Third time's the charm. The previous commit was reverted as a
reverse for-loop in SelectionDAGBuilder::lowerWorkItem did 'I--'
on an iterator at the beginning of a vector, causing asserts
when using debugging iterators. This commit fixes that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235608 91177308-0d34-0410-b5e6-96231b3b80d8
Patch to remove extra bitcasts from shuffles, this is often a legacy of XformToShuffleWithZero being used to combine bitmaskings (of float vectors bitcast to integer vectors) into shuffles: bitcast(shuffle(bitcast(s0),bitcast(s1))) -> shuffle(s0,s1)
Differential Revision: http://reviews.llvm.org/D9097
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235578 91177308-0d34-0410-b5e6-96231b3b80d8
This is a re-commit of r235101, which also fixes the problems with the previous patch:
- Switches with only a default case and non-fallthrough were handled incorrectly
- The previous patch tickled a bug in PowerPC Early-Return Creation which is fixed here.
> This is a major rewrite of the SelectionDAG switch lowering. The previous code
> would lower switches as a binary tre, discovering clusters of cases
> suitable for lowering by jump tables or bit tests as it went along. To increase
> the likelihood of finding jump tables, the binary tree pivot was selected to
> maximize case density on both sides of the pivot.
>
> By not selecting the pivot in the middle, the binary trees would not always
> be balanced, leading to performance problems in the generated code.
>
> This patch rewrites the lowering to search for clusters of cases
> suitable for jump tables or bit tests first, and then builds the binary
> tree around those clusters. This way, the binary tree will always be balanced.
>
> This has the added benefit of decoupling the different aspects of the lowering:
> tree building and jump table or bit tests finding are now easier to tweak
> separately.
>
> For example, this will enable us to balance the tree based on profile info
> in the future.
>
> The algorithm for finding jump tables is quadratic, whereas the previous algorithm
> was O(n log n) for common cases, and quadratic only in the worst-case. This
> doesn't seem to be major problem in practice, e.g. compiling a file consisting
> of a 10k-case switch was only 30% slower, and such large switches should be rare
> in practice. Compiling e.g. gcc.c showed no compile-time difference. If this
> does turn out to be a problem, we could limit the search space of the algorithm.
>
> This commit also disables all optimizations during switch lowering in -O0.
>
> Differential Revision: http://reviews.llvm.org/D8649
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235560 91177308-0d34-0410-b5e6-96231b3b80d8
Only clear out the NSW/NUW flags if we are optimizing 'add'/'sub' while
taking advantage that the sign bit is not set. We do this optimization
to further shrink the mask but shrinking the mask isn't NSW/NUW
preserving in this case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235558 91177308-0d34-0410-b5e6-96231b3b80d8
This removes the -sehprepare flag and makes __C_specific_handler
functions always to use WinEHPrepare.
This was tested by building all of chromium_builder_tests and running a
few tests that use SEH, but if something breaks, we can revert this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235557 91177308-0d34-0410-b5e6-96231b3b80d8
In particular, this handles SSA values that are live *out* of a handler.
The existing code only handles values that are live *in* to a handler.
It also handles phi nodes in the block where normal control should
resume after the end of a catch handler. When EH return points have phi
nodes, we need to split the return edge. It is impossible for phi
elimination to emit copies in the previous block if that block gets
outlined. The indirectbr that we leave in the function is only notional,
and is eliminated from the MachineFunction CFG early on.
Reviewers: majnemer, andrew.w.kaylor
Differential Revision: http://reviews.llvm.org/D9158
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235545 91177308-0d34-0410-b5e6-96231b3b80d8
An nsw/nuw operation relies on the values feeding into it to not
overflow if 'poison' is not to be produced. This means that
optimizations which make modifications to the bottom of a chain (like
SimplifyDemandedBits) must strip out nsw/nuw if they cannot ensure that
they will be preserved.
