Hint to hardware to move the cache line containing the
address to a more distant level of the cache without
writing back to memory.
Reviewers: craig.topper, zvi
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D45256
llvm-svn: 329992
This completes the work started in r329604 and r329605 when we changed clang to no longer use the intrinsics.
We lost some InstCombine SimplifyDemandedBit optimizations through this change as we aren't able to fold 'and', bitcast, shuffle very well.
llvm-svn: 329990
A previously missing intrinsic for an old instruction.
Reviewers: craig.topper, echristo
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D45312
llvm-svn: 329936
This change is exposing UB in source code - as was warned/predicted. :)
See D44909 for discussion. Reverting while we figure out how to fix things.
llvm-svn: 329920
Similar to the wbinvd instruction, except this
one does not invalidate caches. Ring 0 only.
The encoding matches a wbinvd instruction with
an F3 prefix.
Reviewers: craig.topper, zvi, ashlykov
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D43816
llvm-svn: 329847
Atom is the only x86 target that still uses schedule itineraries, if we can remove this then we can begin the work on removing x86 itineraries. I've also found that it will help with PR36550.
I've focussed on matching the existing model as closely as possible (relying on the schedule tests), PR36895 indicated a lot of these were incorrect but we can just as easily fix these after this patch as before. Hopefully we can get llvm-exegesis to help here,
There are a few instructions that rely on itinerary scheduling (mainly push/pop/return) of multiple resource stages, but I don't think any of these are show stoppers.
There are also a few codegen changes that seem related to the post-ra scheduler acting a little differently, I haven't tracked these down but they don't seem critical.
NOTE: I don't have access to any Atom hardware, so this hasn't been tested in the wild.
Differential Revision: https://reviews.llvm.org/D45486
llvm-svn: 329837
This is causing compilation timeouts on code with long sequences of
local values and calls (i.e. foo(1); foo(2); foo(3); ...). It turns out
that code coverage instrumentation is a great way to create sequences
like this, which how our users ran into the issue in practice.
Intel has a tool that detects these kinds of non-linear compile time
issues, and Andy Kaylor reported it as PR37010.
The current sinking code scans the whole basic block once per local
value sink, which happens before emitting each call. In theory, local
values should only be introduced to be used by instructions between the
current flush point and the last flush point, so we should only need to
scan those instructions.
llvm-svn: 329822
The 128/256-bit versions were no longer used by clang. It uses the legacy SSE/AVX2 version and a select. The 512-bit was changed to the same for consistency.
llvm-svn: 329774
With -fno-plt, for example, calls to printf when getting converted to puts
still use the PLT. This patch checks for the metadata "RtLibUseGOT" and
annotates the declaration with the right attributes.
Differential Revision: https://reviews.llvm.org/D45180
llvm-svn: 329768
Summary:
Darwin dynamic linker can handle weak symbols in ConstDataSection.
ReadonReadOnlyWithRel symbols should be emitted in ConstDataSection
instead of normal DataSection.
rdar://problem/39298457
Reviewers: dexonsmith, kledzik
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45472
llvm-svn: 329752
This cleans up a number of operations that only claimed te use EFLAGS
due to using DF. But no instructions which we think of us setting EFLAGS
actually modify DF (other than things like popf) and so this needlessly
creates uses of EFLAGS that aren't really there.
In fact, DF is so restrictive it is pretty easy to model. Only STD, CLD,
and the whole-flags writes (WRFLAGS and POPF) need to model this.
I've also somewhat cleaned up some of the flag management instruction
definitions to be in the correct .td file.
Adding this extra register also uncovered a failure to use the correct
datatype to hold X86 registers, and I've corrected that as necessary
here.
Differential Revision: https://reviews.llvm.org/D45154
llvm-svn: 329673
Prefer to use the 32-bit AND with immediate instead.
Primarily I'm doing this to ensure that immediates created by shrinkAndImmediate will always get absorbed into the AND. But I do believe this would be a reduction in the number of uops that need to execute. Ideally we should shrink the 'and' and the 'load' during DAG combine to re-enable the fold.
