Without the synthesized reference to a symbol in the xray_instr_map,
linker section garbage collection will helpfully remove the whole
xray_instr_map section from the final executable (or archive). This will
cause the runtime to not be able to identify the sleds and hot-patch the
calls/jumps into the runtime trampolines.
This change adds a reference from the text section at the end of the
function to keep around the associated xray_instr_map section as well.
We also make sure that we catch this reference in the test.
Reviewers: chandlerc, echristo, majnemer, mehdi_amini
Subscribers: mehdi_amini, llvm-commits, dberris
Differential Revision: https://reviews.llvm.org/D23398
llvm-svn: 279204
This makes a trivial change in the emission of the per-function XRay
tables, and makes sure that the xray_instr_map section does show up in
the object file.
llvm-svn: 278113
This should ensure that we can atomically write two bytes (on top of the
retq and the one past it) and have those two bytes not straddle cache
lines.
We also move the label past the alignment instruction so that we can refer
to the actual first instruction, as opposed to potential padding before the
aligned instruction.
Update the tests to allow us to reflect the new order of assembly.
Reviewers: rSerge, echristo, majnemer
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23101
llvm-svn: 277701
Summary:
We also add a test to show what currently happens when we create a
section per function and emit an xray_instr_map. This illustrates the
relationship (or lack thereof) between the per-function section and the
xray_instr_map section.
We also change the code generation slightly so that we don't always
create group sections, but rather only do so if a function where the
table is associated with is in a group.
Also in this change:
- Remove the "merge" flag on the xray_instr_map section.
- Test that we're generating the right table for comdat and non-comdat functions.
Reviewers: echristo, majnemer
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23104
llvm-svn: 277580
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
Avoid implicit conversions from MachineInstrBundleIterator to
MachineInstr*, mainly by preferring MachineInstr& over MachineInstr* and
using range-based for loops.
llvm-svn: 275149
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
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
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
This patch adds support for decoding XOP VPPERM instruction when it represents a basic shuffle.
The mask decoding required the existing MCInstrLowering code to be updated to support binary shuffles - the implementation now matches what is done in X86InstrComments.cpp.
Differential Revision: http://reviews.llvm.org/D18441
llvm-svn: 265874
I missed == and != when I removed implicit conversions between iterators
and pointers in r252380 since they were defined outside ilist_iterator.
Since they depend on getNodePtrUnchecked(), they indirectly rely on UB.
This commit removes all uses of these operators. (I'll delete the
operators themselves in a separate commit so that it can be easily
reverted if necessary.)
There should be NFC here.
llvm-svn: 261498
We only want to emit CFI adjustments when actually using DWARF.
This fixes PR25828.
Differential Revision: http://reviews.llvm.org/D15522
llvm-svn: 255664
This removes the code path that generate "synchronous" (only correct at call site) CFA.
We will probably want to re-introduce it once we are capable of emitting different
.eh_frame and .debug_frame sections.
Differential Revision: http://reviews.llvm.org/D14948
llvm-svn: 254874
Almost all these changes are conditioned and only apply to the new
x86-64 f128 type configuration, which will be enabled in a follow up
patch. They are required together to make new f128 work. If there is
any error, we should fix or revert them as a whole.
These changes should have no impact to current configurations.
* Relax type legalization checks to accept new f128 type configuration,
whose TypeAction is TypeSoftenFloat, not TypeLegal, but also has
TLI.isTypeLegal true.
* Relax GetSoftenedFloat to return in some cases f128 type SDValue,
which is TLI.isTypeLegal but not "softened" to i128 node.
* Allow customized FABS, FNEG, FCOPYSIGN on new f128 type configuration,
to generate optimized bitwise operators for libm functions.
* Enhance related Lower* functions to handle f128 type.
* Enhance DAGTypeLegalizer::run, SoftenFloatResult, and related functions
to keep new f128 type in register, and convert f128 operators to library calls.
* Fix Combiner, Emitter, Legalizer routines that did not handle f128 type.
* Add ExpandConstant to handle i128 constants, ExpandNode
to handle ISD::Constant node.
* Add one more parameter to getCommonSubClass and firstCommonClass,
to guarantee that returned common sub class will contain the specified
simple value type.
This extra parameter is used by EmitCopyFromReg in InstrEmitter.cpp.
* Fix infinite loop in getTypeLegalizationCost when f128 is the value type.
* Fix printOperand to handle null operand.
