Commit Graph

10846 Commits

Author SHA1 Message Date
Matt Arsenault
015776f38c Add minnum / maxnum codegen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220342 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 23:01:01 +00:00
NAKAMURA Takumi
c65b578e25 X86AsmInstrumentation.cpp: Dissolve initializer-ranged-for. MSC17 disliked it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220301 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 16:22:52 +00:00
Yuri Gorshenin
7ffc5bb51a [asan-asm-instrumentation] Fixed memory accesses with rbp as a base or an index register.
Summary: Fixed memory accesses with rbp as a base or an index register.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5819

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220283 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 10:22:27 +00:00
Rafael Espindola
45968c54e9 Fix a bit of confusion about .set and produce more readable assembly.
Every target we support has support for assembly that looks like

a = b - c
.long a

What is special about MachO is that the above combination suppresses the
production of a relocation.

With this change we avoid producing the intermediary labels when they don't
add any value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220256 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 01:17:30 +00:00
Quentin Colombet
a37862e2de [X86] Fix a bug in the lowering of the mask of VSELECT.
X86 code to lower VSELECT messed a bit with the bits set in the mask of VSELECT
when it knows it can be lowered into BLEND. Indeed, only the high bits need to be
set for those and it optimizes those accordingly.
However, when the mask is a compile time constant, the lowering will be handled
by the generic optimizer and those modifications will generate bad code in the
generic optimizer.

This patch fixes that by preventing the optimization if the VSELECT will be
handled by the generic optimizer.

<rdar://problem/18675020>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220242 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-20 23:13:30 +00:00
Simon Pilgrim
0d1978b813 [X86] Memory folding for commutative instructions (updated)
This patch improves support for commutative instructions in the x86 memory folding implementation by attempting to fold a commuted version of the instruction if the original folding fails - if that folding fails as well the instruction is 're-commuted' back to its original order before returning.

Updated version of r219584 (reverted in r219595) - the commutation attempt now explicitly ensures that neither of the commuted source operands are tied to the destination operand / register, which was the source of all the regressions that occurred with the original patch attempt.

Added additional regression test case provided by Joerg Sonnenberger.

Differential Revision: http://reviews.llvm.org/D5818



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220239 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-20 22:14:22 +00:00
Andrea Di Biagio
5512b50db5 [X86] Fix missed selection of non-temporal store of zero vector.
When the input to a store instruction was a zero vector, the backend
always selected a normal vector store regardless of the non-temporal
hint. This is fixed by this patch.

This fixes PR19370.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220054 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-17 17:27:06 +00:00
Adam Nemet
fb9d61a8d6 [AVX512] Add DQ subvector inserts
In AVX512f we support 64x2 and 32x8 inserts via matching them to 32x4 and 64x4
respectively.  These are matched by "Alt" Pat<>'s (Alt stands for alternative
VTs).

Since DQ has native support for these intructions, I peeled off the non-"Alt"
part of the baseclass into vinsert_for_size_no_alt. The DQ instructions are
derived from this multiclass.  The "Alt" Pat<>'s are disabled with DQ.

Fixes <rdar://problem/18426089>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219874 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 23:42:17 +00:00
Adam Nemet
ccebe7258e [AVX512] Two new attributes in X86VectorVTInfo for subvector insert
The new attributes are NumElts and the CD8TupleForm.  This prepares the code
to enable x8 and x2 inserts.

NFC, no change in X86.td.expanded except for the new attributes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219871 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 23:42:09 +00:00
Adam Nemet
80b9e006aa [AVX512] Rename arg from Opcode32/64 to Opcode128/256 in vinsert_for_size
It's the W bit that selects between 32 or 64 elt type and not the opcode.  The
opcode selects between the width of the insert (128 or 256).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219870 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 23:42:04 +00:00
Rafael Espindola
90ce9f70e2 Simplify handling of --noexecstack by using getNonexecutableStackSection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219799 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 16:12:52 +00:00
Rafael Espindola
b510f8d08c Move getNonexecutableStackSection up to the base ELF class.
The .note.GNU-stack section is not SystemZ/X86 specific.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219796 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 15:44:16 +00:00
Simon Pilgrim
84a3feea38 [X86][SSE] pslldq/psrldq shuffle mask decodes
Patch to provide shuffle decodes and asm comments for the sse pslldq/psrldq SSE2/AVX2 byte shift instructions.

