George Rimar [Tue, 23 Jul 2019 07:38:44 +0000 (07:38 +0000)]
[yaml2elf] - Treat the SHN_UNDEF section as kind of regular section.
We have a logic that adds a few sections implicitly.
Though the SHT_NULL section with section number 0
is an exception.
In D64913 I want to teach yaml2obj to redefine the null section.
And in this patch I add it to the sections list,
to make it kind of a regular section.
[DAGCombiner] Make ShrinkLoadReplaceStoreWithStore return an SDValue instead of an SDNode*. NFCI
The function was calling getNode() on an SDValue to return and the
caller turned the result back into a SDValue. So just return the
original SDValue to avoid this.
Robert Widmann [Tue, 23 Jul 2019 04:56:44 +0000 (04:56 +0000)]
[LLVM-C] Improve Bindings to The Internalize Pass
Summary: Adds a binding to the internalize pass that allows the caller to pass a function pointer that acts as the visibility-preservation predicate. Previously, one could only pass an unsigned value (not LLVMBool?) that directed the pass to consider "main" or not.
Zi Xuan Wu [Tue, 23 Jul 2019 03:34:40 +0000 (03:34 +0000)]
[PowerPC] Replace float load/store pair with integer load/store pair when it's only used in load/store
Replace float load/store pair with integer load/store pair when it's only used in load/store,
because float load/store instructions cost more cycles then integer load/store.
A typical scenario is when there is a call with more than 13 float arguments passing, we need pass them by stack.
So we need a load/store pair to do such memory operation if the variable is global variable.
Liveness analysis abstract attribute used to indicate which BasicBlocks are dead and can therefore be ignored.
Right now we are only looking at noreturn calls.
Philip Reames [Mon, 22 Jul 2019 23:33:18 +0000 (23:33 +0000)]
[Statepoints] Fix a bug in statepoint lowering for functions w/no-realign-stack
We were silently using the ABI alignment for all of the stores generated for deopt and gc values. We'd gotten the alignment of the stack slot itself properly reduced (via MachineFrameInfo's clamping), but having the MMO on the store incorrect was enough for us to generate an aligned store to a unaligned location.
The simplest fix would have been to just pass the alignment to the helper function, but once we do that, the helper function doesn't really help. So, inline it and directly call the MMO version of DAG.getStore with a properly constructed MMO.
Note that there's a separate performance possibility here. Even if we *can* realign stacks, we probably don't *want to* if all of the stores are in slowpaths. But that's a later patch, if at all. :)
[DWARF] Add more error handling to debug line parser.
This patch exnteds the error handling in the debug line parser to get
rid of the existing MD5 assertion. I want to reuse the debug line parser
from LLVM in LLDB where we cannot crash on invalid input.
Analysis: Don't look through aliases when simplifying GEPs.
It is not safe in general to replace an alias in a GEP with its aliasee
if the alias can be replaced with another definition (i.e. via strong/weak
resolution (linkonce_odr) or via symbol interposition (default visibility
in ELF)) while the aliasee cannot. An example of how this can go wrong is
in the included test case.
I was concerned that this might be a load-bearing misoptimization (it's
possible for us to use aliases to share vtables between base and derived
classes, and on Windows, vtable symbols will always be aliases in RTTI
mode, so this change could theoretically inhibit trivial devirtualization
in some cases), so I built Chromium for Linux and Windows with and without
this change. The file sizes of the resulting binaries were identical, so it
doesn't look like this is going to be a problem.
Liveness analysis abstract attribute used to indicate which BasicBlocks are dead and can therefore be ignored.
Right now we are only looking at noreturn calls.
Roman Lebedev [Mon, 22 Jul 2019 22:08:55 +0000 (22:08 +0000)]
[SimplifyCFG][NFC] Test that we fail to flatten CFG after forming @llvm.umul.with.overflow
Even if we formed @llvm.umul.with.overflow, we are still stuck
with that guard against div-by-zero, which is no longer needed,
because we didn't flatten the CFG.
Roman Lebedev [Mon, 22 Jul 2019 22:08:35 +0000 (22:08 +0000)]
[NFC][PhaseOrdering] Add tests showcasing the problems of unsigned multiply overflow check
While we can form the @llvm.mul.with.overflow easily,
we are still left with that check that was guarding against div-by-0.
And in the second case we won't even flatten the CFG.
Matt Arsenault [Mon, 22 Jul 2019 21:38:11 +0000 (21:38 +0000)]
AMDGPU: Don't use SDNodeXForm for DS offset output
The xform has no real valuewhen it's using out of a complex pattern
output. The complex pattern was already creating TargetConstants with
i16, so this was just unnecessary machinery.
