[VirtRegMap] Fix for PR17825. Do not ignore noreturn definitions when setting

isPhysRegUsed if the unwind information is required.
Indeed, the runtime may need a correct stack to be able to unwind the call.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194271 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 0a08608..e0aa405 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -285,7 +285,11 @@ void VirtRegRewriter::rewrite() {
           if (!MO.isGlobal())
             continue;
           const Function *Func = dyn_cast<Function>(MO.getGlobal());
-          if (!Func || !Func->hasFnAttribute(Attribute::NoReturn))
+          if (!Func || !Func->hasFnAttribute(Attribute::NoReturn) ||
+              // We need to keep correct unwind information
+              // even if the function will not return, since the
+              // runtime may need it.
+              !Func->hasFnAttribute(Attribute::NoUnwind))
             continue;
           NoReturnInsts.insert(MI);
           break;