Shadow stack solution introduces a new stack for return addresses only.
The HW has a Shadow Stack Pointer (SSP) that points to the next return address.
If we return to a different address, an exception is triggered.
The shadow stack is managed using a series of intrinsics that are introduced in this patch as well as the new register (SSP).
The intrinsics are mapped to new instruction set that implements CET mechanism.
The patch also includes initial infrastructure support for IBT.
For more information, please see the following:
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-enforcement-technology-preview.pdf
Differential Revision: https://reviews.llvm.org/D40223
Change-Id: I4daa1f27e88176be79a4ac3b4cd26a459e88fed4
llvm-svn: 318996
As a side effect, the .debug_line section will be dumped in physical
order, rather than in the order that compile units refer to their
associated portions of the .debug_line section. These are probably
always the same order anyway, and no tests noticed the difference.
Differential Revision: https://reviews.llvm.org/D39854
llvm-svn: 318839
In constructAbstractSubprogramScopeDIE there can be a potential mismatch
between `this` and the CU of ContextDIE when a scope is shared between
two DISubprograms belonging to a different CU. In that case, `this` is
the CU that was specified in the IR, but the CU of ContextDIE is that of
the first subprogram that was emitted. This patch fixes the mismatch by
looking up the CU of ContextDIE, and switching to use that.
This fixes PR35212 (https://bugs.llvm.org/show_bug.cgi?id=35212)
Patch by Philip Craig!
Differential revision: https://reviews.llvm.org/D39981
llvm-svn: 318289
Summary:
The associated debug value is updated when the virtual source register
of a copy is completely eliminated and replaced with a rematerialize
value in the defed register of the copy. As the debug value now is
associated with another register it also need to be moved, otherwise
the debug value isn't valid.
Reviewers: aprantl
Reviewed By: aprantl
Subscribers: MatzeB, llvm-commits, qcolombet
Differential Revision: https://reviews.llvm.org/D38024
llvm-svn: 317880
In Rust, a trait can be implemented for any type, and if a trait
object pointer is used for the type, then a virtual table will be
emitted for that trait/type combination.
We would like debuggers to be able to inspect trait objects, which
requires finding the concrete type associated with a given vtable.
This patch changes LLVM so that any type can be passed to
replaceVTableHolder. This allows the Rust compiler to emit the needed
debug info -- associating a vtable with the concrete type for which it
was emitted.
This is a DWARF extension: DWARF only specifies the meaning of
DW_AT_containing_type in one specific situation. This style of DWARF
extension is routine, though, and LLVM already has one such case for
DW_AT_containing_type.
Patch by Tom Tromey!
Differential Revision: https://reviews.llvm.org/D39503
llvm-svn: 317730
In 2010 a commit with no testcase and no further explanation
explicitly disabled the handling of inlined variables in
EmitFuncArgumentDbgValue(). I don't think there is a good reason for
this any more and re-enabling this adds debug locations for variables
associated with an LLVM function argument in functions that are
inlined into the first basic block. The only downside of doing this is
that we may insert a DBG_VALUE before the inlined scope, but (1) this
could be filtered out later, and (2) LiveDebugValues will not
propagate it into subsequent basic blocks if they don't dominate the
variable's lexical scope, so this seems like a small price to pay.
rdar://problem/26228128
llvm-svn: 317702
This preserves the debug info for the cast operation in the original location.
rdar://problem/33460652
Reapplied r317340 with the test moved into an ARM-specific directory.
llvm-svn: 317375
Change the map key from DIFile* to the absolute path string. Computing
the absolute path isn't expensive because we already have a map that
caches the full path keyed on DIFile*.
llvm-svn: 317041
Similar to how llvm::salvagDebugInfo hooks into InstCombine, this adds
a hook that can be invoked before an SDNode that is associated with an
SDDbgValue is erased to capture the effect of the deleted node in a
DIExpression.
The motivating example is an SDDebugValue attached to an ADD operation
that gets folded into a LOAD+OFFSET operation.
rdar://problem/32121503
llvm-svn: 316525
Summary:
This adds a set of new directives that describe 32-bit x86 prologues.