This allows global isel to import the simple cases once the complex
pattern is implemented.
Liveness analysis abstract attribute used to indicate which BasicBlocks are dead and can therefore be ignored.
Right now we are only looking at noreturn calls.
[X86] When using AND+PACKUS in lowerV16I8Shuffle, generate the build vector directly in v16i8 with the correct 0x00 or 0xFF elements rather than using another VT and bitcasting it.
The build_vector will become a constant pool load. By using the
desired type initially, it ensures we don't generate a bitcast
of the constant pool load which will need to be folded with
the load.
While experimenting with another patch, I noticed that when the
load type and the constant pool type don't match, then
SimplifyDemandedBits can't handle it. While we should probably
fix that, this was a simple way to fix the issue I saw.
Jason Liu [Mon, 22 Jul 2019 19:55:33 +0000 (19:55 +0000)]
[NFC][PowerPC]Change ADDIStocHA to ADDIStocHA8 to follow 64-bit naming convention
Summary:
Since we are planning to add ADDIStocHA for 32bit in later patch, we decided
to change 64bit one first to follow naming convention with 8 behind opcode.
Sean Fertile [Mon, 22 Jul 2019 19:15:29 +0000 (19:15 +0000)]
Stubs out TLOF for AIX and add support for common vars in assembly output.
Stubs out a TargetLoweringObjectFileXCOFF class, implementing only
SelectSectionForGlobal for common symbols. Also adds an override of
EmitGlobalVariable in PPCAIXAsmPrinter which adds a number of defensive errors
and adds support for emitting common globals.
The order of operations in the DWARF symbols is incorrect in this case.
Specifically, the deref is incorrect; this appears to be incorrectly
re-inserted in repalceOneDbgValueForAlloca.
With this change which inserts the deref after the offset instead of
before it, LLVM produces correct DWARF:
WholeProgramDevirt: Teach the pass to respect the global's alignment.
The bytes inserted before an overaligned global need to be padded according
to the alignment set on the original global in order for the initializer
to meet the global's alignment requirements. The previous implementation
that padded to the pointer width happened to be correct for vtables on most
platforms but may do the wrong thing if the vtable has a larger alignment.
This issue is visible with a prototype implementation of HWASAN for globals,
which will overalign all globals including vtables to 16 bytes.
There is also no padding requirement for the bytes inserted after the global
because they are never read from nor are they significant for alignment
purposes, so stop inserting padding there.
LowerTypeTests: Teach the pass to respect global alignments.
We were previously ignoring alignment entirely when combining globals
together in this pass. There are two main things that we need to do here:
add additional padding before each global to meet the alignment requirements,
and set the combined global's alignment to the maximum of all of the original
globals' alignments.
Since we now need to calculate layout as we go anyway, use the calculated
layout to produce GlobalLayout instead of using StructLayout.
Sam Parker [Mon, 22 Jul 2019 14:16:40 +0000 (14:16 +0000)]
[ARM][LowOverheadLoops] Revert remaining pseudos
ARMLowOverheadLoops would assert a failure if it did not find all the
pseudo instructions that comprise the hardware loop. Instead of doing
this, iterate through all the instructions of the function and revert
any remaining pseudo instructions that haven't been converted.
Nikola Prica [Mon, 22 Jul 2019 13:07:01 +0000 (13:07 +0000)]
Reland [ELF] Loose a condition for relocation with a symbol
This patch was not the reason of the buildbot failure.
Deleted code was introduced as a work around for a bug in the gold linker
(http://sourceware.org/PR16794). Test case that was given as a reason for
this part of code, the one on previous link, now works for the gold.
This condition is too strict and when a code is compiled with debug info
it forces generation of numerous relocations with symbol for architectures
that do not have relocation addend.
Simon Pilgrim [Mon, 22 Jul 2019 12:44:10 +0000 (12:44 +0000)]
[X86] EltsFromConsecutiveLoads - support common source loads (REAPPLIED)
This patch enables us to find the source loads for each element, splitting them into a Load and ByteOffset, and attempts to recognise consecutive loads that are in fact from the same source load.
A helper function, findEltLoadSrc, recurses to find a LoadSDNode and determines the element's byte offset within it. When attempting to match consecutive loads, byte offsetted loads then attempt to matched against a previous load that has already been confirmed to be a consecutive match.
Next step towards PR16739 - after this we just need to account for shuffling/repeated elements to create a vector load + shuffle.
