George Rimar [Mon, 29 Jul 2019 07:55:39 +0000 (07:55 +0000)]
[llvm-objcopy] - Reimplement strip-dwo-groups.test to stop using the precompiled object.
When llvm-copy removes .dwo sections the index of symbol table,
the indices of the symbols and the indices of the sections which go
after the removed ones changes. That affects on SHT_GROUP sections,
which needs to be updated.
Initially this test used a precompiled object, I rewrote it to use YAML
and improved a bit.
[X86] Don't use PMADDWD for vector add reductions of multiplies if the mul inputs have an additional user.
The pmaddwd inserts a truncate, if that truncate would end up
creating additional instructions instead of making a zext
narrower, then we shouldn't do it.
I've restricted this to only sse4.1 targets since on prior
targets the zext will be done in stages. So the truncate will
probably not create additional instructions. Might need some
more investigation of mul shrinking and the other pmaddwd
transform to be sure this is the right decision.
There might be a slight regression on AVX1 targets due to add
splitting. Hard to say for sure. Maybe we need to look into
using the vector reduction flag to use 2 narrow loads and a
blend instead of extracting and inserting.
[X86] In combineLoopMAddPattern and combineLoopSADPattern, preserve the vector reduction flag on the final add. Handle unrolled loops by letting DAG combine revisit.
This reverts r340478 and r340631 and replaces them with a simpler
method of just letting DAG combine revisit the nodes to handle
the other operand.
[InstCombine] fold fsub+fneg with fdiv/fmul between
The backend already does this via isNegatibleForFree(),
but we may want to alter the fneg IR canonicalizations
that currently exist, so we need to try harder to fold
fneg in IR to avoid regressions.
David Green [Sun, 28 Jul 2019 14:07:48 +0000 (14:07 +0000)]
[ARM] MVE VPNOT
This adds the patterns required to transform xor P0, -1 to a VPNOT. The
instruction operands have to change a little for this, adding an in and an out
VCCR reg and using a custom DecodeMVEVPNOT for the decode.
David Green [Sun, 28 Jul 2019 13:53:39 +0000 (13:53 +0000)]
[ARM] Better patterns for fp <> predicate vectors
These are some better patterns for converting between predicates and floating
points. Much like the extends, we select "1"/"-1" or "0" depending on the
predicate value. Or we perform a compare against 0 to convert to a predicate.
Summary:
In current getPointerAlignemnt implementation, CallBase.getPointerAlignement(..) checks only parameter attriutes in the callsite. For example,
[FunctionAttrs] Annotate "willreturn" for intrinsics
Summary:
In D62801, new function attribute `willreturn` was introduced. In short, a function with `willreturn` is guaranteed to come back to the call site(more precise definition is in LangRef).
In this patch, willreturn is annotated for LLVM intrinsics.
The current pattern would trigger for scheduling changes of the
post-load computation, since those are commutable with the inline asm.
Avoid this by explicitly check the order of load vs asm block.
[InstSimplify] remove quadratic time looping (PR42771)
The test case from:
https://bugs.llvm.org/show_bug.cgi?id=42771
...shows a ~30x slowdown caused by the awkward loop iteration (rL207302) that is
seemingly done just to avoid invalidating the instruction iterator. We can instead
delay instruction deletion until we reach the end of the block (or we could delay
until we reach the end of all blocks).
There's a test diff here for a degenerate case with llvm.assume that is not
meaningful in itself, but serves to verify this change in logic.
This change probably doesn't result in much overall compile-time improvement
because we call '-instsimplify' as a standalone pass only once in the standard
-O2 opt pipeline currently.
Simon Pilgrim [Sat, 27 Jul 2019 13:30:29 +0000 (13:30 +0000)]
[X86][SSE] Replace PMULDQ GetDemandedBits combine with SimplifyMultipleUseDemandedBits handler (Reapplied)
Recommit rL367100 which was reverted at rL367141. Until PR42777 is fixed, we no longer get the benefits of peeking through bitcasts but it does still remove a GetDemandedBits user and gives us the equivalent combines.
