in debugger mode) to accept @import declarations
and pass them to the debugger.
In the preprocessor, accept import declarations
if the debugger is enabled, but don't actually
load the module, just pass the import path on to
the preprocessor callbacks.
In the Objective-C parser, if it sees an import
declaration in statement context (usual for LLDB),
ignore it and return a NullStmt.
llvm-svn: 223855
The issue with Thumb IT (if/then) instructions is the IT instruction preceeds up to four instructions that are made conditional. If a breakpoint is placed on one of the conditional instructions, the instruction either needs to match the thumb opcode size (2 or 4 bytes) or a BKPT instruction needs to be used as these are always unconditional (even in a IT instruction). If BKPT instructions are used, then we might end up stopping on an instruction that won't get executed. So if we do stop at a BKPT instruction, we need to continue if the condition is not true.
When using the BKPT isntructions are easy in that you don't need to detect the size of the breakpoint that needs to be used when setting a breakpoint even in a thumb IT instruction. The bad part is you will now always stop at the opcode location and let LLDB determine if it should auto-continue. If the BKPT instruction is used, the BKPT that is used for ARM code should be something that also triggers the BKPT instruction in Thumb in case you set a breakpoint in the middle of code and the code is actually Thumb code. A value of 0xE120BE70 will work since the lower 16 bits being 0xBE70 happens to be a Thumb BKPT instruction.
The alternative is to use trap or illegal instructions that the kernel will translate into breakpoint hits. On Mac this was 0xE7FFDEFE for ARM and 0xDEFE for Thumb. The darwin kernel currently doesn't recognize any 32 bit Thumb instruction as a instruction that will get turned into a breakpoint exception (EXC_BREAKPOINT), so we had to use the BKPT instruction on Mac. The linux kernel recognizes a 16 and a 32 bit instruction as valid thumb breakpoint opcodes. The benefit of using 16 or 32 bit instructions is you don't stop on opcodes in a IT block when the condition doesn't match.
To further complicate things, single stepping on ARM is often implemented by modifying the BCR/BVR registers and setting the processor to stop when the PC is not equal to the current value. This means single stepping is another way the ARM target can stop on instructions that won't get executed.
This patch does the following:
1 - Fix the internal debugserver for Apple to use the BKPT instruction for ARM and Thumb
2 - Fix LLDB to catch when we stop in the middle of a Thumb IT instruction and continue if we stop at an instruction that won't execute
3 - Fixes this in a way that will work for any target on any platform as long as it is ARM/Thumb
4 - Adds a patch for ignoring conditions that don't match when in ARM mode (see below)
This patch also provides the code that implements the same thing for ARM instructions, though it is disabled for now. The ARM patch will check the condition of the instruction in ARM mode and continue if the condition isn't true (and therefore the instruction would not be executed). Again, this is not enable, but the code for it has been added.
<rdar://problem/19145455>
llvm-svn: 223851
a register value that is live in the stack frame 0 register context.
Fixes a problem where retrieving a register value on stack frame #n
would involved O(n!) stack frame checks. This could be very slow on
a deep stack when retrieving register values that had not been
modified/saved by any of the stack frames. Not common, but annoying
when it was hit.
<rdar://problem/19010211>
llvm-svn: 223843
On Darwin, compiler_rt uses magic linker symbols to find the profile
counters in the __DATA segment. This is a reasonable method for
normal, hosted, userspace programs. However programs with custom
memory layouts, such as the kernel, will need to tell compiler_rt
explicitly where to find these sections.
Patch by Lawrence D'Anna. Thanks!
llvm-svn: 223840
Because of the way they are created, synthetic children cannot (in general) have a sane expression path
A solution to this would be letting the parent front-end generate expression paths for its children
Doing so requires a significant amount of refactoring, and might not always lead to better results (esp. w.r.t. C++ templates)
This commit takes a simpler approach:
- if a synthetic child is of pointer type and it's a target pointer, then emit *((T)value)
- if a synthetic child is a non-pointer, but its location is in the target, then emit *((T*)loadAddr)
- if a synthetic child has a value, emit ((T)value)
- else, don't emit anything
Fixes rdar://18442386
llvm-svn: 223836
Move the combiner-state check into another function, add a few
small comments, and use a more general type in a cast<>.
In preparation for a future patch.
llvm-svn: 223834
It was missing from the VLD1/VST1 handling logic, even though the
corresponding instructions exist (same form as v2i64).