* Enhance ISD::BITCAST node to handle f128 constant.
* Expand new f128 type for BR_CC, SELECT_CC, SELECT, SETCC nodes.
* Enhance X86AsmPrinter to emit f128 values in comments.
Differential Revision: http://reviews.llvm.org/D15134
llvm-svn: 254653
This fixes the issue of wrong CFA calculation in the following case:
0x08048400 <+0>: push %ebx
0x08048401 <+1>: sub $0x8,%esp
0x08048404 <+4>: **call 0x8048409 <test+9>**
0x08048409 <+9>: **pop %eax**
0x0804840a <+10>: add $0x1bf7,%eax
0x08048410 <+16>: mov %eax,%ebx
0x08048412 <+18>: call 0x80483f0 <bar>
0x08048417 <+23>: add $0x8,%esp
0x0804841a <+26>: pop %ebx
0x0804841b <+27>: ret
The highlighted instructions are a product of movpc instruction. The call
instruction changes the stack pointer, and pop instruction restores its
value. However, the rule for computing CFA is not updated and is wrong on
the pop instruction. So, e.g. backtrace in gdb does not work when on the pop
instruction. This adds cfi instructions for both call and pop instructions.
cfi_adjust_cfa_offset** instruction is used with the appropriate offset for
setting the rules to calculate CFA correctly.
Patch by Violeta Vukobrat.
Differential Revision: http://reviews.llvm.org/D14021
llvm-svn: 252176
Catchret transfers control from a catch funclet to an earlier funclet.
However, it is not completely clear which funclet the catchret target is
part of. Make this clear by stapling the catchret target's funclet
membership onto the CATCHRET SDAG node.
llvm-svn: 249052
This makes catchret look more like a branch, and less like a weird use
of BlockAddress. It also lets us get away from
llvm.x86.seh.restoreframe, which relies on the old parentfpoffset label
arithmetic.
llvm-svn: 247936
Summary:
32-bit funclets have short prologues that allocate enough stack for the
largest call in the whole function. The runtime saves CSRs for the
funclet. It doesn't restore CSRs after we finally transfer control back
to the parent funciton via a CATCHRET, but that's a separate issue.
32-bit funclets also have to adjust the incoming EBP value, which is
what llvm.x86.seh.recoverframe does in the old model.
64-bit funclets need to spill CSRs as normal. For simplicity, this just
spills the same set of CSRs as the parent function, rather than trying
to compute different CSR sets for the parent function and each funclet.
64-bit funclets also allocate enough stack space for the largest
outgoing call frame, like 32-bit.
Reviewers: majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12546
llvm-svn: 247092
We can now run 32-bit programs with empty catch bodies. The next step
is to change PEI so that we get funclet prologues and epilogues.
llvm-svn: 246235
After r244870 flush() will only compare two null pointers and return,
doing nothing but wasting run time. The call is not required any more
as the stream and its SmallString are always in sync.
Thanks to David Blaikie for reviewing.
llvm-svn: 244928
Summary: PR24191 finds that the expected memory-register operations aren't generated when relaxed { load ; modify ; store } is used. This is similar to PR17281 which was addressed in D4796, but only for memory-immediate operations (and for memory orderings up to acquire and release). This patch also handles some floating-point operations.
Reviewers: reames, kcc, dvyukov, nadav, morisset, chandlerc, t.p.northover, pete
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11382
llvm-svn: 244128
Summary:
This change generalizes the implicit null checks pass to work with
instructions that don't have any explicit register defs. This lets us
use X86's `cmp` against memory as faulting load instructions.
Reviewers: reames, JosephTremoulet
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11286
llvm-svn: 242703
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
Before this we were producing a TargetExternalSymbol from a MCSymbol.
That meant extracting the symbol name and fetching the symbol again
down the pipeline.
This patch adds a DAG.getMCSymbol that lets the MCSymbol pass unchanged on the
DAG.
Doing so removes the need for MO_NOPREFIX and fixes the root cause of pr23900,
allowing r240130 to be committed again.
llvm-svn: 240300
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
Summary:
This instruction encodes a loading operation that may fault, and a label
to branch to if the load page-faults. The locations of potentially
faulting loads and their "handler" destinations are recorded in a
FaultMap section, meant to be consumed by LLVM's clients.
Nothing generates FAULTING_LOAD_OP instructions yet, but they will be
used in a future change.
