Pull in r183984 from llvm trunk:

  Make PrologEpilogInserter save/restore all callee saved registers in
  functions which call __builtin_unwind_init()

  __builtin_unwind_init() is an undocumented gcc intrinsic which has
  this effect, and is used in libgcc_eh.

  Goes part of the way toward fixing PR8541.

This obsoletes the ugly hack to libgcc's unwind code from r245272, and
should also work for other arches, so revert the hack too.

1 files changed, 3 insertions, 1 deletions

diff --git a/contrib/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/contrib/llvm/lib/CodeGen/PrologEpilogInserter.cpp
index 959dd7d..9487cbd 100644
--- a/contrib/llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/contrib/llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -29,6 +29,7 @@
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/RegisterScavenging.h"
 #include "llvm/IR/InlineAsm.h"
@@ -214,7 +215,8 @@ void PEI::calculateCalleeSavedRegisters(MachineFunction &F) {
   std::vector<CalleeSavedInfo> CSI;
   for (unsigned i = 0; CSRegs[i]; ++i) {
     unsigned Reg = CSRegs[i];
-    if (F.getRegInfo().isPhysRegUsed(Reg)) {
+    // Functions which call __builtin_unwind_init get all their registers saved.
+    if (F.getRegInfo().isPhysRegUsed(Reg) || F.getMMI().callsUnwindInit()) {
       // If the reg is modified, save it!
       CSI.push_back(CalleeSavedInfo(Reg));
     }