There's not much functional change, but it really is an architectural feature
(on v6T2, v7A, v7R and v7EM) rather than something each CPU implements
individually.
The main functional change is the default behaviour you get when specifying
only "-triple".
llvm-svn: 276013
Recommitting after r274347 was reverted. This patch introduces some
classes to refactor the 3 and 4 register Thumb2 multiplication
instruction descriptions, plus improved tests for some of those
instructions.
Differential Revision: https://reviews.llvm.org/D21929
llvm-svn: 275979
The standard local dynamic model for TLS on ARM systems needs two
relocations:
- R_ARM_TLS_LDM32 (module idx)
- R_ARM_TLS_LDO32 (offset of object from origin of module TLS block)
In GNU style assembler we use symbol(tlsldm) and symbol(tlsldo) to
produce these relocations.
llvm-mc for ARM supports symbol(tlsldo) but does not support symbol(tlsldm).
This patch wires up the existing symbol(tlsldm) to R_ARM_TLS_LDM32.
TLS for ARM is defined in Addenda to, and Errata in, the ABI for the
ARM Architecture
Differential Revision: https://reviews.llvm.org/D22461
llvm-svn: 275977
The current logic for handling inline asm operands in DAGToDAGISel interprets
the operands by looking for constants, which should represent the flags
describing the kind of operand we're dealing with (immediate, memory, register
def etc). The operands representing actual data are skipped only if they are
non-const, with the exception of immediate operands which are skipped explicitly
when a flag describing an immediate is found.
The oversight is that memory operands may be const too (e.g. for device drivers
reading a fixed address), so we should explicitly skip the operand following a
flag describing a memory operand. If we don't, we risk interpreting that
constant as a flag, which is definitely not intended.
Fixes PR26038
Differential Revision: https://reviews.llvm.org/D22103
llvm-svn: 275776
At higher optimization levels, we generate the libcall for DIVREM_Ix, which is
fine: aeabi_{u|i}divmod. At -O0 we generate the one for REM_Ix, which is the
default {u}mod{q|h|s|d}i3.
This commit makes sure that we don't generate REM_Ix calls for ABIs that
don't support them (i.e. where we need to use DIVREM_Ix instead). This is
achieved by bailing out of FastISel, which can't handle non-double multi-reg
returns, and letting the legalization infrastructure expand the REM_Ix calls.
It also updates the divmod-eabi.ll test to run under -O0 as well, and adds some
Windows checks to it to make sure we don't break things for it.
Fixes PR27068
Differential Revision: https://reviews.llvm.org/D21926
llvm-svn: 275773
r275042 reverted function-attribute inference for the 'returned' attribute
because the feature triggered self-hosting failures on ARM and AArch64. James
Molloy determined that the this-return argument forwarding feature, which
directly ties the returned input argument to the returned value, was the cause.
It seems likely that this forwarding code contains, or triggers, a subtle bug.
Disabling for now until we can track that down.
llvm-svn: 275677
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
Summary:
Instead, we take a single flags arg (a bitset).
Also add a default 0 alignment, and change the order of arguments so the
alignment comes before the flags.
This greatly simplifies many callsites, and fixes a bug in
AMDGPUISelLowering, wherein the order of the args to getLoad was
inverted. It also greatly simplifies the process of adding another flag
to getLoad.
Reviewers: chandlerc, tstellarAMD
Subscribers: jholewinski, arsenm, jyknight, dsanders, nemanjai, llvm-commits
Differential Revision: http://reviews.llvm.org/D22249
llvm-svn: 275592
Summary:
Previously we took an unsigned.
Hooray for type-safety.
Reviewers: chandlerc
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D22282
llvm-svn: 275591
Thumb-1 doesn't have post-inc or pre-inc load or store instructions. However the LDM/STM instructions with writeback can function as post-inc load/store:
ldm r0!, {r1} @ load from r0 into r1 and increment r0 by 4
Obviously, this only works if the post increment is 4.
llvm-svn: 275540
... When we emit several calls to the same function in the same basic block.
An indirect call uses a "BLX r0" instruction which has a 16-bit encoding. If many calls are made to the same target, this can enable significant code size reductions.
llvm-svn: 275537
constant hoisting. It not only takes into account the number of uses and the
cost of expressions in which constants appear, but now also the resulting
integer range of the offsets. Thus, the algorithm maximizes the number of uses
within an integer range that will enable more efficient code generation. On
ARM, for example, this will enable code size optimisations because less
negative offsets will be created. Negative offsets/immediates are not supported
by Thumb1 thus preventing more compact instruction encoding.
Differential Revision: http://reviews.llvm.org/D21183
llvm-svn: 275382
Immediate branch targets aren't commonly used, but if they are we should make
sure they can actually be encoded. This means they must be divisible by 2 when
targeting Thumb mode, and by 4 when targeting ARM mode.
Also do a little naming cleanup while I was changing everything around anyway.
llvm-svn: 275116
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
Windows on ARM uses a pure thumb-2 environment. This means that it can select a
high register when doing a __builtin_longjmp. We would use a tLDRi which would
truncate the register to a low register. Use a t2LDRi12 to get the full
register file access. Tweak the code to just load into PC, as that is an
interworking branch on all supported cores anyways.
llvm-svn: 274815
This is a follow-up for r273544.