This fixes PR23309.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235544 91177308-0d34-0410-b5e6-96231b3b80d8
ARM32 ELF R_ARM_V4BX relocation format is a special relocation type
that records the location of an ARMv4t BX instruction to enable a
static linker to generate ARMv4 compatible instructions. This
relocation does not contain a reference symbol.
This patch enabled its creation by removing the requeriment of a
relocation symbol target in ELFState<ELFT>::writeSectionContent.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235513 91177308-0d34-0410-b5e6-96231b3b80d8
An assert was triggered when attempting to create a new SCEV
with operands of different types in the visitAddRecExpr. In this
test case, the operand types of the numerator and denominator
are different. The SCEV division code should generate a
conservative answer when this happens.
Differential Revision: http://reviews.llvm.org/D9021
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235511 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a regression introduced at revision 218263.
On AVX, if we optimize for size, a splat build_vector of a load
is lowered into a VBROADCAST node. This is done even if the value type of the
splat build_vector node is v2i64.
Since AVX doesn't support v2f64/v2i64 broadcasts, revision 218263 added two
extra tablegen patterns to allow selecting a VMOVDDUPrm from an X86VBroadcast
where the scalar element comes from a loadi64/loadf64.
However, revision 218263 forgot to add an extra fallback pattern for the case
where we have a X86VBroadcast of a loadi64 with multiple uses.
This patch adds the missing tablegen pattern in X86InstrSSE.td.
This patch also adds an extra test to 'splat-for-size.ll' to verify that ISel
doesn't crash with a 'fatal error in the backend' due to a missing AVX pattern
to select v2i64 X86ISD::BROADCAST nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235509 91177308-0d34-0410-b5e6-96231b3b80d8
This turned up after r235333, but was a pre-existing bug. The optimization
which transforms select(c, load, load) into a load of a select of the addresses
does not handle indexed loads (pre/post inc/dec). However, it did not check for
them either, leading to a crash if it tried to transform one of them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235497 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r235194. It was causing a failure in FastISel buildbots
due to sign-extension issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235495 91177308-0d34-0410-b5e6-96231b3b80d8
Enough concerns were raised that this optimization is pessimising some code patterns.
The obvious fix, to add a Reassociate run afterwards, causes even more pessimisation in some cases due to fewer complex addressing modes being matched. As there isn't a trivial fix for this, backing this out by default until someone gets a chance to fix the addressing mode matcher.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235491 91177308-0d34-0410-b5e6-96231b3b80d8
X86 backend.
The code generated for symbolic targets is identical to the code generated for
constant targets, except that a relocation is emitted to fix up the actual
target address at link-time. This allows IR and object files containing
patchpoints to be cached across JIT-invocations where the target address may
change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235483 91177308-0d34-0410-b5e6-96231b3b80d8
Add a flag to lib/Linker (and `llvm-link`) to override linkage rules.
When set, the functions in the source module *always* replace those in
the destination module.
The `llvm-link` option is `-override=abc.ll`. All the "regular" modules
are loaded and linked first, followed by the `-override` modules. This
is useful for debugging workflows where some subset of the module (e.g.,
a single function) is extracted into a separate file where it's
optimized differently, before being merged back in.
Patch by Luqman Aden!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235473 91177308-0d34-0410-b5e6-96231b3b80d8
With SSE2, we can generate a 'movq' or other 64-bit store op on a 32-bit system
even though 64-bit integers are not legal types.
So instead of producing this:
pshufd $229, %xmm0, %xmm1 ## xmm1 = xmm0[1,1,2,3]
movd %xmm0, (%eax)
movd %xmm1, 4(%eax)
We can do:
movq %xmm0, (%eax)
This is a fix for the problem noted in D7296.
