Summary:
In fuctions that contained debug info but were empty otherwise,
the ARM load/store optimizer could abort. This was because
function MergeReturnIntoLDM handled the special case where a
Machine Basic BLock is empty by calling MBB.empty(). However, this
returns false in presence of debug info, although the function
should be considered empty in the eyes of the load/store optimizer.
This has been fixed by handling the case where searching through the
block finds only debug instructions.
Reviewers: rengolin, dexonsmith, llvm-commits, jmolloy
Subscribers: t.p.northover, aemerson, rengolin, samparker
Differential Revision: https://reviews.llvm.org/D23847
llvm-svn: 279820
Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.
Differential Revision: http://reviews.llvm.org/D23850
llvm-svn: 279698
Initializing them in LLVMInitializeARMTarget() makes them visible early
enough for "llc -run-pass usage".
This required the pass to be renamed from "arm-load-store-opt" to
"arm-ldst-opt", because there already exists an arm-load-store-opt
cl::opt switch which would now clash with the passname getting added as
a switch in opt. On the bright side the pass name now matches the
DEBUG_TYPE name. Renamed "arm-prera-load-store-opt" to
"arm-repra-ldst-opt" as well for consistency.
llvm-svn: 275661
Remove remaining implicit conversions from MachineInstrBundleIterator to
MachineInstr* from the ARM backend. In most cases, I made them less attractive
by preferring MachineInstr& or using a ranged-based for loop.
Once all the backends are fixed I'll make the operator explicit so that this
doesn't bitrot back.
llvm-svn: 274920
This is a follow-up for r273544 and r273853.
The end goal is to get rid of the isSwift / isCortexXY / isWhatever methods.
This commit also marks them as obsolete.
Differential Revision: http://reviews.llvm.org/D21796
llvm-svn: 274616
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.
llvm-svn: 272512
If we have an LDM that uses only low registers and doesn't write to its base register:
ldm.w r0, {r1, r2, r3}
And that base register is dead after the LDM, then we can convert it to writeback form and use a narrow encoding:
ldm.n r0!, {r1, r2, r3}
Obviously, this introduces a new register write and so can cause WAW hazards, so I've enabled it only in minsize mode. This is a code size trick that ARM Compiler 5 ("armcc") does that we don't.
llvm-svn: 272000
Remove the AddPristinesAndCSRs parameters from
addLiveIns()/addLiveOuts().
We need to respect pristine registers after prologue epilogue insertion,
Seeing that we got this wrong in at least two commits already, we should
rather pay the small price to query MachineFrameInfo for it.
There are three cases that did not set AddPristineAndCSRs to true even
after register allocation:
- ExecutionDepsFix: live-out registers are used as a hint that the
register is used soon. This is not true for pristine registers so
use the new addLiveOutsNoPristines() to maintain this behaviour.
- SystemZShortenInst: Not setting AddPristineAndCSRs to true looks like
a bug, should do the right thing automatically now.
- StackMapLivenessAnalysis: Not adding pristine registers looks like a
bug to me. Added a FIXME comment but maintain the current behaviour
as a change may need to get coordinated with GC runtimes.
llvm-svn: 268336
Summary:
This adds the same checks that were added in r264593 to all
target-specific passes that run after register allocation.
Reviewers: qcolombet
Subscribers: jyknight, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D18525
llvm-svn: 265313
Most of the time ARM has the CCR.UNALIGN_TRP bit set to false which
means that unaligned loads/stores do not trap and even extensive testing
will not catch these bugs. However the multi/double variants are not
affected by this bit and will still trap. In effect a more aggressive
load/store optimization will break existing (bad) code.
These bugs do not necessarily manifest in the broken code where the
misaligned pointer is formed but often later in perfectly legal code
where it is accessed. This means recompiling system libraries (which
have no alignment bugs) with a newer compiler will break existing
applications (with alignment bugs) that worked before.
So (under protest) I implemented this safe mode which limits the
formation of multi/double operations to cases that are not affected by
user code (stack operations like spills/reloads) or cases where the
normal operations trap anyway (floating point load/stores). It is
disabled by default.
Differential Revision: http://reviews.llvm.org/D17015
llvm-svn: 262504
Change MachineInstr API to prefer MachineInstr& over MachineInstr*
whenever the parameter is expected to be non-null. Slowly inching
toward being able to fix PR26753.
llvm-svn: 262149
Change TargetInstrInfo API to take `MachineInstr&` instead of
`MachineInstr*` in the functions related to predicated instructions
(I'll try to come back later and get some of the rest). All of these
functions require non-null parameters already, so references are more
clear. As a bonus, this happens to factor away a host of implicit
iterator => pointer conversions.
