Commit Graph

26992 Commits

Author SHA1 Message Date
Hal Finkel
db1e51359d Revert r219432 - "Revert "[BasicAA] Revert "Revert r218714 - Make better use of zext and sign information."""
Let's try this again...

This reverts r219432, plus a bug fix.

Description of the bug in r219432 (by Nick):

The bug was using AllPositive to break out of the loop; if the loop break
condition i != e is changed to i != e && AllPositive then the
test_modulo_analysis_with_global test I've added will fail as the Modulo will
be calculated incorrectly (as the last loop iteration is skipped, so Modulo
isn't updated with its Scale).

Nick also adds this comment:

ComputeSignBit is safe to use in loops as it takes into account phi nodes, and
the  == EK_ZeroEx check is safe in loops as, no matter how the variable changes
between iterations, zero-extensions will always guarantee a zero sign bit. The
isValueEqualInPotentialCycles check is therefore definitely not needed as all
the variable analysis holds no matter how the variables change between loop
iterations.

And this patch also adds another enhancement to GetLinearExpression - basically
to convert ConstantInts to Offsets (see test_const_eval and
test_const_eval_scaled for the situations this improves).

Original commit message:

This reverts r218944, which reverted r218714, plus a bug fix.

Description of the bug in r218714 (by Nick):

The original patch forgot to check if the Scale in VariableGEPIndex flipped the
sign of the variable. The BasicAA pass iterates over the instructions in the
order they appear in the function, and so BasicAliasAnalysis::aliasGEP is
called with the variable it first comes across as parameter GEP1. Adding a
%reorder label puts the definition of %a after %b so aliasGEP is called with %b
as the first parameter and %a as the second. aliasGEP later calculates that %a
== %b + 1 - %idxprom where %idxprom >= 0 (if %a was passed as the first
parameter it would calculate %b == %a - 1 + %idxprom where %idxprom >= 0) -
ignoring that %idxprom is scaled by -1 here lead the patch to incorrectly
conclude that %a > %b.

Revised patch by Nick White, thanks! Thanks to Lang to isolating the bug.
Slightly modified by me to add an early exit from the loop and avoid
unnecessary, but expensive, function calls.

Original commit message:

Two related things:

 1. Fixes a bug when calculating the offset in GetLinearExpression. The code
    previously used zext to extend the offset, so negative offsets were converted
    to large positive ones.

 2. Enhance aliasGEP to deduce that, if the difference between two GEP
    allocations is positive and all the variables that govern the offset are also
    positive (i.e. the offset is strictly after the higher base pointer), then
    locations that fit in the gap between the two base pointers are NoAlias.

Patch by Nick White!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221876 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 09:16:54 +00:00
Chandler Carruth
4ea3097d08 [x86] Teach the vector shuffle lowering to make a more nuanced decision
between splitting a vector into 128-bit lanes and recombining them vs.
decomposing things into single-input shuffles and a final blend.

This handles a large number of cases in AVX1 where the cross-lane
shuffles would be much more expensive to represent even though we end up
with a fast blend at the root. Instead, we can do a better job of
shuffling in a single lane and then inserting it into the other lanes.

This fixes the remaining bits of Halide's regression captured in PR21281
for AVX1. However, the bug persists in AVX2 because I've made this
change reasonably conservative. The cases where it makes sense in AVX2
to split into 128-bit lanes are much more rare because we can often do
full permutations across all elements of the 256-bit vector. However,
the particular test case in PR21281 is an example of one of the rare
cases where it is *always* better to work in a single 128-bit lane. I'm
going to try to teach the logic to detect and form the good code even in
AVX2 next, but it will need to use a separate heuristic.

Finally, there is one pesky regression here where we previously would
craftily use vpermilps in AVX1 to shuffle both high and low halves at
the same time. We no longer pull that off, and not for any really good
reason. Ultimately, I think this is just another missing nuance to the
selection heuristic that I'll try to add in afterward, but this change
already seems strictly worth doing considering the magnitude of the
improvements in common matrix math shuffle patterns.

