Commit Graph

10946 Commits

Author SHA1 Message Date
Roman Lebedev 32bee42719
[NFCI][LoopIdiom] 'left-shift until bittest': assert that BaseX is loop-invariant
Given that BaseX is an incoming value when coming from the preheader,
it *should* be loop-invariant, but let's just document this assumption.
2021-05-24 12:15:06 +03:00
Roman Lebedev aa3dac95ed
[LoopIdiom] 'logical right shift until zero': the value must be loop-invariant
As per the reproducer provided by Mikael Holmén in post-commit review.
2021-05-24 12:15:06 +03:00
maekawatoshiki d65c32fb41 [LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D99149
2021-05-23 22:32:01 +09:00
Florian Hahn a6de8d95db
[Matrix] Bail out early if there are no matrix intrinsics.
If there are no matrix intrinsics in a function, we can directly bail
out, as there's nothing left to do.

Reviewed By: anemet

Differential Revision: https://reviews.llvm.org/D102931
2021-05-22 11:37:25 +01:00
Florian Hahn a0ce6439ca
[Matrix] Remove unused matrix-propagate-shape option.
The option was used during the initial bringup, but it does not add any
value at this point. Remove it.

Reviewed By: anemet

Differential Revision: https://reviews.llvm.org/D102930
2021-05-21 19:01:54 +01:00
maekawatoshiki fd53cb4148 Revert "[LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass"
This reverts commit cea7a3fe3d.
To investigate sanitizer-x86_64-linux-fast failure.
2021-05-22 01:40:43 +09:00
maekawatoshiki cea7a3fe3d [LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D99149
2021-05-21 23:57:39 +09:00
Djordje Todorovic cd49b3ae1a [DebugInfo] Salvage dbg.value() during ADCE
This has been found by using the [0].

[0] https://llvm.org/docs/HowToUpdateDebugInfo.html#\
    test-original-debug-info-preservation-in-optimizations

 Differential Revision: https://reviews.llvm.org/D100844
2021-05-21 05:25:59 -07:00
Jon Roelofs 0af3105b64 Revert "[Remarks] Add analysis remarks for memset/memcpy/memmove lengths"
This reverts commit 4bf69fb52b.

This broke spec2k6/403.gcc under -global-isel. Details to follow once I've
reduced the problem.
2021-05-20 12:19:16 -07:00
Kevin P. Neal f21f1eea05 [FPEnv] EarlyCSE support for constrained intrinsics, default FP environment edition
EarlyCSE cannot distinguish between floating point instructions and
constrained floating point intrinsics that are marked as running in the
default FP environment. Said intrinsics are supposed to behave exactly the
same as the regular FP instructions. Teach EarlyCSE to handle them in that
case.

Differential Revision: https://reviews.llvm.org/D99962
2021-05-20 14:40:51 -04:00
Jon Roelofs 4bf69fb52b [Remarks] Add analysis remarks for memset/memcpy/memmove lengths
Differential revision: https://reviews.llvm.org/D102452
2021-05-19 15:09:18 -07:00
Roman Lebedev 729e18cbf4
[NFCI] SimplifyCFGPass: mergeEmptyReturnBlocks(): use DeleteDeadBlocks()
In this case, it does the same thing as the original pattern does.

SimplifyCFG has a few lurking miscompilations about deleting blocks that
have their address taken, and consistently using DeleteDeadBlocks() instead
 of a hand-rolled pattern will allow to weed those cases out easierly.
2021-05-19 11:32:24 +03:00
Arthur Eubanks 6b9524a05b [NewPM] Don't mark AA analyses as preserved
Currently all AA analyses marked as preserved are stateless, not taking
into account their dependent analyses. So there's no need to mark them
as preserved, they won't be invalidated unless their analyses are.

SCEVAAResults was the one exception to this, it was treated like a
typical analysis result. Make it like the others and don't invalidate
unless SCEV is invalidated.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D102032
2021-05-18 13:49:03 -07:00
Nikita Popov e81334a754 [LICM] Remove MaybePromotable set (PR50367)
The MaybePromotable set keeps track of loads/stores for which
promotion was not attempted yet. Normally, any load/stores that
are promoted in the current iteration will be removed from this
set, because they naturally MustAlias with the promoted value.
However, if the source program has UB with metadata claiming that
a store is NoAlias, while it is actually MustAlias, and multiple
different pointers are promoted in the same iteration, it can
happen that a store is removed that is still in the MaybePromotable
set, causing a use-after-free.