Differential Revision: http://reviews.llvm.org/D5598


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219738 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 22:31:34 +00:00
Hans Wennborg
76806748d4 [x86 asm] allow fwait alias in both At&t and Intel modes (PR21208)
Differential Revision: http://reviews.llvm.org/D5741

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219725 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 21:41:17 +00:00
Robert Khasanov
ad5d223cb5 [AVX512] Extended avx512_binop_rm to DQ/VL subsets.
Added encoding tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219686 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 15:13:56 +00:00
Robert Khasanov
33a95f24bb [AVX512] Extended avx512_binop_rm to BW/VL subsets.
Added encoding tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219685 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 14:36:19 +00:00
Filipe Cabecinhas
40251eb0b0 Fix a broadcast related regression on the vector shuffle lowering.
Summary: Test by Robert Lougher!

Reviewers: chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5745

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219617 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-13 16:16:16 +00:00
Yuri Gorshenin
ec8aeb0bc1 [asan-asm-instrumentation] Follow-up fixes to r219602: asserts are moved into
function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219610 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-13 11:44:06 +00:00
Yuri Gorshenin
eba0a96f8e [asan-asm-instrumentation] Fixed memory references which includes %rsp as a base or an index register.
Summary: [asan-asm-instrumentation] Fixed memory references which includes %rsp as a base or an index register.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5599

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219602 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-13 09:37:47 +00:00
NAKAMURA Takumi
58c0f65bf2 Revert r219584, "[X86] Memory folding for commutative instructions."
It broke i686 selfhosting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219595 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-13 04:17:34 +00:00
Simon Pilgrim
c00cd8e3c8 [X86] Memory folding for commutative instructions.
This patch improves support for commutative instructions in the x86 memory folding implementation by attempting to fold a commuted version of the instruction if the original folding fails - if that folding fails as well the instruction is 're-commuted' back to its original order before returning.

This mainly helps the stack inliner better fold reloads of 3 (or more) operand instructions (VEX encoded SSE etc.) but by performing this in the lowest foldMemoryOperandImpl implementation it also replaces the X86InstrInfo::optimizeLoadInstr version and is now used by FastISel too.

Differential Revision: http://reviews.llvm.org/D5701


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219584 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-12 10:52:55 +00:00
Simon Pilgrim
b6e1b30957 Test commit access (email fix)
Indentation tidyup.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219577 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-11 20:28:56 +00:00
Benjamin Kramer
fedd0e2a21 MC: Bit pack MCSymbolData.
On x86_64 this brings it from 80 bytes to 64 bytes. Also make any member
variables private and clean up uses to go through the existing accessors.

NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219573 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-11 15:07:21 +00:00
Simon Pilgrim
195be17c96 Test commit access
Fix comment typo + spelling.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219572 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-11 14:23:36 +00:00
Chandler Carruth
f2f5070d79 Don't use an unqualified 'abs' function call with a builtin type.
This is dangerous for numerous reasons. The primary risk here is with
floating point or double types where if the wrong header files are
included in a strange order this can implicitly convert to integers and
then call the C abs function on the integers. There is a secondary risk
that even impacts integers where if the namespace the code is written in
ever defines an abs overload for types within that namespace the global
abs will be hidden. The correct form is to call std::abs or write 'using
std::abs' for builtin types (and only the latter is correct in any
generic context).

I've also added the requisite header to be a bit more explicit here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219484 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-10 08:27:19 +00:00
Robert Khasanov
340b5b9ad7 [AVX512] Extended avx512_binop_rm for AVX512VL subsets.
Added avx512_binop_rm_vl multiclass for VL subset
Added encoding tests



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219390 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-09 08:38:48 +00:00
Adam Nemet
8088af2547 [AVX512] Rename AVX512_masking* to AVX512_maskable*
No functional change.

This is the current AVX512_maskable multiclass hierarchy:

                 maskable_custom
                    /       \
                   /         \
          maskable_common   maskable_in_asm
            /         \
           /           \
      maskable        maskable_3src

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219363 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 23:25:39 +00:00
Adam Nemet
fbd0e464dd [AVX512] Intrinsics for vextract*x4
This adds the Pat<>'s for the intrinsics.  These are necessary because we
don't lower these intrinsics to SDNodes but match them directly.  See the
rational in the previous commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219362 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 23:25:37 +00:00
Adam Nemet
e868005a27 [AVX512] Add asm-only support for vextract*x4 masking variants
These derive from the new asm-only masking definitions.

Unfortunately I wasn't able to find a ISel pattern that we could legally
generate for the masking variants.  The problem is that since the destination
is v4* we would need VK4 register classes and v4i1 value types to express the
masking.  These are however not legal types/classes in AVX512f but only in VL,
so things get complicated pretty quickly.  We can revisit this question later
if we have a more pressing need to express something like this.

