It is legal for a PHI node not to have a live value in a predecessor
as long as the end of the predecessor is jointly dominated by an undef
value.
llvm-svn: 335607
This removes debug locations from ConstantSDNode and ConstantSDFPNode.
When this kind of node is materialized we no longer create a line table
entry which jumps back to the constant's first point of use. This makes
single-stepping behavior smoother, and it matches the model used by IR,
where Constants have no locations. See this thread for more context:
http://lists.llvm.org/pipermail/llvm-dev/2018-June/124164.html
I'd like to handle constant BuildVectorSDNodes and to try to eliminate
passing SDLocs to SelectionDAG::getConstant*() in follow-up commits.
Differential Revision: https://reviews.llvm.org/D48468
llvm-svn: 335497
I thought I fixed this in r308673, but that fix was
very broken. The assumption that any frame index can be used
in place of another was more widespread than I realized.
Even when stack slot sharing was disabled, this was still
replacing frame index uses with a different ID with a different
stack slot.
Really fix this by doing the coloring per-stack ID, so all of
the coloring logically done in a separate namespace. This is a lot
simpler than trying to figure out how to change the color if
the stack ID is different.
llvm-svn: 335488
This patch has the same motivating example as D48466:
define void @foo(i64 %x, i32 %c.0282.in, i32 %d.0280, i32* %ptr0, i32* %ptr1) {
%c.0282 = and i32 %c.0282.in, 268435455
%a16 = lshr i64 32508, %x
%a17 = and i64 %a16, 1
%tobool = icmp eq i64 %a17, 0
%. = select i1 %tobool, i32 1, i32 2
%.286 = select i1 %tobool, i32 27, i32 26
%shr97 = lshr i32 %c.0282, %.
%shl98 = shl i32 %c.0282.in, %.286
%or99 = or i32 %shr97, %shl98
%shr100 = lshr i32 %d.0280, %.
%shl101 = shl i32 %d.0280, %.286
%or102 = or i32 %shr100, %shl101
store i32 %or99, i32* %ptr0
store i32 %or102, i32* %ptr1
ret void
}
...but I'm trying to kill the setcc bool math sooner rather than later.
By matching a larger pattern that includes both the low-bit mask and the trailing add/sub,
we can create a universally good fold because we always eliminate the condition code
intermediate value.
Here are Alive proofs for these (currently instcombine folds the 'add' variants, but
misses the 'sub' patterns):
https://rise4fun.com/Alive/Gsyp
Name: sub of zext cmp mask
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%z = zext i1 %c to i32
%r = sub i32 C1, %z
=>
%optional_cast = zext i8 %a to i32
%r = add i32 %optional_cast, C1-1
Name: add of zext cmp mask
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%z = zext i1 %c to i8
%r = add i8 %z, C1
=>
%optional_cast = trunc i32 %a to i8
%r = sub i8 C1+1, %optional_cast
All of the tests look like improvements or neutral to me. But it is possible that x86
test+set+bitop is better than what we now show here. I suspect we could do better by
adding another fold for the 'sub' variants.
We start with select-of-constant in IR in the larger motivating test, so that's why I
included tests with selects. Proofs for those variants:
https://rise4fun.com/Alive/Bx1
Name: true const is bigger
Pre: C2 == (C1 + 1)
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%r = select i1 %c, i64 C2, i64 C1
=>
%z = zext i8 %a to i64
%r = sub i64 C2, %z
Name: false const is bigger
Pre: C2 == (C1 + 1)
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%r = select i1 %c, i64 C1, i64 C2
=>
%z = zext i8 %a to i64
%r = add i64 C1, %z
Differential Revision: https://reviews.llvm.org/D48466
llvm-svn: 335433
With compilation fix.
Original commit message:
D39788 added a '.stack-size' section containing metadata on function stack sizes
to output ELF files behind the new -stack-size-section flag.
This change does following two things on top:
1) Imagine the case when there are -ffunction-sections flag given and there are text sections in COMDATs.
The patch adds a '.stack-size' section into corresponding COMDAT group, so that linker will be able to
eliminate them fast during resolving the COMDATs.
2) Patch sets a SHF_LINK_ORDER flag and links '.stack-size' with the corresponding .text.
With that linker will be able to do -gc-sections on dead stack sizes sections.
Differential revision: https://reviews.llvm.org/D46874
llvm-svn: 335336
D39788 added a '.stack-size' section containing metadata on function stack sizes
to output ELF files behind the new -stack-size-section flag.
This change does following two things on top:
1) Imagine the case when there are -ffunction-sections flag given and there are text sections in COMDATs.
The patch adds a '.stack-size' section into corresponding COMDAT group, so that linker will be able to
eliminate them fast during resolving the COMDATs.
2) Patch sets a SHF_LINK_ORDER flag and links '.stack-size' with the corresponding .text.
