Given
.weak target
.global _start
_start:
b target
The intention is that the branch goes to the instruction after the
branch, effectively turning it on a nop. The branch adds the runtime
PC, but we were adding it statically too.
I noticed the oddity by inspection, but llvm-objdump seems to agree,
since it now prints things like:
b #-4 <_start+0x4>
Obtained from: LLD commit r305212
Differential Revision: https://reviews.freebsd.org/D11191
Reviewed by: dim, Rafael Espíndola
Obtained from: LLD r305212
MFC after: 3 days
No functional change; applied to facilitate merge of later LLD commit.
Reviewed by: dim, Rafael Espíndola
Obtained from: LLD r298797
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D11190
This change is a portion of LLD rev 305212 which accidentally ended
up in my svn tree. We do want to backport the change to LLD 4.0, but
it needs additional work and was not supposed to be included in
r319887.
If two sections contained relocations to absolute symbols with the same
value we would crash when trying to access their sections. Add a check that
both symbols point to sections before accessing their sections, and treat
absolute symbols as equal if their values are equal.
Obtained from: LLD commit r292578
MFC after: 3 days
[PPC] Properly update register save area offsets
The variables MinGPR/MinG8R were not updated properly when resetting the
offsets, which in the included testcase lead to saving the CR register
in the same location as R30.
This fixes another issue reported in PR26519.
Differential Revision: https://reviews.llvm.org/D33017
Reported by: Mark Millard
PR: 206990
MFC after: 3 days
In the absense of a more specific handler for TRAP_CAP (generated by
ENOTCAPABLE or ECAPMODE while in capability mode) treat it as a trace
trap.
Example usage (testing the bug in PR219173):
% proccontrol -m trapcap lldb usr.bin/hexdump/obj/hexdump -- -Cv -s 1 /bin/ls
...
(lldb) run
Process 12980 launching
Process 12980 launched: '.../usr.bin/hexdump/obj/hexdump' (x86_64)
Process 12980 stopped
* thread #1, stop reason = trace
frame #0: 0x0000004b80c65f1a libc.so.7`__sys_lseek + 10
...
In the future we should have LLDB control the trapcap procctl itself
(as it does with ASLR), as well as report a specific stop reason.
This change eliminates an assertion failure from LLDB for now.
[ARM] Clear the constant pool cache on explicit .ltorg directives
Multiple ldr pseudoinstructions with the same constant value will
reuse the same constant pool entry. However, if the constant pool is
explicitly flushed with a .ltorg directive, we should not try to
reference constants in the previous pool any longer, since they may
be out of range.
This fixes assembling hand-written assembler source which repeatedly
loads the same constant value, across a binary size larger than the
pc-relative fixup range for ldr instructions (4096 bytes). Such
assembler source already uses explicit .ltorg instructions to emit
constant pools with regular intervals. However if we try to reuse
constants emitted in earlier pools, they end up out of range.
This makes the output of the testcase match what binutils gas does
(prior to this patch, it would fail to assemble).
Differential Revision: https://reviews.llvm.org/D32847
This should fix "out of range pc-relative fixup value" errors, when
compiling certain ARM inline assembly for www/webkit-gtk[23].
Reported by: mmel
MFC after: 3 days
[PPC] When restoring R30 (PIC base pointer), mark it as <def>
This happened on the PPC32/SVR4 path and was discovered when building
FreeBSD on PPC32. It was a typo-class error in the frame lowering
code.
This fixes PR26519.
Reported by: Mark Millard
PR: 206990
MFC after: 3 days
ARM: avoid handing a deleted node back to TableGen during ISel.
When we replaced the multiplicand the destination node might already
exist. When that happens the original gets CSEd and deleted. However,
it's actually used as the offset so nonsense is produced.
Should fix PR32726.
This fixes an assertion failure when building building www/firefox 53.0
for arm.
Reported by: Bob Prohaska
PR: 218782
MFC after: 3 days
[Assembler] Enable nicer diagnostics for inline assembly.
Fixed test.
Summary:
Enables source location in diagnostic messages from the backend.
This is after parsing, during finalization. This requires the
SourceMgr, the inline assembly string buffer, and DiagInfo to still
be alive after EmitInlineAsm returns.
This patch creates a single SourceMgr for inline assembly inside the
AsmPrinter. MCContext gets a pointer to this SourceMgr. Using one
SourceMgr per call to EmitInlineAsm would make it difficult for
MCContext to figure out in which SourceMgr the SMLoc is located,
while a single SourceMgr can figure it out if it has multiple
buffers.
The Str argument to EmitInlineAsm is copied into a buffer and owned
by the inline asm SourceMgr. This ensures that DiagHandlers won't
print garbage. (Clang emits a "note: instantiated into assembly
here", which refers to this string.)
The AsmParser gets destroyed before finalization, which means that
the DiagHandlers the AsmParser installs into the SourceMgr will be
stale. Restore the saved DiagHandlers.
Since now we're using just one SourceMgr for multiple inline asm
strings, we need to tell the AsmParser which buffer it needs to parse
currently. Hand a buffer id -- returned from SourceMgr::
AddNewSourceBuffer -- to the AsmParser.
Reviewers: rnk, grosbach, compnerd, rengolin, rovka, anemet
Reviewed By: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29441
This improves error reporting for some inline assembly constructs that
clang does not approve of: instead of crashing with a "fatal backend
error", it will now show a normal error message, and point out the
location of the problematic assembly.
Reported by: mmel
MFC after: 1 week
[X86] Remove special handling for 16 bit for A asm constraints.
