[PATCH] D32622: ARM: Compute MaxCallFrame size early

[Matthias Braun via Phabricator via llvm-commits]

MatzeB created this revision.
Herald added subscribers: mcrosier, aemerson.

This avoids
ARMBaseRegisterInfo::canRealignStack()/ARMFrameLowering::hasReservedCallFrame()
giving different answers in early/late phases of codegen.

The attached testcase shows a particular nasty example where we would call TargetRegisterInfo::needsStackRealignment()->canRealignStack()->hasReservedCallFrame() and would end up not aligning the stack because `hasReservedCallFrame()` would report `false` in late passes only.

This exposes a method in MachineFrameInfo that calculates
MaxCallFrameSize and calls it after instruction selection to get the value computed early.


Repository:
  rL LLVM

https://reviews.llvm.org/D32622

Files:
  include/llvm/CodeGen/MachineFrameInfo.h
  lib/CodeGen/MachineFrameInfo.cpp
  lib/CodeGen/PrologEpilogInserter.cpp
  lib/Target/ARM/ARMBaseRegisterInfo.cpp
  lib/Target/ARM/ARMISelLowering.cpp
  lib/Target/ARM/ARMISelLowering.h
  test/CodeGen/ARM/alloca-align.ll

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