So the ISel patterns are empty for the masking instructions and the next patch
will add Pat<>s instead to match the intrinsics calls with instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219361 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 23:25:33 +00:00
Adam Nemet
9d0ec9212b [AVX512] Move DAG for all-zero node to X86VectorVTInfo
No functional change.

No change in X86.td.expanded except for the appearance of the new attributes.

The new attributes will be used in the subsequent patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219360 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 23:25:31 +00:00
Adam Nemet
6feb834941 [AVX512] Peel off an asm-only class from AVX512_masking_common.
No functional change.

This enables the generation of masking instructions that don't provide a
ISel pattern.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219358 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 23:25:23 +00:00
Robin Morisset
b79d91ca1c [X86] Don't transform atomic-load-add into an inc/dec when inc/dec is slow
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219357 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 23:16:23 +00:00
Robin Morisset
48dfa127d7 [X86] Avoid generating inc/dec when slow for x.atomic_store(1 + x.atomic_load())
Summary:
I had forgotten to check for NotSlowIncDec in the patterns that can generate
inc/dec for the above pattern (added in D4796).
This currently applies to Atom Silvermont, KNL and SKX.

Test Plan: New checks on atomic_mi.ll

Reviewers: jfb, nadav

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5677

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219336 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 19:38:18 +00:00
Robert Khasanov
0e3754615e [AVX512] Added intrinsics for 128-, 256- and 512-bit versions of VPCMP/VPCMPU{BWDQ}
Added CMP_MASK_CC intrinsic type.
Added tests for intrinsics.

Patch by Sergey Lisitsyn <sergey.lisitsyn@intel.com>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219316 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 15:49:26 +00:00
Robert Khasanov
e659ba92c8 [AVX512] Refactoring of avx512_binop_rm multiclass through AVX512_masking.
Added new argrument for AVX512_masking: InstrItinClass and bit isCommutable.
No functional change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219310 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 14:37:45 +00:00
Eric Christopher
b7cd35b171 Cache TargetLowering on SelectionDAGISel and update previous
calls to getTargetLowering() with the cached variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219284 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-08 07:32:17 +00:00
Robin Morisset
28127ffb51 [X86] Fix a bug with fetch_add(INT32_MIN)
Summary:
Fix pr21099

The pseudocode of what we were doing (spread through two functions) was:
if (operand.doesNotFitIn32Bits())
  Opc.initializeWithFoo();
if (operand < 0)
  operand = -operand;
if (operand.doesFitIn8Bits())
  Opc.initializeWithBar();
else if (operand.doesFitIn32Bits())
  Opc.initializeWithBlah();
doStuff(Opc);

So for operand == INT32_MIN, Opc was never initialized because the operand changes
from fitting in 32 bits to not fitting, causing the various bugs/error messages
noted by pr21099.

This patch adds an extra test at the beginning for this case, and an
llvm_unreachable to have better error message if the operand ends up
not fitting in 32-bits at the end.

Test Plan: new test + make check

Reviewers: jfb

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5655

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219257 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-07 23:53:57 +00:00
Yuri Gorshenin
86e0844d1c [asan-asm-instrumentation] CFI directives are generated for .S files.
Summary: CFI directives are generated for .S files.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5520

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219199 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-07 11:03:09 +00:00
Craig Topper
95717dbb11 [X86] Fix a bug where the disassembler was ignoring the VEX.W bit in 32-bit mode for certain instructions it shouldn't.
Unfortunately, this isn't easy to fix since there's no simple way to figure out from the disassembler tables whether the W-bit is being used to select a 64-bit GPR or if its a required part of the opcode. The fix implemented here just looks for "64" in the instruction name and ignores the W-bit in 32-bit mode if its present.

Fixes PR21169.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219194 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-07 07:29:50 +00:00
Craig Topper
ada4703cba Formatting fixes. Most putting 'else' on the same line as the preceding curly brace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219193 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-07 07:29:48 +00:00
Craig Topper
038a3b8d65 Fix filename in header and use C++ version of the C header files.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219192 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-07 07:29:46 +00:00
Benjamin Kramer
043994e266 X86: Drop the isConvertibleTo3Addr bit from shufps/shufpd now that we don't convert them anymore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219112 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-06 09:56:40 +00:00
Eric Christopher
e6f32be8df Add subtarget caches to aarch64, arm, ppc, and x86.
These will make it easier to test further changes to the
code generation and optimization pipelines as those are
moved to subtargets initialized with target feature and
target cpu.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219106 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-06 06:45:36 +00:00
Chandler Carruth
1d02acb7a0 [x86] Remove the 2-addr-to-3-addr "optimization" from shufps to pshufd.
This trades a (register-renamer-friendly) movaps for a floating point
/ integer domain cross. That is a very bad trade, even on architectures
where domain crossing is relatively fast. On any chip where there is
even a cycle stall, this is a Very Bad Idea. It doesn't even seem likely
to cause a spill to be introduced because the reason for the copy is to
destructively shuffle in place.

