A number of architectures re-use the same register names (e.g. for both 32-bit
FPRs and 64-bit FPRs). They are currently unable to use the tablegen'erated
MatchRegisterName and MatchRegisterAltName, as tablegen (when built with
asserts enabled) will fail.
When the AllowDuplicateRegisterNames in AsmParser is set, duplicated register
names will be tolerated. A backend can then coerce registers to the desired
register class by (for instance) implementing validateTargetOperandClass.
At least the in-tree Sparc backend could benefit from this, as does RISC-V
(single and double precision floating point registers).
Differential Revision: https://reviews.llvm.org/D39845
llvm-svn: 320018
Summary:
While implementing atomicrmw in https://reviews.llvm.org/D40092 I found that
inheritance is unusable for all the Generic Opcodes in GlobalISel. This is
because the whole header is included inside a 'let mayLoad = 0, mayStore = 0 ... in'
block. In TableGen, the order of precedence for field assignments is:
1. Values from classes the record inherits from.
2. Values from 'let Name=Value in { ... }'
3. Values from 'let Name=Value;'
As such the 'let mayLoad = 0, mayStore = 0, ... in' surrounding the
'include "GenericOpcodes.td"' was overriding any values provided via inheritance.
We hadn't noticed this before because we were only using 'let Name=Value;' to
specialize opcodes.
Fix this by moving the default values to the lowest precedence. This is
accomplished by moving the values to a common base class
(StandardPseudoInstruction for most TargetOpcodes, and GenericOpcode for
GlobalISel specific TargetOpcodes)
Reviewers: qcolombet
Reviewed By: qcolombet
Subscribers: llvm-commits, igorb
Differential Revision: https://reviews.llvm.org/D40096
llvm-svn: 319701
ptypeN is functionally the same as typeN except that it informs the
SelectionDAG importer that an operand should be treated as a pointer even
if it was written as iN. This is important for patterns that use iN instead
of iPTR to represent pointers. E.g.:
(set GPR64:$dst, (load GPR64:$addr))
Previously, this was handled as a hardcoded special case for the appropriate
operands to G_LOAD and G_STORE.
llvm-svn: 318574
D37065 (committed as rL317674) explicitly set hasSideEffects for all
TargetOpcode::* instructions where it was inferred previously. This is a
follow-up to that patch, setting hasSideEffects=0 for CFI_INSTRUCTION,
EH_LABEL, GC_LABEL and ANNOTATION_LABEL. All LLVM tests pass after this
change.
This patch also modifies MachineInstr::isLabel returns true for a
TargetOpcode::ANNOTATION_LABEL, which ensures that an annotation label won't
be incorrectly considered safe to move.
Differential Revision: https://reviews.llvm.org/D39941
llvm-svn: 318174
This reverts r317579, originally committed as r317100.
There is a design issue with marking CFI instructions duplicatable. Not
all targets support the CFIInstrInserter pass, and targets like Darwin
can't cope with duplicated prologue setup CFI instructions. The compact
unwind info emission fails.
When the following code is compiled for arm64 on Mac at -O3, the CFI
instructions end up getting tail duplicated, which causes compact unwind
info emission to fail:
int a, c, d, e, f, g, h, i, j, k, l, m;
void n(int o, int *b) {
if (g)
f = 0;
for (; f < o; f++) {
m = a;
if (l > j * k > i)
j = i = k = d;
h = b[c] - e;
}
}
We get assembly that looks like this:
; BB#1: ; %if.then
Lloh3:
adrp x9, _f@GOTPAGE
Lloh4:
ldr x9, [x9, _f@GOTPAGEOFF]
mov w8, wzr
Lloh5:
str wzr, [x9]
stp x20, x19, [sp, #-16]! ; 8-byte Folded Spill
.cfi_def_cfa_offset 16
.cfi_offset w19, -8
.cfi_offset w20, -16
cmp w8, w0
b.lt LBB0_3
b LBB0_7
LBB0_2: ; %entry.if.end_crit_edge
Lloh6:
adrp x8, _f@GOTPAGE
Lloh7:
ldr x8, [x8, _f@GOTPAGEOFF]
Lloh8:
ldr w8, [x8]
stp x20, x19, [sp, #-16]! ; 8-byte Folded Spill
.cfi_def_cfa_offset 16
.cfi_offset w19, -8
.cfi_offset w20, -16
cmp w8, w0
b.ge LBB0_7
LBB0_3: ; %for.body.lr.ph
Note the multiple .cfi_def* directives. Compact unwind info emission
can't handle that.