Simon Pilgrim [Sat, 27 Jul 2019 12:48:46 +0000 (12:48 +0000)]
[SelectionDAG] Check for any recursion depth greater than or equal to limit instead of just equal the limit.
If anything called the recursive isKnownNeverNaN/computeKnownBits/ComputeNumSignBits/SimplifyDemandedBits/SimplifyMultipleUseDemandedBits with an incorrect depth then we could continue to recurse if we'd already exceeded the depth limit.
This replaces the limit check (Depth == 6) with a (Depth >= 6) to make sure that we don't circumvent it.
This causes a couple of regressions as a mixture of calls (SimplifyMultipleUseDemandedBits + combineX86ShufflesRecursively) were calling with depths that were already over the limit. I've fixed SimplifyMultipleUseDemandedBits to not do this. combineX86ShufflesRecursively is trickier as we get a lot of regressions if we reduce its own limit from 8 to 6 (it also starts at Depth == 1 instead of Depth == 0 like the others....) - I'll see what I can do in future patches.
Simon Pilgrim [Sat, 27 Jul 2019 12:23:36 +0000 (12:23 +0000)]
[TargetLowering] Add depth limit to SimplifyMultipleUseDemandedBits
We're getting reports of massive compile time increases because SimplifyMultipleUseDemandedBits was losing track of the depth and not earlying-out. No repro yet, but consider this a pre-emptive commit.
Reland: [Remarks] Support parsing remark metadata in the YAML remark parser
This adds support to the yaml remark parser to be able to parse remarks
directly from the metadata.
This supports parsing separate metadata and following the external file
with the associated metadata, and also a standalone file containing
metadata + remarks all together.
Wei Mi [Fri, 26 Jul 2019 20:59:22 +0000 (20:59 +0000)]
[JumpThreading] Stop searching predecessor when the current bb is in a
unreachable loop.
updatePredecessorProfileMetadata in jumpthreading tries to find the
first dominating predecessor block for a PHI value by searching upwards
the predecessor block chain.
But jumpthreading may see some temporary IR state which contains
unreachable bb not being cleaned up. If an unreachable loop happens to
be on the predecessor block chain, keeping chasing the predecessor
block will run into an infinite loop.
[Remarks] Support parsing remark metadata in the YAML remark parser
This adds support to the yaml remark parser to be able to parse remarks
directly from the metadata.
This supports parsing separate metadata and following the external file
with the associated metadata, and also a standalone file containing
metadata + remarks all together.
Bob Haarman [Fri, 26 Jul 2019 18:44:06 +0000 (18:44 +0000)]
add 'a' to chmod in llvm-lipo executability tests
Summary:
When specifying symbolic permissions with + or -, if none of
a/u/g/o are specified, bits set in the umask are not affected.
This caused the llvm-lipo executability tests to fail on some
systems, e.g. having an umask of 027 would cause chmod -x to not
clear the executable bit for others. This change instead
uses chmod a-x, which clears all the executable bits regardless
of umask.
Sean Fertile [Fri, 26 Jul 2019 17:25:27 +0000 (17:25 +0000)]
[PowerPC][AIX]Add lowering of MCSymbol MachineOperand.
Adds machine operand lowering for MCSymbolSDNodes to the PowerPC
backend. This is needed to produce call instructions in assembly for AIX
because the callee operand is a MCSymbolSDNode. The test is XFAIL'ed for
asserts due to a (valid) assertion in PEI that the AIX ABI isn't supported yet.
Michal Gorny [Fri, 26 Jul 2019 15:39:05 +0000 (15:39 +0000)]
[llvm] [lit/tests] Replace 'env -u' with more portable construct
Set environment variables to empty values rather than attempting
to unset them via 'env -u', in order to fix NetBSD test regression
caused by r366980. POSIX does not guarantee that env(1) supports '-u'
option, and indeed NetBSD env(1) does not support it.