The end goal is to get rid of the isSwift / isCortexXY / isWhatever methods.
This commit also removes a command line flag that isn't used in any of the tests:
check-vmlx-hazards. It can be replaced easily with the mattr mechanism, since
this is now a subtarget feature.
There is still some work left regarding FeatureExpandMLx. In the past MLx
expansion was enabled for subtargets with hasVFP2(), until r129775 [1] switched
from that to isCortexA9, without too much justification.
In spite of that, the code performing MLx expansion still contains calls to
isSwift/isLikeA9, although the results of those are pretty clear given that
we're only enabling it for the A9.
We should try to enable it for all targets that have FeatureHasVMLxHazards, as
it seems to be closely related to that behaviour, and if that is possible try to
clean up the MLx expansion pass from all calls to isWhatever. This will require
some performance testing, so it will be done in another patch.
[1] http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20110418/119725.html
Differential Revision: http://reviews.llvm.org/D21798
llvm-svn: 274742
This is a follow-up for r273544.
The end goal is to get rid of the isSwift / isCortexXY / isWhatever methods.
This commit also removes two command-line flags that weren't used in any of the
tests: widen-vmovs and swift-partial-update-clearance. The former may be easily
replaced with the mattr mechanism, but the latter may not (as it is a subtarget
property, and not a proper feature).
Differential Revision: http://reviews.llvm.org/D21797
llvm-svn: 274620
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
Not all code-paths set the relocation model to static for Windows. This
currently breaks on Windows ARM with `-mlong-calls` when built with clang.
Loosen the assertion to what it was previously. We would ideally ensure that
all the configuration sets Windows to static relocation model.
llvm-svn: 274570
The important thing I was missing was ensuring newly added constants were kept in topological order. Repositioning the node is correct if the constant is newly added (so it has no topological ordering) but wrong if it already existed - positioning it next in the worklist would break the topological ordering.
Original commit message:
[Thumb] Select a BIC instead of AND if the immediate can be encoded more optimally negated
If an immediate is only used in an AND node, it is possible that the immediate can be more optimally materialized when negated. If this is the case, we can negate the immediate and use a BIC instead;
int i(int a) {
return a & 0xfffffeec;
}
Used to produce:
ldr r1, [CONSTPOOL]
ands r0, r1
CONSTPOOL: 0xfffffeec
And now produces:
movs r1, #255
adds r1, #20 ; Less costly immediate generation
bics r0, r1
llvm-svn: 274543
We were using DAG->getConstant instead of DAG->getTargetConstant. This meant that we could inadvertently increase the use count of a constant if stars aligned, which it did in this testcase. Increasing the use count of the constant could cause ISel to fall over (because DAGToDAG lowering assumed the constant had only one use!)
Original commit message:
[Thumb] Select a BIC instead of AND if the immediate can be encoded more optimally negated
If an immediate is only used in an AND node, it is possible that the immediate can be more optimally materialized when negated. If this is the case, we can negate the immediate and use a BIC instead;
int i(int a) {
return a & 0xfffffeec;
}
Used to produce:
ldr r1, [CONSTPOOL]
ands r0, r1
CONSTPOOL: 0xfffffeec
And now produces:
movs r1, #255
adds r1, #20 ; Less costly immediate generation
bics r0, r1
llvm-svn: 274510
No functional changes. Just created wrapper classes around the 3
and 4 reg mult and mac instruction classes.
Differential Revision: http://reviews.llvm.org/D21549
llvm-svn: 274347
For the most part this simplifies all callers. There were two places in X86 that needed an explicit makeArrayRef to shorten a statically sized array.
llvm-svn: 274337
Change all the methods in LiveVariables that expect non-null
MachineInstr* to take MachineInstr& and update the call sites. This
clarifies the API, and designs away a class of iterator to pointer
implicit conversions.
llvm-svn: 274319
This is a mechanical change to make TargetLowering API take MachineInstr&
(instead of MachineInstr*), since the argument is expected to be a valid
MachineInstr. In one case, changed a parameter from MachineInstr* to
MachineBasicBlock::iterator, since it was used as an insertion point.
As a side effect, this removes a bunch of MachineInstr* to
MachineBasicBlock::iterator implicit conversions, a necessary step
toward fixing PR26753.
llvm-svn: 274287
This is mostly a mechanical change to make TargetInstrInfo API take
MachineInstr& (instead of MachineInstr* or MachineBasicBlock::iterator)
when the argument is expected to be a valid MachineInstr. This is a
general API improvement.
Although it would be possible to do this one function at a time, that
would demand a quadratic amount of churn since many of these functions
call each other. Instead I've done everything as a block and just
updated what was necessary.
This is mostly mechanical fixes: adding and removing `*` and `&`
operators. The only non-mechanical change is to split
ARMBaseInstrInfo::getOperandLatencyImpl out from
ARMBaseInstrInfo::getOperandLatency. Previously, the latter took a
`MachineInstr*` which it updated to the instruction bundle leader; now,
the latter calls the former either with the same `MachineInstr&` or the
bundle leader.
