We have a new policy in place making links to private resources
something we try to avoid in source and test files. Normally, we'd
organically switch to the new policy rather than make a sweeping change
across a project. However, Clang is in a somewhat special circumstance
currently: recently, I've had several new contributors run into rdar
links around test code which their patch was changing the behavior of.
This turns out to be a surprisingly bad experience, especially for
newer folks, for a handful of reasons: not understanding what the link
is and feeling intimidated by it, wondering whether their changes are
actually breaking something important to a downstream in some way,
having to hunt down strangers not involved with the patch to impose on
them for help, accidental pressure from asking for potentially private
IP to be made public, etc. Because folks run into these links entirely
by chance (through fixing bugs or working on new features), there's not
really a set of problematic links to focus on -- all of the links have
basically the same potential for causing these problems. As a result,
this is an omnibus patch to remove all such links.
This was not a mechanical change; it was done by manually searching for
rdar, radar, radr, and other variants to find all the various
problematic links. From there, I tried to retain or reword the
surrounding comments so that we would lose as little context as
possible. However, because most links were just a plain link with no
supporting context, the majority of the changes are simple removals.
Differential Review: https://reviews.llvm.org/D158071
This reverts commit 4e545bdb355a470d601e9bb7f7b2693c99e61a3e.
The newly added test is the third infinite combine loop caused by
this change. In this case, it's a combination of the branch to
common dest and jump threading folds that keeps peeling off loop
iterations.
The core problem here is that we ideally would not thread over
loop backedges, both because it is potentially non-profitable
(it may break canonical loop structure) and because it may result
in these kinds of loops. Unfortunately, due to the lack of a
dominator tree in SimplifyCFG, there is no good way to prevent
this. While we have LoopHeaders, this is an optional structure and
we don't do a good job of keeping it up to date. It would be fine
for a profitability check, but is not suitable for a correctness
check.
So for now I'm just giving up here, as I don't see a good way to
robustly prevent infinite combine loops.
Fixes https://github.com/llvm/llvm-project/issues/56203.
SimplifyCFG implements basic jump threading, if a branch is
performed on a phi node with constant operands. However,
InstCombine canonicalizes such phis to the condition value of a
previous branch, if possible. SimplifyCFG does support this as
well, but only in the very limited case where the same condition
is used in a direct predecessor -- notably, this does not include
the common diamond pattern (i.e. two consecutive if/elses on the
same condition).
This patch extends the code to look back a limited number of
blocks to find a branch on the same value, rather than only
looking at the direct predecessor.
Fixes https://github.com/llvm/llvm-project/issues/54980.
Differential Revision: https://reviews.llvm.org/D124159
This adds -no-opaque-pointers to clang tests whose output will
change when opaque pointers are enabled by default. This is
intended to be part of the migration approach described in
https://discourse.llvm.org/t/enabling-opaque-pointers-by-default/61322/9.
The patch has been produced by replacing %clang_cc1 with
%clang_cc1 -no-opaque-pointers for tests that fail with opaque
pointers enabled. Worth noting that this doesn't cover all tests,
there's a remaining ~40 tests not using %clang_cc1 that will need
a followup change.
Differential Revision: https://reviews.llvm.org/D123115
For a definition (of most linkage types), dso_local is set for ELF -fno-pic/-fpie
and COFF, but not for Mach-O. This nuance causes unneeded binary format differences.
This patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `
if there is an explicit linkage.
* Clang will set dso_local for Mach-O, which is currently implied by TargetMachine.cpp. This will make COFF/Mach-O and executable ELF similar.
* Eventually I hope we can make dso_local the textual LLVM IR default (write explicit "dso_preemptable" when applicable) and -fpic ELF will be similar to everything else. This patch helps move toward that goal.
a normal cleanup when entering a @try or @synchronized to
ensure that we clean that up if an exception is triggered.
Apparently GCC did this, so it's hard to argue that we shouldn't
do at least as much.
rdar://12364847
llvm-svn: 178599