The directives are limited and do not expose the full complexity of
codeview FPO data. They are merely a convenience for the compiler to
generate more readable assembly so we don't need to generate tons of
labels in CodeGen. If our prologue emission changes in the future, we
can change the set of available directives to suit our needs. These are
modelled after the .seh_ directives, which use a different format that
interacts with exception handling.
The directives are:
.cv_fpo_proc _foo
.cv_fpo_pushreg ebp/ebx/etc
.cv_fpo_setframe ebp/esi/etc
.cv_fpo_stackalloc 200
.cv_fpo_endprologue
.cv_fpo_endproc
.cv_fpo_data _foo
I tried to follow the implementation of ARM EHABI CFI directives by
sinking most directives out of MCStreamer and into X86TargetStreamer.
This helps avoid polluting non-X86 code with WinCOFF specific logic.
I used cdb to confirm that this can show locals in parent CSRs in a few
cases, most importantly the one where we use ESI as a frame pointer,
i.e. the one in http://crbug.com/756153#c28
Once we have cdb integration in debuginfo-tests, we can add integration
tests there.
Reviewers: majnemer, hans
Subscribers: aemerson, mgorny, kristof.beyls, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D38776
llvm-svn: 315513
This patch adds printing for DW_AT_type DIEs like it is already the case
for DW_AT_specification DIEs. This is a rather naive approach and only a
start. We should have pretty printers for different languages.
Recommit after being reverted in r315299.
Differential revision: https://reviews.llvm.org/D36993
llvm-svn: 315316
This patch adds printing for DW_AT_type DIEs like it is already the case
for DW_AT_specification DIEs. This is a rather naive approach and only a
start. We should have pretty printers for different languages.
Differential revision: https://reviews.llvm.org/D36993
llvm-svn: 315297
This patch adds two new verifiers:
- It checks that the root DIE of a CU is actually a valid unit DIE.
(based on its tag)
- For DWARF5 which contains a unit type int he CU header, it checks that
this matches the type of the unit DIE.
Differential revision: https://reviews.llvm.org/D38453
llvm-svn: 315121
Summary:
When reinserting debug values after register allocation, make sure to
insert debug values after each redefinition of debug value register in
the slot index range. The reason for this is that DwarfDebug will end
the range of a debug variable when the physical reg is defined. For
instructions with e.g. tied operands this result in prematurely ended
debug range.
This resolves pr34545
Patch by Karl-Johan Karlsson and Bjorn Pettersson
Reviewers: rnk, aprantl
Reviewed By: rnk
Subscribers: bjope, llvm-commits
Differential Revision: https://reviews.llvm.org/D38229
llvm-svn: 314974
The list of register ids was previously written out in a couple of dirrent
places. This puts it in a .def file and also adds a few more registers (e.g.
the x87 regs) which should lead to more readable dumps, but I didn't include
the whole list since that seems unnecessary.
X86_MC::initLLVMToSEHAndCVRegMapping is pretty ugly, but at least it's not
relying on magic constants anymore. The TODO of using tablegen still stands.
Differential revision: https://reviews.llvm.org/D38480
llvm-svn: 314821
Summary:
This should fix a regression introduced by r313786, which switched from
MachineInstr::isIndirectDebugValue() to checking if operand 1 is an
immediate. I didn't have a test case for it until now.
A single UserValue, which approximates a user variable, may have many
DBG_VALUE instructions that disagree about whether the variable is in
memory or in a virtual register. This will become much more common once
we have llvm.dbg.addr, but you can construct such a test case manually
today with llvm.dbg.value.
Before this change, we would get two UserValues: one for direct and one
for indirect DBG_VALUE instructions describing the same variable. If we
build separate interval maps for direct and indirect locations, we will
end up accidentally coalescing identical DBG_VALUE intervals that need
to remain separate because they are broken up by intervals of the
opposite direct-ness.
Reviewers: aprantl
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37932
llvm-svn: 314819
Issues addressed since original review:
- Avoid bug in regalloc greedy/machine verifier when forwarding to use
in an instruction that re-defines the same virtual register.
- Fixed bug when forwarding to use in EarlyClobber instruction slot.
