Add assertions that expose the PR7713 miscompilation: Accessing a stack slot
with a too-big register class.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109488 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 6126622..4d7faf9 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -1998,6 +1998,8 @@
                                        const TargetRegisterClass *RC,
                                        const TargetRegisterInfo *TRI) const {
   const MachineFunction &MF = *MBB.getParent();
+  assert(MF.getFrameInfo()->getObjectSize(FrameIdx) >= RC->getSize() &&
+         "Stack slot too small for store");
   bool isAligned = (RI.getStackAlignment() >= 16) || RI.canRealignStack(MF);
   unsigned Opc = getStoreRegOpcode(SrcReg, RC, isAligned, TM);
   DebugLoc DL = MBB.findDebugLoc(MI);
@@ -2030,6 +2032,8 @@
                                         const TargetRegisterClass *RC,
                                         const TargetRegisterInfo *TRI) const {
   const MachineFunction &MF = *MBB.getParent();
+  assert(MF.getFrameInfo()->getObjectSize(FrameIdx) >= RC->getSize() &&
+         "Stack slot too small for load");
   bool isAligned = (RI.getStackAlignment() >= 16) || RI.canRealignStack(MF);
   unsigned Opc = getLoadRegOpcode(DestReg, RC, isAligned, TM);
   DebugLoc DL = MBB.findDebugLoc(MI);