Fix error reporting in register scavenger (lack of emergency spill slot)

- Do not store Twine objects.
- Remove report_fatal_error, since llvm_unreachable does terminate the
  program in release mode.

llvm-svn: 270233

1 files changed, 4 insertions, 7 deletions

diff --git a/llvm/lib/CodeGen/RegisterScavenging.cpp b/llvm/lib/CodeGen/RegisterScavenging.cpp
index 34302a0cac6..4017f88f4ef 100644
--- a/llvm/lib/CodeGen/RegisterScavenging.cpp
+++ b/llvm/lib/CodeGen/RegisterScavenging.cpp
@@ -440,13 +440,10 @@ unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC,
     // Spill the scavenged register before I.
     int FI = Scavenged[SI].FrameIndex;
     if (FI < FIB || FI >= FIE) {
-      Twine Msg = Twine("Error while trying to spill ") + TRI->getName(SReg) +
-           " from class " + TRI->getRegClassName(RC) +
-           ": Cannot scavenge register without an emergency spill slot!";
-      // Keep both error functions, since llvm_unreachable prints the call
-      // stack, but it does not terminate program in release mode.
-      llvm_unreachable(Msg.str().c_str());
-      report_fatal_error(Msg);
+      std::string Msg = std::string("Error while trying to spill ") +
+          TRI->getName(SReg) + " from class " + TRI->getRegClassName(RC) +
+          ": Cannot scavenge register without an emergency spill slot!";
+      llvm_unreachable(Msg.c_str());
     }
     TII->storeRegToStackSlot(*MBB, I, SReg, true, Scavenged[SI].FrameIndex,
                              RC, TRI);