- Fixed incorrect forwarding to register definitions that showed up in
explicit_uses() iterator (e.g. in INLINEASM).
- Moved removal of dead instructions found by
LiveIntervals::shrinkToUses() outside of loop iterating over
instructions to avoid instructions being deleted while pointed to by
iterator.
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
doing so can break code that implicitly relies on the physical
register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
can break the machine verifier by creating LiveRanges that don't
end on a use (since the undef operand is not considered a use).
[MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
llvm-svn: 314729
This came out of a recent discussion on llvm-dev
(https://reviews.llvm.org/D38042). Currently the Verifier will strip
the debug info metadata from a module if it finds the dbeug info to be
malformed. This feature is very valuable since it allows us to improve
the Verifier by making it stricter without breaking bcompatibility,
but arguable the Verifier pass should not be modifying the IR. This
patch moves the stripping of broken debug info into AutoUpgrade
(UpgradeDebugInfo to be precise), which is a much better location for
this since the stripping of malformed (i.e., produced by older, buggy
versions of Clang) is a (harsh) form of AutoUpgrade.
This change is mostly NFC in nature, the one big difference is the
behavior when LLVM module passes are introducing malformed debug
info. Prior to this patch, a NoAsserts build would have printed a
warning and stripped the debug info, after this patch the Verifier
will report a fatal error. I believe this behavior is actually more
desirable anyway.
Differential Revision: https://reviews.llvm.org/D38184
llvm-svn: 314699
Summary:
A DBG_VALUE that is referring to a physical register is
valid up until the next def of the register, or the end
of the basic block that it belongs to.
LiveDebugVariables is computing live intervals (slot index
ranges) for DBG_VALUE instructions, before regalloc, in order
to be able to re-insert DBG_VALUE instructions again after
regalloc. When the DBG_VALUE is mapping a variable to a
physical register we do not need to compute the range. We
should simply re-insert the DBG_VALUE at the start position.
The problem that was found, resulting in this patch, was a
situation when the DBG_VALUE was the last real use of the
physical register. The computeIntervals/extendDef methods
extended the range to cover the whole basic block, even though
the physical register very well could be allocated to some
virtual register inside the basic block. So the extended
range could not be trusted.
This patch is a preparation for https://reviews.llvm.org/D38229,
where the goal is to insert DBG_VALUE after each new definition
of a variable, even if the virtual registers that the variable
was connected to has been coalesced into using the same physical
register (e.g. due to two address instructions). For more info
see https://bugs.llvm.org/show_bug.cgi?id=34545
Reviewers: aprantl, rnk, echristo
Reviewed By: aprantl
Subscribers: Ka-Ka, llvm-commits
Differential Revision: https://reviews.llvm.org/D38140
llvm-svn: 314414
Summary:
This code iterates the 'Orders' vector in parallel with the DbgValue
list, emitting all DBG_VALUEs that occurred between the last IR order
insertion point and the next insertion point. This assumes the
SDDbgValue list is sorted in IR order, which it usually is. However, it
is not sorted when a node with a debug value is replaced with another
one. When this happens, TransferDbgValues is called, and the new value
is added to the end of the list.
The problem can be solved by stably sorting the list by IR order.
Reviewers: aprantl, Ka-Ka
Reviewed By: aprantl
Subscribers: MatzeB, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D38197
llvm-svn: 314114
The code wasn't yelling at the user when there's a reference
from a DIGlobalVariableExpression. Thanks to Adrian for the
reduced testcase. Fixes PR34672.
llvm-svn: 314069
This patch adds dumping of line table instructions as well as the final
state at each specified pc value in verbose mode. This is essentially
the same as the default in Darwin's dwarfdump. Dumping the actual line
table opcodes can be particularly useful for something like debugging a
bad `.debug_line` section.
Differential revision: https://reviews.llvm.org/D37971
llvm-svn: 313910
The fix is to avoid invalidating our insertion point in
replaceDbgDeclare:
Builder.insertDeclare(NewAddress, DIVar, DIExpr, Loc, InsertBefore);
+ if (DII == InsertBefore)
+ InsertBefore = &*std::next(InsertBefore->getIterator());
DII->eraseFromParent();
I had to write a unit tests for this instead of a lit test because the
use list order matters in order to trigger the bug.