As a side effect, this removes a bunch of MachineInstr* to
MachineBasicBlock::iterator implicit conversions, a necessary step
toward fixing PR26753.
Note: I updated WebAssembly, Lanai, and AVR (despite being
off-by-default) since it turned out to be easy. I couldn't run tests
for AVR since llc doesn't link with it turned on.
llvm-svn: 274189
Summary:
This fixes bug: https://llvm.org/bugs/show_bug.cgi?id=28282
Currently the cost model of constant hoisting checks the bit width of the data type of the constants.
However, the actual immediate value is small enough and not need to be hoisted.
This patch checks for the actual bit width needed for the constant.
Reviewers: t.p.northover, rengolin
Subscribers: aemerson, rengolin, llvm-commits
Differential Revision: http://reviews.llvm.org/D21668
llvm-svn: 274073
This is a follow-up for r273544.
The end goal is to get rid of the isSwift / isCortexXY / isWhatever methods.
Since the ARM backend seems to have quite a lot of calls to these methods, I
intend to submit 5-6 subtarget features at a time, instead of one big lump.
Differential Revision: http://reviews.llvm.org/D21685
llvm-svn: 273853
Summary:
SSAT saturates an integer, making sure that its value lies within
an interval [-k, k]. Since the constant is given to SSAT as the
number of bytes set to one, k + 1 must be a power of 2, otherwise
the optimization is not possible. Also, the select_cc must use <
and > respectively so that they define an interval.
Reviewers: mcrosier, jmolloy, rengolin
Subscribers: aemerson, rengolin, llvm-commits
Differential Revision: http://reviews.llvm.org/D21372
llvm-svn: 273581
Move most of the initializations in ARMSubtarget::initializeEnvironment to
member initializers.
Change suggested by Matthias Braun (see http://reviews.llvm.org/D21432).
llvm-svn: 273556
This is a cleanup commit similar to r271555, but for ARM.
The end goal is to get rid of the isSwift / isCortexXY / isWhatever methods.
Since the ARM backend seems to have quite a lot of calls to these methods, I
intend to submit 5-6 subtarget features at a time, instead of one big lump.
Differential Revision: http://reviews.llvm.org/D21432
llvm-svn: 273544
The setCallee function will set the number of fixed arguments based
on the size of the argument list. The FixedArgs parameter was often
explicitly set to 0, leading to a lack of consistent value for non-
vararg functions.
Differential Revision: http://reviews.llvm.org/D20376
llvm-svn: 273403
TargetLowering and DAGToDAG are used to combine ADDC, ADDE and UMLAL
dags into UMAAL. Selection is split into the two phases because it
is easier to match the two patterns at those different times.
Differential Revision: http://http://reviews.llvm.org/D21461
llvm-svn: 273165
Reduces a bit of code duplication and clarify where we are interested
just on position independence and no the location of the symbol.
llvm-svn: 273164
Recommiting after fixing non-atomic insert to front of SmallVector in
MCAsmLexer.h
Add explicit Comment Token in Assembly Lexing for future support for
outputting explicit comments from inline assembly. As part of this,
CPPHash Directives are now explicitly distinguished from Hash line
comments in Lexer.
Line comments are recorded as EndOfStatement tokens, not Comment tokens
to simplify compatibility with current TargetParsers. This slightly
complicates comment output.
This remove all lexing tasks out of the parser, does minor cleanup
to remove extraneous newlines Asm Output, and some improvements white
space handling.
Reviewers: rtrieu, dwmw2, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20009
llvm-svn: 273007
Reapplying patch as it was reverted when it was first
committed because of an assertion failure when the
mrrc2 intrinsic was called in ARM mode. The failure
was happening because the instruction was being built
in ARMISelDAGToDAG.cpp and the tablegen description for
mrrc2 instruction doesn't allow you to use a predicate.
The ARM architecture manuals do say that mrrc2 in ARM
mode can be predicated with AL in assembly but this has
no effect on the encoding of the instruction as the top
4 bits will always be 1111 not 1110 which is the encoding
for the condition AL.
Differential Revision: http://reviews.llvm.org/D21408
llvm-svn: 272982
Add explicit Comment Token in Assembly Lexing for future support for
outputting explicit comments from inline assembly. As part of this,
CPPHash Directives are now explicitly distinguished from Hash line
comments in Lexer.
Line comments are recorded as EndOfStatement tokens, not Comment tokens
to simplify compatibility with current TargetParsers. This slightly
complicates comment output.
This remove all lexing tasks out of the parser, does minor cleanup
to remove extraneous newlines Asm Output, and some improvements white
space handling.
Reviewers: rtrieu, dwmw2, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20009
llvm-svn: 272953
The R_ARM_PLT32 relocation is deprecated and is not produced by MC.
This means that the code being deleted is dead from the .o point of
view and was making the .s more confusing.
llvm-svn: 272909
We can only generate immediates up to #510 with a MOV+ADD, not #511, because there's no such instruction as add #256.
Found by Oliver Stannard and csmith!
llvm-svn: 272665
MRRC/MRRC2 instruction writes to two registers. The
intrinsic definition returns a single uint64_t to
represent the write, this is a compact way of
representing a write to two 32 bit registers,
the alternative might have been two return a
struct of 2 uint32_t's but this isn't as nice.