With that linker will be able to do -gc-sections on dead stack sizes sections.
Differential revision: https://reviews.llvm.org/D46874
llvm-svn: 335332
This is the first pass in the main pipeline to use the legacy PM's
ability to run function analyses "on demand". Unfortunately, it turns
out there are bugs in that somewhat-hacky approach. At the very least,
it leaks memory and doesn't support -debug-pass=Structure. Unclear if
there are larger issues or not, but this should get the sanitizer bots
back to green by fixing the memory leaks.
llvm-svn: 335320
This patch adds support for generating a call graph profile from Branch Frequency Info.
The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.
After scanning all the functions, it generates an appending module flag containing the data. The format looks like:
!llvm.module.flags = !{!0}
!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}
Differential Revision: https://reviews.llvm.org/D48105
llvm-svn: 335306
Summary:
GCC and the binutils COFF linker do comdats differently from MSVC.
If we want to be ABI compatible, we have to do what they do, which is to
emit unique section names like ".text$_Z3foov" instead of short section
names like ".text". Otherwise, the binutils linker gets confused and
reports multiple definition errors when two object files from GCC and
Clang containing the same inline function are linked together.
The best description of the issue is probably at
https://github.com/Alexpux/MINGW-packages/issues/1677, we don't seem to
have a good one in our tracker.
I fixed up the .pdata and .xdata sections needed everywhere other than
32-bit x86. GCC doesn't use associative comdats for those, it appears to
rely on the section name.
Reviewers: smeenai, compnerd, mstorsjo, martell, mati865
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D48402
llvm-svn: 335286
Summary:
The logic for handling the sinking of COPY instructions was generating
different code when building with debug flags.
The original code did not take into consideration debug instructions. This
resulted in the registers in the DBG_VALUE instructions being treated as used,
and prevented the COPY from being sunk. This patch avoids analyzing debug
instructions when trying to sink COPY instructions.
This patch also creates a routine from the code in MachineSinking::SinkInstruction to
perform the logic of sinking an instruction along with its debug instructions.
This functionality is used in multiple places, including the code for sinking COPY instrs.
Reviewers: junbuml, javed.absar, MatzeB, bjope
Reviewed By: bjope
Subscribers: aprantl, probinson, thegameg, jonpa, bjope, vsk, kristof.beyls, JDevlieghere, llvm-commits
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D45637
llvm-svn: 335264
Allowed folding for "and/or" binops with non-constant operand if
arguments of select are 0/-1 values.
Normally this code with "and" opcode does not get to a DAG combiner
and simplified yet in the InstCombine. However AMDGPU produces it
during lowering and InstCombine has no chance to optimize it out.
In turn the same pattern with "or" opcode can reach DAG.
Differential Revision: https://reviews.llvm.org/D48301
llvm-svn: 335250
Summary:
In some cases, these operands lacked the IsDebug property, which is meant to signal that
they should not affect codegen. This patch adds a check for this property in the
MachineVerifier and adds it where it was missing.
This includes refactorings to use MachineInstrBuilder construction functions instead of
manually setting up the intrinsic everywhere.
Patch by: JesperAntonsson
Reviewers: aprantl, rnk, echristo, javed.absar
Reviewed By: aprantl
Subscribers: qcolombet, sdardis, nemanjai, JDevlieghere, atanasyan, llvm-commits
Differential Revision: https://reviews.llvm.org/D48319
llvm-svn: 335214
The alignment parameter to getExtLoad is treated as a base alignment,
not the alignment of the load (base + offset). When we infer a better
alignment for a Ptr we need to ensure that it applies to the base to
prevent the alignment on the load from being wrong.
This fixes a bug where the alignment could then be used to incorrectly
prove noalias between a load and a store, leading to a miscompile.
Differential Revision: https://reviews.llvm.org/D48029
llvm-svn: 335210
Summary:
Fixes PR36579.
For cases where we had e.g.
DBG_VALUE 42
[...]
DBG_VALUE undef
LiveDebugVariables would discard all undef DBG_VALUEs and then it would
look like the variable had the value 42 throughout the rest of the
function, which is incorrect.
With this patch we don't remove all undef DBG_VALUEs in LiveDebugVariables
so they will be kept after register allocation just like other DBG_VALUEs
which will yield more correct debug information.
Reviewers: aprantl
Reviewed By: aprantl
Subscribers: bjope, Ka-Ka, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D48277
llvm-svn: 335205
Summary:
Two utils methods have essentially the same functionality. This is an attempt to merge them into one.
1. lib/Transforms/Utils/Local.cpp : MergeBasicBlockIntoOnlyPred
2. lib/Transforms/Utils/BasicBlockUtils.cpp : MergeBlockIntoPredecessor
Prior to the patch:
1. MergeBasicBlockIntoOnlyPred
Updates either DomTree or DeferredDominance
Moves all instructions from Pred to BB, deletes Pred
Asserts BB has single predecessor
If address was taken, replace the block address with constant 1 (?)
