[GlobalOpt] Remove unreachable blocks before optimizing a function.
While the change is presumably correct, it exposes a latent bug
in DI which breaks on of the CFI checks. I'll analyze it further
and try to understand what's going on.
llvm-svn: 307729
Summary:
Custom DFS implementation allows us to skip over certain nodes without adding them to the visited map, which is not easily doable with llvm's dfs iterators. What's more, caching predecessors becomes easy.
This patch implements a single DFS function (template) for both forward and reverse DFS, which should be easier to maintain then separate two ones.
Skipping over nodes based on a predicate will be necessary later to implement incremental updates.
There also seems to be a very slight performance improved when bootstrapping clang with this patch on my machine (3:28s -> 3:26s) .
Reviewers: dberlin, sanjoy, davide, grosser
Reviewed By: dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34651
llvm-svn: 307727
I encountered these when linking LLD, which uses atls.lib. Those objects
appear to use these uncommon symbol records:
0x115E S_HEAPALLOCSITE
0x113D S_ENVBLOCK
0x1113 S_GTHREAD32
0x1153 S_FILESTATIC
llvm-svn: 307725
OpenCL 2.0 introduces the notion of memory scopes in atomic operations to
global and local memory. These scopes restrict how synchronization is
achieved, which can result in improved performance.
This change extends existing notion of synchronization scopes in LLVM to
support arbitrary scopes expressed as target-specific strings, in addition to
the already defined scopes (single thread, system).
The LLVM IR and MIR syntax for expressing synchronization scopes has changed
to use *syncscope("<scope>")*, where <scope> can be "singlethread" (this
replaces *singlethread* keyword), or a target-specific name. As before, if
the scope is not specified, it defaults to CrossThread/System scope.
Implementation details:
- Mapping from synchronization scope name/string to synchronization scope id
is stored in LLVM context;
- CrossThread/System and SingleThread scopes are pre-defined to efficiently
check for known scopes without comparing strings;
- Synchronization scope names are stored in SYNC_SCOPE_NAMES_BLOCK in
the bitcode.
Differential Revision: https://reviews.llvm.org/D21723
llvm-svn: 307722
This patch implements the .module and .set directives for the MT ASE,
notably that .module sets the relevant flags in .MIPS.abiflags and .set
doesn't.
Reviewers: slthakur, atanasyan
Differential Revision: https://reviews.llvm.org/D35249
llvm-svn: 307716
For ELF, a movw+movt pair is handled as two separate relocations.
If an offset should be applied to the symbol address, this offset is
stored as an immediate in the instruction (as opposed to stored as an
offset in the relocation itself).
Even though the actual value stored in the movt immediate after linking
is the top half of the value, we need to store the unshifted offset
prior to linking. When the relocation is made during linking, the offset
gets added to the target symbol value, and the upper half of the value
is stored in the instruction.
This makes sure that movw+movt with offset symbols get properly
handled, in case the offset addition in the lower half should be
carried over to the upper half.
This makes the output from the additions to the test case match
the output from GNU binutils.
For COFF and MachO, the movw/movt relocations are handled as a pair,
and the overflow from the lower half gets carried over to the movt,
so they should keep the shifted offset just as before.
Differential Revision: https://reviews.llvm.org/D35242
llvm-svn: 307713
This is fine as nothing in the code relies on leader and memory
leader being the same for a given congruency class. Ack'ed by
Dan.
Fixes PR33720.
llvm-svn: 307699
The warning is reproducible with GCC 4.8. Thanks to David Blaikie for
the suggested fix.
The reported warning was
```
/usr/local/google/home/echristo/sources/llvm/lib/Fuzzer/FuzzerExtFunctions.def:29:10: warning: ISO C++ forbids casting between pointer-to-function and pointer-to-object [-Wpedantic]
EXT_FUNC(__lsan_enable, void, (), false);
^
/usr/local/google/home/echristo/sources/llvm/lib/Fuzzer/FuzzerExtFunctionsWeak.cpp:44:24: note: in definition of macro ‘EXT_FUNC’
CheckFnPtr((void *)::NAME, #NAME, WARN);
^
```
Differential Revision: https://reviews.llvm.org/D35243
llvm-svn: 307686
Preparatory work for adding the MIPS MT (multi-threading) ASE instructions.
Reviewers: slthakur, atanasyan
Differential Revision: https://reviews.llvm.org/D35247
llvm-svn: 307679
The loop structure for the outer loop does not contain the epilog
preheader when we try to unroll inner loop with multiple exits and
epilog code is generated. For now, we just bail out in such cases.
Added a test case that shows the problem. Without this bailout, we would
trip on assert saying LCSSA form is incorrect for outer loop.
llvm-svn: 307676
Summary:
Patch by Klaus Kretzschmar
We would like to introduce a new type of llvm error handler for handling
bad alloc fault situations. LLVM already provides a fatal error handler
for serious non-recoverable error situations which by default writes
some error information to stderr and calls exit(1) at the end (functions
are marked as 'noreturn').
For long running processes (e.g. a server application), exiting the
process is not an acceptable option, especially not when the system is
in a temporary resource bottleneck with a good chance to recover from
this fault situation. In such a situation you would rather throw an
exception to stop the current compilation and try to overcome the
resource bottleneck. The user should be aware of the problem of throwing
an exception in bad alloc situations, e.g. you must not do any
allocations in the unwind chain. This is especially true when adding
exceptions in existing unfamiliar code (as already stated in the comment
of the current fatal error handler)
So the new handler can also be used to distinguish from general fatal
error situations where recovering is no option. It should be used in
cases where a clean unwind after the allocation is guaranteed.