The reduced C test case for this was:
void useit(int*);
static inline void inlineme() {
int x[2];
useit(x);
}
void f() {
inlineme();
inlineme();
}
llvm-svn: 313905
.. as well as the two subsequent changes r313826 and r313875.
This leads to segfaults in combination with ASAN. Will forward repro
instructions to the original author (rnk).
llvm-svn: 313876
Summary:
There already was code that tried to remove the dbg.declare, but that code
was placed after we had called
I->replaceAllUsesWith(UndefValue::get(I->getType()));
on the alloca, so when we searched for the relevant dbg.declare, we
couldn't find it.
Now we do the search before we call RAUW so there is a chance to find it.
An existing testcase needed update due to this. Two dbg.declare with undef
were removed and then suddenly one of the two CHECKS failed.
Before this patch we got
call void @llvm.dbg.declare(metadata i24* undef, metadata !14, metadata !DIExpression(DW_OP_LLVM_fragment, 32, 24)), !dbg !15
call void @llvm.dbg.declare(metadata %struct.prog_src_register* undef, metadata !14, metadata !DIExpression()), !dbg !15
call void @llvm.dbg.value(metadata i32 0, metadata !14, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32)), !dbg !15
call void @llvm.dbg.value(metadata i32 0, metadata !14, metadata !DIExpression(DW_OP_LLVM_fragment, 32, 24)), !dbg !15
and with it we get
call void @llvm.dbg.value(metadata i32 0, metadata !14, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32)), !dbg !15
call void @llvm.dbg.value(metadata i32 0, metadata !14, metadata !DIExpression(DW_OP_LLVM_fragment, 32, 24)), !dbg !15
However, the CHECKs in the testcase checked things in a silly order, so
they only passed since they found things in the first dbg.declare. Now
we changed the order of the checks and the test passes.
Reviewers: rnk
Reviewed By: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37900
llvm-svn: 313875
Summary:
This implements the design discussed on llvm-dev for better tracking of
variables that live in memory through optimizations:
http://lists.llvm.org/pipermail/llvm-dev/2017-September/117222.html
This is tracked as PR34136
llvm.dbg.addr is intended to be produced and used in almost precisely
the same way as llvm.dbg.declare is today, with the exception that it is
control-dependent. That means that dbg.addr should always have a
position in the instruction stream, and it will allow passes that
optimize memory operations on local variables to insert llvm.dbg.value
calls to reflect deleted stores. See SourceLevelDebugging.rst for more
details.
The main drawback to generating DBG_VALUE machine instrs is that they
usually cause LLVM to emit a location list for DW_AT_location. The next
step will be to teach DwarfDebug.cpp how to recognize more DBG_VALUE
ranges as not needing a location list, and possibly start setting
DW_AT_start_offset for variables whose lifetimes begin mid-scope.
Reviewers: aprantl, dblaikie, probinson
Subscribers: eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D37768
llvm-svn: 313825
After r313775, it's easier to maintain a parallel BitVector of spilled
locations indexed by location number.
I wasn't able to build a good reduced test case for this iteration of
the bug, but I added a more direct assertion that spilled values must
use frame index locations. If this bug reappears, it won't only fire on
the NEON vector code that we detected it on, but on medium-sized
integer-only programs as well.
llvm-svn: 313786
Remove unneeded attributes from test/DebugInfo/Generic/imported-name-inlined.ll because it was causing failures on pure MIPS builds.
Patch by Miloš Stojanović!
Differential Revision: https://reviews.llvm.org/D38079
llvm-svn: 313762
This reverts r313640, originally r313400, one more time for essentially
the same issue. My BitVector of spilled location numbers isn't working
because we coalesce identical DBG_VALUE locations as we rewrite them,
invalidating the location numbers used to index the BitVector.
llvm-svn: 313679
I forgot to zero out the BitVector when reusing it between UserValues.