Michal Gorny [Fri, 26 Jul 2019 15:38:57 +0000 (15:38 +0000)]
[llvm] [FileCheck] Use FILECHECK_DUMP_INPUT_ON_FAILURE only when non-empty
Enable dumping output only if FILECHECK_DUMP_INPUT_ON_FAILURE is set to
a non-empty value. This is necessary to support disabling it via
POSIX-compliant env(1) that does not support '-u' argument,
and therefore fix regression caused by r366980.
Sean Fertile [Fri, 26 Jul 2019 14:02:17 +0000 (14:02 +0000)]
[PowerPC] Add getCRSaveOffset to improve readability. [NFC]
In preperation for AIX support in FrameLowering: replace a number of literal
'8' that represent the stack offset of the condition register save area with
a member in PPCFrameLowering.
Petar Avramovic [Fri, 26 Jul 2019 13:19:37 +0000 (13:19 +0000)]
[MIPS GlobalISel] Fix check for void return during lowerCall
Void return used to have unsigned with value 0 for virtual register
but with addition of Register class and changes to arguments to lowerCall
this is no longer valid.
Check for void return by inspecting the Ty field in OrigRet.
(Y * (1.0 - Z)) + (X * Z) -->
Y - (Y * Z) + (X * Z) -->
Y + Z * (X - Y)
This is part of solving:
https://bugs.llvm.org/show_bug.cgi?id=42716
Factoring eliminates an instruction, so that should be a good canonicalization.
The potential conversion to FMA would be handled by the backend based on target
capabilities.
Embedded Trace Extension and Trace Buffer Extension are optional
future architecture extensions.
(cf. https://developer.arm.com/architectures/cpu-architecture/a-profile/exploration-tools)
Their system registers are documented here:
https://developer.arm.com/docs/ddi0601/a
ETE shares register names with ETM. One exception is the ETE
TRCEXTINSELR0 register, which has the same encoding as the ETM
TRCEXTINSELR register (but different semantics). This patch treats
them as aliases: the assembler will accept both names, emitting
identical encoding, and the disassembler will keep disassembling
to TRCEXRINSELR.
Simon Pilgrim [Fri, 26 Jul 2019 09:13:29 +0000 (09:13 +0000)]
[SelectionDAG] GetDemandedBits - update OR/XOR ops to just call SimplifyMultipleUseDemandedBits.
Eventually all of these will be moved over, but we create nodes in GetDemandedBits recursion at the moment which causes regressions when we try to remove them all.
Sam Parker [Fri, 26 Jul 2019 08:15:01 +0000 (08:15 +0000)]
[ARM][LowOverheadLoops] Add CPSR defs
Both WhileLoopStart and LoopEnd may get turned into a cmp and br pair,
so add an implicit def to these pseudo instructions in case that WLS
and LE aren't generated.
Pengfei Wang [Fri, 26 Jul 2019 07:33:15 +0000 (07:33 +0000)]
[WinEH] Allocate space in funclets stack to save XMM CSRs
Summary:
This is an alternate approach to D57970.
Currently funclets reuse the same stack slots that are used in the
parent function for saving callee-saved xmm registers. If the parent
function modifies a callee-saved xmm register before an excpetion is
thrown, the catch handler will overwrite the original saved value.
This patch allocates space in funclets stack for saving callee-saved xmm
registers and uses RSP instead RBP to access memory.
Matt Arsenault [Fri, 26 Jul 2019 02:36:05 +0000 (02:36 +0000)]
AMDGPU/GlobalISel: Handle most function return types
handleAssignments gives up pretty easily on structs, and i8 values for
some reason. The other case that doesn't work is when an implicit sret
needs to be inserted if the return size exceeds the number of return
registers.
Kang Zhang [Fri, 26 Jul 2019 01:58:53 +0000 (01:58 +0000)]
[PowerPC] Do the Simple Early Return in block-placement pass to optimize the blocks
Summary:
In `block-placement` pass, it will create some patterns for unconditional we can do the simple early retrun.
But the `early-ret` pass is before `block-placement`, we don't want to run it again.
This patch is to do the simple early return to optimize the blocks at the last of `block-placement`.
Below is an example
```
BB: | BB:
XOR 3, 3, 4 | XOR 3, 3, 4
B TBB | B ChainBB
... | ...