While this could be fixed by explicitly invalidating values in
MaybePromotable in the LoopPromoter, I'm going with the more
radical option of dropping the set entirely here and check all
load/stores on each promotion iteration. As promotion, and especially
repeated promotion, are quite rare, this doesn't seem to have any
impact on compile-time.

Fixes https://bugs.llvm.org/show_bug.cgi?id=50367.
2021-05-18 20:26:01 +02:00
Adam Nemet ab1f6ffa56 [GVN] Improve analysis for missed optimization remark
This change tries to handle multiple dominating users of the pointer operand
by choosing the most immediately dominating one, if possible.  While making
this change I also found that the previous implementation had a missing break
statement, making all loads with an odd number of dominating users emit an
OtherAccess value, so that has also been fixed.

Patch by Henrik G Olsson!

Differential Revision: https://reviews.llvm.org/D79097
2021-05-17 21:51:15 -07:00
Adam Nemet fcffd087c6 [Matrix] Fold the transpose into the matmul operand used to fetch scalars
For column-major this is:
  A * B^t
whereas for row-major:
  A^t * B

Differential Revision: https://reviews.llvm.org/D101762
2021-05-17 17:40:46 -07:00
Roman Lebedev 0633d5ce7b
[LoopIdiom] 'logical right-shift until zero' ('count active bits') "on steroids" idiom recognition.
I think i've added exhaustive test coverage, and i have verified that alive2 is happy with all the tests,
so in principle i'm fine with landing this without review, but just in case..

This adds support for the "count active bits" pattern, i.e.:
```
int countActiveBits(unsigned val) {
    int cnt = 0;
    for( ; (val >> cnt) != 0; ++cnt)
        ;
    return cnt;
}
```
but a somewhat more general one, since that is what i need:
```
int countActiveBits(unsigned val, int start, int off) {
    int cnt;
    for (cnt = start; val >> (cnt + off); cnt++)
        ;
    return cnt;
}
```

I've followed in footstep of 'left-shift until bittest' idiom (D91038),
in the sense that iff the `ctlz` intrinsic is cheap, we'll transform,
regardless of all other factors.

This can have a shocking effect on certain benchmarks:
```
raw.pixls.us-unique/Olympus/XZ-1$ /repositories/googlebenchmark/tools/compare.py -a benchmarks ~/rawspeed/build-{old,new}/src/utilities/rsbench/rsbench --benchmark_counters_tabular=true --benchmark_min_time=0.00000001 --benchmark_repetitions=128 p1319978.orf
RUNNING: /home/lebedevri/rawspeed/build-old/src/utilities/rsbench/rsbench --benchmark_counters_tabular=true --benchmark_min_time=0.00000001 --benchmark_repetitions=128 p1319978.orf --benchmark_display_aggregates_only=true --benchmark_out=/tmp/tmp49_28zcm
2021-05-09T01:06:05+03:00
Running /home/lebedevri/rawspeed/build-old/src/utilities/rsbench/rsbench
Run on (32 X 3600.24 MHz CPU s)
CPU Caches:
  L1 Data 32 KiB (x16)
  L1 Instruction 32 KiB (x16)
  L2 Unified 512 KiB (x16)
  L3 Unified 32768 KiB (x2)
Load Average: 5.26, 6.29, 3.49
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Benchmark                                                      Time             CPU   Iterations  CPUTime,s CPUTime/WallTime     Pixels Pixels/CPUTime Pixels/WallTime Raws/CPUTime Raws/WallTime WallTime,s
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
p1319978.orf/threads:32/process_time/real_time_mean          145 ms          145 ms          128   0.145319         0.999981   10.1568M       69.8949M        69.8936M      6.88159       6.88146   0.145322
p1319978.orf/threads:32/process_time/real_time_median        145 ms          145 ms          128   0.145317         0.999986   10.1568M       69.8941M        69.8931M      6.88151       6.88141   0.145319
p1319978.orf/threads:32/process_time/real_time_stddev      0.766 ms        0.766 ms          128   766.586u         15.1302u          0       354.167k        354.098k    0.0348699     0.0348631   766.469u
RUNNING: /home/lebedevri/rawspeed/build-new/src/utilities/rsbench/rsbench --benchmark_counters_tabular=true --benchmark_min_time=0.00000001 --benchmark_repetitions=128 p1319978.orf --benchmark_display_aggregates_only=true --benchmark_out=/tmp/tmpwb9sw2x0
2021-05-09T01:06:24+03:00
Running /home/lebedevri/rawspeed/build-new/src/utilities/rsbench/rsbench
Run on (32 X 3599.95 MHz CPU s)
CPU Caches:
  L1 Data 32 KiB (x16)
  L1 Instruction 32 KiB (x16)
  L2 Unified 512 KiB (x16)
  L3 Unified 32768 KiB (x2)
Load Average: 4.05, 5.95, 3.43
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Benchmark                                                      Time             CPU   Iterations  CPUTime,s CPUTime/WallTime     Pixels Pixels/CPUTime Pixels/WallTime Raws/CPUTime Raws/WallTime WallTime,s
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
p1319978.orf/threads:32/process_time/real_time_mean         99.8 ms         99.8 ms          128  0.0997758         0.999972   10.1568M       101.797M        101.794M      10.0225       10.0222  0.0997786
p1319978.orf/threads:32/process_time/real_time_median       99.7 ms         99.7 ms          128  0.0997165         0.999985   10.1568M       101.857M        101.854M      10.0284       10.0281  0.0997195
p1319978.orf/threads:32/process_time/real_time_stddev      0.224 ms        0.224 ms          128   224.166u          34.345u          0        226.81k        227.231k    0.0223309     0.0223723   224.586u
Comparing /home/lebedevri/rawspeed/build-old/src/utilities/rsbench/rsbench to /home/lebedevri/rawspeed/build-new/src/utilities/rsbench/rsbench
Benchmark                                                               Time             CPU      Time Old      Time New       CPU Old       CPU New
----------------------------------------------------------------------------------------------------------------------------------------------------
p1319978.orf/threads:32/process_time/real_time_pvalue                 0.0000          0.0000      U Test, Repetitions: 128 vs 128
p1319978.orf/threads:32/process_time/real_time_mean                  -0.3134         -0.3134           145           100           145           100
p1319978.orf/threads:32/process_time/real_time_median                -0.3138         -0.3138           145           100           145           100
p1319978.orf/threads:32/process_time/real_time_stddev                -0.7073         -0.7078             1             0             1             0