As always, please let me know if this causes a surprising regression for
you.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221861 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 04:06:10 +00:00
Rui Ueyama
08f70b58cb llvm-readobj: Print out address table when dumping COFF delay-import table
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221855 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 03:22:54 +00:00
Frederic Riss
7880ed5d21 Add an assert and a test that verify r221709's fix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221854 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 03:20:23 +00:00
Chandler Carruth
927a5f45e0 [x86] Don't form overly fragmented blends when splitting and
re-combining shuffles because nothing was available in the wider vector
type.

The key observation (which I've put in the comments for future
maintainers) is that at this point, no further combining is really
possible. And so even though these shuffles trivially could be combined,
we need to actually do that as we produce them when producing them this
late in the lowering.

This fixes another (huge) part of the Halide vector shuffle regressions.
As it happens, this was already well covered by the tests, but I hadn't
noticed how bad some of these got. The specific patterns that turn
directly into unpckl/h patterns were occurring *many* times in common
vector processing code.

There are still more problems here sadly, but trying to incrementally
tease them apart and it looks like this is the core of the problem in
the splitting logic.

There is some chance of regression here, you can see it in the test
changes. Specifically, where we stop forming pshufb in some cases, it is
possible that pshufb was in fact faster. Intel "says" that pshufb is
slower than the instruction sequences replacing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221852 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 02:42:08 +00:00
Quentin Colombet
e8a8deab8c [CodeGenPrepare] Handle zero extensions in the TypePromotionHelper.
Prior to this patch the TypePromotionHelper was promoting only sign extensions.
Supporting zero extensions changes:
- How constants are extended.
- How sign extensions, zero extensions, and truncate are composed together.
- How the type of the extended operation is recorded. Now we need to know the
  kind of the extension as well as its type.

Each change is fairly small, unlike the diff.
Most of the diff are comments/variable renaming to say "extension" instead of
"sign extension".

The performance improvements on the test suite are within the noise.

Related to <rdar://problem/18310086>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221851 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 01:44:51 +00:00
Juergen Ributzka
9bb95ddae4 [FastISel][AArch64] Optimize select when one of the operands is a 'true' or 'false' value.
Optimize selects of i1 in the presence of 'true' and 'false' operands to simple
logic operations.

This fixes rdar://problem/18960150.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221848 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 00:36:46 +00:00
Juergen Ributzka
b80d6be6d7 [FastISel][AArch64] Fold the cmp into the select when possible.
This folds the compare emission into the select emission when possible, so we
can directly use the flags and don't have to emit a separate compare.

Related to rdar://problem/18960150.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221847 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 00:36:43 +00:00
Juergen Ributzka
8d6824ea4c [FastISel][AArch64] Extend 'select' lowering to support also i1 to i16.
Related to rdar://problem/18960150.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221846 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 00:36:38 +00:00
Frederic Riss
8839439547 Revert "[dwarfdump] Add support for dumping accelerator tables."
This reverts commit r221836.

The tests are asserting on some buildbots. This also reverts the
test part of r221837 as it relies on dwarfdump dumping the
accelerator tables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221842 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 00:15:15 +00:00
Sanjoy Das
de87c9165a Teach ScalarEvolution to sharpen range information.
If x is known to have the range [a, b), in a loop predicated by (icmp
ne x, a) its range can be sharpened to [a + 1, b).  Get
ScalarEvolution and hence IndVars to exploit this fact.

This change triggers an optimization to widen-loop-comp.ll, so it had
to be edited to get it to pass.

This change was originally landed in r219834 but had a bug and broke
ASan. It was reverted in r219878, and is now being re-landed after
fixing the original bug.

phabricator: http://reviews.llvm.org/D5639
reviewed by: atrick



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221839 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 00:00:58 +00:00
Frederic Riss
72c32c6c82 Fix emission of Dwarf accelerator table when there are multiple CUs.
The DIE offset in the accel tables is an offset relative to the start
of the debug_info section, but we were encoding the offset to the
start of the containing CU.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221837 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 23:48:14 +00:00
Frederic Riss
931e22fd7c [dwarfdump] Add support for dumping accelerator tables.
The class used for the dump only allows to dump for the moment, but
it can (and will) be easily extended to support search also.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221836 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 23:48:10 +00:00
Ahmed Bougacha
b990a25d5a [CodeGenPrepare][AArch64] Fix a TLI legality check on iPTR to use a lowered instead.
Fixes PR21548.  Related to PR20474.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221820 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 22:16:55 +00:00
Sanjay Patel
dab91bcc3a Expose the number of Newton-Raphson iterations applied to the hardware's reciprocal estimate as a parameter (x86).
This is a follow-on to r221706 and r221731 and discussed in more detail in PR21385.