ChainBB: | ChainBB:
B TBB | ADD 3, 3, 4
... | BLR
TBB: |
ADD 3, 3, 4 |
BLR |
```
[CodeGen] Don't resolve the stack protector frame accesses until PEI
Currently, stack protector loads and stores are resolved during
LocalStackSlotAllocation (if the pass needs to run). When this is the
case, the base register assigned to the frame access is going to be one
of the vregs created during LocalStackSlotAllocation. This means that we
are keeping a pointer to the stack protector slot, and we're using this
pointer to load and store to it.
In case register pressure goes up, we may end up spilling this pointer
to the stack, which can be a security concern.
Instead, leave it to PEI to resolve the frame accesses. In order to do
that, we make all stack protector accesses go through frame index
operands, then PEI will resolve this using an offset from sp/fp/bp.
Yonghong Song [Thu, 25 Jul 2019 21:47:27 +0000 (21:47 +0000)]
[BPF] fix typedef issue for offset relocation
Currently, the CO-RE offset relocation does not work
if any struct/union member or array element is a typedef.
For example,
typedef const int arr_t[7];
struct input {
arr_t a;
};
func(...) {
struct input *in = ...;
... __builtin_preserve_access_index(&in->a[1]) ...
}
The BPF backend calculated default offset is 0 while
4 is the correct answer. Similar issues exist for struct/union
typedef's.
When getting struct/union member or array element type,
we should trace down to the type by skipping typedef
and qualifiers const/volatile as this is what clang did
to generate getelementptr instructions.
(const/volatile member type qualifiers are already
ignored by clang.)
This patch fixed this issue, for each access index,
skipping typedef and const/volatile/restrict BTF types.
Signed-off-by: Yonghong Song <yhs@fb.com>
Differential Revision: https://reviews.llvm.org/D65259
Alex Lorenz [Thu, 25 Jul 2019 21:47:11 +0000 (21:47 +0000)]
[FileCollector] add support for recording empty directories
The file collector class is useful for constructing reproducers by
creating a snapshot of the files that are accessed. Sometimes it might
also be important to construct directories that don't necessarily have files,
but are still accessed by some tool that we want to make a reproducer for.
This is useful for instance for modeling the behavior of Clang's header search,
which scans through a number of directories it doesn't actually access when
looking for framework headers. This commit extends the file collector to allow
it to work with paths that are just directories, by constructing them as the
files are copied over.
Leonard Chan [Thu, 25 Jul 2019 20:53:15 +0000 (20:53 +0000)]
Reland the "[NewPM] Port Sancov" patch from rL365838. No functional
changes were made to the patch since then.
--------
[NewPM] Port Sancov
This patch contains a port of SanitizerCoverage to the new pass manager. This one's a bit hefty.
Changes:
- Split SanitizerCoverageModule into 2 SanitizerCoverage for passing over
functions and ModuleSanitizerCoverage for passing over modules.
- ModuleSanitizerCoverage exists for adding 2 module level calls to initialization
functions but only if there's a function that was instrumented by sancov.
- Added legacy and new PM wrapper classes that own instances of the 2 new classes.
- Update llvm tests and add clang tests.
[PredicateInfo] Replace pointer comparisons with deterministic compares.
Currently there are a few pointer comparisons in ValueDFS_Compare, which
can cause non-deterministic ordering when materializing values. There
are 2 cases this patch fixes:
1. Order defs before uses used to compare pointers, which guarantees
defs before uses, but causes non-deterministic ordering between 2
uses or 2 defs, depending on the allocation order. By converting the
pointers to booleans, we can circumvent that problem.
2. comparePHIRelated was comparing the basic block pointers of edges,
which also results in a non-deterministic order and is also not
really meaningful for ordering. By ordering by their destination DFS
numbers we guarantee a deterministic order.
For the example below, we can end up with 2 different uselist orderings,
when running `opt -mem2reg -ipsccp` hundreds of times. Because the
non-determinism is caused by allocation ordering, we cannot reproduce it
with ipsccp alone.