```

Reviewed By: craig.topper, zhuhan0

Differential Revision: https://reviews.llvm.org/D102116
2021-05-17 20:33:33 +03:00
Nikita Popov fb9ed1979a [IR] Add BasicBlock::isEntryBlock() (NFC)
This is a recurring and somewhat awkward pattern. Add a helper
method for it.
2021-05-15 12:41:58 +02:00
Vitaly Buka 6ce7b2f026 Fix "is not used" warning 2021-05-14 20:58:58 -07:00
Philip Reames fcd12fed41 Extract a helper routine to simplify D91481 [NFC] 2021-05-14 18:40:23 -07:00
Nick Desaulniers 8c72749bd9 [LowerConstantIntrinsics] reuse isManifestLogic from ConstantFolding
GlobalVariables are Constants, yet should not unconditionally be
considered true for __builtin_constant_p.

Via the LangRef
https://llvm.org/docs/LangRef.html#llvm-is-constant-intrinsic:

    This intrinsic generates no code. If its argument is known to be a
    manifest compile-time constant value, then the intrinsic will be
    converted to a constant true value. Otherwise, it will be converted
    to a constant false value.

    In particular, note that if the argument is a constant expression
    which refers to a global (the address of which _is_ a constant, but
    not manifest during the compile), then the intrinsic evaluates to
    false.

Move isManifestConstant from ConstantFolding to be a method of
Constant so that we can reuse the same logic in
LowerConstantIntrinsics.

pr/41459

Reviewed By: rsmith, george.burgess.iv

Differential Revision: https://reviews.llvm.org/D102367
2021-05-14 15:35:21 -07:00
Philip Reames 3f1c218318 [rs4gc] Strip memory related attributes consistently
I noticed that rs4gc is not stripping a number of memory aliasing related attributes. We do strip some from call sites, but don't strip the same ones from declarations or parameters.

Why do we need to strip these? Two answers:

    Safepoints conceptually read and write to the entire garbage collected heap in the physical model. We need this to preserve ordering of all loads and stores with respect to possible relocation.
    We can infer other attributes from these. For instance, readnone can imply both nofree and nosync. Both of which don't hold after physical rewriting.

Note: This exposed a latent issue which was fixed a couple weeks back in 01801d5274.

Differential Revision: https://reviews.llvm.org/D99802
2021-05-14 07:54:56 -07:00
dfukalov fdae3fc8b3 [GVN] Clobber partially aliased loads.
Use offsets stored in `AliasResult` implemented in D98718.

Updated with fix of issue reported in https://reviews.llvm.org/D95543#2745161

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D95543
2021-05-14 11:17:14 +03:00
David Green f7cb654763 [DSE] Move isOverwrite into DSEState. NFC
This moves the isOverwrite function into the DSEState so that it can
share the analyses and members from the state.