Fixes PR37063.
llvm-svn: 329667
The key idea is to lower COPY nodes populating EFLAGS by scanning the
uses of EFLAGS and introducing dedicated code to preserve the necessary
state in a GPR. In the vast majority of cases, these uses are cmovCC and
jCC instructions. For such cases, we can very easily save and restore
the necessary information by simply inserting a setCC into a GPR where
the original flags are live, and then testing that GPR directly to feed
the cmov or conditional branch.
However, things are a bit more tricky if arithmetic is using the flags.
This patch handles the vast majority of cases that seem to come up in
practice: adc, adcx, adox, rcl, and rcr; all without taking advantage of
partially preserved EFLAGS as LLVM doesn't currently model that at all.
There are a large number of operations that techinaclly observe EFLAGS
currently but shouldn't in this case -- they typically are using DF.
Currently, they will not be handled by this approach. However, I have
never seen this issue come up in practice. It is already pretty rare to
have these patterns come up in practical code with LLVM. I had to resort
to writing MIR tests to cover most of the logic in this pass already.
I suspect even with its current amount of coverage of arithmetic users
of EFLAGS it will be a significant improvement over the current use of
pushf/popf. It will also produce substantially faster code in most of
the common patterns.
This patch also removes all of the old lowering for EFLAGS copies, and
the hack that forced us to use a frame pointer when EFLAGS copies were
found anywhere in a function so that the dynamic stack adjustment wasn't
a problem. None of this is needed as we now lower all of these copies
directly in MI and without require stack adjustments.
Lots of thanks to Reid who came up with several aspects of this
approach, and Craig who helped me work out a couple of things tripping
me up while working on this.
Differential Revision: https://reviews.llvm.org/D45146
llvm-svn: 329657
LowerIntUnary as its name says has an assert for integer types. But for the bitcast case one side might be an FP type.
Rather than making sure the function really works for fp types and renaming it. Just do really basic splitting directly. The LowerIntUnary has the advantage that it can peek through BUILD_VECTOR because every other call is during Lowering. But these calls are during legalization and will be followed by a DAG combine round.
Revert some change to LowerVectorIntUnary that were originally made just to make these two calls work even in pure integer cases.
This was found purely by compiling the avx512f-builtins.c test from clang so I've copied over the offending function from that.
llvm-svn: 329616
In somes cases fast-isel fails to remove the and/shifts and uses blends or conditional moves.
But once masking gets involved, fast-isel aborts on the mask portion and we DAG combine more thorougly.
llvm-svn: 329604
While it appears to be correct information based on Intel's optimization manual and Agner's data, it causes perf regressions on a couple of the benchmarks in our internal list.
llvm-svn: 329593
Recommitting r329283, third time lucky...
If the SRL node is only used by an AND, we may be able to set the
ExtVT to the width of the mask, making the AND redundant. To support
this, another check has been added in isLegalNarrowLoad which queries
whether the load is valid.
Differential Revision: https://reviews.llvm.org/D41350
llvm-svn: 329551
Summary:
Currently MachineLoopInfo is used in only two places:
1) for computing IsBasicBlockInsideInnermostLoop field of MCCodePaddingContext, and it is never used.
2) in emitBasicBlockLoopComments, which is called only if `isVerbose()` is true.
Despite that, we currently have a dependency on MachineLoopInfo, which makes
pass manager to compute it and MachineDominator Tree. This patch removes the
use (1) and makes the use (2) lazy, thus avoiding some redundant
recomputations.
Reviewers: opaparo, gadi.haber, rafael, craig.topper, zvi
Subscribers: rengolin, javed.absar, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D44812
llvm-svn: 329542
Summary:
Cmov and setcc previously used WriteALU, but on Intel processors at least they are more restricted than basic ALU ops.
This patch adds new SchedWrites for them and removes the InstRWs. I had to leave some InstRWs for CMOVA/CMOVBE and SETA/SETBE because those have an extra uop relative to the other condition codes on Intel CPUs.
The test changes are due to fixing a missing ZnAGU dependency on the memory form of setcc.