llvm-svn: 317726
Previously, hasSideEffects was ? for TargetOpcode::PHI and would be inferred
as 1. D37065 sets the previously inferred properties explicitly. This patch sets
hasSideEffects=0 for PHI, as it is for G_PHI. MachineInstr::isSafeToMove has
been updated so it still returns false for PHI.
Additionally, HexagonBitSimplify relied on a PHI node having the
hasUnmodeledSideEffects property. This patch fixes that assumption.
Differential Revision: https://reviews.llvm.org/D37097
llvm-svn: 317721
rL162640 introduced CodeGenTarget::guessInstructionProperties. If a target
sets guessInstructionProperties=0 in its FooInstrInfo, tablegen will error if
it has to guess properties from patterns. Unfortunately,
guessInstructionProperties=0 can't be used with current upstream LLVM as
instructions in the TargetOpcode namespace are always included and sometimes
have inferred properties for mayLoad, mayStore, and hasSideEffects. This patch
provides the simplest possible fix to this problem, setting default values for
these fields in the TargetOpcode scope. There is no intended functional
change, as the explicitly set properties should match what was previously
inferred. A number of the instructions had hasSideEffects=1 inferred
unintentionally. This patch makes it explicit, while future patches (such as
D37097) correct the property.
Differential Revision: https://reviews.llvm.org/D37065
llvm-svn: 317674
Reland r317100 with minor fix regarding ComputeCommonTailLength function in
BranchFolding.cpp. Skipping top CFI instructions block needs to executed on
several more return points in ComputeCommonTailLength().
Original r317100 message:
"Correct dwarf unwind information in function epilogue for X86"
This patch aims to provide correct dwarf unwind information in function
epilogue for X86.
It consists of two parts. The first part inserts CFI instructions that set
appropriate cfa offset and cfa register in emitEpilogue() in
X86FrameLowering. This part is X86 specific.
The second part is platform independent and ensures that:
- CFI instructions do not affect code generation
- Unwind information remains correct when a function is modified by
different passes. This is done in a late pass by analyzing information
about cfa offset and cfa register in BBs and inserting additional CFI
directives where necessary.
Changed CFI instructions so that they:
- are duplicable
- are not counted as instructions when tail duplicating or tail merging
- can be compared as equal
Added CFIInstrInserter pass:
- analyzes each basic block to determine cfa offset and register valid at
its entry and exit
- verifies that outgoing cfa offset and register of predecessor blocks match
incoming values of their successors
- inserts additional CFI directives at basic block beginning to correct the
rule for calculating CFA
Having CFI instructions in function epilogue can cause incorrect CFA
calculation rule for some basic blocks. This can happen if, due to basic
block reordering, or the existence of multiple epilogue blocks, some of the
blocks have wrong cfa offset and register values set by the epilogue block
above them.
CFIInstrInserter is currently run only on X86, but can be used by any target
that implements support for adding CFI instructions in epilogue.
Patch by Violeta Vukobrat.
llvm-svn: 317579
This patch aims to provide correct dwarf unwind information in function
epilogue for X86.
It consists of two parts. The first part inserts CFI instructions that set
appropriate cfa offset and cfa register in emitEpilogue() in
X86FrameLowering. This part is X86 specific.
The second part is platform independent and ensures that:
- CFI instructions do not affect code generation
- Unwind information remains correct when a function is modified by
different passes. This is done in a late pass by analyzing information
about cfa offset and cfa register in BBs and inserting additional CFI
directives where necessary.