A few extra loop tests were also added to test stores in and around
multi block loops for D100464.
2021-05-14 09:16:51 +01:00
Jingu Kang 107d19eb01 Revert "[SimpleLoopUnswitch] Port partially invariant unswitch from LoopUnswitch to SimpleLoopUnswitch"
This reverts commit 88b259c014.

It needs to fix below bugs.

https://bugs.llvm.org/show_bug.cgi?id=50279
https://bugs.llvm.org/show_bug.cgi?id=50302
2021-05-13 08:40:49 +01:00
Stelios Ioannou 1124ad2f5d [LoopFlatten] Simplify loops so that the pass can operate on unsimplified loops.
The loop flattening pass requires loops to be in simplified form. If the
loops are not in simplified form, the pass cannot operate. This patch
simplifies all loops before flattening. As a result, all loops will be
simplified regardless of whether anything ends up being flattened.

This change was inspired by observing a certain loop that was not flatten
because the loops were not in simplified form. This loop is added as a
test to verify that it is now flattened.

Differential Revision: https://reviews.llvm.org/D102249

Change-Id: I45bcabe70fb99b0d89f0effafc82eb9e0585ec30
2021-05-12 19:22:01 +01:00
Congzhe Cao 3f8be15f29 [LoopInterchange] Handle lcssa PHIs with multiple predecessors
This is a bugfix in the transformation phase.

If the original outer loop header branches to both the inner loop
(header) and the outer loop latch, and if there is an lcssa PHI
node outside the loop nest, then after interchange the new outer latch
will have an lcssa PHI node inserted which has two predecessors, i.e.,
the original outer header and the original outer latch. Currently
the transformation assumes it has only one predecessor (the original
outer latch) and crashes, since the inserted lcssa PHI node does
not take both predecessors as incoming BBs.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D100792
2021-05-11 21:30:54 -04:00
Jordan Rupprecht fec2945998 Revert "[GVN] Clobber partially aliased loads."
This reverts commit 6c57044231.

It causes assertion errors due to widening atomic loads, and potentially causes miscompile elsewhere too. Repro, also posted to D95543:

```
$ cat repro.ll
; ModuleID = 'repro.ll'
source_filename = "repro.ll"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%struct.widget = type { i32 }
%struct.baz = type { i32, %struct.snork }
%struct.snork = type { %struct.spam }
%struct.spam = type { i32, i32 }

@global = external local_unnamed_addr global %struct.widget, align 4
@global.1 = external local_unnamed_addr global i8, align 1
@global.2 = external local_unnamed_addr global i32, align 4

define void @zot(%struct.baz* %arg) local_unnamed_addr align 2 {
bb:
  %tmp = getelementptr inbounds %struct.baz, %struct.baz* %arg, i64 0, i32 1
  %tmp1 = bitcast %struct.snork* %tmp to i64*
  %tmp2 = load i64, i64* %tmp1, align 4
  %tmp3 = getelementptr inbounds %struct.baz, %struct.baz* %arg, i64 0, i32 1, i32 0, i32 1
  %tmp4 = icmp ugt i64 %tmp2, 4294967295
  br label %bb5

bb5:                                              ; preds = %bb14, %bb
  %tmp6 = load i32, i32* %tmp3, align 4
  %tmp7 = icmp ne i32 %tmp6, 0
  %tmp8 = select i1 %tmp7, i1 %tmp4, i1 false
  %tmp9 = zext i1 %tmp8 to i8
  store i8 %tmp9, i8* @global.1, align 1
  %tmp10 = load i32, i32* @global.2, align 4
  switch i32 %tmp10, label %bb11 [
    i32 1, label %bb12
    i32 2, label %bb12
  ]

bb11:                                             ; preds = %bb5
  br label %bb14

bb12:                                             ; preds = %bb5, %bb5
  %tmp13 = load atomic i32, i32* getelementptr inbounds (%struct.widget, %struct.widget* @global, i64 0, i32 0) acquire, align 4
  br label %bb14

bb14:                                             ; preds = %bb12, %bb11
  br label %bb5
}
$ opt -O2 repro.ll -disable-output
opt: /home/rupprecht/src/llvm-project/llvm/lib/Transforms/Utils/VNCoercion.cpp:496: llvm::Value *llvm::VNCoercion::getLoadValueForLoad(llvm::LoadInst *, unsigned int, llvm::Type *, llvm::Instruction *, const llvm::DataLayout &): Assertion `SrcVal->isSimple() && "Cannot widen volatile/atomic load!"' failed.
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /home/rupprecht/dev/opt -O2 repro.ll -disable-output
...
```
2021-05-11 16:08:53 -07:00
Congzhe Cao 40e3aa39bd [LoopInterchange] Fix legality for triangular loops
This is a bug fix in legality check.