Reviewers: RKSimon, andreadb, GGanesh
Reviewed By: RKSimon
Subscribers: GGanesh, llvm-commits
Differential Revision: https://reviews.llvm.org/D45380
llvm-svn: 329539
Summary:
This removes the InstRWs for BLENDVPS/PD in favor of WriteFVarBlend. The latency listed was 3 cycles but WriteFVarBlend is defined as 1 cycle latency. The 1 cycle latency matches Agner Fog's data.
The patterns were missing the VEX forms which is why there are no test changes. We don't test "-mcpu=znver1 -mattr=-avx"
Reviewers: RKSimon, GGanesh
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44841
llvm-svn: 329538
In our real world application, we found the following optimization is missed in DAGCombiner
(zext (and/or/xor (shl/shr (load x), cst), cst)) -> (and/or/xor (shl/shr (zextload x), (zext cst)), (zext cst))
If the user of original zext is an add, it may enable further lea optimization on x86.
This patch add a new function CombineZExtLogicopShiftLoad to do this optimization.
Differential Revision: https://reviews.llvm.org/D44402
llvm-svn: 329516
Previously we used a custom lowering for this because of the AVX1 splitting requirement. But we can do the split during DAG combine if we check the types and subtarget
llvm-svn: 329510
Should fix UBSan bot by also checking there's no "uwtable" attribute
before skipping. Otherwise the unwind table will be useless since its
moves expect CSRs to actually be preserved.
A noreturn nounwind function can be expected to never return in any way, and by
never returning it will also never have to restore any callee-saved registers
for its caller. This makes it possible to skip spills of those registers during
function entry, saving some stack space and time in the process. This is rather
useful for embedded targets with limited stack space.
Should fix PR9970.
Patch mostly by myeisha (pmb).
llvm-svn: 329494
Summary:
The 'strong' StackProtector heuristic takes into consideration call instructions.
Certain intrinsics, such as lifetime.start, can cause the
StackProtector to protect functions that do not need to be protected.
Specifically, a volatile variable, (not optimized away), but belonging to a stack
allocation will encourage a llvm.lifetime.start to be inserted during
compilation. Because that intrinsic is a 'call' the strong StackProtector
will see that the alloca'd variable is being passed to a call instruction, and
insert a stack protector. In this case the intrinsic isn't really lowered to a
call. This can cause unnecessary stack checking, at the cost of additional
(wasted) CPU cycles.
In the future we should rely on TargetTransformInfo::isLoweredToCall, but as of
now that routine considers all intrinsics as not being lowerable. That needs
to be corrected, and such a change is on my list of things to get moving on.
As a side note, the updated stack-protector-dbginfo.ll test always seems to
pass. I never see the dbg.declare/dbg.value reaching the
StackProtector::HasAddressTaken, but I don't see any code excluding dbg
intrinsic calls either, so I think it's the safest thing to do.
Reviewers: void, timshen
Reviewed By: timshen
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45331
llvm-svn: 329450
Summary:
This patch removes InstRW overrides for basic arithmetic/logic instructions. To do this I've added the store address port to RMW. And used a WriteSequence to make the latency additive. It does not cover ADC/SBB because they have different latency.
Apparently we were inconsistent about whether the store has latency or not thus the test changes.
I've also left out Sandy Bridge because the load latency there is currently 4 cycles and should be 5.
Reviewers: RKSimon, andreadb
Reviewed By: andreadb
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45351
llvm-svn: 329416
As mentioned on D44647, this patch increases the default memory latency to +5cy , which more closely matches what most custom cases are doing for reg-mem instructions.
I've bumped LoadLatency, ReadAfterLd and WriteLoad values to 5cy to be consistent.
As Sandy Bridge is currently our default generic model, this affects a lot of scheduling tests...
Differential Revision: https://reviews.llvm.org/D44654
llvm-svn: 329388
This is the 32-bit mode version of LEAVE64. It should be at least somewhat similar to LEAVE64.
