explicit about the operands. Split out the different variants into separate
instructions. This gives us the ability to, among other things, assign
different scheduling itineraries to the variants. rdar://8477752.
llvm-svn: 117409
offset for stack references. Make sure we take that into account when
deciding whether to reserver an emergency spill slot for the register
scavenger. rdar://8559625
llvm-svn: 116714
between the high and low registers for prologue/epilogue code. This was
a Darwin-only thing that wasn't providing a realistic benefit anymore.
Combining the save areas simplifies the compiler code and results in better
ARM/Thumb2 codegen.
For example, previously we would generate code like:
push {r4, r5, r6, r7, lr}
add r7, sp, #12
stmdb sp!, {r8, r10, r11}
With this change, we combine the register saves and generate:
push {r4, r5, r6, r7, r8, r10, r11, lr}
add r7, sp, #12
rdar://8445635
llvm-svn: 114340
functions in ARMBaseInfo.h so it can be used in the MC library as well.
For anything bigger than this, we may want a means to have a small support
library for shared helper functions like this. Cross that bridge when we
come to it.
llvm-svn: 114016
"For ARM stack frames that utilize variable sized objects and have either
large local stack areas or require dynamic stack realignment, allocate a
base register via which to access the local frame. This allows efficient
access to frame indices not accessible via the FP (either due to being out
of range or due to dynamic realignment) or the SP (due to variable sized
object allocation). In particular, this greatly improves efficiency of access
to spill slots in Thumb functions which contain VLAs."
r112986 fixed a latent bug exposed by the above.
llvm-svn: 112989
alignment should be performed. Otherwise dynamic realignment may trigger
when the register allocator has already used the frame pointer as a general
purpose register. That is, we need to make sure that the list of reserved
registers doesn't change after register allocation.
llvm-svn: 112986
large local stack areas or require dynamic stack realignment, allocate a
base register via which to access the local frame. This allows efficient
access to frame indices not accessible via the FP (either due to being out
of range or due to dynamic realignment) or the SP (due to variable sized
object allocation). In particular, this greatly improves efficiency of access
to spill slots in Thumb functions which contain VLAs.
rdar://7352504
rdar://8374540
rdar://8355680
llvm-svn: 112883
still having a significant effect. It shouldn't be now that the pre-RA
virtual base reg stuff is in. Assuming that's valididated by the nightly
testers, we can simplify a lot of the PEI frame index code.
llvm-svn: 112220
Intended to help ease reproducing problems by increasing base register usage
after heuristics for only using the when needed are in place.
llvm-svn: 111930
frame index reference to an object in the local block is seen, check if
it's near enough to any previously allocaated base register to re-use.
rdar://8277890
llvm-svn: 111443
Nothing fancy, just ask the target if any currently available base reg
is in range for the instruction under consideration and use the first one
that is. Placeholder ARM implementation simply returns false for now.
ongoing saga of rdar://8277890
llvm-svn: 111374
the local block. Resolve references to those indices to a new base register.
For simplification and testing purposes, a new virtual base register is
allocated for each frame index being resolved. The result is truly horrible,
but correct, code that's good for exercising the new code paths.
Next up is adding thumb1 support, which should be very simple. Following that
will be adding base register re-use and implementing a reasonable ARM
heuristic for when a virtual base register should be generated at all.
llvm-svn: 111315
whether to allocate a virtual frame base register to resolve the frame
index reference in it. Implement a simple version for ARM to aid debugging.
In LocalStackSlotAllocation, scan the function for frame index references
to local frame indices and ask the target whether to allocate virtual
frame base registers for any it encounters. Purely infrastructural for
debug output. Next step is to actually allocate base registers, then add
intelligent re-use of them.
rdar://8277890
llvm-svn: 111262
Also added a test case to check for the added benefit of this patch: it's optimizing away the unnecessary restore of sp from fp for some non-leaf functions.
llvm-svn: 110707
reserved, not available for general allocation. This eliminates all the
extra checks for Darwin.
This change also fixes the use of FP to access frame indices in leaf
functions and cleaned up some confusing code in epilogue emission.
llvm-svn: 110655
This will always be false before PEI:
(DisableFramePointerElim(MF) && MFI->adjustsStack())
Which means it's going to make r11 available as a general purpose register even
if -disable-fp-elim is specified. It's working on Darwin only because r7 is
always reserved. But it's obviously broken for other targets.
llvm-svn: 110614
register for local access when it's closer to the stack slot being refererenced
than the stack pointer. Make sure to take into account any argument frame
SP adjustments that are in affect at the time.
rdar://8256090
llvm-svn: 110366
simplify the call frame pseudo instructions. In that situation, the
calculations for estimating the stack size will be way off, leading to
not having an emergency spill slot when we need one. It should be possible
to be more precise about tracking the adjustment values, but not really
necessary for correctness. Upcoming cleanups for PEI in general will
render that moot.
llvm-svn: 110258
Add support for using the FPSCR in conjunction with the vcvtr instruction, for controlling fp to int rounding.