Our 16 bit support is assembler-only + the terrible hack that is
.code16gcc. Simply using 32 bit registers does the right thing for
the latter.
Fixes PR32681.
This fixes some cases of assembling 16 bit code (i.e. SeaBIOS) that uses
the 'A' inline asm constraint, after r316989.
MFC after: 3 days
X-MFC-With: r316989
Use correct registers for "A" inline asm constraint
Summary:
In PR32594, inline assembly using the 'A' constraint on x86_64 causes
llvm to crash with a "Cannot select" stack trace. This is because
`X86TargetLowering::getRegForInlineAsmConstraint` hardcodes that 'A'
means the EAX and EDX registers.
However, on x86_64 it means the RAX and RDX registers, and on 16-bit
x86 (ia16?) it means the old AX and DX registers.
Add new register classes in `X86RegisterInfo.td` to support these
cases, and amend the logic in `getRegForInlineAsmConstraint` to cope
with different subtargets. Also add a test case, derived from
PR32594.
Reviewers: craig.topper, qcolombet, RKSimon, ab
Reviewed By: ab
Subscribers: ab, emaste, royger, llvm-commits
Differential Revision: https://reviews.llvm.org/D31902
This should fix crashes when using the 'A' constraint on amd64, for
example as it is being used in Xen.
Reported by: royger
MFC after: 3 days
GNU libtool checks the output from invoking the linker with --version
and --help, in order to determine the linker "flavour" and the command-
ine arguments to use for various link operations (e.g. generating shared
libraries). To detect GNU ld it looks for the strings "GNU" and
"supported targets:.*elf". Since LLD is compatible with GNU ld we
include those same strings to fool libtool.
Quoting from a comment in the change:
This is somewhat ugly hack, but in reality, we had no choice other
than doing this. Considering the very long release cycle of Libtool,
it is not easy to improve it to recognize LLD as a GNU compatible
linker in a timely manner. Even if we can make it, there are still a
lot of "configure" scripts out there that are generated by old
version of Libtool. We cannot convince every software developer to
migrate to the latest version and re-generate scripts. So we have
this hack.
Upstream LLVM revisions r298532, r298568, r298591
Obtained from: LLVM
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
[SCEV] limit recursion depth of CompareSCEVComplexity
Summary:
CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
loop) and runs almost infinite time.
Added cache of "equal" SCEV pairs to earlier cutoff of further
estimation. Recursion depth limit was also introduced as a parameter.
Reviewers: sanjoy
Subscribers: mzolotukhin, tstellarAMD, llvm-commits
Differential Revision: https://reviews.llvm.org/D26389
Pull in r296992 from upstream llvm trunk (by Sanjoy Das):
[SCEV] Decrease the recursion threshold for CompareValueComplexity
Fixes PR32142.
r287232 accidentally increased the recursion threshold for
CompareValueComplexity from 2 to 32. This change reverses that
change by introducing a separate flag for CompareValueComplexity's
threshold.
The latter revision fixes the excessive compile times for skein_block.c.
[SCEV] limit recursion depth of CompareSCEVComplexity
Summary:
CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
loop) and runs almost infinite time.
Added cache of "equal" SCEV pairs to earlier cutoff of further
estimation. Recursion depth limit was also introduced as a parameter.
Reviewers: sanjoy
Subscribers: mzolotukhin, tstellarAMD, llvm-commits
Differential Revision: https://reviews.llvm.org/D26389
This commit is the cause of excessive compile times on skein_block.c
(and possibly other files) during kernel builds on amd64.
We never saw the problematic behavior described in this upstream commit,
so for now it is better to revert it. An upstream bug has been filed
here: https://bugs.llvm.org/show_bug.cgi?id=32142
Reported by: mjg
[ValueTracking] avoid crashing from bad assumptions (PR31809)
A program may contain llvm.assume info that disagrees with other
analysis. This may be caused by UB in the program, so we must not
crash because of that.
As noted in the code comments:
https://llvm.org/bugs/show_bug.cgi?id=31809
...we can do better, but this at least avoids the assert/crash in the
bug report.
Differential Revision: https://reviews.llvm.org/D29395
This fixes an assertion when building editors/emacs-devel.
PR: 216614
The change was made to support glibc and believed to be a no-op on
FreeBSD, but that is not the case for architectures with multiple page
sizes, such as arm64. The relro p_memsz header was rounded up to the
default maximum page size (64K). When 4K pages are in use, multiple
pages beyond the final PT_LOAD segment had their permissions changed to
read-only after application of relocations and copy relocations, which
led to a segfault in certain cases.
This reverts upstream r290986. I have started a discussion about the
upstream fix on the LLVM mailing list.
Reported by: andrew
Sponsored by: The FreeBSD Foundation
Fix use-after-free bug in AffectedValueCallbackVH::allUsesReplacedWith
When transferring affected values in the cache from an old value,
identified by the value of the current callback, to the specified new
value we might need to insert a new entry into the DenseMap which
constitutes the cache. Doing so might delete the current callback
object. Move the copying logic into a new function, a member of the
assumption cache itself, so that we don't run into UB should the
callback handle itself be removed mid-copy.
Differential Revision: https://reviews.llvm.org/D28749
This should fix crashes when building lld (as part of the llvmXY ports).
Reported by: jbeich
PR: 216117
Fix PR31644 introduced by r287138 and add a regression test.
Thanks Dimitry Andric for the report and fix!
This should restore -MP output to what it was before.
Reported by: jbeich
PR: 216043
