Commit Graph

74206 Commits

Author SHA1 Message Date
Frederic Riss
0275be3a97 Allow DWARFFormValue::extractValue to be called with a null CU.
Currently FormValues are only used for attributes of DIEs and thus
uers always have a CU lying around when calling into the FormValue
API.
Accelerator tables encode their information using the same Forms
as the attributes, thus it is natural to use DWARFFormValue to
extract/dump them. There is no CU in that case though. Allow the
API to be called with a null CU arguemnt by making the RelocMap
lookup conditional on the CU pointer validity. And document this
new behvior in the header. (Test coverage for this use of the API
comes in the DwarfAccelTable support patch)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221835 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 23:48:04 +00:00
Frederic Riss
f1faaf2e09 Remove unsused variables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221834 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 23:48:01 +00:00
Ahmed Bougacha
cd2f8c95a7 [CodeGenPrepare] Replace other uses of EVT::getEVT with TL::getValueType.
r221820 fixed a problem (PR21548) where an iPTR was used in TLI legality checks,
which isn't valid and resulted in a failed assertion.
The solution was to lower pointer types into the correct target's VT, by
using TL::getValueType instead of EVT::getEVT.

This commit changes 3 other uses of EVT::getEVT, but without any tests:
- One of these non-lowered EVTs is passed to allowsMisalignedMemoryAccesses,
which goes into target's TL implementation and doesn't cause any problem (yet.)
- Two others are passed to TLI.isOperationLegalOrCustom:
  - one only looks at extensions, so doesn't concern pointers.
  - one only looks at binary operators, so also isn't a problem.

The latter might some day be exposed to pointers and cause the same assert as
the original PR, because there's a comment hinting at also supporting cast ops.

For consistency, update all of them and be done with it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221827 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 23:05:03 +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
Ahmed Bougacha
f9e1e56ea1 Add fortified (__*_chk) library functions to TLI (NFC)
One of them (__memcpy_chk) was already there, the others were checked
by comparing function names.
Note that the fortified libfuncs are now part of TLI, but are always
available, because they aren't generated, only optimized into the
non-checking versions.

Differential Revision: http://reviews.llvm.org/D6179


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221817 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 21:23:34 +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
Aaron Ballman
027b4c711b Changing a StringRef::begin() call into StringRef::data(); NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221808 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 19:43:13 +00:00
Rafael Espindola
ea3c2111f4 Use the return of readBytes to find out if we are at the end of the stream.
This allows the removal of isObjectEnd and opens the way for reading 64 bits
at a time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221804 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 18:37:00 +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
dc9e73b4f8 Fix broken doxygen annotations, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221801 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 18:25:06 +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
Sanjay Patel
04a3fdf788 remove function names from comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221798 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 18:07:42 +00:00
Rafael Espindola
d0ab58245f Return the number of read bytes in MemoryObject::readBytes.
Returning more information will allow BitstreamReader to be simplified a bit
and changed to read 64 bits at a time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221794 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 17:11:16 +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
8c2a55264a Reduce code duplication a bit. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221785 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 14:48:38 +00:00
Aaron Ballman
ba7dc2970b Fixing a -Wcast-qual warning; NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221781 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 13:55:27 +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
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
Rafael Espindola
d0518569ec Merge StreamableMemoryObject into MemoryObject.
Every MemoryObject is a StreamableMemoryObject since the removal of
StringRefMemoryObject, so just merge the two.

I will clean up the MemoryObject interface in the upcoming commits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221766 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 03:55:46 +00:00
Rafael Espindola
b0022d46da Remove unused method. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221759 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 02:35:31 +00:00
Rafael Espindola
ccb2a0e99a Make readBytes pure virtual. Every real implementation has it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221758 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 02:30:38 +00:00
Rafael Espindola
67a38a848e Remove unused method. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221757 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 02:27:40 +00:00
Rafael Espindola
a48b83ebfd Remove the now unused StringRefMemoryObject.h.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221755 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 02:13:27 +00:00
Rafael Espindola
6a222ec893 Pass an ArrayRef to MCDisassembler::getInstruction.
With this patch MCDisassembler::getInstruction takes an ArrayRef<uint8_t>
instead of a MemoryObject.

Even on X86 there is a maximum size an instruction can have. Given
that, it seems way simpler and more efficient to just pass an ArrayRef
to the disassembler instead of a MemoryObject and have it do a virtual
call every time it wants some extra bytes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221751 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 02:04:27 +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
Rafael Espindola
dc70865b5b Remove a bit of dead code.
Every "real" object file implements this an ptx doesn't use it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221746 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 01:27:22 +00:00
Philip Reames
25703e8fa3 Extend intrinsic name mangling to support arrays, named structs, and function types.
Currently, we have a type parameter mechanism for intrinsics. Rather than having to specify a separate intrinsic for each combination of argument and return types, we can specify a single intrinsic with one or more type parameters. These type parameters are passed explicitly to Intrinsic::getDeclaration or can be specified implicitly in the naming of the intrinsic function in an LL file.

Today, the types are limited to integer, floating point, and pointer types. With a goal of supporting symbolic targets for patchpoints and statepoints, this change adds support for function types.  The change also includes support for first class aggregate types (named structures and arrays) since these appear in function types we've encountered.  

Reviewed by: atrick, ributzka
Differential Revision: http://reviews.llvm.org/D4608



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221742 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 00:21:51 +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
Sanjay Patel
4e9c3e9cee Initialize new subtarget feature variable for generating reciprocal estimate instructions.
This was missed in r221706.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221731 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:13:15 +00:00
Duncan P. N. Exon Smith
ab75fd0694 libLTO: Assert if LTOCodeGenerator and LTOModule are from different contexts
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221730 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:13:10 +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
Duncan P. N. Exon Smith
18a16fd279 libLTO: Allow LTOModule to own a context
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221728 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:08:05 +00:00
Duncan P. N. Exon Smith
bce40075a9 libLTO: Allow LTOCodeGenerator to own a context
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221726 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:03:29 +00:00
Kostya Serebryany
d54a2bf8e1 [asan] adding ShadowOffset64 for mips64, patch by Kumar Sukhani
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221725 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 23:02:57 +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
Duncan P. N. Exon Smith
5bf8ade9d0 Revert "IR: MDNode => Value"
Instead, we're going to separate metadata from the Value hierarchy.  See
PR21532.

This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221711 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:30:22 +00:00
Tom Roeder
15d6f7c3cc Fix build break: remove unused variable in FCFI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221710 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:26:33 +00:00
Frederic Riss
6eb7964b7d Totally forget deallocated SDNodes in SDDbgInfo.
What would happen before that commit is that the SDDbgValues associated with
a deallocated SDNode would be marked Invalidated, but SDDbgInfo would keep
a map entry keyed by the SDNode pointer pointing to this list of invalidated
SDDbgNodes. As the memory gets reused, the list might get wrongly associated
with another new SDNode. As the SDDbgValues are cloned when they are transfered,
this can lead to an exponential number of SDDbgValues being produced during
DAGCombine like in http://llvm.org/bugs/show_bug.cgi?id=20893

Note that the previous behavior wasn't really buggy as the invalidation made
sure that the SDDbgValues won't be used. This commit can be considered a
memory optimization and as such is really hard to validate in a unit-test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221709 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:21:08 +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
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



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221706 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 20:51:00 +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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221703 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 20:44:09 +00:00