunctionImport/Inputs/cg_profile.ll
 create mode 100644 llvm/test/Transforms/FunctionImport/cg_profile.ll

diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index f69b96a295bf..6f9268fbb4ec 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -345,7 +345,7 @@ void TargetLoweringObjectFileELF::emitModuleMetadata(MCStreamer &Streamer,
     if (!MDO)
       return nullptr;
     auto V = cast<ValueAsMetadata>(MDO);
-    const Function *F = cast<Function>(V->getValue());
+    const Function *F = cast<Function>(V->getValue()->stripPointerCasts());
     return TM->getSymbol(F);
   };
 
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 907993c400d9..6c57369f8d80 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -1578,8 +1578,8 @@ void Verifier::visitModuleFlagCGProfileEntry(const MDOperand &MDO) {
     if (!FuncMDO)
       return;
     auto F = dyn_cast<ValueAsMetadata>(FuncMDO);
-    Assert(F && isa<Function>(F->getValue()), "expected a Function or null",
-           FuncMDO);
+    Assert(F && isa<Function>(F->getValue()->stripPointerCasts()),
+           "expected a Function or null", FuncMDO);
   };
   auto Node = dyn_cast_or_null<MDNode>(MDO);
   Assert(Node && Node->getNumOperands() == 3, "expected a MDNode triple", MDO);
diff --git a/llvm/test/Transforms/FunctionImport/Inputs/cg_profile.ll b/llvm/test/Transforms/FunctionImport/Inputs/cg_profile.ll
new file mode 100644
index 000000000000..5143575e1712
--- /dev/null
+++ b/llvm/test/Transforms/FunctionImport/Inputs/cg_profile.ll
@@ -0,0 +1,12 @@
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%class.A = type { [16 x i8] }
+
+define void @bar(%class.A*) {
+  ret void
+}
+
+!llvm.module.flags = !{!1}
+
+!1 = !{i32 1, !"EnableSplitLTOUnit", i32 0}
diff --git a/llvm/test/Transforms/FunctionImport/cg_profile.ll b/llvm/test/Transforms/FunctionImport/cg_profile.ll
new file mode 100644
index 000000000000..2cf920c2a5dd
--- /dev/null
+++ b/llvm/test/Transforms/FunctionImport/cg_profile.ll
@@ -0,0 +1,32 @@
+; Check that bitcast in "CG Profile" related metadata nodes (in this test case,
+; generated during function importing in IRMover's RAUW operations) are accepted
+; by verifier.
+; RUN: opt -cg-profile -module-summary %s -o %t.bc
+; RUN: opt -module-summary %p/Inputs/cg_profile.ll -o %t2.bc
+; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+; RUN: opt -function-import -print-imports -summary-file %t3.thinlto.bc %t.bc \
+; RUN:   -S 2>&1 | FileCheck %s
+
+; CHECK:      !0 = !{i32 1, !"EnableSplitLTOUnit", i32 0}
+; CHECK-NEXT: !1 = !{i32 5, !"CG Profile", !2}
+; CHECK-NEXT: !2 = !{!3}
+; CHECK-NEXT: !3 = !{void ()* @foo, void (%class.A*)* bitcast (void (%class.A.0*)* @bar to void (%class.A*)*), i64 2753}
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; %class.A is defined differently in %p/Inputs/cg_profile.ll. This is to trigger
+; bitcast.
+%class.A = type { i8 }
+
+define void @foo() !prof !2 {
+  call void @bar(%class.A* null)
+  ret void
+}
+
+declare void @bar(%class.A*)
+
+!llvm.module.flags = !{!1}
+
+!1 = !{i32 1, !"EnableSplitLTOUnit", i32 0}
+!2 = !{!"function_entry_count", i64 2753}