When setting up the frame pointer, add it as a live-in register to all

non-entry blocks, so that it doesn't appear use-before-def anywhere.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61214 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 4bdfd8c101d92352ca44c7089d41175678e76741..4f4a33db74bb3ca81d2edbf63db8f215d9256c1a 100644 (file)
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -745,6 +745,11 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
     BuildMI(MBB, MBBI, TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr), FramePtr)
       .addReg(StackPtr);
 
+    // Mark the FramePtr as live-in in every block except the entry.
+    for (MachineFunction::iterator I = next(MF.begin()), E = MF.end();
+         I != E; ++I)
+      I->addLiveIn(FramePtr);
+
     // Realign stack
     if (needsStackRealignment(MF))
       BuildMI(MBB, MBBI,