No functionality change intended.
llvm-svn: 261605
In the discussion on http://reviews.llvm.org/D15730, Andy pointed out we had a utility function for merging MMO lists. Since it turned we actually had two copies and there's another review in progress (http://reviews.llvm.org/D15230) which needs the same, extract it into a utility function and clean up the interfaces to make it easier to use with a MachineInstBuilder.
I introduced a pair here to track size and allocation together. I think we should probably move in the direction of the MachineOperandsRef helper class, but I'm leaving that for further work. I want to get the poison state introduced before I make major changes to the interface.
Differential Revision: http://reviews.llvm.org/D15757
llvm-svn: 256909
Summary:
* avoid generating POP {LR} in Thumb1 epilogues
* combine MOV LR, Rx + BX LR -> BX Rx in a peephole optimization pass
* combine POP {LR} + B + BX LR -> POP {PC} on v5T+
Test cases by Ana Pazos
Differential Revision: http://reviews.llvm.org/D15707
llvm-svn: 256523
Summary: Among other things, this allows -print-after-all/-print-before-all to dump IR around this pass.
Subscribers: aemerson, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D11373
llvm-svn: 243052
Re-apply of r241928 which had to be reverted because of the r241926
revert.
This commit factors out common code from MergeBaseUpdateLoadStore() and
MergeBaseUpdateLSMultiple() and introduces a new function
MergeBaseUpdateLSDouble() which merges adds/subs preceding/following a
strd/ldrd instruction into an strd/ldrd instruction with writeback where
possible.
Differential Revision: http://reviews.llvm.org/D10676
llvm-svn: 242743
Re-apply r241926 with an additional check that r13 and r15 are not used
for LDRD/STRD. See http://llvm.org/PR24190. This also already includes
the fix from r241951.
Differential Revision: http://reviews.llvm.org/D10623
llvm-svn: 242742
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.
This patch is quite boring overall, except for some uglyness in
ASMPrinter which has a getDataLayout function but has some clients
that use it without a Module (llmv-dsymutil, llvm-dwarfdump), so
some methods are taking a DataLayout as parameter.
Reviewers: echristo
Subscribers: yaron.keren, rafael, llvm-commits, jholewinski
Differential Revision: http://reviews.llvm.org/D11090
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 242386
The pass here was clearing kill flags on instructions which had
their sources killed in the instruction being combined. But
given that the new instruction is inserted after the existing ones,
any existing instructions with kill flags will lead to the verifier
complaining that we are reading an undefined physreg.
For example, what we had prior to this optimization is
t2STRi12 %R1, %SP, 12
t2STRi12 %R1<kill>, %SP, 16
t2STRi12 %R0<kill>, %SP, 8
and prior to this fix that would generate
t2STRi12 %R1<kill>, %SP, 16
t2STRDi8 %R0<kill>, %R1, %SP, 8
This is clearly incorrect as it didn't clear the kill flag on R1
used with offset 16 because there was no kill flag on the instruction
with offset 12.
After this change we clear the kill flag on the offset 16 instruction
because we know it will be used afterwards in the new instruction.
I haven't provided a test case. I have a small test, but even it is
very sensitive to register allocation order which isn't ideal.
llvm-svn: 242359
This commit factors out common code from MergeBaseUpdateLoadStore() and
MergeBaseUpdateLSMultiple() and introduces a new function
MergeBaseUpdateLSDouble() which merges adds/subs preceding/following a
strd/ldrd instruction into an strd/ldrd instruction with writeback where
possible.
Differential Revision: http://reviews.llvm.org/D10676
llvm-svn: 241928
This improves the logic in several ways and is a preparation for
followup patches:
- First perform an analysis and create a list of merge candidates, then
transform. This simplifies the code in that you have don't have to
care to much anymore that you may be holding iterators to
MachineInstrs that get removed.
- Analyze/Transform basic blocks in reverse order. This allows to use
LivePhysRegs to find free registers instead of the RegisterScavenger.
The RegisterScavenger will become less precise in the future as it
relies on the deprecated kill-flags.
- Return the newly created node in MergeOps so there's no need to look
around in the schedule to find it.
- Rename some MBBI iterators to InsertBefore to make their role clear.
- General code cleanup.