Differential Revision:
llvm-svn: 272544
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
ReplaceTailWithBranchTo assumed that if an instruction is predicated, it must be part of an IT block. This is not correct for conditional branches.
No testcase as this was triggered by the reverted patch r272017 - test coverage will occur when that patch is re-reverted and there is no known way to trigger this in the meantime.
llvm-svn: 272258
If an immediate is only used in an AND node, it is possible that the immediate can be more optimally materialized when negated. If this is the case, we can negate the immediate and use a BIC instead;
int i(int a) {
return a & 0xfffffeec;
}
Used to produce:
ldr r1, [CONSTPOOL]
ands r0, r1
CONSTPOOL: 0xfffffeec
And now produces:
movs r1, #255
adds r1, #20 ; Less costly immediate generation
bics r0, r1
llvm-svn: 272251
The MSR instructions can write to the CPSR, but we did not model this
fact, so we could emit them in the middle of IT blocks, changing the
condition flags for later instructions in the block.
The tests use two calls to llvm.write_register.i32 because it is valid
to use these instructions at the end of an IT block, which if conversion
does do in some cases. With two calls, the first clobbers the flags, so
a branch has to be used to make the second one conditional.
Differential Revision: http://reviews.llvm.org/D21139
llvm-svn: 272154
As suggested by clang-tidy's performance-unnecessary-copy-initialization.
This can easily hit lifetime issues, so I audited every change and ran the
tests under asan, which came back clean.
llvm-svn: 272126
These instructions end in "S" but are not flag-setting, so they need including
in the list of special cases in the assembly parser.
Differential Revision: http://reviews.llvm.org/D21077
llvm-svn: 272015
A Thumb-2 post-indexed LDR instruction such as:
ldr.w r0, [r1], #4
Can be rewritten as:
ldm.n r1!, {r0}
LDMs can be more expensive than LDRs on some cores, so this has been enabled only in minsize mode.
llvm-svn: 272002
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
The Thumb2 conditional branch B<cond>.W has a different encoding (T3)
to the unconditional branch B.W (T4) as it needs to record <cond>.
As the encoding is different the B<cond>.W is given a different
relocation type.
ELF for the ARM Architecture 4.6.1.6 (Table-13) states that
R_ARM_THM_JUMP19 should be used for B<cond>.W. At present the
MC layer is using the R_ARM_THM_JUMP24 from B.W.
This change makes B<cond>.W use R_ARM_THM_JUMP19 and alters the
existing test that checks for R_ARM_THM_JUMP24 to expect
R_ARM_THM_JUMP19.
llvm-svn: 271997
TLS access requires an offset from the TLS index. The index itself is the
section-relative distance of the symbol. For ARM, the relevant relocation
(IMAGE_REL_ARM_SECREL) is applied as a constant. This means that the value may
not be an immediate and must be lowered into a constant pool. This offset will
not be base relocated. We were previously emitting the actual address of the
symbol which would be base relocated and would therefore be the vaue offset by
the ImageBase + TLS Offset.
llvm-svn: 271974
new instruction to ARM and AArch64 targets and several system registers.
Patch by: Roger Ferrer Ibanez and Oliver Stannard
Differential Revision: http://reviews.llvm.org/D20282
llvm-svn: 271670
forces having special checks in ArmInstPrinter::printInstruction. This
patch addresses this issue.
Not all special checks could be removed: either they involve elaborated
conditions under which the alias is emitted (e.g. ldm/stm on sp may be
pop/push but only if the number of registers is >= 2) or the number
of registers is multivalued (like happens again with ldm/stm) and they
do not match the InstAlias pattern which assumes single-valued operands
in the pattern.
Patch by: Roger Ferrer Ibanez
Differential Revision: http://reviews.llvm.org/D20237
llvm-svn: 271667
This adds an additional matcher to select UBFX(..) from SRL(AND(..)) in
ARMISelDAGToDAG to help with code size.
Patch by David Green.
Differential Revision: http://reviews.llvm.org/D20667
llvm-svn: 271384
Physregs have no associated register class, do not attempt to modify it
in Thumb2InstrInfo::storeRegToStackSlot()/loadFromStackSlot().
llvm-svn: 271339
Added support to map intrinsics
__builtin_arm_{ldc,ldcl,ldc2,ldc2l,stc,stcl,stc2,stc2l}
to their ARM instructions.
Differential Revision: http://reviews.llvm.org/D20564
llvm-svn: 271271
Having an enum member named Default is quite confusing: Is it distinct
from the others?
This patch removes that member and instead uses Optional<Reloc> in
places where we have a user input that still hasn't been maped to the
default value, which is now clear has no be one of the remaining 3
options.
llvm-svn: 269988
Since r207518 they are printed exactly like non-hidden stubs on x86 and
since r207517 on ARM.
This means we can use a single set for all stubs in those platforms.
llvm-svn: 269776
The movw instruction is only available in ARM state for V6T2 and above.
The MOVi16 instruction has requirement HasV6T2 but the InstAlias
for mov rd, imm where the operand is imm0_65535_expr:$imm does not.