When we encounter triangular loops such as the following form:
    for (int i = 0; i < m; i++)
      for (int j = 0; j < i; j++), or

    for (int i = 0; i < m; i++)
      for (int j = 0; j*i < n; j++),

we should not perform interchange since the number of executions
of the loop body will be different before and after interchange,
resulting in incorrect results.

Reviewed By: bmahjour

Differential Revision: https://reviews.llvm.org/D101305
2021-05-11 18:36:53 -04:00
Congzhe Cao d3f89d4d16 Revert "[LoopInterchange] Fix legality for triangular loops"
This reverts commit 29342291d2.

The test case requires an assert build. Will add REQUIRES and re-commit.
2021-05-11 18:10:58 -04:00
Congzhe Cao 29342291d2 [LoopInterchange] Fix legality for triangular loops
This is a bug fix in legality check.

When we encounter triangular loops such as the following form:
    for (int i = 0; i < m; i++)
      for (int j = 0; j < i; j++), or

    for (int i = 0; i < m; i++)
      for (int j = 0; j*i < n; j++),

we should not perform interchange since the number of executions of the loop body
will be different before and after interchange, resulting in incorrect results.

Reviewed By: bmahjour

Differential Revision: https://reviews.llvm.org/D101305
2021-05-11 11:00:46 -04:00
Roman Lebedev 1acd9a1a29
Revert "[LICM] Hoist loads with invariant.group metadata"
This appears to miscompile google benchmark's GetCacheSizesFromKVFS()
when compiling with -fstrict-vtable-pointers.
Runnable reproducer: https://godbolt.org/z/f9ovKqTzb
The "f.fail()" crashes with BUS error, it is compiled into testb,
and the adress it is testing is non-sensical.

This reverts commit 4c89bcadf6.
2021-05-08 15:44:49 +03:00
Arthur Eubanks 34a8a437bf [NewPM] Hide pass manager debug logging behind -debug-pass-manager-verbose
Printing pass manager invocations is fairly verbose and not super
useful.

This allows us to remove DebugLogging from pass managers and PassBuilder
since all logging (aside from analysis managers) goes through
instrumentation now.

This has the downside of never being able to print the top level pass
manager via instrumentation, but that seems like a minor downside.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D101797
2021-05-07 21:51:47 -07:00
Han Zhu da1cdffbb1 [loop-idiom] Hoist loop memcpys to loop preheader
For a simple loop like:
```
struct S {
  int x;
  int y;
  char b;
};

unsigned foo(S* __restrict__ a, S* b, int n) {
  for (int i = 0; i < n; i++)
    a[i] = b[i];

  return sizeof(a[0]);
}
```
We could eliminate the loop and convert it to a large memcpy of 12*n bytes. Currently this is not handled. Output of `opt -loop-idiom -S < memcpy_before.ll`
```
%struct.S = type { i32, i32, i8 }

define dso_local i32 @_Z3fooP1SS0_i(%struct.S* noalias nocapture %a, %struct.S* nocapture readonly %b, i32 %n) local_unnamed_addr {
entry:
  %cmp7 = icmp sgt i32 %n, 0
  br i1 %cmp7, label %for.body.preheader, label %for.cond.cleanup

for.body.preheader:                               ; preds = %entry
  br label %for.body

for.cond.cleanup.loopexit:                        ; preds = %for.body
  br label %for.cond.cleanup

for.cond.cleanup:                                 ; preds = %for.cond.cleanup.loopexit, %entry
  ret i32 12

for.body:                                         ; preds = %for.body, %for.body.preheader
  %i.08 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
  %idxprom = zext i32 %i.08 to i64
  %arrayidx = getelementptr inbounds %struct.S, %struct.S* %b, i64 %idxprom
  %arrayidx2 = getelementptr inbounds %struct.S, %struct.S* %a, i64 %idxprom
  %0 = bitcast %struct.S* %arrayidx2 to i8*
  %1 = bitcast %struct.S* %arrayidx to i8*
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* nonnull align 4 dereferenceable(12) %0, i8* nonnull align 4 dereferenceable(12) %1, i64 12, i1 false)
  %inc = add nuw nsw i32 %i.08, 1
  %cmp = icmp slt i32 %inc, %n
  br i1 %cmp, label %for.body, label %for.cond.cleanup.loopexit
}

; Function Attrs: argmemonly nofree nosync nounwind willreturn
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* noalias nocapture writeonly, i8* noalias nocapture readonly, i64, i1 immarg) #0

attributes #0 = { argmemonly nofree nosync nounwind willreturn }

```
The loop idiom pass currently only handles load and store instructions. Since struct S is too big to fit in a register, the loop body contains a memcpy intrinsic.