The Sandy Bridge version was missing a load port use.
llvm-svn: 329347
We were forcing the latency of these instructions to 5 cycles, but every other scheduler model had them as 1 cycle. I'm sure I didn't get everything, but this gets a big portion.
llvm-svn: 329339
A noreturn nounwind function can be expected to never return in any way, and by
never returning it will also never have to restore any callee-saved registers
for its caller. This makes it possible to skip spills of those registers during
function entry, saving some stack space and time in the process. This is rather
useful for embedded targets with limited stack space.
Should fix PR9970.
Patch by myeisha (pmb).
llvm-svn: 329287
It's failing on the bots and I'm not sure why.
This reverts:
[X86] Synchronize the SchedRW on some EVEX instructions with their VEX equivalents.
[X86] Use WriteFShuffle256 for VEXTRACTF128 to be consistent with VEXTRACTI128 which uses WriteShuffle256.
[X86] Remove some InstRWs for plain store instructions on Sandy Bridge.
[X86] Auto-generate complete checks. NFC
llvm-svn: 329256
We were forcing the latency of these instructions to 5 cycles, but every other scheduler model had them as 1 cycle. I'm sure I didn't get everything, but this gets a big portion.
llvm-svn: 329252
Recommitting rL321259. Previosuly this caused an issue with PPCBE but
I didn't receieve a reproducer and didn't have the time to follow up.
If the issue appears again, please provide a reproducer so I can fix
it.
Original commit message:
If the SRL node is only used by an AND, we may be able to set the
ExtVT to the width of the mask, making the AND redundant. To support
this, another check has been added in isLegalNarrowLoad which queries
whether the load is valid.
Differential Revision: https://reviews.llvm.org/D41350
llvm-svn: 329160
Summary:
The ShadowCallStack pass instruments functions marked with the
shadowcallstack attribute. The instrumented prolog saves the return
address to [gs:offset] where offset is stored and updated in [gs:0].
The instrumented epilog loads/updates the return address from [gs:0]
and checks that it matches the return address on the stack before
returning.
Reviewers: pcc, vitalybuka
Reviewed By: pcc
Subscribers: cryptoad, eugenis, craig.topper, mgorny, llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D44802
llvm-svn: 329139
This commit is similar to r329120, but uses the existing getUsesRedZone() function
in X86MachineFunctionInfo. This teaches the outliner to look at whether or not a
function *truly* uses a redzone instead of just the noredzone attribute on a
function.
Thus, after this commit, it's possible to outline from x86 without using
-mno-red-zone and still get outlining results.
This also adds a new test for the new redzone behaviour.
llvm-svn: 329134
The linkage type on outlined functions was private before. This meant that if
you set a breakpoint in an outlined function, the debugger wouldn't be able to
give a sane name to the outlined function.
This commit changes the linkage type to internal and updates any tests that
relied on the prefixes on the names of outlined functions.
llvm-svn: 329116
We don't constant fold any of these, but we could...but if we
do, we must produce the right answer.
Unlike the IR fptosi instruction or its DAG node counterpart
ISD::FP_TO_SINT, these are not undef for an out-of-range input.
llvm-svn: 329100
fact use regular expression syntax to use regular expressions.
Should restore the bots. Sorry for the noise on this test.
Thanks to Philip for spotting the bug!
llvm-svn: 329057
This adds the basic test cases from all the EFLAGS bugs in more direct
forms. It also switches to generated check lines, and includes both
32-bit and 64-bit variations.
No functionality changing here, just setting things up to have a nice
clean asm diff in my EFLAGS patch.
llvm-svn: 329056
do explicit scrubbing of the offsets of stack spills and reloads.
You can always turn this off in order to test specific stack slot usage.
We were already hiding most of this, but the new logic hides it more
generically. Notably, we should effectively hide stack slot churn in
functions that have a frame pointer now, and should also hide it when
changing a function from stack pointer to frame pointer. That transition
already changes enough to be clearly noticed in the test case diff,
showing *every* spill and reload is really noisy without benefit. See
the test case I ran this on as a classic example.
llvm-svn: 329055
Just adds basic block labels and tidies up where comments go in the test
case and then generates fresh CHECK lines with the script. This way, the
check lines are much easier to maintain. They were already close to this
but not quite there.
llvm-svn: 329040
If a load follows a store and reloads data that the store has written to memory, Intel microarchitectures can in many cases forward the data directly from the store to the load, This "store forwarding" saves cycles by enabling the load to directly obtain the data instead of accessing the data from cache or memory.