The documentation (FaultMaps.rst) needs improvement and I will update
this diff with a more expanded version shortly.
Depends on D10196
Reviewers: rnk, reames, AndyAyers, ab, atrick, pgavlin
Reviewed By: atrick, pgavlin
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10197
llvm-svn: 239740
This reverts commit r239437.
This broke clang-cl self-hosts. We'd end up calling the __imp_ symbol
directly instead of using it to do an indirect function call.
llvm-svn: 239502
Summary:
This change adds two new parameters to the statepoint intrinsic, `i64 id`
and `i32 num_patch_bytes`. `id` gets propagated to the ID field
in the generated StackMap section. If the `num_patch_bytes` is
non-zero then the statepoint is lowered to `num_patch_bytes` bytes of
nops instead of a call (the spill and reload code remains unchanged).
A non-zero `num_patch_bytes` is useful in situations where a language
runtime requires complete control over how a call is lowered.
This change brings statepoints one step closer to patchpoints. With
some additional work (that is not part of this patch) it should be
possible to get rid of `TargetOpcode::STATEPOINT` altogether.
PlaceSafepoints generates `statepoint` wrappers with `id` set to
`0xABCDEF00` (the old default value for the ID reported in the stackmap)
and `num_patch_bytes` set to `0`. This can be made more sophisticated
later.
Reviewers: reames, pgavlin, swaroop.sridhar, AndyAyers
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9546
llvm-svn: 237214
x86 Windows uses the '_' prefix for all global symbols, and this was
mistakenly being applied to frameescape labels, which are not externally
visible global symbols. They use the private global prefix 'L'.
The *right* way to fix this is probably to stop masquerading this label
as an ExternalSymbol and create a new SDNode type. These labels are not
"external", and we know they will be resolved by assembly time. Having a
custom SDNode type would allow us to do better X86 address mode
matching, so it's probably worth doing eventually.
llvm-svn: 236123
X86 backend.
The code generated for symbolic targets is identical to the code generated for
constant targets, except that a relocation is emitted to fix up the actual
target address at link-time. This allows IR and object files containing
patchpoints to be cached across JIT-invocations where the target address may
change.
llvm-svn: 235483
MSDN's x64 software conventions page says that this is one of the fixed
list of legal epilogues:
https://msdn.microsoft.com/en-us/library/tawsa7cb.aspx
Presumably this is how the unwinder distinguishes epilogue jumps from
in-function control flow.
Also normalize the way we place "## TAILCALL" comments on such jumps.
llvm-svn: 227611
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
It's possible for the constant pool entry for the shuffle mask to come
from a completely different operation. This occurs when Constants have
the same bit pattern but have different types.
Make DecodePSHUFBMask tolerant of types which, after a bitcast, are
appropriately sized vector types.
This fixes PR22188.
llvm-svn: 225597
Overall this seems simpler. It reduces duplication of patterns between both modes and it simplifies the memory folding/unfolding tables as they don't need to create fake instructions just to keep track of 64-bitness.
llvm-svn: 225252
The assembler backend will relax to the long form if necessary. This removes a swap from long form to short form in the MCInstLowering code. Selecting the long form used to be required by the old JIT.
llvm-svn: 225242
This is the second patch in a small series. This patch contains the MachineInstruction and x86-64 backend pieces required to lower Statepoints. It does not include the code to actually generate the STATEPOINT machine instruction and as a result, the entire patch is currently dead code. I will be submitting the SelectionDAG parts within the next 24-48 hours. Since those pieces are by far the most complicated, I wanted to minimize the size of that patch. That patch will include the tests which exercise the functionality in this patch. The entire series can be seen as one combined whole in http://reviews.llvm.org/D5683.
The STATEPOINT psuedo node is generated after all gc values are explicitly spilled to stack slots. The purpose of this node is to wrap an actual call instruction while recording the spill locations of the meta arguments used for garbage collection and other purposes. The STATEPOINT is modeled as modifing all of those locations to prevent backend optimizations from forwarding the value from before the STATEPOINT to after the STATEPOINT. (Doing so would break relocation semantics for collectors which wish to relocate roots.)
The implementation of STATEPOINT is closely modeled on PATCHPOINT. Eventually, much of the code in this patch will be removed. The long term plan is to merge the functionality provided by statepoints and patchpoints. Merging their implementations in the backend is likely to be a good starting point.