With this change, re-run `opt -loop-idiom -S < memcpy_before.ll`. The loop memcpy is promoted to loop preheader. For this trivial case, the loop is dead and will be removed by another pass.
```
%struct.S = type { i32, i32, i8 }

define dso_local i32 @_Z3fooP1SS0_i(%struct.S* noalias nocapture %a, %struct.S* nocapture readonly %b, i32 %n) local_unnamed_addr {
entry:
  %a1 = bitcast %struct.S* %a to i8*
  %b2 = bitcast %struct.S* %b to i8*
  %cmp7 = icmp sgt i32 %n, 0
  br i1 %cmp7, label %for.body.preheader, label %for.cond.cleanup

for.body.preheader:                               ; preds = %entry
  %0 = zext i32 %n to i64
  %1 = mul nuw nsw i64 %0, 12
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %a1, i8* align 4 %b2, i64 %1, i1 false)
  br label %for.body

for.cond.cleanup.loopexit:                        ; preds = %for.body
  br label %for.cond.cleanup

for.cond.cleanup:                                 ; preds = %for.cond.cleanup.loopexit, %entry
  ret i32 12

for.body:                                         ; preds = %for.body, %for.body.preheader
  %i.08 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
  %idxprom = zext i32 %i.08 to i64
  %arrayidx = getelementptr inbounds %struct.S, %struct.S* %b, i64 %idxprom
  %arrayidx2 = getelementptr inbounds %struct.S, %struct.S* %a, i64 %idxprom
  %2 = bitcast %struct.S* %arrayidx2 to i8*
  %3 = bitcast %struct.S* %arrayidx to i8*
  %inc = add nuw nsw i32 %i.08, 1
  %cmp = icmp slt i32 %inc, %n
  br i1 %cmp, label %for.body, label %for.cond.cleanup.loopexit
}

; Function Attrs: argmemonly nofree nosync nounwind willreturn
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* noalias nocapture writeonly, i8* noalias nocapture readonly, i64, i1 immarg) #0

attributes #0 = { argmemonly nofree nosync nounwind willreturn }
```

Reviewed By: zino

Differential Revision: https://reviews.llvm.org/D97667
2021-05-04 17:05:04 -07:00
Philip Reames 11326cbcdb [IndVarSimplify][NFC] Removed mayThrow from if-condition in predicateLoopExits of IndVarSimplify
Instruction has mayHaveSideEffects method that returns true if mayThrow return true because this is called internally in the first method.  As such, the call being removed is redundant.

Patch By: vdsered (Daniil Seredkin)
Differential Revision: https://reviews.llvm.org/D101685
2021-05-03 18:25:07 -07:00
Nikita Popov ffa5a402a9 [IndVars] Remove redundant loop invariance check (NFC)
This is checked again directly below this condition.
2021-05-01 17:22:00 +02:00
Jingu Kang 88b259c014 [SimpleLoopUnswitch] Port partially invariant unswitch from LoopUnswitch to SimpleLoopUnswitch
Differential Revision: https://reviews.llvm.org/D99354
2021-04-30 15:55:56 +01:00
Evgeniy Brevnov 7861cb600c [NARY] Don't optimize min/max if there are side uses (part2)
Previous attempt to fix infinite recursion in min/max reassociation was not fully successful (D100170). Newly discovered failing case is due to not properly handled when there is a single use. It should be processed separately from 2 uses case.

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D101359
2021-04-30 19:02:02 +07:00
Tres Popp efce19c3b0 Revert "[loop-idiom] Hoist loop memcpys to loop preheader"
This reverts commit 75d6b8bb40.