Fixed out of bounds load assert identified in rL366501
George Rimar [Mon, 22 Jul 2019 12:01:52 +0000 (12:01 +0000)]
[yaml2obj] - Change how we handle implicit sections.
Instead of having the special list of implicit sections,
that are mixed with the sections read from YAML on late
stages, I just create the placeholders and add them to
the main sections list early.
Stefan Granitz [Mon, 22 Jul 2019 09:47:40 +0000 (09:47 +0000)]
Add location of SVN staging dir to git-llvm error output
Summary:
In pre-monorepo times the svn staging directory was `.git/svn`. The below error message wasn't mentioning the new name yet.
Example before:
```
Can't push git rev 104cfa289d9 because svn status is not empty:
! llvm/trunk/include/llvm
```
Example after:
```
Can't push git rev 104cfa289d9 because status in svn staging dir (.git/llvm-upstream-svn) is not empty:
! llvm/trunk/include/llvm
```
Oliver Stannard [Mon, 22 Jul 2019 08:44:36 +0000 (08:44 +0000)]
[IPRA][ARM] Make use of the "returned" parameter attribute
ARM has code to recognise uses of the "returned" function parameter
attribute which guarantee that the value passed to the function in r0
will be returned in r0 unmodified. IPRA replaces the regmask on call
instructions, so needs to be told about this to avoid reverting the
optimisation.
Jay Foad [Mon, 22 Jul 2019 07:19:44 +0000 (07:19 +0000)]
[AMDGPU] Save some work when an atomic op has no uses
Summary:
In the atomic optimizer, save doing a bunch of work and generating a
bunch of dead IR in the fairly common case where the result of an
atomic op (i.e. the value that was in memory before the atomic op was
performed) is not used. NFC.
[Loop Peeling] Fix the handling of branch weights of peeled off branches.
Current algorithm to update branch weights of latch block and its copies is
based on the assumption that number of peeling iterations is approximately equal
to trip count.
However it is not correct. According to profitability check in one case we can decide to peel
in case it helps to reduce the number of phi nodes. In this case the number of peeled iteration
can be less then estimated trip count.
This patch introduces another way to set the branch weights to peeled of branches.
Let F is a weight of the edge from latch to header.
Let E is a weight of the edge from latch to exit.
F/(F+E) is a probability to go to loop and E/(F+E) is a probability to go to exit.
Then, Estimated TripCount = F / E.
For I-th (counting from 0) peeled off iteration we set the the weights for
the peeled latch as (TC - I, 1). It gives us reasonable distribution,
The probability to go to exit 1/(TC-I) increases. At the same time
the estimated trip count of remaining loop reduces by I.
As a result after peeling off N iteration the weights will be
(F - N * E, E) and trip count of loop becomes
F / E - N or TC - N.
The idea is taken from the review of the patch D63918 proposed by Philip.
[InstCombine] Add foldAndOfICmps test cases inspired by PR42691.
icmp ne %x, INT_MIN can be treated similarly to icmp sgt %x, INT_MIN.
icmp ne %x, INT_MAX can be treated similarly to icmp slt %x, INT_MAX.
icmp ne %x, UINT_MAX can be treated similarly to icmp ult %x, UINT_MAX.
We already treat icmp ne %x, 0 similarly to icmp ugt %x, 0
[InstCombine] Remove insertRangeTest code that handles the equality case.
For equality, the function called getTrue/getFalse with the VT
of the comparison input. But getTrue/getFalse need the boolean VT.
So if this code ever executed, it would assert.
I believe these cases are removed by InstSimplify so we don't get here.
So this patch just fixes up an assert to exclude the equality
possibility and removes the broken code.
[InstCombine] Don't use AddOne/SubOne to see if two APInts are 1 apart. Use APInt operations instead. NFCI
AddOne/SubOne create new Constant objects. That seems heavy for
comparing ConstantInts which wrap APInts. Just do the math on
on the APInts and compare them.
Roman Lebedev [Sat, 20 Jul 2019 16:33:15 +0000 (16:33 +0000)]
[Codegen][SelectionDAG] X u% C == 0 fold: non-splat vector improvements
Summary:
Four things here:
1. Generalize the fold to handle non-splat divisors. Reasonably trivial.
2. Unban power-of-two divisors. I don't see any reason why they should
be illegal.
* There is no ban in Hacker's Delight
* I think the ban came from the same bug that caused the miscompile
in the base patch - in `floor((2^W - 1) / D)` we were dividing by
`D0` instead of `D`, and we **were** ensuring that `D0` is not `1`,
which made sense.
