This class is turning into a useful interface, rather than an implementation
detail, so I'm dropping the 'Base' suffix.
No functional change.
llvm-svn: 254693
DenseMap is most applicable when both keys and values are small.
In this case, the value violates that assumption, causing quite
significant memory overhead. A std::unordered_map is more appropriate
in this case (or at least fixed the memory problems I was seeing).
Differential Revision: http://reviews.llvm.org/D14910
llvm-svn: 254651
r253918 had refactored expressions like "A - B.Address + C" to "A -
B.getAddressWithOffset(C)". This is incorrect, since the latter really
computes "A - B.Address - C".
None of the tests I can run locally on x86 broke due to this bug, but it
is the current suspect for breakage on the AArch64 buildbots.
llvm-svn: 254017
Summary:
For relocation types that are known to not require stub functions, there
is no need to allocate extra space for the stub functions.
Reviewers: lhames, reames, maksfb
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14676
llvm-svn: 253920
Summary:
Change SectionEntry to keep track of the size of its underlying
allocation, and use that to bounds check advanceStubOffset.
Reviewers: lhames, andrew.w.kaylor, reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14675
llvm-svn: 253919
Summary:
Remove naked access to the data members in `SectionEntry` and route
accesses through accessor functions. This makes it obvious how the
instances of the class are used, and will also facilitate adding bounds
checking to `advanceStubOffset` in a later change.
Reviewers: lhames, loladiro, andrew.w.kaylor
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14674
llvm-svn: 253918
When resolving R_PPC64_REL24, code used to check for an address delta
that fits in 24 bits, while the instructions that take this relocation
actually can process address deltas that fit into *26* bits (as those
instructions have a 24 bit field, but implicitly append two zero bits
at the end since all instruction addresses are a multiple of 4).
This means that code would signal overflow once a single object's text
section exceeds 8 MB, while we can actually support up to 32 MB.
Partially fixes PR25540.
llvm-svn: 253369
The needed lld matching changes to be submitted immediately next,
but this revision will cause lld failures with this alone which is expected.
This removes the eating of the error in Archive::Child::getSize() when the characters
in the size field in the archive header for the member is not a number. To do this we
have all of the needed methods return ErrorOr to push them up until we get out of lib.
Then the tools and can handle the error in whatever way is appropriate for that tool.
So the solution is to plumb all the ErrorOr stuff through everything that touches archives.
This include its iterators as one can create an Archive object but the first or any other
Child object may fail to be created due to a bad size field in its header.
Thanks to Lang Hames on the changes making child_iterator contain an
ErrorOr<Child> instead of a Child and the needed changes to ErrorOr.h to add
operator overloading for * and -> .
We don’t want to use llvm_unreachable() as it calls abort() and is produces a “crash”
and using report_fatal_error() to move the error checking will cause the program to
stop, neither of which are really correct in library code. There are still some uses of
these that should be cleaned up in this library code for other than the size field.
The test cases use archives with text files so one can see the non-digit character,
in this case a ‘%’, in the size field.
These changes will require corresponding changes to the lld project. That will be
committed immediately after this change. But this revision will cause lld failures
with this alone which is expected.
llvm-svn: 252192
Bypassing LLVM for this has a number of benefits:
1) Laziness support becomes asm-syntax agnostic (previously lazy jitting didn't
work on Windows as the resolver block was in Darwin asm).
2) For cross-process JITs, it allows resolver blocks and trampolines to be
emitted directly in the target process, reducing cross process traffic.
3) It should be marginally faster.
llvm-svn: 251933
This adds support for COFF I386. This is sufficient for code execution in a
32-bit JIT, though, imported symbols need to custom lowered for the redirection.
llvm-svn: 251761
Summary: ELF's STT_File symbols may overlap with regular globals in
other files, so we should ignore them here in order to avoid having
bogus entries in the symbol table that confuse us when resolving relocations.
Reviewers: lhames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13888
llvm-svn: 250942
in the size field in the archive header for the member is not a number. To do this we
have all of the needed methods return ErrorOr to push them up until we get out of lib.