The reasoning is mentioned in https://reviews.llvm.org/D97667
2021-04-28 13:16:34 +02:00
Dávid Bolvanský e81819377e [DSE] Eliminate zero memset after calloc
Solves PR11896

As noted, this can be improved futher (calloc -> malloc) in some cases. But for know, this is the first step.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D101391
2021-04-28 03:30:52 +02:00
Han Zhu 75d6b8bb40 [loop-idiom] Hoist loop memcpys to loop preheader
For a simple loop like:
```
struct S {
  int x;
  int y;
  char b;
};

unsigned foo(S* __restrict__ a, S* b, int n) {
  for (int i = 0; i < n; i++)
    a[i] = b[i];

  return sizeof(a[0]);
}
```
We could eliminate the loop and convert it to a large memcpy of 12*n bytes. Currently this is not handled. Output of `opt -loop-idiom -S < memcpy_before.ll`
```
%struct.S = type { i32, i32, i8 }

define dso_local i32 @_Z3fooP1SS0_i(%struct.S* noalias nocapture %a, %struct.S* nocapture readonly %b, i32 %n) local_unnamed_addr {
entry:
  %cmp7 = icmp sgt i32 %n, 0
  br i1 %cmp7, label %for.body.preheader, label %for.cond.cleanup

for.body.preheader:                               ; preds = %entry
  br label %for.body

for.cond.cleanup.loopexit:                        ; preds = %for.body
  br label %for.cond.cleanup

for.cond.cleanup:                                 ; preds = %for.cond.cleanup.loopexit, %entry
  ret i32 12

for.body:                                         ; preds = %for.body, %for.body.preheader
  %i.08 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
  %idxprom = zext i32 %i.08 to i64
  %arrayidx = getelementptr inbounds %struct.S, %struct.S* %b, i64 %idxprom
  %arrayidx2 = getelementptr inbounds %struct.S, %struct.S* %a, i64 %idxprom
  %0 = bitcast %struct.S* %arrayidx2 to i8*
  %1 = bitcast %struct.S* %arrayidx to i8*
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* nonnull align 4 dereferenceable(12) %0, i8* nonnull align 4 dereferenceable(12) %1, i64 12, i1 false)
  %inc = add nuw nsw i32 %i.08, 1
  %cmp = icmp slt i32 %inc, %n
  br i1 %cmp, label %for.body, label %for.cond.cleanup.loopexit
}

; Function Attrs: argmemonly nofree nosync nounwind willreturn
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* noalias nocapture writeonly, i8* noalias nocapture readonly, i64, i1 immarg) #0

attributes #0 = { argmemonly nofree nosync nounwind willreturn }

```
The loop idiom pass currently only handles load and store instructions. Since struct S is too big to fit in a register, the loop body contains a memcpy intrinsic.

With this change, re-run `opt -loop-idiom -S < memcpy_before.ll`. The loop memcpy is promoted to loop preheader. For this trivial case, the loop is dead and will be removed by another pass.
```
%struct.S = type { i32, i32, i8 }

define dso_local i32 @_Z3fooP1SS0_i(%struct.S* noalias nocapture %a, %struct.S* nocapture readonly %b, i32 %n) local_unnamed_addr {
entry:
  %a1 = bitcast %struct.S* %a to i8*
  %b2 = bitcast %struct.S* %b to i8*
  %cmp7 = icmp sgt i32 %n, 0
  br i1 %cmp7, label %for.body.preheader, label %for.cond.cleanup

for.body.preheader:                               ; preds = %entry
  %0 = zext i32 %n to i64
  %1 = mul nuw nsw i64 %0, 12
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %a1, i8* align 4 %b2, i64 %1, i1 false)
  br label %for.body

for.cond.cleanup.loopexit:                        ; preds = %for.body
  br label %for.cond.cleanup

for.cond.cleanup:                                 ; preds = %for.cond.cleanup.loopexit, %entry
  ret i32 12

for.body:                                         ; preds = %for.body, %for.body.preheader
  %i.08 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
  %idxprom = zext i32 %i.08 to i64
  %arrayidx = getelementptr inbounds %struct.S, %struct.S* %b, i64 %idxprom
  %arrayidx2 = getelementptr inbounds %struct.S, %struct.S* %a, i64 %idxprom
  %2 = bitcast %struct.S* %arrayidx2 to i8*
  %3 = bitcast %struct.S* %arrayidx to i8*
  %inc = add nuw nsw i32 %i.08, 1
  %cmp = icmp slt i32 %inc, %n
  br i1 %cmp, label %for.body, label %for.cond.cleanup.loopexit
}

; Function Attrs: argmemonly nofree nosync nounwind willreturn
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* noalias nocapture writeonly, i8* noalias nocapture readonly, i64, i1 immarg) #0

attributes #0 = { argmemonly nofree nosync nounwind willreturn }
```

Reviewed By: zino

Differential Revision: https://reviews.llvm.org/D97667
2021-04-27 17:37:51 -07:00
Han Zhu cd13f19031 [loop-idiom][NFC] Extract processLoopStoreOfLoopLoad into a helper function
Differential Revision: https://reviews.llvm.org/D100979
2021-04-27 13:42:30 -07:00
Sanjay Patel e808289fe6 [IndVars] avoid crash in LFTR when assuming an add recurrence
The test is a crasher reduced from:
https://llvm.org/PR49993

linearFunctionTestReplace() assumes that we have an add recurrence,
so check for that as a condition of matching a loop counter.