3. Unban `1` divisors. I no longer believe Hacker's Delight actually says
that the fold is invalid for `D = 0`. Further considerations:
* We know that
* `(X u% 1) == 0` can be constant-folded to `1`,
* `(X u% 1) != 0` can be constant-folded to `0`,
* Also, we know that
* `X u<= -1` can be constant-folded to `1`,
* `X u> -1` can be constant-folded to `0`,
* https://godbolt.org/z/7jnZJX https://rise4fun.com/Alive/oF6p
* We know will end up with the following:
`(setule/setugt (rotr (mul N, P), K), Q)`
* Therefore, for given new DAG nodes and comparison predicates
(`ule`/`ugt`), we will still produce the correct answer if:
`Q` is a all-ones constant; and both `P` and `K` are *anything*
other than `undef`.
* The fold will indeed produce `Q = all-ones`.
4. Try to re-splat the `P` and `K` vectors - we don't care about
their values for the lanes where divisor was `1`.
Simon Pilgrim [Sat, 20 Jul 2019 15:20:11 +0000 (15:20 +0000)]
[X86][SSE] Use PSADBW to improve vXi8 sum reduction (PR42674)
As detailed on PR42674, we can reduce a vXi8 down until we have the final <8 x i8>, and then use PSADBW with zero, to sum those values. We then extract the bottom i8, discarding any overflow from the upper bits of the i16 result.
[GlobalISel][AArch64] Contract trivial same-size cross-bank copies into G_STOREs
Sometimes, you can end up with cross-bank copies between same-sized GPRs and
FPRs, which feed into G_STOREs. When these copies feed only into stores, they
aren't necessary; we can just store using the original register bank.
This provides some minor code size savings for some floating point SPEC
benchmarks. (Around 0.2% for 453.povray and 450.soplex)
This issue doesn't seem to show up due to regbankselect or anything similar. So,
this patch introduces an early select function, `contractCrossBankCopyIntoStore`
which performs the contraction when possible. The selector then continues
normally and selects the correct store opcode, eliminating needless copies
along the way.
Daniel Sanders [Fri, 19 Jul 2019 22:46:47 +0000 (22:46 +0000)]
Re-commit: r366610 and r366612: Expand pseudo-components before embedding in llvm-config
There were two main problems:
* The 'nativecodegen' pseudo-component was unconditionally adding
${native_tgt}CodeGen even though it conditionally added ${native_tgt}Info and
${native_tgt}Desc. This has been fixed by making ${native_tgt}CodeGen
conditional too
* The 'all' pseudo-component was causing library names like LLVMLLVMDemangle as
the expansion was to a library name and not a component. There doesn't seem to
be a list of available components anywhere so this has been fixed by moving the
expansion of 'all' back where it was before. This manifested in different ways
on different builders but it was the same root cause
Daniel Sanders [Fri, 19 Jul 2019 21:11:05 +0000 (21:11 +0000)]
Revert r366610 and r366612: Expand pseudo-components before embedding in llvm-config
Some targets are missing LLVMDemangle, one is adding the LLVM prefix twice, and two
are hitting the very error this patch fixes for my target. Reverting while I work
through the reports.
Daniel Sanders [Fri, 19 Jul 2019 20:58:11 +0000 (20:58 +0000)]
Fix a latent bug discovered by r366610: nativecodegen includes X86CodeGen when X86 is not compiled
I believe this to have been a latent bug as the same expansion checks for the
existence of ${native_tgt}Info and ${native_tgt}Desc and only adds them if
they were compiled but unconditionally adds ${native_tgt}CodeGen.
This should fix llvm-clang-x86_64-win-fast which builds ARM only on an X86 host and similar builders.
Daniel Sanders [Fri, 19 Jul 2019 20:38:05 +0000 (20:38 +0000)]
Expand pseudo-components before embedding in llvm-config
Summary:
If you use pseudo-targets like AllTargetsCodeGens in LLVM_DYLIB_COMPONENTS
then a test will fail because `./bin/llvm-config --shared-mode` can't
handle these targets. We can fix this by expanding them before embedding
the string into llvm-config
Matt Arsenault [Fri, 19 Jul 2019 19:32:00 +0000 (19:32 +0000)]
LiveIntervals: Fix handleMove asserting on BUNDLE
The top-level BUNDLE instruction should behave as an ordinary
instruction. It is supposed to have all relevant registers as implicit
operands. Moving it should work as any other instruction. I believe
the assert intended to avoid moving instructions inside bundles.
projects / llvm / log