Commit Graph

8 Commits

Author SHA1 Message Date
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Rafael Espindola 65e4902156 Drop prelink support.
The way prelink used to work was

* The compiler decides if a given section only has relocations that
are know to point to the same DSO. If so, it names it
.data.rel.ro.local<something>.
* The static linker puts all of these together.
* The prelinker program assigns addresses to each library and resolves
the local relocations.

There are many problems with this:
* It is incompatible with address space randomization.
* The information passed by the compiler is redundant. The linker
knows if a given relocation is in the same DSO or not. If could sort
by that if so desired.
* There are newer ways of speeding up DSO (gnu hash for example).
* Even if we want to implement this again in the compiler, the previous
  implementation is pretty broken. It talks about relocations that are
  "resolved by the static linker". If they are resolved, there are none
  left for the prelinker. What one needs to track is if an expression
  will require only dynamic relocations that point to the same DSO.

At this point it looks like the prelinker is an historical curiosity.
For example, fedora has retired it because it failed to build for two
releases
(http://pkgs.fedoraproject.org/cgit/prelink.git/commit/?id=eb43100a8331d91c801ee3dcdb0a0bb9babfdc1f)

This patch removes support for it. That is, it stops printing the
".local" sections.

llvm-svn: 253280
2015-11-17 00:51:23 +00:00
Ulrich Weigand 7db6918e2b [SystemZ] Support all TLS access models - CodeGen part
The current SystemZ back-end only supports the local-exec TLS access model.
This patch adds all required CodeGen support for the other TLS models, which
means in particular:

- Expand initial-exec TLS accesses by loading TLS offsets from the GOT
  using @indntpoff relocations.

- Expand general-dynamic and local-dynamic accesses by generating the
  appropriate calls to __tls_get_offset.  Note that this routine has
  a non-standard ABI and requires loading the GOT pointer into %r12,
  so the patch also adds support for the GLOBAL_OFFSET_TABLE ISD node.

- Add a new platform-specific optimization pass to remove redundant
  __tls_get_offset calls in the local-dynamic model (modeled after
  the corresponding X86 pass).

- Add test cases verifying all access models and optimizations.

llvm-svn: 229654
2015-02-18 09:13:27 +00:00
Benjamin Kramer a7c40ef022 Canonicalize header guards into a common format.
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)

Changes made by clang-tidy with minor tweaks.

llvm-svn: 215558
2014-08-13 16:26:38 +00:00
Richard Sandiford b4d67b593e [SystemZ] Remove "virtual" from override methods
Also fix a couple of cases where "override" was missing.  No behavioural
change intended.

llvm-svn: 203110
2014-03-06 12:03:36 +00:00
Richard Sandiford c231269ff9 [SystemZ] Update namespace formatting to match current guidelines
No functional change intended.

llvm-svn: 203103
2014-03-06 10:38:30 +00:00
Craig Topper 73156025e0 Switch all uses of LLVM_OVERRIDE to just use 'override' directly.
llvm-svn: 202621
2014-03-02 09:09:27 +00:00
Ulrich Weigand 5f613dfd1f [SystemZ] Add back end
This adds the actual lib/Target/SystemZ target files necessary to
implement the SystemZ target.  Note that at this point, the target
cannot yet be built since the configure bits are missing.  Those
will be provided shortly by a follow-on patch.

This version of the patch incorporates feedback from reviews by
Chris Lattner and Anton Korobeynikov.  Thanks to all reviewers!

Patch by Richard Sandiford.

llvm-svn: 181203
2013-05-06 16:15:19 +00:00