Roman Lebedev [Thu, 25 Jul 2019 20:26:34 +0000 (20:26 +0000)]
[NFC][DivRemPairs] Tests with rem in expanded form (PR42673)
As discussed in https://bugs.llvm.org/show_bug.cgi?id=42673
there is a TTI hook hasDivRemOp() that matters here.
While -div-rem-pairs will decompose 'rem' if that hook returns false,
nothing does the opposite transform.
We can't to this in InstCombine, because it does not currently
access TTI, and i'm not sure we should change that.
We can't really do that in DAGCombine since it also currently does not
access TTI.
We'd like to determine the idom of exit block after peeling one iteration.
Let Exit is exit block.
Let ExitingSet - is a set of predecessors of Exit block. They are exiting blocks.
Let Latch' and ExitingSet' are copies after a peeling.
We'd like to find an idom'(Exit) - idom of Exit after peeling.
It is an evident that idom'(Exit) will be the nearest common dominator of ExitingSet and ExitingSet'.
idom(Exit) is a nearest common dominator of ExitingSet.
idom(Exit)' is a nearest common dominator of ExitingSet'.
Taking into account that we have a single Latch, Latch' will dominate Header and idom(Exit).
So the idom'(Exit) is nearest common dominator of idom(Exit)' and Latch'.
All these basic blocks are in the same loop, so what we find is
(nearest common dominator of idom(Exit) and Latch)'.
[DDG] DirectedGraph as a base class for various dependence graphs such
as DDG and PDG.
Summary:
This is an implementation of a directed graph base class with explicit
representation of both nodes and edges. This implementation makes the
edges explicit because we expect to assign various attributes (such as
dependence type, distribution interference weight, etc) to the edges in
the derived classes such as DDG and DIG. The DirectedGraph consists of a
list of DGNode's. Each node consists of a (possibly empty) list of
outgoing edges to other nodes in the graph. A DGEdge contains a
reference to a single target node. Note that nodes do not know about
their incoming edges so the DirectedGraph class provides a function to
find all incoming edges to a given node.
This is the first patch in a series of patches that we are planning to
contribute upstream in order to implement Data Dependence Graph and
Program Dependence Graph.
More information about the proposed design can be found here:
https://ibm.ent.box.com/v/directed-graph-and-ddg
Authored By: bmahjour
Reviewer: Meinersbur, myhsum hfinkel, fhahn, jdoerfert, kbarton
Reviewed By: Meinersbur
Subscribers: mgorny, wuzish, jsji, lebedev.ri, dexonsmith, kristina,
llvm-commits, Whitney, etiotto
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D64088
[SimplifyCFG] avoid crashing after simplifying a switch (PR42737)
Later code in TryToSimplifyUncondBranchFromEmptyBlock() assumes that
we have cleaned up unreachable blocks, but that was not happening
with this switch transform.
As discussed in https://bugs.llvm.org/show_bug.cgi?id=42673
there is a TTI hook hasDivRemOp() that matters here.
While -div-rem-pairs will decompose 'rem' if that hook returns false,
nothing does the opposite transform.
We can't to this in InstCombine, because it does not currently
access TTI, and i'm not sure we should change that.
We may be able to teach DivRemPairs to do this, but this really is a
per-target perf optimization, and we seem to do the opposite transform
in backend if hasDivRemOp() returned false: https://godbolt.org/z/ttt4HZ
I think it makes sense to be consistent.
[LOOPINFO] Introduce the loop guard API.
Summary:
This is the first patch for the loop guard. We introduced
getLoopGuardBranch() and isGuarded().
This currently only works on simplified loop, as it requires a preheader
and a latch to identify the guard.
It will work on loops of the form:
/// GuardBB:
/// br cond1, Preheader, ExitSucc <== GuardBranch
/// Preheader:
/// br Header
/// Header:
/// ...