Changed CFI instructions so that they:
- are duplicable
- are not counted as instructions when tail duplicating or tail merging
- can be compared as equal
Added CFIInstrInserter pass:
- analyzes each basic block to determine cfa offset and register valid at
its entry and exit
- verifies that outgoing cfa offset and register of predecessor blocks match
incoming values of their successors
- inserts additional CFI directives at basic block beginning to correct the
rule for calculating CFA
Having CFI instructions in function epilogue can cause incorrect CFA
calculation rule for some basic blocks. This can happen if, due to basic
block reordering, or the existence of multiple epilogue blocks, some of the
blocks have wrong cfa offset and register values set by the epilogue block
above them.
CFIInstrInserter is currently run only on X86, but can be used by any target
that implements support for adding CFI instructions in epilogue.
Patch by Violeta Vukobrat.
Differential Revision: https://reviews.llvm.org/D35844
llvm-svn: 317100
This patch enables the import of stores. Unfortunately, doing so by itself,
loses an optimization where storing 0 to memory makes use of WZR/XZR.
To mitigate this, this patch also introduces a new feature that allows register
operands to nominate a zero register. When this is done, GlobalISel will
substitute (G_CONSTANT 0) with the nominated register automatically. This
is currently configured to only apply to the stores.
Applying it to GPR32/GPR64 register classes in general will be done after
review see (https://reviews.llvm.org/D39150).
llvm-svn: 316360
This allows a DiagnosticType and/or DiagnosticString to be associated
with a RegisterClass in tablegen, so that we can emit diagnostics in the
assembler when a register operand is incorrect.
DiagnosticType creates a predictable enum value, which gets returned as
the error code when an operand does not match, and can be used by the
assembly parser to map to a user-facing diagnostic. DiagnosticString
creates an anonymous enum value (currently based on the tablegen class
name), and a function to map from enum values to strings will be
generated. Both of these work the same was as they do for AsmOperand.
This isn't used by any targets yet, but has one (positive) side-effect.
It improves the diagnostic codes returned by validateOperandClass - we
always want to emit the diagnostic that relates to the expected operand
class, but this wasn't always being done when the expected and actual
classes were completely different (token/register/custom). This causes a
few AArch64 diagnostics to be improved, as Match_InvalidOperand was
being returned instead of a specific diagnostic type.
Differential revision: https://reviews.llvm.org/D36691
llvm-svn: 315295
This adds a DiagnosticString member to the AsmOperand tablegen class, so
that the diagnostic text to be used when an assembly operand is
incorrect can be stored in the tablegen description of the operand,
rather than in a separate switch statement in the AsmParser.
If DiagnosticString is used for any operands, tablegen will emit a
getMatchKindDiag function, to map from diagnostic enums to strings.
Differential revision: https://reviews.llvm.org/D31606
llvm-svn: 314803
The current table-generated assembly instruction matcher returns a
64-bit error code when matching fails. Since multiple instruction
encodings with the same mnemonic can fail for different reasons, it uses
some heuristics to decide which message is important.
This heuristic does not work well for targets that have many encodings
with the same mnemonic but different operands, or which have different
versions of instructions controlled by subtarget features, as it is hard
to know which encoding the user was intending to use.
Instead of trying to improve the heuristic in the table-generated
matcher, this patch changes it to report a list of near-miss encodings.
This list contains an entry for each encoding with the correct mnemonic,
but with exactly one thing preventing it from being valid. This thing
could be a single invalid operand, a missing target feature or a failed
target-specific validation function.
The target-specific assembly parser can then report an error message
giving multiple options for instruction variants that the user may have
been trying to use. For example, I am working on a patch to use this for
ARM, which can give this error for an invalid instruction for ARMv6-M:
<stdin>:8:3: error: invalid instruction, multiple near-miss encodings found
adds r0, r1, #0x8
^
<stdin>:8:3: note: for one encoding: instruction requires: thumb2
adds r0, r1, #0x8
^
<stdin>:8:16: note: for one encoding: expected an integer in range [0, 7]
adds r0, r1, #0x8
^
<stdin>:8:16: note: for one encoding: expected a register in range [r0, r7]
adds r0, r1, #0x8
^
This also allows the target-specific assembly parser to apply its own
heuristics to suppress some errors. For example, the error "instruction
requires: arm-mode" is never going to be useful when targeting an
M-profile architecture (which does not have ARM mode).