This means that movw can incorrectly be used in ARMv4 and ARMv5 by
writing mov rd, 0x1234. The simple fix is to the requirement HasV6T2
to the InstAlias. Tests added to not-armv4.s.
Patch by Peter Smith.
llvm-svn: 269761
It seems that cl will emit the export directives for Windows ARM targets. The
fact that it did this had originally been missed and this functionality was
never implemented. This makes it possible to rely solely on the source code for
indicating what the exported interfaces are and brings us more compatibility
with cl.
llvm-svn: 269574
When setting the frame pointer, the offset from SP is calculated based on the
stack slot it gets allocated, but this slot is in turn based on the order of
the CSR list so that list should match the order we actually save the registers
in. Mostly it did, but in the edge-case of MachO AAPCS targets it was wrong.
llvm-svn: 269459
This change implements the transformation in processInstruction() for the
LDR rt, =expression to MOV rt, expression when the expression can be evaluated
and can fit into the immediate field of the MOV or a MVN.
Across the ARM and Thumb instruction sets there are several cases to consider,
each with a different range of representatble constants.
In ARM we have:
* Modified immediate (All ARM architectures)
* MOVW (v6t2 and above)
In Thumb we have:
* Modified immediate (v6t2, v7m and v8m.mainline)
* MOVW (v6t2, v7m, v8.mainline and v8m.baseline)
* Narrow Thumb MOV that can be used in an IT block (non flag-setting)
If the immediate fits any of the available alternatives then we make the transformation.
Fixes 25722.
Patch by Peter Smith.
llvm-svn: 269354
This change adds a new constant pool kind to ARMOperand. When parsing the
operand for =immediate we create an instance of this operand rather than
creating a constant pool entry and rewriting the operand.
As the new operand kind is only created for ldr rt,= we can make ldr rt,=
an explicit pseudo instruction in ARM, Thumb and Thumb2
The pseudo instruction is expanded in processInstruction(). This creates the
constant pool and transforms the pseudo instruction into a pc-relative ldr to
the constant pool.
There are no functional changes and no modifications needed to existing tests.
Required by the patch that fixes PR25722.
Patch by Peter Smith.
llvm-svn: 269352
Fix "Logic error" warnings of the type "Called C++ object pointer is
null" reported by Clang Static Analyzer.
Patch by Apelete Seketeli.
llvm-svn: 269285
This is a large change, but it's pretty mechanical:
- Where we were returning a node before, call ReplaceNode instead.
- Where we would return null to fall back to another selector, rename
the method to try* and return a bool for success.
- Where we were calling SelectNodeTo, just return afterwards.
Part of llvm.org/pr26808.
llvm-svn: 269258
I'm really not sure why we were in the first place, it's the linker's job to
convert between BL/BLX as necessary. Even worse, using BLX left Thumb calls
that could be locally resolved completely unencodable since all offsets to BLX
are multiples of 4.
rdar://26182344
llvm-svn: 269101
Many files include Passes.h but only a fraction needs to know about the
TargetPassConfig class. Move it into an own header. Also rename
Passes.cpp to TargetPassConfig.cpp while we are at it.
llvm-svn: 269011
(re-apply r268810 as it exposed an uninitialized variable in ARM MFI.
Patch 268868 should fix that.)
Summary:
Currently, when checking if a stack is "BigStack" or not, it doesn't count into spills and arguments. Therefore, LLVM won't reserve spill slot for this actually "BigStack". This may cause scavenger failure.
Reviewers: rengolin
Subscribers: vitalybuka, aemerson, rengolin, tberghammer, danalbert, srhines, llvm-commits
Differential Revision: http://reviews.llvm.org/D19896
llvm-svn: 268869
(this is resubmit of r268529 with minor refactoring. r268529 was reverted
at r268536 due a memory sanitizer failure. I have not been able to
reproduce that failure and I checked all the variable used in my change
but I could not spot an issue. I did some refactoring and see if it will
give a clearer hint)
Summary:
Currently, when checking if a stack is "BigStack" or not, it doesn't count into spills and arguments. Therefore, LLVM won't reserve spill slot for this actually "BigStack". This may cause scavenger failure.
Reviewers: rengolin
Subscribers: vitalybuka, aemerson, rengolin, tberghammer, danalbert, srhines, llvm-commits
Differential Revision: http://reviews.llvm.org/D19896
llvm-svn: 268810
This is a step towards removing the rampant undefined behaviour in
SelectionDAG, which is a part of llvm.org/PR26808.
We rename SelectionDAGISel::Select to SelectImpl and update targets to
match, and then change Select to return void and consolidate the
sketchy behaviour we're trying to get away from there.
Next, we'll update backends to implement `void Select(...)` instead of
SelectImpl and eventually drop the base Select implementation.
llvm-svn: 268693
Given something like:
ldr r0, .LCPI0_0 (== pc-rel var)
add r0, pc
ldr r1, .LCPI0_1 (== pc-rel var)
add r1, pc
we cannot combine the 2 ldr instructions and litpools because they get added to
a different pc to form the correct address. I think the original logic came
from a time when we fused the LDRpci/PICADD instructions into one
pseudo-instruction so the PC was always immediately at-hand. That's no longer
the case.