This patch also loosens the testcase checking for btver2. We know that the "1.0" will be loaded, but
we can't tell exactly when, so replace the CHECK-NEXT specifiers with plain CHECKs. The CHECK-NEXT
sequence relied on a quirk of post-RA-scheduling that may change independently of anything in these tests.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221819 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 21:39:01 +00:00
Timur Iskhodzhanov
fc0d323d01 Temporary fix for PR21528 - use mangled C++ function names in COFF debug info to un-break ASan on Windows
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221813 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 20:21:20 +00:00
Timur Iskhodzhanov
629ba0ac0d [COFF] Make it clearer that the symbols subsection holds function display name rather than just name
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221812 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 20:10:09 +00:00
Cameron McInally
be30336912 [AVX512] Add integer shift by immediate intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 19:58:54 +00:00
Sanjay Patel
bc8114f733 CGSCC should not treat intrinsic calls like function calls (PR21403)
Make the handling of calls to intrinsics in CGSCC consistent: 
they are not treated like regular function calls because they
are never lowered to function calls.

Without this patch, we can get dangling pointer asserts from
the subsequent loop that processes callsites because it already
ignores intrinsics.

See http://llvm.org/bugs/show_bug.cgi?id=21403 for more details / discussion.

Differential Revision: http://reviews.llvm.org/D6124



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221802 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 18:25:47 +00:00
Jingyue Wu
83c8e732dd Disable indvar widening if arithmetics on the wider type are more expensive
Summary:
Reapply r221772. The old patch breaks the bot because the @indvar_32_bit test
was run whether NVPTX was enabled or not.

IndVarSimplify should not widen an indvar if arithmetics on the wider
indvar are more expensive than those on the narrower indvar. For
instance, although NVPTX64 treats i64 as a legal type, an ADD on i64 is
twice as expensive as that on i32, because the hardware needs to
simulate a 64-bit integer using two 32-bit integers.

Split from D6188, and based on D6195 which adds NVPTXTargetTransformInfo.

Fixes PR21148.

Test Plan:
Added @indvar_32_bit that verifies we do not widen an indvar if the arithmetics
on the wider type are more expensive. This test is run only when NVPTX is
enabled.

Reviewers: jholewinski, eliben, meheff, atrick

Reviewed By: atrick

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D6196



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221799 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 18:09:15 +00:00
Justin Hibbits
86a3cdff6b Revert part of the PIC tests (TLS part)
This change actually wasn't warranted for -O0, and the new changes prove it and
break the build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221793 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 16:50:15 +00:00
Justin Hibbits
5a3eb1d38c Fix thet tests.
I seem to have missed the update I made for changing 'flag_pic' to "PIC Level".
Mea culpa.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221792 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 16:40:00 +00:00
Justin Hibbits
fcd08c294a Add support for small-model PIC for PowerPC.
Summary:
Large-model was added first.  With the addition of support for multiple PIC
models in LLVM, now add small-model PIC for 32-bit PowerPC, SysV4 ABI.  This
generates more optimal code, for shared libraries with less than about 16380
data objects.

Test Plan: Test cases added or updated

Reviewers: joerg, hfinkel

Reviewed By: hfinkel

Subscribers: jholewinski, mcrosier, emaste, llvm-commits

Differential Revision: http://reviews.llvm.org/D5399

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221791 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 15:16:30 +00:00
Rafael Espindola
e4e7ad3101 Fix the test.
It was broken since r221708.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221783 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 14:23:04 +00:00
Zoran Jovanovic
cb5fadfe6a [mips][micromips] Add predicate 'InMicroMips' at CodeGen patterns for microMIPS instructions
Differential Revision: http://reviews.llvm.org/D6198