Add support for the FLT_ROUNDS_ node now that the FPSCR is exposed.
llvm-svn: 110152
This is probably not the best way to implement "Force LR to
be spilled if the Thumb function size is > 2048." do this,
it should use the branch shortening infrastructure, but I'm
just preserving functionality here.
llvm-svn: 109165
stack realignment on ARM.
Also check for function attributes as we do on X86 as well as
make explicit that we're checking can as well as needs in this function.
llvm-svn: 108582
Add explicit testcases for tail calls within the same module.
Duplicate some code to humor those who think .w doesn't apply on ARM.
Leave this disabled on Thumb1, and add some comments explaining why it's hard
and won't gain much.
llvm-svn: 107851
call must not be callee-saved; following x86, add a new
regclass to represent this. Also fixes a couple of bugs.
Still disabled by default; Thumb doesn't work yet.
llvm-svn: 106053
A temporary flag -arm-tail-calls defaults to off,
so there is no functional change by default.
Intrepid users may try this; simple cases work
but there are bugs.
llvm-svn: 105413
too large limit.
The function would return immediately when finding an addrmode 3/5 instruction.
It needs to keep scanning in case there is an addrmode 6 instruction which drops
the limit to 0.
A test case is very difficult to produce because it will only fail when the
scavenger is used.
rdar://problem/7894847
llvm-svn: 103995
instructions.
e.g.
%reg1026<def> = VLDMQ %reg1025<kill>, 260, pred:14, pred:%reg0
%reg1027<def> = EXTRACT_SUBREG %reg1026, 6
%reg1028<def> = EXTRACT_SUBREG %reg1026<kill>, 5
...
%reg1029<def> = REG_SEQUENCE %reg1028<kill>, 5, %reg1027<kill>, 6, %reg1028, 7, %reg1027, 8, %reg1028, 9, %reg1027, 10, %reg1030<kill>, 11, %reg1032<kill>, 12
After REG_SEQUENCE is eliminated, we are left with:
%reg1026<def> = VLDMQ %reg1025<kill>, 260, pred:14, pred:%reg0
%reg1029:6<def> = EXTRACT_SUBREG %reg1026, 6
%reg1029:5<def> = EXTRACT_SUBREG %reg1026<kill>, 5
The regular coalescer will not be able to coalesce reg1026 and reg1029 because it doesn't
know how to combine sub-register indices 5 and 6. Now 2-address pass will consult the
target whether sub-registers 5 and 6 of reg1026 can be combined to into a larger
sub-register (or combined to be reg1026 itself as is the case here). If it is possible,
it will be able to replace references of reg1026 with reg1029 + the larger sub-register
index.
llvm-svn: 103835
the variable actually tracks.
N.B., several back-ends are using "HasCalls" as being synonymous for something
that adjusts the stack. This isn't 100% correct and should be looked into.
llvm-svn: 103802
Reverse-merging r103156 into '.':
U lib/Target/ARM/ARMInstrNEON.td
U lib/Target/ARM/ARMRegisterInfo.h
U lib/Target/ARM/ARMBaseRegisterInfo.cpp
U lib/Target/ARM/ARMBaseInstrInfo.cpp
U lib/Target/ARM/ARMRegisterInfo.td
llvm-svn: 103159
load/store optimizer would incorrectly think that registers D26 and D28
were consecutive and would generate a VLDM instruction to load them.
The assembler was not convinced.
llvm-svn: 99043
is preparatory to having PEI's scavenged frame index value reuse logic
properly distinguish types of frame values (e.g., whether the value is
stack-pointer relative or frame-pointer relative).
No functionality change.
llvm-svn: 98086
register is involved for thumb1. Work around this for the moment by only
re-using SP-relative offsets. This is temporary 'til the code can distinguish
multiple base registers.
llvm-svn: 98071
- Function uses all scratch registers AND
- Function does not use any callee saved registers AND
- Stack size is too big to address with immediate offsets.
In this case a register must be scavenged to calculate the address of a stack
object, and the scavenger needs a spare register or emergency spill slot.
llvm-svn: 97071
126.gcc nightly tests. These failures uncovered latent bugs that machine DCE
could remove one half of a stack adjust down/up pair, causing PEI to assert.
This update fixes that, and the tests now pass.
llvm-svn: 96822
for ARM to just check if a function has a FP to determine if it's safe
to simplify the stack adjustment pseudo ops prior to eliminating frame
indices. Allow targets to override the default behavior and does so for ARM
and Thumb2.
llvm-svn: 96634
created. This ensures it's updated at all time. It means targets which perform
dynamic stack alignment would know whether it is required and whether frame
pointer register cannot be made available register allocation.
This is a fix for rdar://7625239. Sorry, I can't create a reasonably sized test
case.
llvm-svn: 96069
function can support dynamic stack realignment. That's a much easier question
to answer at instruction selection stage than whether the function actually
will have dynamic alignment prologue. This allows the removal of the
stack alignment heuristic pass, and improves code quality for cases where
the heuristic would result in dynamic alignment code being generated when
it was not strictly necessary.
llvm-svn: 93885