2. MergeBlockIntoPredecessor
Updates DomTree, LoopInfo and MemoryDependenceResults
Moves all instruction from BB to Pred, deletes BB
Returns if doesn't have a single predecessor
Returns if BB's address was taken
After the patch:
Method 2. MergeBlockIntoPredecessor is attempting to become the new default:
Updates DomTree or DeferredDominance, and LoopInfo and MemoryDependenceResults
Moves all instruction from BB to Pred, deletes BB
Returns if doesn't have a single predecessor
Returns if BB's address was taken
Uses of MergeBasicBlockIntoOnlyPred that need to be replaced:
1. lib/Transforms/Scalar/LoopSimplifyCFG.cpp
Updated in this patch. No challenges.
2. lib/CodeGen/CodeGenPrepare.cpp
Updated in this patch.
i. eliminateFallThrough is straightforward, but I added using a temporary array to avoid the iterator invalidation.
ii. eliminateMostlyEmptyBlock(s) methods also now use a temporary array for blocks
Some interesting aspects:
- Since Pred is not deleted (BB is), the entry block does not need updating.
- The entry block was being updated with the deleted block in eliminateMostlyEmptyBlock. Added assert to make obvious that BB=SinglePred.
- isMergingEmptyBlockProfitable assumes BB is the one to be deleted.
- eliminateMostlyEmptyBlock(BB) does not delete BB on one path, it deletes its unique predecessor instead.
- adding some test owner as subscribers for the interesting tests modified:
test/CodeGen/X86/avx-cmp.ll
test/CodeGen/AMDGPU/nested-loop-conditions.ll
test/CodeGen/AMDGPU/si-annotate-cf.ll
test/CodeGen/X86/hoist-spill.ll
test/CodeGen/X86/2006-11-17-IllegalMove.ll
3. lib/Transforms/Scalar/JumpThreading.cpp
Not covered in this patch. It is the only use case using the DeferredDominance.
I would defer to Brian Rzycki to make this replacement.
Reviewers: chandlerc, spatel, davide, brzycki, bkramer, javed.absar
Subscribers: qcolombet, sanjoy, nemanjai, nhaehnle, jlebar, tpr, kbarton, RKSimon, wmi, arsenm, llvm-commits
Differential Revision: https://reviews.llvm.org/D48202
llvm-svn: 335183
Previously this folding was done only if select is a first operand.
However, for non-commutative operations constant may go before
select.
Differential Revision: https://reviews.llvm.org/D48223
llvm-svn: 335167
Summary:
Found some regressions (infinite loop in DAGTypeLegalizer::RemapId)
after r334880. This patch makes sure that we do map a TableId to
itself.
Reviewers: niravd
Reviewed By: niravd
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48364
llvm-svn: 335141
Summary:
If we get an error building the SelectionDAG for inline assembly we try to continue and still build the DAG.
But if the return type for the inline assembly is a struct we end up crashing because we try to create an UNDEF node with a struct type which isn't valid.
Instead we need to create an UNDEF for each element of the struct and join them with merge_values.
This patch relies on single operand merge_values being handled gracefully by getMergeValues. If the return type is void there will be no VTs returned by ComputeValueVTs and now we just return instead of calling setValue. Hopefully that's ok, I assumed nothing would need to look up the mapped value for void node.
Fixes PR37359
Reviewers: rengolin, rovka, echristo, efriedma, bogner
Reviewed By: efriedma
Subscribers: craig.topper, llvm-commits
Differential Revision: https://reviews.llvm.org/D46560
llvm-svn: 335093
This patch covers up a fairly fundemental issue around remat and register allocation which shows up with psuedo instructions with more vreg uses than there are physical registers. This patch essentially just disables remat for STATEPOINTs which are the only case we've seen so far, but long term we need a better fix.
For STATEPOINTs specifically, this is a strict improvement. It unblocks progress towards enabling a currently off-by-default mode which integrates deopt bundle operand lowering with register allocator spilling so that we end up with smaller stack sizes and more optimally placed spills. Assming no other issues turn up during my next round of integration testing - which based on experience so far, is admittedly unlikely - we might finally be able to enable something I've been working towards in small bits and pieces for years now. :)
For psuedo ops in general, there are a couple of ideas for a "proper fix" discussed on the bug, but I'm far enough outside my knowledge area to not be able to see any of them through to a successful conclusion. If anyone wants to help out here, please do.
Differential Revision: https://reviews.llvm.org/D41098
llvm-svn: 335077
insertOutlinerPrologue was not used by any target, and prologue-esque code was
beginning to appear in insertOutlinerEpilogue. Refactor that into one function,
buildOutlinedFrame.