Thanks to Ben Kramer for fixing a bug in this code that my new shuffle
lowering exposed and highlighting that perhaps it should just go away.
=]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219090 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-05 22:57:31 +00:00
Benjamin Kramer
88b3a52eec X86: Don't drop half of the mask when converting 2-address shufps into 3-address pshufd.
It's debatable whether this transform is useful at all, but for now make sure
we don't generate invalid asm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219084 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-05 16:14:29 +00:00
Elena Demikhovsky
a0cb2c75b0 AVX-512-SKX: Added instruction VPMOVM2B/W/D/Q.
This instruction allows to broadacst mask vector to data vector.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219083 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-05 14:11:08 +00:00
Chandler Carruth
30ae72f02c [x86] Fix PR21139, one of the last remaining regressions found in the
new vector shuffle lowering.

This is loosely based on a patch by Marius Wachtler to the PR (thanks!).
I refactored it a bi to use std::count_if and a mutable array ref but
the core idea was exactly right. I also added some direct testing of
this case.

I believe PR21137 is now the only remaining regression.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219081 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-05 12:07:34 +00:00
Chandler Carruth
a644b090de [x86] Teach the new vector shuffle lowering how to lower 128-bit
shuffles using AVX and AVX2 instructions. This fixes PR21138, one of the
few remaining regressions impacting benchmarks from the new vector
shuffle lowering.

You may note that it "regresses" many of the vperm2x128 test cases --
these were actually "improved" by the naive lowering that the new
shuffle lowering previously did. This regression gave me fits. I had
this patch ready-to-go about an hour after flipping the switch but
wasn't sure how to have the best of both worlds here and thought the
correct solution might be a completely different approach to lowering
these vector shuffles.

I'm now convinced this is the correct lowering and the missed
optimizations shown in vperm2x128 are actually due to missing
target-independent DAG combines. I've even written most of the needed
DAG combine and will submit it shortly, but this part is ready and
should help some real-world benchmarks out.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219079 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-05 11:41:36 +00:00
Chandler Carruth
03a77831cc [x86] Enable the new vector shuffle lowering by default.
Update the entire regression test suite for the new shuffles. Remove
most of the old testing which was devoted to the old shuffle lowering
path and is no longer relevant really. Also remove a few other random
tests that only really exercised shuffles and only incidently or without
any interesting aspects to them.

Benchmarking that I have done shows a few small regressions with this on
LNT, zero measurable regressions on real, large applications, and for
several benchmarks where the loop vectorizer fires in the hot path it
shows 5% to 40% improvements for SSE2 and SSE3 code running on Sandy
Bridge machines. Running on AMD machines shows even more dramatic
improvements.

When using newer ISA vector extensions the gains are much more modest,
but the code is still better on the whole. There are a few regressions
being tracked (PR21137, PR21138, PR21139) but by and large this is
expected to be a win for x86 generated code performance.

It is also more correct than the code it replaces. I have fuzz tested
this extensively with ISA extensions up through AVX2 and found no
crashes or miscompiles (yet...). The old lowering had a few miscompiles
and crashers after a somewhat smaller amount of fuzz testing.

There is one significant area where the new code path lags behind and
that is in AVX-512 support. However, there was *extremely little*
support for that already and so this isn't a significant step backwards
and the new framework will probably make it easier to implement lowering
that uses the full power of AVX-512's table-based shuffle+blend (IMO).

Many thanks to Quentin, Andrea, Robert, and others for benchmarking
assistance. Thanks to Adam and others for help with AVX-512. Thanks to
Hal, Eric, and *many* others for answering my incessant questions about
how the backend actually works. =]

I will leave the old code path in the tree until the 3 PRs above are at
least resolved to folks' satisfaction. Then I will rip it (and 1000s of
lines of code) out. =] I don't expect this flag to stay around for very
long. It may not survive next week.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219046 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-04 03:52:55 +00:00
Chandler Carruth
1e663cf69c [x86] Fix a bug in the VZEXT DAG combine that I just made more powerful.
It turns out this combine was always somewhat flawed -- there are cases
where nested VZEXT nodes *can't* be combined: if their types have
a mismatch that can be observed in the result. While none of these show
up in currently, once I switch to the new vector shuffle lowering a few
test cases actually form such nested VZEXT nodes. I've not come up with
any IR pattern that I can sensible write to exercise this, but it will
be covered by tests once I flip the switch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219044 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-04 02:51:03 +00:00