[PATCH] D135757: [LoongArch] Add emergency spill slot for GPR for large frames

[wanglei via Phabricator via llvm-commits]

wangleiat created this revision.
wangleiat added reviewers: SixWeining, xen0n, xry111, gonglingqin, MaskRay.
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An emergency spill slot is created when the stack size cannot be
represented by an 11-bit signed number.

This patch also modifies how the `sp` is adjusted in the prologue.

`RegScavenger` will place the spill instruction before the prologue
if a VReg is created in the prologue. This will pollute the caller's
stack data. Therefore, until there is better way, we just use the
`addi.w/d` instruction for stack adjustment to ensure that VReg will
not be created. (RISCV has the same issue #58286)


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D135757

Files:
  llvm/lib/Target/LoongArch/LoongArchFrameLowering.cpp
  llvm/lib/Target/LoongArch/LoongArchFrameLowering.h
  llvm/test/CodeGen/LoongArch/emergency-spill-slot.ll
  llvm/test/CodeGen/LoongArch/frame.ll

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