From: Peter Collingbourne <peter@pcc.me.uk>
Date: Wed, 19 Jul 2017 17:54:29 +0000 (+0000)
Subject: ThinLTOBitcodeWriter: Do not rewrite intrinsic functions when splitting modules.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0bd44fcf7ce6241eb750ba45a3eb3ea3c04c5bfb;p=llvm

ThinLTOBitcodeWriter: Do not rewrite intrinsic functions when splitting modules.

Changing the type of an intrinsic may invalidate the IR.

Differential Revision: https://reviews.llvm.org/D35593

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308500 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp b/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
index 8ef6bb65230..c33ce14c759 100644
--- a/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
+++ b/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
@@ -141,7 +141,9 @@ void simplifyExternals(Module &M) {
       continue;
     }
 
-    if (!F.isDeclaration() || F.getFunctionType() == EmptyFT)
+    if (!F.isDeclaration() || F.getFunctionType() == EmptyFT ||
+        // Changing the type of an intrinsic may invalidate the IR.
+        F.getName().startswith("llvm."))
       continue;
 
     Function *NewF =
diff --git a/test/Transforms/ThinLTOBitcodeWriter/split-vfunc.ll b/test/Transforms/ThinLTOBitcodeWriter/split-vfunc.ll
index 0793459af41..66d37d5e8ae 100644
--- a/test/Transforms/ThinLTOBitcodeWriter/split-vfunc.ll
+++ b/test/Transforms/ThinLTOBitcodeWriter/split-vfunc.ll
@@ -25,9 +25,13 @@ define i64 @ok1(i8* %this) {
 ; M0: define i64 @ok2
 ; M1: define available_externally i64 @ok2
 define i64 @ok2(i8* %this, i64 %arg) {
+  %1 = tail call { i64, i1 } @llvm.sadd.with.overflow.i64(i64 %arg, i64 %arg)
   ret i64 %arg
 }
 
+; M1: declare { i64, i1 } @llvm.sadd.with.overflow.i64(i64, i64)
+declare { i64, i1 } @llvm.sadd.with.overflow.i64(i64, i64)
+
 ; M0: define void @wrongtype1
 ; M1: declare void @wrongtype1()
 define void @wrongtype1(i8*) {