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
Optimize eliminate FP mechanism. This time optimize a function which has
no call but fixed stack objects. LLVM eliminates FP on such functions now.
Also, optimize GOT/PLT registers save/restore instructions if a given
function doesn't uses them. In addition, remove generating mechanism of
`.cfi` instructions since those are taken from other architectures and not
inspected yet. Update regression tests, also.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D92251
Optimize emitSPAdjustment function to generate as small as possible
instructions to adjust SP.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D92174
Implement JumpTable to make BRIND work on VE. Update an existing
br_jt regression test also.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D91582
To accommodate frame layouts that have both fixed and scalable objects
on the stack, describing a stack location or offset using a pointer + uint64_t
is not sufficient. For this reason, we've introduced the StackOffset class,
which models both the fixed- and scalable sized offsets.
The TargetFrameLowering::getFrameIndexReference is made to return a StackOffset,
so that this can be used in other interfaces, such as to eliminate frame indices
in PEI or to emit Debug locations for variables on the stack.
This patch is purely mechanical and doesn't change the behaviour of how
the result of this function is used for fixed-sized offsets. The patch adds
various checks to assert that the offset has no scalable component, as frame
offsets with a scalable component are not yet supported in various places.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D90018
Summary:
This patch implements dynamic stack allocation for the VE target. Changes:
* compiler-rt: `__ve_grow_stack` to request stack allocation on the VE.
* VE: base pointer support, dynamic stack allocation.
Differential Revision: https://reviews.llvm.org/D79084
Summary:
Changing all mnemonic to match assembly instructions to simplify mnemonic
naming rules. This time update all fixed-point arithmetic instructions.
This also corrects smax/smin code generations.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D77856
Summary:
VE has special operands to represent 0b000...000111...111 (`(m)0`) and
0b111...111000...000 (`(m)1`) bit sequences. This patch supports those
operands not only in machine instructions but also in DAG lowering.
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D77769
Summary:
Modify lea/load/store instructions to accept `disp(index, base)`
style addressing mode (called ASX format). Also, uniform the
number of DAG nodes to have 3 operands for this ASX format
instructions, and update selectADDR functions to lower
appropriate MI.
Reviewers: arsenm, simoll, k-ishizaka
Reviewed By: simoll
Differential Revision: https://reviews.llvm.org/D76822
Summary:
Function calls and stack-passing of function arguments.
Custom lowering, isel patterns and tests.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D73461
Summary: Support for i64 arguments (in register), return values and constants along with tests.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D72776
Summary:
This patch implements minimal VE code generation for empty function bodies (no args, no value return).
Contents
* empty function code generation test.
* Minimal function prologue & epilogue emission
* Instruction formats and instruction definitions as far as required for the empty function prologue & epilogue.
* I64 register class definitions.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D72598
Tomas Matheson