A "store forward block" occurs in cases that a store cannot be forwarded to the load. The most typical case of store forward block on Intel Core microarchiticutre that a small store cannot be forwarded to a large load.
The estimated penalty for a store forward block is ~13 cycles.
This pass tries to recognize and handle cases where "store forward block" is created by the compiler when lowering memcpy calls to a sequence
of a load and a store.
The pass currently only handles cases where memcpy is lowered to XMM/YMM registers, it tries to break the memcpy into smaller copies.
breaking the memcpy should be possible since there is no atomicity guarantee for loads and stores to XMM/YMM.
Differential revision: https://reviews.llvm.org/D41330
Change-Id: Ib48836ccdf6005989f7d4466fa2035b7b04415d9
llvm-svn: 328973
fptosi / fptoui round towards zero, and that's the same behavior as ISD::FTRUNC,
so replace a pair of casts with the equivalent node. We don't have to account for
special cases (NaN, INF) because out-of-range casts are undefined.
Differential Revision: https://reviews.llvm.org/D44909
llvm-svn: 328921
Summary:
It seems many CPUs don't implement this instruction as well as the other vector multiplies. Often using a multi uop flow. Silvermont in particular has a 7 uop flow with 11 cycle throughput. Sandy Bridge implements it as a single uop with 5 cycle latency and 1 cycle throughput. But Haswell and later use 2 uops with 10 cycle latency and 2 cycle throughput.
This patch adds a new X86SchedWritePair we can use to tag this instruction separately. I've provided correct information for Silvermont, Btver2, and Sandy Bridge. I've removed the InstRWs for SandyBridge. I've left Haswell/Broadwell/Skylake InstRWs in place because I wasn't sure how to account for the different load latency between 128 and 256 bits. I also left Znver1 InstRWs in place because the existing values don't match Agner's spreadsheet.
I also left a FIXME in the SandyBridge model because it being used for the "generic" model is too optimistic for the 256/512-bit versions since those are multiple uops on all known CPUs.
Reviewers: RKSimon, GGanesh, courbet
Reviewed By: RKSimon
Subscribers: gchatelet, gbedwell, andreadb, llvm-commits
Differential Revision: https://reviews.llvm.org/D44972
llvm-svn: 328914
The code has bugs dealing with -0.0.
Since D44550 introduced FABS pattern folding in InstCombine,
this patch removes the now-redundant code that causes
https://bugs.llvm.org/show_bug.cgi?id=36600.
Patch by Mikhail Dvoretckii!
Differential Revision: https://reviews.llvm.org/D44683
llvm-svn: 328872
These instructions have the memory operand before the register operand. So we need to put ReadDefault for all the load ops first. Then the ReadAfterLd
Differential Revision: https://reviews.llvm.org/D44838
llvm-svn: 328823
Summary: Mark CFG is preserved since this pass do not make any change in CFG.
Reviewers: sebpop, mzolotukhin, mcrosier
Reviewed By: mzolotukhin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44845
llvm-svn: 328727
If a given split type unit does not have source locations, don't have
it refer to the split line table.
If no split type unit refers to the split line table, don't emit the
line table at all.
This will save a little space on rare occasions, but also refactors
things a bit to improve which class is responsible for what.
Responding to review comments on r326395.
Differential Revision: https://reviews.llvm.org/D44220
llvm-svn: 328670
Currently MOVMSK instructions use the WriteVecLogic class, which is a very poor choice given that MOVMSK involves a SSE->GPR transfer.
Differential Revision: https://reviews.llvm.org/D44924
llvm-svn: 328664
On Hexagon "x = y" is a syntax used in most instructions, and is not
treated as a directive.
Differential Revision: https://reviews.llvm.org/D44256
llvm-svn: 328635
Tim Northover