Some targets (e.g. PPC and Hexagon) already did this. I think it's best
to do this consistently so that frontend authors don't run into
inconsistent results when they emit `naked` functions. For example, in
Zig, we had to change our emit code to also set `frame-pointer=none` to
get reliable results across targets.
Note: I don't have commit access.
No other target checks this, and this is untested. I am trying
to remove the MachineModuleInfo reference from MachineFunction,
and this is the stickiest blocker.
MachineFunction's probably should not include a backreference to
the owning MachineModuleInfo. Most of these references were used
just to query the MCContext, which MachineFunction already directly
stores. Other contexts are using it to query the LLVMContext, which
can already be accessed through the IR function reference.
Previously ADD & ADDA (as well as SUB & SUBA) instructions are mixed
together, which not only violated Motorola assembly's syntax but also
made asm parsing more difficult. This patch separates these two kinds of
instructions migrate rest of the tests from
test/CodeGen/M68k/Encoding/Arithmetic to test/MC/M68k/Arithmetic.
Note that we observed minor regressions on codegen quality: Sometimes
isel uses ADD instead of ADDA even the latter can lead to shorter
sequence of code. This issue implies that some isel patterns might need
to be updated.
`TargetFrameLowering::emitCalleeSavedFrameMoves` with 4 arguments is not
used anywhere in CodeGen. Thus it shouldn't be exposed as a virtual
function. NFC.
Differential Revision: https://reviews.llvm.org/D103328
Fixes the following warnings observerd when building the experimental
m68k backend (-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="M68k"):
../lib/Target/M68k/M68kMachineFunction.h:71:3: warning: explicitly
defaulted default constructor is implicitly deleted
[-Wdefaulted-function-deleted]
M68kMachineFunctionInfo() = default;
^
../lib/Target/M68k/M68kMachineFunction.h:24:20: note: default
constructor of 'M68kMachineFunctionInfo' is implicitly deleted because
field 'MF' of reference type 'llvm::MachineFunction &' would not be
initialized
MachineFunction &MF;
^
In file included from ../lib/Target/M68k/M68kISelLowering.cpp:18:
In file included from ../lib/Target/M68k/M68kSubtarget.h:17:
../lib/Target/M68k/M68kFrameLowering.h:60:8: warning:
'llvm::M68kFrameLowering::emitCalleeSavedFrameMoves' hides overloaded
virtual functions [-Woverloaded-virtual]
void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
^
../include/llvm/CodeGen/TargetFrameLowering.h:215:3: note: hidden
overloaded virtual function
'llvm::TargetFrameLowering::emitCalleeSavedFrameMoves' declared here:
different number of parameters (2 vs 3)
emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
^
../include/llvm/CodeGen/TargetFrameLowering.h:218:16: note: hidden
overloaded virtual function
'llvm::TargetFrameLowering::emitCalleeSavedFrameMoves' declared here:
different number of parameters (4 vs 3)
virtual void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
^
pr/50071
Reviewed By: myhsu
Differential Revision: https://reviews.llvm.org/D101588
Currently needsStackRealignment returns false if canRealignStack returns false.
This means that the behavior of needsStackRealignment does not correspond to
it's name and description; a function might need stack realignment, but if it
is not possible then this function returns false. Furthermore,
needsStackRealignment is not virtual and therefore some backends have made use
of canRealignStack to indicate whether a function needs stack realignment.
This patch attempts to clarify the situation by separating them and introducing
new names:
- shouldRealignStack - true if there is any reason the stack should be
realigned
- canRealignStack - true if we are still able to realign the stack (e.g. we
can still reserve/have reserved a frame pointer)
- hasStackRealignment = shouldRealignStack && canRealignStack (not target
customisable)
Targets can now override shouldRealignStack to indicate that stack realignment
is required.
This change will make it easier in a future change to handle the case where we
need to realign the stack but can't do so (for example when the register
allocator creates an aligned spill after the frame pointer has been
eliminated).
Differential Revision: https://reviews.llvm.org/D98716
Change-Id: Ib9a4d21728bf9d08a545b4365418d3ffe1af4d87