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221780 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 13:30:10 +00:00
Chandler Carruth
556578ec0c [x86] Start improving the matching of unpck instructions based on test
cases from Halide folks. This initial step was extracted from
a prototype change by Clay Wood to try and address regressions found
with Halide and the new vector shuffle lowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221779 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 10:05:18 +00:00
Chandler Carruth
3baea18935 [x86] Clean up a bunch of vector shuffle tests with my script. Notably,
removes windows line endings and other noise. This is in prelude to
making substantive changes to these tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221776 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 09:17:15 +00:00
Elena Demikhovsky
5f9c438577 AVX-512: Intrinsics for ERI
3 instructions: vrcp28, vrsqrt28, vexp2, only vector forms.
Intrinsics include SAE (Suppres All Exceptions) parameter.

http://reviews.llvm.org/D6214



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221774 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 07:31:03 +00:00
Jingyue Wu
ee709fe497 Reverts r221772 which fails tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221773 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 07:19:25 +00:00
Jingyue Wu
69adc159ee Disable indvar widening if arithmetics on the wider type are more expensive
Summary:
IndVarSimplify should not widen an indvar if arithmetics on the wider
indvar are more expensive than those on the narrower indvar. For
instance, although NVPTX64 treats i64 as a legal type, an ADD on i64 is
twice as expensive as that on i32, because the hardware needs to
simulate a 64-bit integer using two 32-bit integers.

Split from D6188, and based on D6195 which adds NVPTXTargetTransformInfo.

Fixes PR21148.

Test Plan:
Added @indvar_32_bit that verifies we do not widen an indvar if the arithmetics
on the wider type are more expensive.

Reviewers: jholewinski, eliben, meheff, atrick

Reviewed By: atrick

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D6196

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221772 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 06:58:45 +00:00
Bill Schmidt
fc22bfd921 [PowerPC] Add vec_vsx_ld and vec_vsx_st intrinsics
This patch enables the vec_vsx_ld and vec_vsx_st intrinsics for
PowerPC, which provide programmer access to the lxvd2x, lxvw4x,
stxvd2x, and stxvw4x instructions.

New LLVM intrinsics are provided to represent these four instructions
in IntrinsicsPowerPC.td.  These are patterned after the similar
intrinsics for lvx and stvx (Altivec).  In PPCInstrVSX.td, these
intrinsics are tied to the code gen patterns, with additional patterns
to allow plain vanilla loads and stores to still generate these
instructions.

At -O1 and higher the intrinsics are immediately converted to loads
and stores in InstCombineCalls.cpp.  This will open up more
optimization opportunities while still allowing the correct
instructions to be generated.  (Similar code exists for aligned
Altivec loads and stores.)

The new intrinsics are added to the code that checks for consecutive
loads and stores in PPCISelLowering.cpp, as well as to
PPCTargetLowering::getTgtMemIntrinsic().

There's a new test to verify the correct instructions are generated.
The loads and stores tend to be reordered, so the test just counts
their number.  It runs at -O2, as it's not very effective to test this
at -O0, when many unnecessary loads and stores are generated.

I ended up having to modify vsx-fma-m.ll.  It turns out this test case
is slightly unreliable, but I don't know a good way to prevent
problems with it.  The xvmaddmdp instructions read and write the same
register, which is one of the multiplicands.  Commutativity allows
either to be chosen.  If the FMAs are reordered differently than
expected by the test, the register assignment can be different as a
result.  Hopefully this doesn't change often.

There is a companion patch for Clang.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221767 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 04:19:40 +00:00
Nick Kledzik
9abbcb7453 Object, support both mach-o archive t.o.c file names
For historical reasons archives on mach-o have two possible names for the 
file containing the table of contents for the archive: "__.SYMDEF SORTED" 
and "__.SYMDEF".  But the libObject archive reader only supported the former.

This patch fixes llvm::object::Archive to support both names.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221747 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 01:37:45 +00:00
Chad Rosier
7ad8db4cbb [Reassociate] Canonicalize negative constants out of expressions.
Add support for FDiv, which was regressed by the previous commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221738 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:36:42 +00:00
Philip Reames
a03cda02ab Canonicalize an assume(load != null) into !nonnull metadata
We currently have two ways of informing the optimizer that the result of a load is never null: metadata and assume. This change converts the second in to the former. This avoids a need to implement optimizations using both forms.

We should probably extend this basic idea to metadata of other forms; in particular, range metadata. We view is that assumes should be considered a "last resort" for when there isn't a more canonical way to represent something.