This patch contains:
- A report_bad_alloc function which calls a user defined bad alloc
error handler. If no user handler is registered the
report_fatal_error function is called. This function is not marked as
'noreturn'.
- A install/restore_bad_alloc_error_handler to install/restore the bad
alloc handler.
- An example (in Mutex.cpp) where the report_bad_alloc function is
called in case of a malloc returns a nullptr.
If this patch gets accepted we would create similar patches to fix
corresponding malloc/calloc usages in the llvm code.
Reviewers: chandlerc, greened, baldrick, rnk
Reviewed By: rnk
Subscribers: llvm-commits, MatzeB
Differential Revision: https://reviews.llvm.org/D34753
llvm-svn: 307673
1. The available program storage region of the red zone to compilers is 288
bytes rather than 244 bytes.
2. The formula for negative number alignment calculation should be
y = x & ~(n-1) rather than y = (x + (n-1)) & ~(n-1).
Differential Revision: https://reviews.llvm.org/D34337
llvm-svn: 307672
Summary:
This speeds up the LLD test suite on Windows by 3x. Most of the time is
spent on lld/test/ELF/linkerscript/diagnostics.s, which repeatedly
constructs linker scripts with appending echo commands.
Reviewers: dlj, zturner, modocache
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35093
llvm-svn: 307668
Use CHECK-NEXT for the comparison sequence, to make sure we don't get
any unexpected instructions in the middle of our flag manipulation
efforts.
llvm-svn: 307656
There were two errors in the parsing of opt's command line options for
extension point pipelines. The EP callbacks are not supposed to return a
value. To check the pipeline text for correctness, I now try to parse it
into a temporary PM object, and print a message on failure. This solves
the compile time error for the lambda return type, as well as correctly
handles unparsable pipelines now.
llvm-svn: 307649
Make sure that all the legalizer tests where the original instruction
needs to be removed check for the removal. We do this by adding
CHECK-NOT lines before and after the replacement sequence. This won't
catch pathological cases where the instruction remains somewhere in the
middle of the instruction sequence that's supposed to replace it, but
hopefully that won't occur in practice (since ideally we'd be setting
the insert point for the new instruction sequence either before or after
the original instruction and not fiddle with it while building the
sequence).
llvm-svn: 307647
In each rule, each use of ComplexPattern is assigned an element in the Renderers
array. The matcher then collects renderer functions in this array and they are
used to render instructions. This works well for a single instruction but a
bug in the allocation mechanism causes the elements to be assigned on a
per-instruction basis rather than a per-rule basis.
So in the case of:
(set GPR32:$dst, (Op complex:$src1, complex:$src2))
tablegen currently assigns elements 0 and 1 to $src1 and $src2 respectively,
but for:
(set GPR32:$dst, (Op complex:$src1, (Op complex:$src2)))
it currently assigned both $src1 and $src2 the same element (0). This results in
one complex operand being rendered twice and the other being forgotten.
This patch corrects the allocation such that $src1 and $src2 are still allocated
different elements in this case.
llvm-svn: 307646
This change allows the pc to be used as a destination register for the
pseudo instruction LDR pc,=expression . The pseudo instruction must not be
transformed into a MOV, but it can use the Thumb2 LDR (literal) instruction
to a constant pool entry. See (A7.7.43 from ARMv7M ARM ARM).
Differential Revision: https://reviews.llvm.org/D34751
llvm-svn: 307640
We used to forget to erase the original instruction when replacing a
G_FCMP true/false. Fix this bug and make sure the tests check for it.
llvm-svn: 307639
TreePatternNode considers them to be plain integers but MachineInstr considers
them to be a distinct kind of operand.
The tweak to AArch64InstrInfo.td to produce a simple test case is a NFC for
everything except GlobalISelEmitter (confirmed by diffing the tablegenerated
files). GlobalISelEmitter is currently unable to infer the type of operands in
the Dst pattern from the operands in the Src pattern.
llvm-svn: 307634
This is a second attempt to land this patch.
The first one resulted in a crash of clang sanitizer buildbot.
The fix is here and regression test is added.
This is a last fix for the corner case of PR32214. Actually this is not really corner case in general.
We should not do a loop rotation if we create an additional branch due to it.
Consider the case where we have a loop chain H, M, B, C , where
H is header with viable fallthrough from pre-header and exit from the loop
M - some middle block
B - backedge to Header but with exit from the loop also.
C - some cold block of the loop.
Let's H is determined as a best exit. If we do a loop rotation M, B, C, H we can introduce the extra branch.
Let's compute the change in number of branches:
+1 branch from pre-header to header
-1 branch from header to exit
+1 branch from header to middle block if there is such
-1 branch from cold bock to header if there is one
So if C is not a predecessor of H then we introduce extra branch.
This change actually prohibits rotation of the loop if both true
Best Exit has next element in chain as successor.
Last element in chain is not a predecessor of first element of chain.
Reviewers: iteratee, xur, sammccall, chandlerc
Reviewed By: iteratee
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34745
llvm-svn: 307631
CodeGenPrepare::optimizeMemoryInst contains a check that we do nothing
if all instructions combining the address for memory instruction is in the same
block as memory instruction itself.
However if any of these instruction are placed after memory instruction then
address calculation will not be folded to memory instruction.
The added test case shows an example.
Reviewers: loladiro, spatel, efriedma
Reviewed By: efriedma
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34862
llvm-svn: 307628
Davide Italiano