Then the tools and can handle the error in whatever way is appropriate for that tool.
So the solution is to plumb all the ErrorOr stuff through everything that touches archives.
This include its iterators as one can create an Archive object but the first or any other
Child object may fail to be created due to a bad size field in its header.
Thanks to Lang Hames on the changes making child_iterator contain an
ErrorOr<Child> instead of a Child and the needed changes to ErrorOr.h to add
operator overloading for * and -> .
We don’t want to use llvm_unreachable() as it calls abort() and is produces a “crash”
and using report_fatal_error() to move the error checking will cause the program to
stop, neither of which are really correct in library code. There are still some uses of
these that should be cleaned up in this library code for other than the size field.
Also corrected the code where the size gets us to the “at the end of the archive”
which is OK but past the end of the archive will return object_error::parse_failed now.
The test cases use archives with text files so one can see the non-digit character,
in this case a ‘%’, in the size field.
llvm-svn: 250906
memory, rather than representing the stubs in IR. Update the CompileOnDemand
layer to use this functionality.
Directly emitting stubs is much cheaper than building them in IR and codegen'ing
them (see below). It also plays well with remote JITing - stubs can be emitted
directly in the target process, rather than having to send them over the wire.
The downsides are:
(1) Care must be taken when resolving symbols, as stub symbols are held in a
separate symbol table. This is only a problem for layer writers and other
people using this API directly. The CompileOnDemand layer hides this detail.
(2) Aliases of function stubs can't be symbolic any more (since there's no
symbol definition in IR), but must be converted into a constant pointer
expression. This means that modules containing aliases of stubs cannot be
cached. In practice this is unlikely to be a problem: There's no benefit to
caching such a module anyway.
On balance I think the extra performance is more than worth the trade-offs: In a
simple stress test with 10000 dummy functions requiring stubs and a single
executed "hello world" main function, directly emitting stubs reduced user time
for JITing / executing by over 90% (1.5s for IR stubs vs 0.1s for direct
emission).
llvm-svn: 250712
(e.g. bss sections).
MachO and ELF have been silently letting this pass, but COFFObjectFile contains
an assertion to catch this kind of (ab)use of the getSectionContents, and this
was causing the JIT to crash on COFF objects with BSS sections. This patch
should fix that.
llvm-svn: 250371
Summary:
Rather than just iterating over all sections and checking whether we have relocations for them, iterate over the relocation map instead. This showed up heavily in an artificial julia benchmark that does lots of compilation. On that particular benchmark, this patch gives
~15% performance improvements. As far as I can tell the primary reason why the original
loop was so expensive is that Relocations[i] actually constructs a relocationList (allocating memory & doing lots of other unnecessary computing) if none is found.
Reviewers: lhames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13545
llvm-svn: 249942
This allows modules containing aliases to be lazily jit'd. Previously these
failed with missing symbol errors because the aliases weren't cloned from the
original module.
llvm-svn: 249481
Summary:
Without this patch, the memory manager would call `mprotect` on every memory
region it ever allocated whenever it wanted to finalize memory (i.e. not just
the ones it just allocated). This caused terrible performance problems for
long running memory managers. In one particular compile heavy julia benchmark,
we were spending 50% of time in `mprotect` if running under MCJIT.
Fix this by splitting allocated memory blocks into those on which memory
permissions have been set and those on which they haven't and only running
`mprotect` on the latter.
Reviewers: lhames
Subscribers: reames, llvm-commits
Differential Revision: http://reviews.llvm.org/D13156
llvm-svn: 248981
Because mod is always exact, this function should have never taken a rounding mode argument. The actual implementation still has issues, which I'll look at resolving in a subsequent patch.
llvm-svn: 248195
before any relocations have been applied, and again after all relocations have
been applied.
Previously each section was dumped before and after relocations targetting it
were applied, but this only shows the impact of relocations that point to other
symbols in the same section.
llvm-svn: 247335
Except the changes that defined virtual destructors as =default, because that
ran into problems with GCC 4.7 and overriding methods that weren't noexcept.
llvm-svn: 247298