Reviewed by: atrick, ributzka
llvm-svn: 223085
For a call to not return in to the stackmap shadow, the shadow must end with the call.
To do this, we must insert any required nops *before* the call, and not after it.
llvm-svn: 220728
To avoid emitting too many nops, a stackmap shadow can include emitted instructions in the shadow, but these must not include branch targets.
A return from a call should count as a branch target as patching over the instructions after the call would lead to incorrect behaviour for threads currently making that call, when they return.
llvm-svn: 220710
Every target we support has support for assembly that looks like
a = b - c
.long a
What is special about MachO is that the above combination suppresses the
production of a relocation.
With this change we avoid producing the intermediary labels when they don't
add any value.
llvm-svn: 220256
lowering.
This also implements the fancy blend lowering for v16i16 using AVX2 and
teaches the X86 backend to print shuffle masks for 256-bit PSHUFB
and PBLENDW instructions. It also makes the mask decoding correct for
PBLENDW instructions. The yaks, they are legion.
Tests are updated accordingly. There are some missing tests for the
VBLENDVB lowering, but I'll add those in a follow-up as this commit has
accumulated enough cruft already.
llvm-svn: 218430
pool data being loaded into a vector register.
The comments take the form of:
# ymm0 = [a,b,c,d,...]
# xmm1 = <x,y,z...>
The []s are used for generic sequential data and the <>s are used for
specifically ConstantVector loads. Undef elements are printed as the
letter 'u', integers in decimal, and floating point values as floating
point values. Suggestions on improving the formatting or other aspects
of the display are very welcome.
My primary use case for this is to be able to FileCheck test masks
passed to vector shuffle instructions in-register. It isn't fantastic
for that (no decoding special zeroing semantics or other tricks), but it
at least puts the mask onto an instruction line that could reasonably be
checked. I've updated many of the new vector shuffle lowering tests to
leverage this in their test cases so that we're actually checking the
shuffle masks remain as expected.
Before implementing this, I tried a *bunch* of different approaches.
I looked into teaching the MCInstLower code to scan up the basic block
and find a definition of a register used in a shuffle instruction and
then decode that, but this seems incredibly brittle and complex.
I talked to Hal a lot about the "right" way to do this: attach the raw
shuffle mask to the instruction itself in some form of unencoded
operands, and then use that to emit the comments. I still think that's
the optimal solution here, but it proved to be beyond what I'm up for
here. In particular, it seems likely best done by completing the
plumbing of metadata through these layers and attaching the shuffle mask
in metadata which could have fully automatic dropping when encoding an
actual instruction.
llvm-svn: 218377
attempt didn't work out so well. It looks like it will be much better
for introducing extra logic to find a shuffle mask if the finding logic
is totally separate. This also makes it easy to sink the opcode logic
completely out of the routine so we don't re-dispatch across it.
Still no functionality changed.
llvm-svn: 218363
asm. This can be somewhat expensive and there is no reason to do it
outside of tests or debugging sessions. I'm also likely to make it
significantly more expensive to support more styles of shuffles.
llvm-svn: 218362
from the MachineInstr into the caller which is already doing a switch
over the instruction.
This will make it more clear how to compute different operands to feed
the comment selection for example.
Also, in a drive-by-fix, don't append an empty comment string (which is
a no-op ultimately).
No functionality changed.
llvm-svn: 218361
vector shuffles.
This is just the beginning by hoisting it into its own function and
making use of early exit to dramatically simplify the flow of the
function. I'm going to be incrementally refactoring this until it is
a bit less magical how this applies to other instructions, and I can
teach it how to dig a shuffle mask out of a register. Then I plan to
hook it up to VPERMD so we get our mask comments for it.
No functionality changed yet.
llvm-svn: 218357
undef in the shuffle mask. This shows up when we're printing comments
during lowering and we still have an IR-level constant hanging around
that models undef.
A nice consequence of this is *much* prettier test cases where the undef
lanes actually show up as undef rather than as a particular set of
values. This also allows us to print shuffle comments in cases that use
undef such as the recently added variable VPERMILPS lowering. Now those
test cases have nice shuffle comments attached with their details.
The shuffle lowering for PSHUFB has been augmented to use undef, and the
shuffle combining has been augmented to comprehend it.
llvm-svn: 218301
trick that I missed.
VPERMILPS has a non-immediate memory operand mode that allows it to do
asymetric shuffles in the two 128-bit lanes. Use this rather than two
shuffles and a blend.