Later uses of the same location number for a different UserValue would
falsely indicate that they were spilled. Usually this would lead to
incorrect debug info, but in some cases they would indicate something
nonsensical like a memory location based on a vector register (Q8 on
ARM).
llvm-svn: 313640
This caused asserts in Chromium. See http://crbug.com/766261
> Summary:
> This comes up in optimized debug info for C++ programs that pass and
> return objects indirectly by address. In these programs,
> llvm.dbg.declare survives optimization, which causes us to emit indirect
> DBG_VALUE instructions. The fast register allocator knows to insert
> DW_OP_deref when spilling indirect DBG_VALUE instructions, but the
> LiveDebugVariables did not until this change.
>
> This fixes part of PR34513. I need to look into why this doesn't work at
> -O0 and I'll send follow up patches to handle that.
>
> Reviewers: aprantl, dblaikie, probinson
>
> Subscribers: qcolombet, hiraditya, llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D37911
llvm-svn: 313589
This patch makes the `.eh_frame` extension an alias for `.debug_frame`.
Up till now it was only possible to dump the section using objdump, but
not with dwarfdump. Since the two are essentially interchangeable, we
dump whichever of the two is present.
As a workaround, this patch also adds parsing for 3 currently
unimplemented CFA instructions: `DW_CFA_def_cfa_expression`,
`DW_CFA_expression`, and `DW_CFA_val_expression`. Because I lack the
required knowledge, I just parse the fields without actually creating
the instructions.
Finally, this also fixes the typo in the `.debug_frame` section name
which incorrectly contained a trailing `s`.
Differential revision: https://reviews.llvm.org/D37852
llvm-svn: 313530
This reverts commit 6389e7aa724ea7671d096f4770f016c3d86b0d54.
There is a bug in this implementation where the string value of the
checksum is outputted, instead of the actual hex bytes. Therefore the
checksum is incorrect, and this prevent pdbs from being loaded by visual
studio. Revert this until the checksum is emitted correctly.
llvm-svn: 313431
Summary:
This comes up in optimized debug info for C++ programs that pass and
return objects indirectly by address. In these programs,
llvm.dbg.declare survives optimization, which causes us to emit indirect
DBG_VALUE instructions. The fast register allocator knows to insert
DW_OP_deref when spilling indirect DBG_VALUE instructions, but the
LiveDebugVariables did not until this change.
This fixes part of PR34513. I need to look into why this doesn't work at
-O0 and I'll send follow up patches to handle that.
Reviewers: aprantl, dblaikie, probinson
Subscribers: qcolombet, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D37911
llvm-svn: 313400
Summary:
Fixes PR34513.
Indirect DBG_VALUEs typically come from dbg.declares of non-trivially
copyable C++ objects that must be passed by address. We were already
handling the case where the virtual register gets allocated to a
physical register and is later spilled. That's what usually happens for
normal parameters that aren't NRVO variables: they usually appear in
physical register parameters, and are spilled later in the function,
which would correctly add deref.
NRVO variables are different because the dbg.declare can come much later
after earlier instructions cause the incoming virtual register to be
spilled.
Also, clean up this code. We only need to look at the first operand of a
DBG_VALUE, which eliminates the operand loop.
Reviewers: aprantl, dblaikie, probinson
Subscribers: MatzeB, qcolombet, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37929
llvm-svn: 313399
Summary:
The checksums had already been placed in the IR, this patch allows
MCCodeView to actually write it out to an MCStreamer.
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D37157
llvm-svn: 313374
This breaks bootstrap builds, and is actually unnecessary. Tested
locally and it seems we can remove -debug-comile just fine.
Follow-up to D37791.
llvm-svn: 313238
Summary:
XRay had been assuming that the previous section is the "text" section
of the function when lowering the instrumentation map. Unfortunately
this is not a safe assumption, because we may be coming from lowering
debug type information for the function being lowered.
This fixes an issue with combining -gsplit-dwarf, -generate-type-units,
-debug-compile and -fxray-instrument for sole member functions. When the
split dwarf section is stripped, we're left with references from the
xray_instr_map to the debug section. The change now uses the function's
symbol instead of the previous section's start symbol.
We found the bug while attempting to strip the split debug sections off
an XRay-instrumented object file, which had a peculiar edge-case for
single-function classes where the single function is being lowered.