This patch just adds the target-independent mechanism for doing this,
all targets still use the old mechanism. I've added a bit in the
AsmParser tablegen class to allow targets to switch to this new
mechanism. To use this, the target-specific assembly parser will have to
be modified for the change in signature of MatchInstructionImpl, and to
report errors based on the list of near-misses.
Differential revision: https://reviews.llvm.org/D27620
llvm-svn: 314774
Summary: Conditional returns were not taken into consideration at all. Implement them by turning them into jumps and normal returns. This means there is a slightly higher performance penalty for conditional returns, but this is the best we can do, and it still disturbs little of the rest.
Reviewers: dberris, echristo
Subscribers: sanjoy, nemanjai, hiraditya, kbarton, llvm-commits
Differential Revision: https://reviews.llvm.org/D38102
llvm-svn: 314005
This replaces TableGen's type inference to operate on parameterized
types instead of MVTs, and as a consequence, some interfaces have
changed:
- Uses of MVTs are replaced by ValueTypeByHwMode.
- EEVT::TypeSet is replaced by TypeSetByHwMode.
This affects the way that types and type sets are printed, and the
tests relying on that have been updated.
There are certain users of the inferred types outside of TableGen
itself, namely FastISel and GlobalISel. For those users, the way
that the types are accessed have changed. For typical scenarios,
these replacements can be used:
- TreePatternNode::getType(ResNo) -> getSimpleType(ResNo)
- TreePatternNode::hasTypeSet(ResNo) -> hasConcreteType(ResNo)
- TypeSet::isConcrete -> TypeSetByHwMode::isValueTypeByHwMode(false)
For more information, please refer to the review page.
Differential Revision: https://reviews.llvm.org/D31951
llvm-svn: 313271
Summary:
This intrinsic represents a label with a list of associated metadata
strings. It is modelled as reading and writing inaccessible memory so
that it won't be removed as dead code. I think the intention is that the
annotation strings should appear at most once in the debug info, so I
marked it noduplicate. We are allowed to inline code with annotations as
long as we strip the annotation, but that can be done later.
Reviewers: majnemer
Subscribers: eraman, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D36904
llvm-svn: 312569
CFI instructions that set appropriate cfa offset and cfa register are now
inserted in emitEpilogue() in X86FrameLowering.
Majority of the changes in this patch:
1. Ensure that CFI instructions do not affect code generation.
2. Enable maintaining correct information about cfa offset and cfa register
in a function when basic blocks are reordered, merged, split, duplicated.
These changes are target independent and described below.
Changed CFI instructions so that they:
1. are duplicable
2. are not counted as instructions when tail duplicating or tail merging
3. can be compared as equal
Add information to each MachineBasicBlock about cfa offset and cfa register
that are valid at its entry and exit (incoming and outgoing CFI info). Add
support for updating this information when basic blocks are merged, split,
duplicated, created. Add a verification pass (CFIInfoVerifier) that checks
that outgoing cfa offset and register of predecessor blocks match incoming
values of their successors.
Incoming and outgoing CFI information is used by a late pass
(CFIInstrInserter) that corrects CFA calculation rule for a basic block if
needed. That means that additional CFI instructions get inserted at basic
block beginning to correct the rule for calculating CFA. Having CFI
instructions in function epilogue can cause incorrect CFA calculation rule
for some basic blocks. This can happen if, due to basic block reordering,
or the existence of multiple epilogue blocks, some of the blocks have wrong
cfa offset and register values set by the epilogue block above them.
Patch by Violeta Vukobrat.
Differential Revision: https://reviews.llvm.org/D18046
llvm-svn: 306529
This patch introduces an LLVM intrinsic and a target opcode for custom event
logging in XRay. Initially, its use case will be to allow users of XRay to log
some type of string ("poor man's printf"). The target opcode compiles to a noop
sled large enough to enable calling through to a runtime-determined relative
function call. At runtime, when X-Ray is enabled, the sled is replaced by
compiler-rt with a trampoline to the logic for creating the custom log entries.
Future patches will implement the compiler-rt parts and clang-side support for
emitting the IR corresponding to this intrinsic.