This just removes insertOutlinerPrologue and renames insertOutlinerEpilogue.
llvm-svn: 335076
Summary:
Patch r323922 changed the sigil for physical registers to '$', instead of '%'.
An error message was missed during this change, and reports the wrong sigil.
This patch corrects that diagnostic and the tests that check that error string.
Reviewers: zer0, bjope
Reviewed By: bjope
Subscribers: bjope, thegameg, plotfi, llvm-commits
Differential Revision: https://reviews.llvm.org/D48086
llvm-svn: 335066
Summary:
Add WasmEHFuncInfo and routines to calculate and fill in this struct to
keep track of unwind destination information. This will be used in
other EH related passes.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, chrib, llvm-commits
Differential Revision: https://reviews.llvm.org/D48263
llvm-svn: 335005
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed.
Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar
Reviewed By: spatel
Subscribers: wdng, nhaehnle
Differential Revision: https://reviews.llvm.org/D47909
llvm-svn: 334996
Summary: Refactoring for all constant cases which require AllowNewConst and some staging for future fmf usage.
Reviewers: spatel, hfinkel, wristow
Reviewed By: spatel
Subscribers: nhaehnle
Differential Revision: https://reviews.llvm.org/D48289
llvm-svn: 334984
Relanding after fixing expensive check from modifying tables.
To avoid redundant work, during DAG legalization we keep tables
mapping pre-legalized SDValues to post-legalized SDValues and a
SDValue-to-SDValue map to enable fast node replacements. However, as
the keys are nodes which may be reused it is possible that an entry in
a table refers to a now deleted node N (that should have been renamed
by the value replacement map) while a new node N' exists. If N' is
then replaced that entry would be wrong. Previously we avoided this by
when potentially violating this property, walking every table and
updating all node pointers. This is very expensive but hopefully rare
occurance.
This patch assigns each instance of a SDValue used in legalization a
unique id and uses these ids in the legalization tables. This avoids
any such aliasing issue, avoiding the full table search and allowing
more aggressive incremental table pruning.
In some cases this is a 1000x speedup to compilation.
Reviewers: jyknight, echristo, bogner, tra
Reviewed By: bogner
Subscribers: dberris, grandinj, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D47959
llvm-svn: 334880
Summary: This patch originated from D47388 and is a proper subset of the originating changes, containing only the fmf optimization guard extensions.
Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar, rampitec, nhaehnle, nemanjai
Reviewed By: rampitec, nhaehnle
Subscribers: tpr, nemanjai, wdng
Differential Revision: https://reviews.llvm.org/D47918
llvm-svn: 334876
Modify ExpandStrictFPOp(...) to handle nodes that have scalar
operands.
Also, add a Strict FMA test and do some other light cleanup in the
Strict FP code.
Differential Revision: https://reviews.llvm.org/D48149
llvm-svn: 334863
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed.
Reviewers: spatel, hfinkel, wristow, arsenm
Reviewed By: spatel
Subscribers: wdng, nhaehnle
Differential Revision: https://reviews.llvm.org/D47954
llvm-svn: 334862
When coalescing a small register into a subregister of a larger register,
if the larger register is rematerialized, the function updateRegDefUses
can add an <undef> flag to the rematerialized definition (since it's
treating it as only definining the coalesced subregister). While with that
assumption doing so is not incorrect, make sure to remove the flag later
on after the call to updateRegDefUses.
llvm-svn: 334845
Summary:
Here we relax the old constraint which utilized unsafe with the TargetOption flag HonorSignDependentRoundingFPMathOption, with the assertion that unsafe is no longer needed or never was required for correctness on FDIV/FMUL.
Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar
Reviewed By: spatel
Subscribers: efriedma, wdng, tpr
Differential Revision: https://reviews.llvm.org/D48057
llvm-svn: 334769
This is r334750 (which was reverted in r334754) with a fix for an
uninitialized variable that was caught by msan.
Original commit message:
> If a copy bundle happens to involve overlapping registers, we can end
> up with emitting the copies in an order that ends up clobbering some
> of the subregisters. Since instructions in the copy bundle
> semantically happen at the same time, this is incorrect and we need to
> make sure we order the copies such that this doesn't happen.
llvm-svn: 334756
Summary: A FMF constraint is added to FADD with unsafe still available as the fallback
Reviewers: spatel, wristow, arsenm, hfinkel
Reviewed By: spatel
Subscribers: wdng
Differential Revision: https://reviews.llvm.org/D48180
llvm-svn: 334753
WebAssembly doesn't support more than one function per section
and we rely on function sections being unique. This change ignores
the section provided by the function to avoid two functions being
in the same section.
Without this change the object writer produces the following
error for this test:
LLVM ERROR: section already has a defining function: baz
Differential Revision: https://reviews.llvm.org/D48178
llvm-svn: 334752
Krzysztof Parzyszek