[llvm] [LLVM] [X86] Fix integer overflows in frame layout for huge frames (PR #101840)

[Matt Arsenault via llvm-commits]

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@@ -4140,6 +4141,14 @@ void X86FrameLowering::processFunctionBeforeFrameFinalized(
   // emitPrologue if it gets called and emits CFI.
   MF.setHasWinCFI(false);
 
+  MachineFrameInfo &MFI = MF.getFrameInfo();
+  // If the frame is big enough that we might need to scavenge a register to
+  // handle huge offsets, reserve a stack slot for that now.
+  if (STI.is64Bit() && !isInt<32>(MFI.estimateStackSize(MF))) {
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arsenm wrote:

Don't see the point in checking for 64-bit, just check the value 

https://github.com/llvm/llvm-project/pull/101840