Reviewers: timshen, dberris
Subscribers: igorb, pelikan, rSerge, timshen, echristo, dberris, llvm-commits
Differential Revision: https://reviews.llvm.org/D27503
llvm-svn: 302405
Summary:
Predicate<> now has a field to indicate how often it must be recomputed.
Currently, there are two frequencies, per-module (RecomputePerFunction==0)
and per-function (RecomputePerFunction==1). Per-function predicates are
currently recomputed more frequently than necessary since the only predicate
in this category is cheap to test. Per-module predicates are now computed in
getSubtargetImpl() while per-function predicates are computed in selectImpl().
Tablegen now manages the PredicateBitset internally. It should only be
necessary to add the required includes.
Also fixed a problem revealed by the test case where
constrainSelectedInstRegOperands() would attempt to tie operands that
BuildMI had already tied.
Reviewers: ab, qcolombet, t.p.northover, rovka, aditya_nandakumar
Reviewed By: rovka
Subscribers: kristof.beyls, igorb, llvm-commits
Differential Revision: https://reviews.llvm.org/D32491
llvm-svn: 301750
Summary:
Adds a new kind of MachineOperand: MO_Placeholder.
This operand must not appear in the MIR and only exists as a way of
creating an 'uninitialized' operand until a matcher function overwrites it.
Depends on D30046, D29712
Reviewers: t.p.northover, ab, rovka, aditya_nandakumar, javed.absar, qcolombet
Reviewed By: qcolombet
Subscribers: dberris, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D30089
llvm-svn: 297782
Summary:
This change allows usage of store instruction for implicit null check.
Memory Aliasing Analisys is not used and change conservatively supposes
that any store and load may access the same memory. As a result
re-ordering of store-store, store-load and load-store is prohibited.
Patch by Serguei Katkov!
Reviewers: reames, sanjoy
Reviewed By: sanjoy
Subscribers: atrick, llvm-commits
Differential Revision: https://reviews.llvm.org/D29400
llvm-svn: 294338
Summary:
Adds a RegisterBank tablegen class that can be used to declare the register
banks and an associated tablegen pass to generate the necessary code.
Changes since first commit attempt:
* Added missing guards
* Added more missing guards
* Found and fixed a use-after-free bug involving Twine locals
Reviewers: t.p.northover, ab, rovka, qcolombet
Reviewed By: qcolombet
Subscribers: aditya_nandakumar, rengolin, kristof.beyls, vkalintiris, mgorny, dberris, llvm-commits, rovka
Differential Revision: https://reviews.llvm.org/D27338
llvm-svn: 292478
Summary:
Adds a RegisterBank tablegen class that can be used to declare the register
banks and an associated tablegen pass to generate the necessary code.
Changes since last commit:
The new tablegen pass is now correctly guarded by LLVM_BUILD_GLOBAL_ISEL and
this should fix the buildbots however it may not be the whole fix. The previous
buildbot failures suggest there may be a memory bug lurking that I'm unable to
reproduce (including when using asan) or spot in the source. If they re-occur
on this commit then I'll need assistance from the bot owners to track it down.
Reviewers: t.p.northover, ab, rovka, qcolombet
Reviewed By: qcolombet
Subscribers: aditya_nandakumar, rengolin, kristof.beyls, vkalintiris, mgorny, dberris, llvm-commits, rovka
Differential Revision: https://reviews.llvm.org/D27338
llvm-svn: 292367
Summary:
Adds a RegisterBank tablegen class that can be used to declare the register
banks and an associated tablegen pass to generate the necessary code.
Reviewers: t.p.northover, ab, rovka, qcolombet
Subscribers: aditya_nandakumar, rengolin, kristof.beyls, vkalintiris, mgorny, dberris, llvm-commits, rovka
Differential Revision: https://reviews.llvm.org/D27338
llvm-svn: 292132
This adds a basic tablegen backend that analyzes the SelectionDAG
patterns to find simple ones that are eligible for GlobalISel-emission.
That's similar to FastISel, with one notable difference: we're not fed
ISD opcodes, so we need to map the SDNode operators to generic opcodes.