In preparation for a future patch.
llvm-svn: 223832
track of the checksum of the object so we can
track if it is modified. This fixes a testcase
(test/expression_command/issue_11588) on OS X.
Patch by Enrico Granata.
llvm-svn: 223830
RAUW in a deterministic order to try to recover the hexagon bot [1],
whose tests started failing once my GCC fixes were in for r223802.
Otherwise, I'm not sure why tests would fail there and not here.
[1]: http://lab.llvm.org:8011/builders/llvm-hexagon-elf/builds/13426
llvm-svn: 223829
LLVM_EXPLICIT is only supported by recent version of MSVC, and it seems
the not-so-recent versions get confused about the operator bool() when
tryint to resolve operator== calls.
This removed the operator bool()'s since they don't seem to be used
anyway.
llvm-svn: 223824
- adds a new flag to mark ValueObjects as "synthetic children generated"
- vends new Create functions as part of the SyntheticChildrenFrontEnd that set the flag automatically
- moves synthetic child providers over to using these new functions
No visible feature change, but preparatory work for feature change
llvm-svn: 223819
The load/store value type is currently not available when lowering the memcpy
intrinsic. Add the missing nullptr check to support this in 'computeAddress'.
Fixes rdar://problem/19178947.
llvm-svn: 223818
Getting this working correctly is a significant amount of work.
Assertions on Windows show up as error code 0xC0000409, which is
STATUS_STACK_BUFFER_OVERRUN. In order to accurately determine
that this is not just any stack buffer overrun, but one triggered
by a call to abort, we would need to analyze the call stack. This
in turn requires better symbol support for Windows executables,
and work on LLDB to make stack frames better on Windows.
For now, these are XFAIL'ed and tracked in http://llvm.org/pr21793.
llvm-svn: 223816
patterns.
This is causing Clang to miscompile itself for 32-bit x86 somehow, and likely
also on ARM and PPC. I really don't know how, but reverting now that I've
confirmed this is actually the culprit. I have a reproduction as well and so
should be able to restore this shortly.
This reverts commit r223764.
Original commit log follows:
Teach instcombine to canonicalize "element extraction" from a load of an
integer and "element insertion" into a store of an integer into actual
element extraction, element insertion, and vector loads and stores.
Previously various parts of LLVM (including instcombine itself) would
introduce integer loads and stores into the code as a way of opaquely
loading and storing "bits". In some cases (such as a memcpy of
std::complex<float> object) we will eventually end up using those bits
in non-integer types. In order for SROA to effectively promote the
allocas involved, it splits these "store a bag of bits" integer loads
and stores up into the constituent parts. However, for non-alloca loads
and tsores which remain, it uses integer math to recombine the values
into a large integer to load or store.
All of this would be "fine", except that it forces LLVM to go through
integer math to combine and split up values. While this makes perfect
sense for integers (and in fact is critical for bitfields to end up
lowering efficiently) it is *terrible* for non-integer types, especially
floating point types. We have a much more canonical way of representing
the act of concatenating the bits of two SSA values in LLVM: a vector
and insertelement. This patch teaching InstCombine to use this
representation.
With this patch applied, LLVM will no longer introduce integer math into
the critical path of every loop over std::complex<float> operations such
as those that make up the hot path of ... oh, most HPC code, Eigen, and
any other heavy linear algebra library.
For the record, I looked *extensively* at fixing this in other parts of
the compiler, but it just doesn't work:
- We really do want to canonicalize memcpy and other bit-motion to
integer loads and stores. SSA values are tremendously more powerful
than "copy" intrinsics. Not doing this regresses massive amounts of
LLVM's scalar optimizer.
- We really do need to split up integer loads and stores of this form in
SROA or every memcpy of a trivially copyable struct will prevent SSA
formation of the members of that struct. It essentially turns off
SROA.
- The closest alternative is to actually split the loads and stores when
partitioning with SROA, but this has all of the downsides historically
discussed of splitting up loads and stores -- the wide-store
information is fundamentally lost. We would also see performance
regressions for bitfield-heavy code and other places where the
integers aren't really intended to be split without seemingly
arbitrary logic to treat integers totally differently.
- We *can* effectively fix this in instcombine, so it isn't that hard of
a choice to make IMO.
llvm-svn: 223813
David Majnemer