Reviewed by: Hal
Differential Revision: http://reviews.llvm.org/D5951



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221737 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:33:19 +00:00
Juergen Ributzka
4f0d671b97 [FastISel][AArch64] Add support for fabs intrinsic.
Lower the llvm.fabs intrinsic to the 'fabs' MI instruction.

This fixes rdar://problem/18946552.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221729 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:10:44 +00:00
Chad Rosier
2244d9a5d2 [Reassociate] Canonicalize negative constants out of expressions.
This is a reapplication of r221171, but we only perform the transformation
on expressions which include a multiplication.  We do not transform rem/div
operations as this doesn't appear to be safe in all cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221721 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 22:58:35 +00:00
Kostya Serebryany
abb3335f6d Move asan-coverage into a separate phase.
Summary:
This change moves asan-coverage instrumentation
into a separate Module pass.
The other part of the change in clang introduces a new flag
-fsanitize-coverage=N.
Another small patch will update tests in compiler-rt.

With this patch no functionality change is expected except for the flag name.
The following changes will make the coverage instrumentation work with tsan/msan

Test Plan: Run regression tests, chromium.

Reviewers: nlewycky, samsonov

Reviewed By: nlewycky, samsonov

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6152

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221718 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 22:14:37 +00:00
Tom Roeder
63dea2c952 Add Forward Control-Flow Integrity.
This commit adds a new pass that can inject checks before indirect calls to
make sure that these calls target known locations. It supports three types of
checks and, at compile time, it can take the name of a custom function to call
when an indirect call check fails. The default failure function ignores the
error and continues.

This pass incidentally moves the function JumpInstrTables::transformType from
private to public and makes it static (with a new argument that specifies the
table type to use); this is so that the CFI code can transform function types
at call sites to determine which jump-instruction table to use for the check at
that site.

Also, this removes support for jumptables in ARM, pending further performance
analysis and discussion.

Review: http://reviews.llvm.org/D4167



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221708 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:08:02 +00:00
Colin LeMahieu
6d093fd78a [llvm-mc] Fixing case where if a file ended with non-newline whitespace or a comma it would access invalid memory.
Cleaned up parse loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221707 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:03:09 +00:00
Sanjay Patel
e7c966f067 Use rcpss/rcpps (X86) to speed up reciprocal calcs (PR21385).
This is a first step for generating SSE rcp instructions for reciprocal
calcs when fast-math allows it. This is very similar to the rsqrt optimization
enabled in D5658 ( http://reviews.llvm.org/rL220570 ).

For now, be conservative and only enable this for AMD btver2 where performance
improves significantly both in terms of latency and throughput.

We may never enable this codegen for Intel Core* chips because the divider circuits
are just too fast. On SandyBridge, divss can be as fast as 10 cycles versus the 21
cycle critical path for the rcp + mul + sub + mul + add estimate.

Follow-on patches may allow configuration of the number of Newton-Raphson refinement
steps, add AVX512 support, and enable the optimization for more chips.

More background here: http://llvm.org/bugs/show_bug.cgi?id=21385

Differential Revision: http://reviews.llvm.org/D6175



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2014-11-11 20:51:00 +00:00
Rafael Espindola
612f7d7e00 Simplify testcase. NFC.
Thanks to Filipe Cabecinhas for the tip.

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2014-11-11 20:49:16 +00:00
Bill Schmidt
10161a0cce [PowerPC] Replace foul hackery with real calls to __tls_get_addr
My original support for the general dynamic and local dynamic TLS
models contained some fairly obtuse hacks to generate calls to
__tls_get_addr when lowering a TargetGlobalAddress.  Rather than
generating real calls, special GET_TLS_ADDR nodes were used to wrap
the calls and only reveal them at assembly time.  I attempted to
provide correct parameter and return values by chaining CopyToReg and
CopyFromReg nodes onto the GET_TLS_ADDR nodes, but this was also not
fully correct.  Problems were seen with two back-to-back stores to TLS
variables, where the call sequences ended up overlapping with unhappy
results.  Additionally, since these weren't real calls, the proper
register side effects of a call were not recorded, so clobbered values
were kept live across the calls.