Differential Revision: http://reviews.llvm.org/D9134
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235460 91177308-0d34-0410-b5e6-96231b3b80d8
We should also teach the inliner to collapse framerecover of
frameaddress of the current frame down to an alloca, but that can happen
later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235459 91177308-0d34-0410-b5e6-96231b3b80d8
https://llvm.org/bugs/show_bug.cgi?id=23163.
Gep merging sometimes behaves like a reverse CSE/LICM optimization,
which has negative impact on performance. In this patch we restrict
gep merging to happen only when the indexes to be merged are both consts,
which ensures such merge is always beneficial.
The patch makes gep merging only happen in very restrictive cases.
It is possible that some analysis/optimization passes rely on the merged
geps to get better result, and we havn't notice them yet. We will be ready
to further improve it once we see the cases.
Differential Revision: http://reviews.llvm.org/D8911
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235455 91177308-0d34-0410-b5e6-96231b3b80d8
https://llvm.org/bugs/show_bug.cgi?id=23163.
Gep merging sometimes behaves like a reverse CSE/LICM optimizations,
which has negative impact on performance. In this patch we restrict
gep merging to happen only when the indexes to be merged are both consts,
which ensures such merge is always beneficial.
The patch makes gep merging only happen in very restrictive cases.
It is possible that some analysis/optimization passes rely on the merged
geps to get better result, and we havn't notice them yet. We will be ready
to further improve it once we see the cases.
Differential Revision: http://reviews.llvm.org/D9007
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235451 91177308-0d34-0410-b5e6-96231b3b80d8
MemIntrinsic::getDest() looks through pointer casts, and using it
directly when building the new GEP+memset results in stuff like:
%0 = getelementptr i64* %p, i32 16
%1 = bitcast i64* %0 to i8*
call ..memset(i8* %1, ...)
instead of the correct:
%0 = bitcast i64* %p to i8*
%1 = getelementptr i8* %0, i32 16
call ..memset(i8* %1, ...)
Instead, use getRawDest, which just gives you the i8* value.
While there, use the memcpy's dest, as it's live anyway.
In most cases, when the optimization triggers, the memset and memcpy
sizes are the same, so the built memset is 0-sized and eliminated.
The problem occurs when they're different.
Fixes a regression caused by r235232: PR23300.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235419 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
After we rewrite a candidate, the instructions used by the old form may
become unused. This patch cleans up these unused instructions so that we
needn't run DCE after SLSR.
Test Plan: removed -dce in all the SLSR tests
Reviewers: broune, meheff
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9101
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235410 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: so that we needn't run DCE after this pass.
Test Plan: removed -dce from the commandline in split-gep.ll and split-gep-and-gvn.ll
Reviewers: meheff
Subscribers: llvm-commits, HaoLiu, hfinkel, jholewinski
Differential Revision: http://reviews.llvm.org/D9096
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235409 91177308-0d34-0410-b5e6-96231b3b80d8
Keep the old SEH fan-in lowering on by default for now, since projects
rely on it. This will make it easy to test this change with a simple
flag flip.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235399 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This directive is exactly the same as .asciz, except it's only used by MIPS.
It is used to store null terminated strings in object files.
Reviewers: rafael, dsanders, echristo
Reviewed By: dsanders, echristo
Subscribers: echristo, llvm-commits
Differential Revision: http://reviews.llvm.org/D7530
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235382 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The 64-bit version of the variable shift instructions uses the
shift_rotate_reg class which uses a GPR32Opnd to specify the variable
shift amount. With this patch we avoid the generation of a redundant
SLL instruction for the variable shift instructions in 64-bit targets.
Reviewers: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D7413
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235376 91177308-0d34-0410-b5e6-96231b3b80d8
This is an updated version of Chandler's patch D7402 that got accepted but never committed, and has bit-rotted a bit since.
I've updated the execution domain declarations to match the approach of the packed templates and also added some extra scalar unary tests.
Differential Revision: http://reviews.llvm.org/D9095
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235372 91177308-0d34-0410-b5e6-96231b3b80d8