That's done using GINodeEquiv in TargetGlobalISel.td.
Otherwise, this is mostly boilerplate, and lots of filtering of any kind
of "complicated" pattern. On AArch64, this is sufficient to match G_ADD
up to s64 (to ADDWrr/ADDXrr) and G_BR (to B).
Differential Revision: https://reviews.llvm.org/D26878
llvm-svn: 290284
This is a port of XRay to ARM 32-bit, without Thumb support yet. The XRay instrumentation support is moving up to AsmPrinter.
This is one of 3 commits to different repositories of XRay ARM port. The other 2 are:
https://reviews.llvm.org/D23932 (Clang test)
https://reviews.llvm.org/D23933 (compiler-rt)
Differential Revision: https://reviews.llvm.org/D23931
llvm-svn: 281878
descriptions now tag add instructions, and the Hexagon backend is using this to
identify loop induction statements.
Patch by Sam Parker and Sjoerd Meijer.
Differential Revision: https://reviews.llvm.org/D23601
llvm-svn: 281304
We want each register to have a canonical type, which means the best place to
store this is in MachineRegisterInfo rather than on every MachineInstr that
happens to use or define that register.
Most changes following from this are pretty simple (you need an MRI anyway if
you're going to be doing any transformations, so just check the type there).
But legalization doesn't really want to check redundant operands (when, for
example, a G_ADD only ever has one type) so I've made use of MCInstrDesc's
operand type field to encode these constraints and limit legalization's work.
As an added bonus, more validation is possible, both in MachineVerifier and
MachineIRBuilder (coming soon).
llvm-svn: 281035
And associated commits, as they broke the Thumb bots.
This reverts commit r280935.
This reverts commit r280891.
This reverts commit r280888.
llvm-svn: 280967
Summary:
This allows specifying instructions that are available only in specific assembler variant. If AsmVariantName is specified then instruction will be presented only in MatchTable for this variant. If not specified then assembler variants will be determined based on AsmString.
Also this allows splitting assembler match tables in same way as it is done in dissasembler.
Reviewers: ab, tstellarAMD, craig.topper, vpykhtin
Subscribers: wdng
Differential Revision: https://reviews.llvm.org/D24249
llvm-svn: 280952
This is a port of XRay to ARM 32-bit, without Thumb support yet. The XRay instrumentation support is moving up to AsmPrinter.
This is one of 3 commits to different repositories of XRay ARM port. The other 2 are:
1. https://reviews.llvm.org/D23932 (Clang test)
2. https://reviews.llvm.org/D23933 (compiler-rt)
Differential Revision: https://reviews.llvm.org/D23931
llvm-svn: 280888
Summary:
This change promotes the 'isTailCall(...)' member function to
TargetInstrInfo as a query interface for determining on a per-target
basis whether a given MachineInstr is a tail call instruction. We build
upon this in the XRay instrumentation pass to emit special sleds for
tail call optimisations, where we emit the correct kind of sled.
The tail call sleds look like a mix between the function entry and
function exit sleds. Form-wise, the sled comes before the "jmp"
instruction that implements the tail call similar to how we do it for
the function entry sled. Functionally, because we know this is a tail
call, it behaves much like an exit sled -- i.e. at runtime we may use
the exit trampolines instead of a different kind of trampoline.
A follow-up change to recognise these sleds will be done in compiler-rt,
so that we can start intercepting these initially as exits, but also
have the option to have different log entries to more accurately reflect
that this is actually a tail call.
Reviewers: echristo, rSerge, majnemer
Subscribers: mehdi_amini, dberris, llvm-commits
Differential Revision: https://reviews.llvm.org/D23986
llvm-svn: 280334
This is for a situation where the encoding for a register may be
different depending on the specific operand. For some instructions,
we want to apply additional restrictions beyond the encoding's
constraints.
In AMDGPU some operands are VSrc_32, using the VS_32 pseudo register
class which accept VGPRs, SGPRs, or immediates in the encoding.
Some specific instructions with the same encoding operand do not want
to allow immediates or SGPRs, but the encoding format is different
in this case than a regular VGPR_32 operand.