/// br Latch
/// Latch:
/// br cond2, Header, ExitBlock
/// ExitBlock:
/// br ExitSucc
/// ExitSucc:
Prior discussions leading upto the decision to introduce the loop guard
API: http://lists.llvm.org/pipermail/llvm-dev/2019-May/132607.html
Reviewer: reames, kbarton, hfinkel, jdoerfert, Meinersbur, dmgreen
Reviewed By: reames
Subscribers: wuzish, hiraditya, jsji, llvm-commits, bmahjour, etiotto
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D63885
CrashHandler: be careful about crashing while handling
Summary:
Looking at the current Apple-specific code for crash handling it does a few
silly things that I think we should avoid while handling crashes:
* Try real hard not to allocate.
* Set the global crash reporter string early so that any crash while
generating the stack trace will still report some info.
* Prevent reordering of operations in the current thread.
Yonghong Song [Thu, 25 Jul 2019 16:01:26 +0000 (16:01 +0000)]
[BPF] fix CO-RE incorrect index access string
Currently, we expect the CO-RE offset relocation records
a string encoding the original getelementptr access index,
so kernel bpf loader can decode it correctly.
For example,
struct s { int a; int b; };
struct t { int c; int d; };
#define _(x) (__builtin_preserve_access_index(x))
int get_value(const void *addr1, const void *addr2);
int test(struct s *arg1, struct t *arg2) {
return get_value(_(&arg1->b), _(&arg2->d));
}
We expect two offset relocations:
reloc 1: type s, access index 0, 1
reloc 2: type t, access index 0, 1
Two globals are created to retain access indexes for the
above two relocations with global variable names.
The first global has a name "0:1:". Unfortunately,
the second global has the name "0:1:.1" as the llvm
internals automatically add suffix ".1" to a global
with the same name. Later on, the BPF peels the last
character and record "0:1" and "0:1:." in the
relocation table.
This is not desirable. BPF backend could use the global
variable suffix knowledge to generate correct access str.
This patch rather took an approach not relying on
that knowledge. It generates "s:0:1:" and "t:0:1:" to
avoid global variable suffixes and later on generate
correct index access string "0:1" for both records.
Signed-off-by: Yonghong Song <yhs@fb.com>
Differential Revision: https://reviews.llvm.org/D65258
Revert "[InstCombine] try to narrow a truncated load"
This reverts commit bc4a63fd3c29c1a8ce22891bf34ee4dccfef578c, this is a
speculative revert to fix a number of sanitizer bots (like
sanitizer-x86_64-linux-bootstrap-ubsan) that have started to see stage2
compiler crashes, presumably due to a miscompile.
[PredicateInfo] Use SmallVector instead of SmallPtrSet.
We do not need the SmallPtrSet to avoid adding duplicates to
OpsToRename, because we already keep a ValueInfo mapping. If we see an
op for the first time, Infos will be empty and we can also add it to
OpsToRename.
We process operands by visiting BBs depth-first and then iterate over
all instructions & users, so the order should be deterministic.
Therefore we can skip one round of sorting, which we purely needed for
guaranteeing a deterministic order when iterating over the SmallPtrSet.
Michael Liao [Thu, 25 Jul 2019 14:50:18 +0000 (14:50 +0000)]
[AMDGPU] Run `unreachable-mbb-elimination` after isel to clean up PHIs.
Summary:
- As LCSSA is turned on just before isel, it may create PHI of the flow,
which is consumed by pseudo structurized CFG instructions. When that
PHIs are eliminated in O0, COPY may be placed wrongly as the these
pseudo structurized CFG instructions are considering prologue of MBB.
- Run extra `unreachable-mbb-elimination` at the end of isel to clean up
PHIs.
[AArch64][SVE] Allow explicit size specifier for predicate operand
... for the vector forms of `{SQ,UQ,}{INC,DEC}P` instructions. Also continue
supporting the exsting behaviour of not requiring an explicit size
specifier. The preferred disasembly is *with* the specifier.
This is implemented by redefining intruction forms to require vector predicates
with explicit size and adding aliases, which allow a predicate with no size.
Summary:
It is a good idea to do as much matching inside of `match()` as possible.
If some checking is done afterwards, and we don't fold because of it,
chances are we may have missed some commutative pattern.