Differential Revision: https://reviews.llvm.org/D101291
2021-04-27 08:26:02 -04:00
Vitaly Buka f2a585e6d3 [NFC] Fix "not used" warning 2021-04-26 22:09:23 -07:00
William S. Moses 7aa3cad46a [NVPTX] Enable lowering of atomics on local memory
LLVM does not have valid assembly backends for atomicrmw on local memory. However, as this memory is thread local, we should be able to lower this to the relevant load/store.

Differential Revision: https://reviews.llvm.org/D98650
2021-04-26 20:12:12 -04:00
Hongtao Yu 30bb5be389 [CSSPGO] Unblock optimizations with pseudo probe instrumentation part 2.
As a follow-up to D95982, this patch continues unblocking optimizations that are blocked by pseudu probe instrumention.

The optimizations unblocked are:
		- In-block load propagation.
		- In-block dead store elimination
		- Memory copy optimization that turns stores to consecutive memories into a memset.

These optimizations are local to a block, so they shouldn't affect the profile quality.

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D100075
2021-04-26 16:52:33 -07:00
Fangrui Song 18839be9c5 [ADT] Remove StatisticBase and make NoopStatistic empty
In LLVM_ENABLE_STATS=0 builds, `llvm::Statistic` maps to `llvm::NoopStatistic`
but has 3 mostly unused pointers. GlobalOpt considers that the pointers can
potentially retain allocated objects, so GlobalOpt cannot optimize out the
`NoopStatistic` variables (see D69428 for more context), wasting 23KiB for stage
2 clang.

This patch makes `NoopStatistic` empty and thus reclaims the wasted space.  The
clang size is even smaller than applying D69428 (slightly smaller in both .bss and
.text).
```
# This means the D69428 optimization on clang is mostly nullified by this patch.
HEAD+D69428: size(.bss) = 0x0725a8
HEAD+D101211: size(.bss) = 0x072238

# bloaty - HEAD+D69428 vs HEAD+D101211
# With D101211, we also save a lot of string table space (.rodata).
    FILE SIZE        VM SIZE
 --------------  --------------
  -0.0%     -32  -0.0%     -24    .eh_frame
  -0.0%    -336  [ = ]       0    .symtab
  -0.0%    -360  [ = ]       0    .strtab
  [ = ]       0  -0.2%    -880    .bss
  -0.0% -2.11Ki  -0.0% -2.11Ki    .rodata
  -0.0% -2.89Ki  -0.0% -2.89Ki    .text
  -0.0% -5.71Ki  -0.0% -5.88Ki    TOTAL
```

Note: LoopFuse is a disabled pass. For now this patch adds
`#if LLVM_ENABLE_STATS` so `OptimizationRemarkMissed` is skipped in
LLVM_ENABLE_STATS==0 builds.  If these `OptimizationRemarkMissed` are useful in
LLVM_ENABLE_STATS==0 builds, we can replace `llvm::Statistic` with
`llvm::TrackingStatistic`, or use a different abstraction to keep track of the strings.

Similarly, skip the code in `mlir/lib/Pass/PassStatistics.cpp` which
calls `getName`/`getDesc`/`getValue`.

Reviewed By: lattner

Differential Revision: https://reviews.llvm.org/D101211
2021-04-26 16:47:32 -07:00
William S. Moses 8ede96493c Revert "[NVPTX] Enable lowering of atomics on local memory"
This reverts commit fede99d386.
2021-04-26 19:33:01 -04:00
William S. Moses fede99d386 [NVPTX] Enable lowering of atomics on local memory
LLVM does not have valid assembly backends for atomicrmw on local memory. However, as this memory is thread local, we should be able to lower this to the relevant load/store.

Differential Revision: https://reviews.llvm.org/D98650
2021-04-26 19:27:27 -04:00
Lei Zhang 254e289d45 Revert "[ADT] Remove StatisticBase and make NoopStatistic empty"
This reverts commit b540311781
because it breaks MLIR build:

https://buildkite.com/mlir/mlir-core/builds/13299#ad0f8901-dfa4-43cf-81b8-7940e2c6c15b
2021-04-26 18:31:04 -04:00