This allows specifying the encoding should be treated the same
without introducing yet another dummy register class.
llvm-svn: 275929
Summary:
In this patch we implement the following parts of XRay:
- Supporting a function attribute named 'function-instrument' which currently only supports 'xray-always'. We should be able to use this attribute for other instrumentation approaches.
- Supporting a function attribute named 'xray-instruction-threshold' used to determine whether a function is instrumented with a minimum number of instructions (IR instruction counts).
- X86-specific nop sleds as described in the white paper.
- A machine function pass that adds the different instrumentation marker instructions at a very late stage.
- A way of identifying which return opcode is considered "normal" for each architecture.
There are some caveats here:
1) We don't handle PATCHABLE_RET in platforms other than x86_64 yet -- this means if IR used PATCHABLE_RET directly instead of a normal ret, instruction lowering for that platform might do the wrong thing. We think this should be handled at instruction selection time to by default be unpacked for platforms where XRay is not availble yet.
2) The generated section for X86 is different from what is described from the white paper for the sole reason that LLVM allows us to do this neatly. We're taking the opportunity to deviate from the white paper from this perspective to allow us to get richer information from the runtime library.
Reviewers: sanjoy, eugenis, kcc, pcc, echristo, rnk
Subscribers: niravd, majnemer, atrick, rnk, emaste, bmakam, mcrosier, mehdi_amini, llvm-commits
Differential Revision: http://reviews.llvm.org/D19904
llvm-svn: 275367
Summary:
This change allows to specify "DefaultMethod" for optional operand (IsOptional = 1) in AsmOperandClass that return default value for operand. This is used in convertToMCInst to set default values in MCInst.
Previously if you wanted to set default value for operand you had to create custom converter method. With this change it is possible to use standard converters even when optional operands presented.
Reviewers: tstellarAMD, ab, craig.topper
Subscribers: jyknight, dsanders, arsenm, nhaustov, llvm-commits
Differential Revision: http://reviews.llvm.org/D18242
llvm-svn: 268726
This operation may branch to the handler block and we do not want it
to happen anywhere within the basic block.
Moreover, by marking it "terminator and branch" the machine verifier
does not wrongly assume (because of AnalyzeBranch not knowing better)
the branch is analyzable. Indeed, the target was seeing only the
unconditional branch and not the faulting load op and thought it was
a simple unconditional block.
The machine verifier was complaining because of that and moreover,
other optimizations could have done wrong transformation!
In the process, simplify the representation of the handler block in
the faulting load op. Now, we directly reference the handler block
instead of using a label. This has the benefits of:
1. MC knows how to issue a label for a BB, so leave that to it.
2. Accessing the target BB from its label is painful, whereas it is
direct from a MBB operand.
Note: The 2 bytes offset in implicit-null-check.ll comes from the
fact the unconditional jumps are not removed anymore, as the whole
terminator sequence is not analyzable anymore.
Will fix it in a subsequence commit.
llvm-svn: 268327
Summary:
The `"patchable-function"` attribute can be used by an LLVM client to
influence LLVM's code generation in ways that makes the generated code
easily patchable at runtime (for instance, to redirect control).
Right now only one patchability scheme is supported,
`"prologue-short-redirect"`, but this can be expanded in the future.
Reviewers: joker.eph, rnk, echristo, dberris
Subscribers: joker.eph, echristo, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D19046
llvm-svn: 266715
They do have a def machine operand.
Fixing the definition is necessary for an upcoming patch.
Differential Revision: http://reviews.llvm.org/D18384
llvm-svn: 264607
This introduces a new flag that indicates that a specific instruction
will never be present when the MachineScheduler runs and therefore needs
no scheduling information.
This is in preparation for an upcoming commit which checks completeness
of a scheduling model when tablegen runs.
Differential Revision: http://reviews.llvm.org/D17728
llvm-svn: 262383
Summary:
This makes it possible to specify some operands as optional to the AsmMatcher.
Setting this field to true will prevent the AsmMatcher from emitting
'too few operands' errors when there are missing optional operands.
Reviewers: olista01, ab
Subscribers: nhaustov, arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D15755
llvm-svn: 259913