Because XRay had assocaited the instrumentation map for a function to
the debug types section instead of the function's section, the objcopy
call will fail due to the misplaced reference from the xray_instr_map
section.
Reviewers: pcc, dblaikie, echristo
Subscribers: llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D37791
llvm-svn: 313233
Since users typically don't really care about the .dwo / non.dwo
distinction, this patch makes it so dwarfdump --debug-<info,...> dumps
.debug_info and (if available) also .debug_info.dwo. This simplifies
the command line interface (I've removed all dwo-specific dump
options) and makes the tool friendlier to use.
Differential Revision: https://reviews.llvm.org/D37771
llvm-svn: 313207
Previously we used a size of '1' for VLAs because we weren't sure what
MSVC did. However, MSVC does support declaring an array without a size,
for which it emits an array type with a size of zero. Clang emits the
same DI metadata for VLAs and arrays without bound, so we would describe
arrays without bound as having one element. This lead to Microsoft
debuggers only printing a single element.
Emitting a size of zero appears to cause these debuggers to search the
symbol information to find a definition of the variable with accurate
array bounds.
Fixes http://crbug.com/763580
llvm-svn: 313203
Summary:
To improve CodeView quality for static member functions, we need to make the
static explicit. In addition to a small change in LLVM's CodeViewDebug to
return the appropriate MethodKind, this requires a small change in Clang to
note the staticness in the debug info metadata.
Subscribers: aprantl, hiraditya
Differential Revision: https://reviews.llvm.org/D37715
llvm-svn: 313192
This flag is unnecessary for testing because we can get the coverage
we need by adjusting CU attributes.
Differential Revision: https://reviews.llvm.org/D37725
llvm-svn: 313079
A prologue-end line record is emitted with an incorrect associated address,
which causes a debugger to show the beginning of function body to be inside
the prologue.
Patch written by Carlos Alberto Enciso.
Differential Revision: https://reviews.llvm.org/D37625
llvm-svn: 313047
As discussed on llvm-dev in
http://lists.llvm.org/pipermail/llvm-dev/2017-September/117301.html
this changes the command line interface of llvm-dwarfdump to match the
one used by the dwarfdump utility shipping on macOS. In addition to
being shorter to type this format also has the advantage of allowing
more than one section to be specified at the same time.
In a nutshell, with this change
$ llvm-dwarfdump --debug-dump=info
$ llvm-dwarfdump --debug-dump=apple-objc
becomes
$ dwarfdump --debug-info --apple-objc
Differential Revision: https://reviews.llvm.org/D37714
llvm-svn: 312970
S_UDT records are basically the "bridge" between the debugger's
expression evaluator and the type information. If you type
(Foo*)nullptr into the watch window, the debugger looks for an
S_UDT record named Foo. If it can find one, it displays your type.
Otherwise you get an error.
We have always understood this to mean that if you have code like
this:
struct A {
int X;
};
struct B {
typedef A AT;
AT Member;
};
that you will get 3 S_UDT records. "A", "B", and "B::AT". Because
if you were to type (B::AT*)nullptr into the debugger, it would
need to find an S_UDT record named "B::AT".
But "B::AT" is actually the S_UDT record that would be generated
if B were a namespace, not a struct. So the debugger needs to be
able to distinguish this case. So what it does is:
1. Look for an S_UDT named "B::AT". If it finds one, it knows
that AT is in a namespace.
2. If it doesn't find one, split at the scope resolution operator,
and look for an S_UDT named B. If it finds one, look up the type
for B, and then look for AT as one of its members.
With this algorithm, S_UDT records for nested typedefs are not just
unnecessary, but actually wrong!
The results of implementing this in clang are dramatic. It cuts
our /DEBUG:FASTLINK PDB sizes by more than 50%, and we go from
being ~20% larger than MSVC PDBs on average, to ~40% smaller.
It also slightly speeds up link time. We get about 10% faster
links than without this patch.
Differential Revision: https://reviews.llvm.org/D37410
llvm-svn: 312583
It solves issue of wrong section index evaluating for ranges when
base address is used.