The proper thing to do is to lower these into calls in the first
place.  This is relatively straightforward; see the changes to
PPCTargetLowering::LowerGlobalTLSAddress() in PPCISelLowering.cpp.
The changes here are standard call lowering, except that we need to
track the fact that these calls will require a relocation.  This is
done by adding a machine operand flag of MO_TLSLD or MO_TLSGD to the
TargetGlobalAddress operand that appears earlier in the sequence.

The calls to LowerCallTo() eventually find their way to
LowerCall_64SVR4() or LowerCall_32SVR4(), which call FinishCall(),
which calls PrepareCall().  In PrepareCall(), we detect the calls to
__tls_get_addr and immediately snag the TargetGlobalTLSAddress with
the annotated relocation information.  This becomes an extra operand
on the call following the callee, which is expected for nodes of type
tlscall.  We change the call opcode to CALL_TLS for this case.  Back
in FinishCall(), we change it again to CALL_NOP_TLS for 64-bit only,
since we require a TOC-restore nop following the call for the 64-bit
ABIs.

During selection, patterns in PPCInstrInfo.td and PPCInstr64Bit.td
convert the CALL_TLS nodes into BL_TLS nodes, and convert the
CALL_NOP_TLS nodes into BL8_NOP_TLS nodes.  This replaces the code
removed from PPCAsmPrinter.cpp, as the BL_TLS or BL8_NOP_TLS
nodes can now be emitted normally using their patterns and the
associated printTLSCall print method.

Finally, as a result of these changes, all references to get-tls-addr
in its various guises are no longer used, so they have been removed.

There are existing TLS tests to verify the changes haven't messed
anything up).  I've added one new test that verifies that the problem
with the original code has been fixed.


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2014-11-11 20:44:09 +00:00
Rafael Espindola
71c70733b7 Use a 8 bit immediate when possible.
This fixes pr21529.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221700 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 19:46:36 +00:00
Dario Domizioli
949d328bee [X86][ELF] Fix PR20243 - leaf frame pointer bug with TLS access
The ISel lowering for global TLS access in PIC mode was creating a pseudo 
instruction that is later expanded to a call, but the code was not 
setting the hasCalls flag in the MachineFrameInfo alongside the adjustsStack 
flag. This caused some functions to be mistakenly recognized as leaf functions,
and this in turn affected the decision to eliminate the frame pointer.

With the fix, hasCalls is properly set and the leaf frame pointer is correctly
preserved.




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2014-11-11 18:44:49 +00:00
Oliver Stannard
659b1491b8 LLVM incorrectly folds xor into select
LLVM replaces the SelectionDAG pattern (xor (set_cc cc x y) 1) with
(set_cc !cc x y), which is only correct when the xor has type i1.
Instead, we should check that the constant operand to the xor is all
ones.



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2014-11-11 17:36:01 +00:00
Vasileios Kalintiris
328bc2f89e [mips] Add preliminary support for the MIPS II target.
Summary:
This patch enables code generation for the MIPS II target. Pre-Mips32
targets don't have the MUL instruction, so we add the correspondent
pattern that uses the MULT/MFLO combination in order to retrieve the
product.

This is WIP as we don't support code generation for select nodes due to
the lack of conditional-move instructions.

Reviewers: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6150

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2014-11-11 11:43:55 +00:00
Vasileios Kalintiris
b001cb6423 [mips] Add hardware register name "hwr_ulr" ($29)
The canonical name when printing assembly is still $29. The reason is that
GAS does not accept "$hwr_ulr" at the moment.

This addresses the comments from r221307, which reverted the original
commit r221299.

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2014-11-11 11:22:39 +00:00
Andrea Di Biagio
d6548ad013 [X86] Add missing check for 'isINSERTPSMask' in method 'isShuffleMaskLegal'.
This helps the DAGCombiner to identify more opportunities to fold shuffles.


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2014-11-11 11:20:31 +00:00
Vasileios Kalintiris
d3da72c5b3 Recommit "[mips] Add names and tests for the hardware registers"
The original commit r221299 was reverted in r221307.  I removed the name
"hrw_ulr" ($29) from the original commit because two tests were failing.

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2014-11-11 10:31:31 +00:00
David Majnemer
1dd631fe02 llvm-objdump: Skip empty sections when dumping contents
Empty sections are just noise when using objdump.
This is similar to what binutils does.

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2014-11-11 09:58:25 +00:00