However, it turns out the variable shuffle path to VPERMILPS (and
VPERMILPD, although that one offers no functional differenc from the
immediate operand other than variability) wasn't even plumbed through
codegen. Do such plumbing so that we can reasonably emit
a variable-masked VPERMILP instruction. Also plumb basic comment parsing
and printing through so that the tests are reasonable.
There are still a few tests which don't show the shuffle pattern. These
are tests with undef lanes. I'll teach the shuffle decoding and printing
to handle undef mask entries in a follow-up. I've looked at the masks
and they seem reasonable.
llvm-svn: 218300
The only valid lowering of atomic stores in the X86 backend was mov from
register to memory. As a result, storing an immediate required a useless copy
of the immediate in a register. Now these can be compiled as a simple mov.
Similarily, adding/and-ing/or-ing/xor-ing an
immediate to an atomic location (but through an atomic_store/atomic_load,
not a fetch_whatever intrinsic) can now make use of an 'add $imm, x(%rip)'
instead of using a register. And the same applies to inc/dec.
This second point matches the first issue identified in
http://llvm.org/bugs/show_bug.cgi?id=17281
llvm-svn: 216980
When the last instruction prior to a function epilogue is a call, we
need to emit a nop so that the return address is not in the epilogue IP
range. This is consistent with MSVC's behavior, and may be a workaround
for a bug in the Win64 unwinder.
Differential Revision: http://reviews.llvm.org/D4751
Patch by Vadim Chugunov!
llvm-svn: 214775
instructions which happen to have a constant mask.
Currently, this only handles a very narrow set of cases, but those
happen to be the cases that I care about for testing shuffles sanely.
This is a bit trickier than other shuffle instructions because we're
decoding constants out of the constant pool. The current MC layer makes
it completely impossible to inspect a constant pool entry, so we have to
do it at the MI level and attach the comment to the streamer on its way
out. So no joy for disassembling, but it does make test cases and asm
dumps *much* nicer.
Sorry for no test cases, but it didn't really seem that valuable to go
trolling through existing old test cases and updating them. I'll have
lots of testing of this in the upcoming patch for SSSE3 emission in the
new vector shuffle lowering code paths.
llvm-svn: 213986
This patch minimizes the number of nops that must be emitted on X86 to satisfy
stackmap shadow constraints.
To minimize the number of nops inserted, the X86AsmPrinter now records the
size of the most recent stackmap's shadow in the StackMapShadowTracker class,
and tracks the number of instruction bytes emitted since the that stackmap
instruction was encountered. Padding is emitted (if it is required at all)
immediately before the next stackmap/patchpoint instruction, or at the end of
the basic block.
This optimization should reduce code-size and improve performance for people
using the llvm stackmap intrinsic on X86.
<rdar://problem/14959522>
llvm-svn: 213892
Rename the routines to reflect the reality that they are more related to call
frame information than to Win64 EH. Although EH is implemented in an intertwined
manner by augmenting with an exception handler and an associated parameter, the
majority of these routines emit information required to unwind the frames. This
also helps identify that these routines are generic for most windows platforms
(they apply equally to nearly all architectures except x86) although the
encoding of the information is architecture dependent.
Unwinding data is emitted via EmitWinCFI* and exception handling information via
EmitWinEH*.
llvm-svn: 211994
--
This patch enables LLVM to emit Win64-native unwind info rather than
DWARF CFI. It handles all corner cases (I hope), including stack
realignment.
Because the unwind info is not flexible enough to describe stack frames
with a gap of unknown size in the middle, such as the one caused by
stack realignment, I modified register spilling code to place all spills
into the fixed frame slots, so that they can be accessed relative to the
frame pointer.
Patch by Vadim Chugunov!
Reviewed By: rnk
Differential Revision: http://reviews.llvm.org/D4081
llvm-svn: 211691
This patch enables LLVM to emit Win64-native unwind info rather than
DWARF CFI. It handles all corner cases (I hope), including stack
realignment.
Because the unwind info is not flexible enough to describe stack frames
with a gap of unknown size in the middle, such as the one caused by
stack realignment, I modified register spilling code to place all spills
into the fixed frame slots, so that they can be accessed relative to the
frame pointer.
Patch by Vadim Chugunov!
Reviewed By: rnk
Differential Revision: http://reviews.llvm.org/D4081
llvm-svn: 211399
Dean Michael Berris