Based on David Blaikie's patch D36097.
Differential revision: https://reviews.llvm.org/D37214
llvm-svn: 312477
Debug information can be, and was, corrupted when the runtime
remainder loop was fully unrolled. This is because a !null node can
be created instead of a unique one describing the loop. In this case,
the original node gets incorrectly updated with the NewLoopID
metadata.
In the case when the remainder loop is going to be quickly fully
unrolled, there isn't the need to add loop metadata for it anyway.
Differential Revision: https://reviews.llvm.org/D37338
llvm-svn: 312471
We have llvm-readobj for dumping CodeView from object files, and
llvm-pdbutil has always been more focused on PDB. However,
llvm-pdbutil has a lot of useful options for summarizing debug
information in aggregate and presenting high level statistical
views. Furthermore, it's arguably better as a testing tool since
we don't have to write tests to conform to a state-machine like
structure where you match multiple lines in succession, each
depending on a previous match. llvm-pdbutil dumps much more
concisely, so it's possible to use single-line matches in many
cases where as with readobj tests you have to use multi-line
matches with an implicit state machine.
Because of this, I'm adding object file support to llvm-pdbutil.
In fact, this mirrors the cvdump tool from Microsoft, which also
supports both object files and pdb files. In the future we could
perhaps rename this tool llvm-cvutil.
In the meantime, this allows us to deep dive into object files
the same way we already can with PDB files.
llvm-svn: 312358
Issues addressed since original review:
- Moved removal of dead instructions found by
LiveIntervals::shrinkToUses() outside of loop iterating over
instructions to avoid instructions being deleted while pointed to by
iterator.
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
doing so can break code that implicitly relies on the physical
register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
can break the machine verifier by creating LiveRanges that don't
end on a use (since the undef operand is not considered a use).
[MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
llvm-svn: 312328
This adds a new command line option, -udt-stats, which breaks
down the stats of S_UDT records. These are one of the biggest
contributors to the size of /DEBUG:FASTLINK PDBs, so they need
some additional tools to be able to analyze their usage. This
option will dig into each S_UDT record and determine what kind
of record it points to, and then break down the statistics by
the target type. The goal here is to identify how our object
files differ from MSVC object files in S_UDT records, so that
we can output fewer of them and reach size parity.
llvm-svn: 312276
It caused PR34387: Assertion failed: (RegNo < NumRegs && "Attempting to access record for invalid register number!")
> Issues identified by buildbots addressed since original review:
> - Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
> - The pass no longer forwards COPYs to physical register uses, since
> doing so can break code that implicitly relies on the physical
> register number of the use.
> - The pass no longer forwards COPYs to undef uses, since doing so
> can break the machine verifier by creating LiveRanges that don't
> end on a use (since the undef operand is not considered a use).
>
> [MachineCopyPropagation] Extend pass to do COPY source forwarding
>
> This change extends MachineCopyPropagation to do COPY source forwarding.
>
> This change also extends the MachineCopyPropagation pass to be able to
> be run during register allocation, after physical registers have been
> assigned, but before the virtual registers have been re-written, which
> allows it to remove virtual register COPY LiveIntervals that become dead
> through the forwarding of all of their uses.
llvm-svn: 312178
Previously we would just describe the first register and then call it
quits. This patch emits fragment expressions for each register.
<rdar://problem/34075307>
llvm-svn: 312169
Issues identified by buildbots addressed since original review:
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
doing so can break code that implicitly relies on the physical
register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
can break the machine verifier by creating LiveRanges that don't
end on a use (since the undef operand is not considered a use).
[MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.
This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.
llvm-svn: 312154
This change simplifies code that has to deal with
DIGlobalVariableExpression and mirrors how we treat DIExpressions in
debug info intrinsics. Before this change there were two ways of
representing empty expressions on globals, a nullptr and an empty
!DIExpression().
If someone needs to upgrade out-of-tree testcases:
perl -pi -e 's/(!DIGlobalVariableExpression\(var: ![0-9]*)\)/\1, expr: !DIExpression())/g' <MYTEST.ll>
will catch 95%.
llvm-svn: 312144
Oren Ben Simhon