X86: remove a dead store (NFC)

The SP was always unconditionally assigned to later, but initialised early.
This delays the initialisation, and avoids the dead store.  Identified by
clang static analysis.  No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244423 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86CallFrameOptimization.cpp b/lib/Target/X86/X86CallFrameOptimization.cpp
index a7e4ad9cf5a40f08e4a7b8558fa8483bbd52617b..4fdb89631a98c25af6a039a7df0b9436c59f8b78 100644 (file)
--- a/lib/Target/X86/X86CallFrameOptimization.cpp
+++ b/lib/Target/X86/X86CallFrameOptimization.cpp
@@ -304,7 +304,6 @@ void X86CallFrameOptimization::collectCallInfo(MachineFunction &MF,
   // transformation.
   const X86RegisterInfo &RegInfo = *static_cast<const X86RegisterInfo *>(
                                        MF.getSubtarget().getRegisterInfo());
-  unsigned StackPtr = RegInfo.getStackRegister();
   unsigned FrameDestroyOpcode = TII->getCallFrameDestroyOpcode();
 
   // We expect to enter this at the beginning of a call sequence
@@ -334,7 +333,8 @@ void X86CallFrameOptimization::collectCallInfo(MachineFunction &MF,
   if (!I->isCopy() || !I->getOperand(0).isReg())
     return;
   Context.SPCopy = I++;
-  StackPtr = Context.SPCopy->getOperand(0).getReg();
+
+  unsigned StackPtr = Context.SPCopy->getOperand(0).getReg();
 
   // Scan the call setup sequence for the pattern we're looking for.
   // We only handle a simple case - a sequence of MOV32mi or MOV32mr