Differential Revision: http://reviews.llvm.org/D10140
llvm-svn: 241920
When the store sequence being combined actually stores the base register, we
should not mark it as killed until the end.
rdar://21504262
llvm-svn: 241003
When UpdateBaseRegUses sees an instruction that defines the base
register it must stop, as the base register value it is updating is no
longer live. Ideally we would already have seen the register be killed
(which is already checked for), but the kill flags may be inaccurate
and we have to account for this.
Differential Revision: http://reviews.llvm.org/D10566
llvm-svn: 240424
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
The existing code would unnecessarily break LDRD/STRD apart with
non-adjacent registers, on thumb2 this is not necessary.
Ideally on thumb2 we shouldn't match for ldrd/strd pre-regalloc anymore
as there is not reason to set register hints anymore, changing that is
something for a future patch however.
Differential Revision: http://reviews.llvm.org/D9694
Recommiting after the revert in r238821, the buildbot still failed with
the patch removed so there seems to be another reason for the breakage.
llvm-svn: 238935
This reverts commit r238795, as it broke the Thumb2 self-hosting buildbot.
Since self-hosting issues with Clang are hard to investigate, I'm taking the
liberty to revert now, so we can investigate it offline.
llvm-svn: 238821
The existing code would unnecessarily break LDRD/STRD apart with
non-adjacent registers, on thumb2 this is not necessary.
Ideally on thumb2 we shouldn't match for ldrd/strd pre-regalloc anymore
as there is not reason to set register hints anymore, changing that is
something for a future patch however.
Differential Revision: http://reviews.llvm.org/D9694
llvm-svn: 238795
MIOperands/ConstMIOperands are classes iterating over the MachineOperand
of a MachineInstr, however MachineInstr::mop_iterator does the same
thing.
I assume these two iterators exist to have a uniform interface to
iterate over the operands of a machine instruction bundle and a single
machine instruction. However in practice I find it more confusing to have 2
different iterator classes, so this patch transforms (nearly all) the
code to use mop_iterators.
The only exception being MIOperands::anlayzePhysReg() and
MIOperands::analyzeVirtReg() still needing an equivalent, I leave that
as an exercise for the next patch.
Differential Revision: http://reviews.llvm.org/D9932
This version is slightly modified from the proposed revision in that it
introduces MachineInstr::getOperandNo to avoid the extra counting
variable in the few loops that previously used MIOperands::getOperandNo.
llvm-svn: 238539
This was previously returning int. However there are no negative opcode
numbers and more importantly this was needlessly different from
MCInstrDesc::getOpcode() (which even is the value returned here) and
SDValue::getOpcode()/SDNode::getOpcode().
llvm-svn: 237611
Thumb-1 only allows SP-based LDR and STR to be word-sized, and SP-base LDR,
STR, and ADD only allow offsets that are a multiple of 4. Make some changes
to better make use of these instructions:
* Use word loads for anyext byte and halfword loads from the stack.
* Enforce 4-byte alignment on objects accessed in this way, to ensure that
the offset is valid.
* Do the same for objects whose frame index is used, in order to avoid having
to use more than one ADD to generate the frame index.
* Correct how many bits of offset we think AddrModeT1_s has.
Patch by John Brawn.
llvm-svn: 230496
derived classes.
Since global data alignment, layout, and mangling is often based on the
DataLayout, move it to the TargetMachine. This ensures that global
data is going to be layed out and mangled consistently if the subtarget
changes on a per function basis. Prior to this all targets(*) have
had subtarget dependent code moved out and onto the TargetMachine.
*One target hasn't been migrated as part of this change: R600. The
R600 port has, as a subtarget feature, the size of pointers and
this affects global data layout. I've currently hacked in a FIXME
to enable progress, but the port needs to be updated to either pass
the 64-bitness to the TargetMachine, or fix the DataLayout to
avoid subtarget dependent features.
llvm-svn: 227113
Thumbv4t does not have lo->lo copies other than MOVS,
and that can't be predicated. So emit MOVS when needed
and bail if there's a predicate.
http://reviews.llvm.org/D6592
llvm-svn: 226711
If it's safe to clobber the condition flags, we can do a few extra things:
it's then possible to reset the base register writeback using a SUBS, so
we can try to merge even if the base register isn't dead after the merged
instruction.
This is effectively a (heavily bug-fixed) rewrite of r208992.
llvm-svn: 218386
ADDS/SUBS unless it's safe to clobber the condition flags.