Should fix general-dynamic TLS access on Linux, and quite possibly other -fPIC
code that relies on litpools (e.g. v6m and -Oz compilations) though trivial
tweaks of the .ll test didn't provoke anything.
llvm-svn: 268662
The code here is recursively Select-ing a new Node to avoid issues
where N is CSE'd during replaceDAGValue and stops being valid. We can
accomplish the same goal in a more principled way by using a
HandleSDNode.
This is essentially a less dodgy fix for PR25733 than the original
attempt back in r255120.
llvm-svn: 268590
Summary:
Currently, when checking if a stack is "BigStack" or not, it doesn't count into spills and arguments. Therefore, LLVM won't reserve spill slot for this actually "BigStack". This may cause scavenger failure.
Reviewers: rengolin
Subscribers: aemerson, rengolin, tberghammer, danalbert, srhines, llvm-commits
Differential Revision: http://reviews.llvm.org/D19896
llvm-svn: 268529
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
We were negating an immediate that was going to be used in a SUBri form
unnecessarily. Since ADD/SUB are very similar we *can* do that, but we have to
change the SUB to an ADD at the same time. This also applies to ADD, and allows
us to handle a slightly larger range of immediates for those two operations.
rdar://25992245
llvm-svn: 268276
Summary:
Historically, we had a switch in the Makefiles for turning on "expensive
checks". This has never been ported to the cmake build, but the
(dead-ish) code is still around.
This will also make it easier to turn it on in buildbots.
Reviewers: chandlerc
Subscribers: jyknight, mzolotukhin, RKSimon, gberry, llvm-commits
Differential Revision: http://reviews.llvm.org/D19723
llvm-svn: 268050
transferSuccessors() would LoadCmpBB a successor of DoneBB, whereas
it should be a successor of the original MBB.
The testcase changes are caused by Thumb2SizeReduction, which
was previously confused by the broken CFG.
Follow-up to r266679.
Unfortunately, it's tricky to catch this in the verifier.
llvm-svn: 267778
Summary:
We don't use MinLatency any more since r184032.
Reviewers: atrick, hfinkel, mcrosier
Differential Revision: http://reviews.llvm.org/D19474
llvm-svn: 267502
Summary:
This patch adds support for the X asm constraint.
To do this, we lower the constraint to either a "w" or "r" constraint
depending on the operand type (both constraints are supported on ARM).
Fixes PR26493
Reviewers: t.p.northover, echristo, rengolin
Subscribers: joker.eph, jgreenhalgh, aemerson, rengolin, llvm-commits
Differential Revision: http://reviews.llvm.org/D19061
llvm-svn: 267411
This corrects the MI annotations for the stack adjustment following the __chkstk
invocation. We were marking the original SP usage as a Def rather than Kill.
The (new) assigned value is the definition, the original reference is killed.
Adjust the ISelLowering to mark Kills and FrameSetup as well.
This partially resolves PR27480.
llvm-svn: 267361
The relative vtable ABI (PR26723) needs PLT relocations to refer to virtual
functions defined in other DSOs. The unnamed_addr attribute means that the
function's address is not significant, so we're allowed to substitute it
with the address of a PLT entry.
Also includes a bonus feature: addends for COFF image-relative references.
Differential Revision: http://reviews.llvm.org/D17938
llvm-svn: 267211
WIN__DBZCHK will insert a CBZ instruction into the stream. This instruction
reserves 3 bits for the condition register (rn). As such, we must ensure that
we restrict the register to a low register. Use the tGPR class instead of GPR
to ensure that this is properly constrained. In debug builds, we would attempt
to use lr as a condition register which would silently get truncated with no
hint that the register selection was incorrect.
llvm-svn: 267080
We'd disabled them on x86 because back in the early days some host tools
couldn't handle the new load commands. This no longer holds: anyone capable of
deploying Clang should be able to deploy its copies of ar/ranlib/etc.
rdar://25254790
llvm-svn: 267075
Because lowering of CMP_SWAP_64 occurs during type legalization, there can be
i64 types produced by more than just a BUILD_PAIR or similar. My initial tests
used just incoming function args.
llvm-svn: 266828
Both AArch64 and ARM support llvm.<arch>.thread.pointer intrinsics that
just return the thread pointer. I have a pending patch that does the same
for SystemZ (D19054), and there are many more targets that could benefit
from one.
This patch merges the ARM and AArch64 intrinsics into a single target
independent one that will also be used by subsequent targets.
Differential Revision: http://reviews.llvm.org/D19098
llvm-svn: 266818
The fast register-allocator cannot cope with inter-block dependencies without
spilling. This is fine for ldrex/strex loops coming from atomicrmw instructions
where any value produced within a block is dead by the end, but not for
cmpxchg. So we lower a cmpxchg at -O0 via a pseudo-inst that gets expanded
after regalloc.
Fortunately this is at -O0 so we don't have to care about performance. This
simplifies the various axes of expansion considerably: we assume a strong
seq_cst operation and ensure ordering via the always-present DMB instructions
rather than v8 acquire/release instructions.
Should fix the 32-bit part of PR25526.
llvm-svn: 266679
Removed some unused headers, replaced some headers with forward class declarations.
Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'
Patch by Eugene Kosov <claprix@yandex.ru>
Differential Revision: http://reviews.llvm.org/D19219
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
Divisions by a constant can be converted into multiplies which are usually
cheaper, but this isn't possible if the constant gets separated (particularly
in loops). Fix this by telling ConstantHoisting that the immediate in a DIV is
cheap.
I considered making the check generic, but neither AArch64 (strangely) nor x86
showed any benefit on the tests I had.
llvm-svn: 266464
Some SIMD implementations are not IEEE-754 compliant, for example ARM's NEON.
This patch teaches the loop vectorizer to only allow transformations of loops
that either contain no floating-point operations or have enough allowance
flags supporting lack of precision (ex. -ffast-math, Darwin).
For that, the target description now has a method which tells us if the
vectorizer is allowed to handle FP math without falling into unsafe
representations, plus a check on every FP instruction in the candidate loop
to check for the safety flags.
This commit makes LLVM behave like GCC with respect to ARM NEON support, but
it stops short of fixing the underlying problem: sub-normals. Neither GCC
nor LLVM have a flag for allowing sub-normal operations. Before this patch,
GCC only allows it using unsafe-math flags and LLVM allows it by default with
no way to turn it off (short of not using NEON at all).
As a first step, we push this change to make it safe and in sync with GCC.
The second step is to discuss a new sub-normal's flag on both communitues
and come up with a common solution. The third step is to improve the FastMath
flags in LLVM to encode sub-normals and use those flags to restrict NEON FP.
Fixes PR16275.
llvm-svn: 266363
At some point, ARM stopped getting any benefit from ConstantHoisting because
the pass called a different variant of getIntImmCost. Reimplementing the
correct variant revealed some problems, however:
+ ConstantHoisting was modifying switch statements. This is simply invalid,
the cases must remain integer constants no matter the notional cost.
+ ConstantHoisting was mangling alloca instructions in the entry block. These
should be handled by FrameLowering, so constants actually have a cost of 0.
Worse, the resulting bitcasts meant they became dynamic allocas.
rdar://25707382
llvm-svn: 266260
It is very likely that the swiftself parameter is alive throughout most
functions function so putting it into a callee save register should
avoid spills for the callers with only a minimum amount of extra spills
in the callees.
Currently the generated code is correct but unnecessarily spills and
reloads arguments passed in callee save registers, I will address this
in upcoming patches.
This also adds a missing check that for tail calls the preserved value
of the caller must be the same as the callees parameter.
Differential Revision: http://reviews.llvm.org/D18901
llvm-svn: 266253
This is better for a few reasons:
+ It matches the other tooling for iOS.
+ It matches EABI in more cases (i.e. Thumb-mode, and in practice we don't
use ARM mode).
+ It leads to infinitesimally smaller code (0.2%, yay!).
rdar://25369506
llvm-svn: 266003
When we see a .arch or .cpu directive, we should try to avoid switching
ARM/Thumb mode if possible.
If we do have to switch modes, we also need to emit the correct mapping
symbol for the new ISA. We did not do this previously, so could emit
ARM code with Thumb mapping symbols (or vice-versa).
The GAS behaviour is to always stay in the same mode, and to emit an
error on any instructions seen when the current mode is not available on
the current target. We can't represent that situation easily (we assume
that Thumb mode is available if ModeThumb is set), so we differ from the
GAS behaviour when switching to a target that can't support the old
mode. I've added a warning for when this implicit mode-switch occurs.
Differential Revision: http://reviews.llvm.org/D18955
llvm-svn: 265936
Added ISelDAGToDAG functions to enable selection of the smlawb, smlawt,
smulwb and smulwt instructions for the ARM backend. Also updated the smul
CodeGen test and removed the smulw one.
Differential Revision: http://reviews.llvm.org/D18892
llvm-svn: 265793
Summary:
In the context of http://wg21.link/lwg2445 C++ uses the concept of
'stronger' ordering but doesn't define it properly. This should be fixed
in C++17 barring a small question that's still open.
The code currently plays fast and loose with the AtomicOrdering
enum. Using an enum class is one step towards tightening things. I later
also want to tighten related enums, such as clang's
AtomicOrderingKind (which should be shared with LLVM as a 'C++ ABI'
enum).
This change touches a few lines of code which can be improved later, I'd
like to keep it as NFC for now as it's already quite complex. I have
related changes for clang.
As a follow-up I'll add:
bool operator<(AtomicOrdering, AtomicOrdering) = delete;
bool operator>(AtomicOrdering, AtomicOrdering) = delete;
bool operator<=(AtomicOrdering, AtomicOrdering) = delete;
bool operator>=(AtomicOrdering, AtomicOrdering) = delete;
This is separate so that clang and LLVM changes don't need to be in sync.
Reviewers: jyknight, reames
Subscribers: jyknight, llvm-commits
Differential Revision: http://reviews.llvm.org/D18775
llvm-svn: 265602
Removed the SDNode argument passed to the AI_smul and AI_smla multiclass
definitions as they are always mul.
Differential Revision: http://reviews.llvm.org/D18791
llvm-svn: 265409
We can only perform a tail call to a callee that preserves all the
registers that the caller needs to preserve.