If the merged instructions are in a range where the CPSR is live,
e.g. between a CMP -> Bcc, we can't safely materialize a new base
register.
This problem is quite rare, I couldn't come up with a test case and I've
never actually seen this happen in the tests I'm running - there is a
potential trigger for this in LNT/oggenc (spills being inserted between
a CMP/Bcc), but at the moment this isn't being merged. I'll try to
reduce that into a small test case once I've committed my upcoming patch
to make merging less conservative.
llvm-svn: 217881
There are two add-immediate instructions in Thumb1: tADDi8 and tADDi3. Only
the latter supports using different source and destination registers, so
whenever we materialize a new base register (at a certain offset) we'd do
so by moving the base register value to the new register and then adding in
place. This patch changes the code to use a single tADDi3 if the offset is
small enough to fit in 3 bits.
Differential Revision: http://reviews.llvm.org/D5006
llvm-svn: 216193
In a previous iteration of the pass, we would try to compensate for
writeback by updating later instructions and/or inserting a SUBS to
reset the base register if necessary.
Since such a SUBS sets the condition flags it's not generally safe to do
this. For now, only merge LDR/STRs if there is no writeback to the base
register (LDM that loads into the base register) or the base register is
killed by one of the merged instructions. These cases are clear wins
both in terms of instruction count and performance.
Also add three new test cases, and update the existing ones accordingly.
llvm-svn: 215729
This adds some code back that was deleted in r92053. The location of the
last merged memory operation needs to be kept up-to-date since MemOps
may be in a different order to the original instruction stream to
allow merging (since registers need to be in ascending order). Also
simplify the logic to determine BaseKill using findRegisterUseOperandIdx
to use an equivalent function call instead.
llvm-svn: 215728
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.
Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.
llvm-svn: 214838
Originally I switched the LD/ST optimizer off in TargetMachine as it was previously, but Eric has suggested he'd prefer that it be short-circuited in the pass itself.
No functionality change.
llvm-svn: 211037
Previously, the basic block was searched for future uses of the base register,
and if necessary any writeback to the base register was reset using a SUB
instruction (e.g. before calling a function) just before such a use. However,
this step happened *before* the merged LDM/STM instruction was built. So if
there was (e.g.) a function call directly after the not-yet-formed LDM/STM,
the pass would first insert a SUB instruction to reset the base register,
and then (at the same location, incorrectly) insert the LDM/STM itself.
This patch fixes PR19972. Patch by Moritz Roth.
llvm-svn: 210542
When we had a sequence like:
s1 = VLDRS [r0, 1], Q0<imp-def>
s3 = VLDRS [r0, 2], Q0<imp-use,kill>, Q0<imp-def>
s0 = VLDRS [r0, 0], Q0<imp-use,kill>, Q0<imp-def>
s2 = VLDRS [r0, 4], Q0<imp-use,kill>, Q0<imp-def>
we were gathering the {s0, s1} loads below the s3 load. This is fine,
but confused the verifier since now the s3 load had Q0<imp-use> with
no definition above it.
This should mark such uses <undef> as well. The liveness structure at
the beginning and end of the block is unaffected, and the true sN
definitions should prevent any dodgy reorderings being introduced
elsewhere.
rdar://problem/15124449
llvm-svn: 192344
it at the moment.
This allows to form more paired loads even when stack coloring pass destroys the
memoryoperand's value.
<rdar://problem/13978317>
llvm-svn: 184492
sure the base register and would-be writeback register don't conflict for
stores. This was already being done for loads.
Unfortunately, it is rather difficult to create a test case for this issue. It
was exposed in 450.soplex at LTO and requires unlucky register allocation.
<rdar://13394908>
llvm-svn: 177874
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.
There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.
The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.
I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).
I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.
llvm-svn: 171366
This function is often used to decorate dangling instructions, so a
context reference is required to allocate memory for the operands.
Also add a corresponding MachineInstrBuilder method.
llvm-svn: 170797
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
llvm-svn: 169131
the register info for getEncodingValue. This builds on the
small patch of yesterday to set HWEncoding in the register
file.
One (deprecated) use was turned into a hard number to avoid
needing register info in the old JIT.
llvm-svn: 161628
The getPointerRegClass() hook can return register classes that depend on
the calling convention of the current function (ptr_rc_tailcall).
So far, we have been able to infer the calling convention from the
subtarget alone, but as we add support for multiple calling conventions
per target, that no longer works.
Patch by Yiannis Tsiouris!
llvm-svn: 156328
Pablo Barrio