This situation happens with calling conventions like preserver_mostcc or
cxx_fast_tls. It was explicitely handled for fast_tls and failing for
preserve_most. This patch generalizes the check to any calling
convention.
Related to rdar://24207743
Differential Revision: http://reviews.llvm.org/D18680
llvm-svn: 265329
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
ThreadModel::Single is already handled already by ARMPassConfig adding
LowerAtomicPass to the pass list, which lowers all atomics to non-atomic
ops and deletes fences.
So by the time we get to ISel, there's no atomic fences left, so they
don't need special handling.
llvm-svn: 265178
Some ARM instructions encode 32-bit immediates as a 8-bit integer (0-255)
and a 4-bit rotation (0-30, even) in its least significant 12 bits. The
original fixup, FK_Data_4, patches the instruction by the value bit-to-bit,
regardless of the encoding. For example, assuming the label L1 and L2 are
0x0 and 0x104 respectively, the following instruction:
add r0, r0, #(L2 - L1) ; expects 0x104, i.e., 260
would be assembled to the following, which adds 1 to r0, instead of 260:
e2800104 add r0, r0, #4, 2 ; equivalently 1
The new fixup kind fixup_arm_mod_imm takes care of the encoding:
e2800f41 add r0, r0, #260
Patch by Ting-Yuan Huang!
llvm-svn: 265122
This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.
It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.
Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.
Differential Revision: http://reviews.llvm.org/D18627
llvm-svn: 265036
These checks are redundant and can be removed
Reviewers: hans
Subscribers: llvm-commits, mzolotukhin
Differential Revision: http://reviews.llvm.org/D18564
llvm-svn: 264872
It is possible to have a fallthrough MBB prior to MBB placement. The original
addition of the BB would result in reordering the BB as not preceding the
successor. Because of the fallthrough nature of the BB, we could end up
executing incorrect code or even a constant pool island! Insert the spliced BB
into the same location to avoid that.
Thanks to Tim Northover for invaluable hints and Fiora for the discussion on
what may have been occurring!
llvm-svn: 264454
We did not have an explicit branch to the continuation BB. When the check was
hoisted, this could permit control follow to fall through into the division
trap. Add the explicit branch to the continuation basic block to ensure that
code execution is correct.
llvm-svn: 264370
This introduces a custom lowering for ISD::SETCCE (introduced in r253572)
that allows us to emit a short code sequence for 64-bit compares.
Before:
push {r7, lr}
cmp r0, r2
mov.w r0, #0
mov.w r12, #0
it hs
movhs r0, #1
cmp r1, r3
it ge
movge.w r12, #1
it eq
moveq r12, r0
cmp.w r12, #0
bne .LBB1_2
@ BB#1: @ %bb1
bl f
pop {r7, pc}
.LBB1_2: @ %bb2
bl g
pop {r7, pc}
After:
push {r7, lr}
subs r0, r0, r2
sbcs.w r0, r1, r3
bge .LBB1_2
@ BB#1: @ %bb1
bl f
pop {r7, pc}
.LBB1_2: @ %bb2
bl g
pop {r7, pc}
Saves around 80KB in Chromium's libchrome.so.
Some notes on this patch:
- I don't much like the ARMISD::BRCOND and ARMISD::CMOV combines I
introduced (nothing else needs them). However, they are necessary in
order to avoid poor codegen, and they seem similar to existing combines
in other backends (e.g. X86 combines (brcond (cmp (setcc Compare))) to
(brcond Compare)).
- No support for Thumb-1. This is in principle possible, but we'd need
to implement ARMISD::SUBE for Thumb-1.
Differential Revision: http://reviews.llvm.org/D15256
llvm-svn: 263962
We need to be careful on which registers can be explicitly handled
via copies. Prologue, Epilogue use physical registers and if one belongs
to the set of CSRsViaCopy, it will no longer be CSRed, since PEI overwrites
it after the explicit copies.
llvm-svn: 263857
The two changes together weakened the test and caused a regression with division
handling in MSVC mode. They were applied to avoid an assertion being triggered
in the block frequency analysis. However, the underlying problem was simply
being masked rather than solved properly. Address the actual underlying problem
and revert the changes. Rather than analyze the cause of the assertion, the
division failure was assumed to be an overflow.
The underlying issue was a subtle bug in the BB construction in the emission of
the div-by-zero check (WIN__DBZCHK). We did not construct the proper successor
information in the basic blocks, nor did we update the PHIs associated with the
basic block when we split them. This would result in assertions being triggered
in the block frequency analysis pass.
Although the original tests are being removed, the tests themselves performed
very little in terms of validation but merely tested that we did not assert when
generating code. Update this with new tests that actually ensure that we do not
regress on the code generation.
llvm-svn: 263714
- Rename getATOMIC to getSYNC, as llvm will soon be able to emit both
'__sync' libcalls and '__atomic' libcalls, and this function is for
the '__sync' ones.
- getInsertFencesForAtomic() has been replaced with
shouldInsertFencesForAtomic(Instruction), so that the decision can be
made per-instruction. This functionality will be used soon.
- emitLeadingFence/emitTrailingFence are no longer called if
shouldInsertFencesForAtomic returns false, and thus don't need to
check the condition themselves.
llvm-svn: 263665
Tim Northover