Commit Graph

928 Commits

Author SHA1 Message Date
Hal Finkel
e05b232c20 [PowerPC/BlockPlacement] Allow target to provide a per-loop alignment preference
The existing code provided for specifying a global loop alignment preference.
However, the preferred loop alignment might depend on the loop itself. For
recent POWER cores, loops between 5 and 8 instructions should have 32-byte
alignment (while the others are better with 16-byte alignment) so that the
entire loop will fit in one i-cache line.

To support this, getPrefLoopAlignment has been made virtual, and can be
provided with an optional MachineLoop* so the target can inspect the loop
before answering the query. The default behavior, as before, is to return the
value set with setPrefLoopAlignment. MachineBlockPlacement now queries the
target for each loop instead of only once per function. There should be no
functional change for other targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225117 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-03 17:58:24 +00:00
Hal Finkel
a1d22cc789 [PowerPC] Use 16-byte alignment for modern cores for functions/loops
Most modern PowerPC cores prefer that functions and loops start on
16-byte-aligned boundaries (*), so instruct block placement, etc. to make this
happen. The branch selector has also been adjusted so account for the extra
nops that might now be inserted before loop headers.

(*) Some cores actually prefer other alignments for small loops, but that will
    be addressed in a follow-up commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225115 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-03 14:58:25 +00:00
Hal Finkel
958b670c34 [PowerPC] Add support for the CMPB instruction
Newer POWER cores, and the A2, support the cmpb instruction. This instruction
compares its operands, treating each of the 8 bytes in the GPRs separately,
returning a 'mask' result of 0 (for false) or -1 (for true) in each byte.

Code generation support is added, in the form of a PPCISelDAGToDAG
DAG-preprocessing routine, that recognizes patterns close to what the
instruction computes (either exactly, or related by a constant masking
operation), and generates the cmpb instruction (along with any necessary
constant masking operation). This can be expanded if use cases arise.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225106 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-03 01:16:37 +00:00
Hal Finkel
c9e5247ea7 [PowerPC] Ensure that the TOC reload directly follows bctrl on PPC64
On non-Darwin PPC64, the TOC reload needs to come directly after the bctrl
instruction (for indirect calls) because the 'bctrl/ld 2, 40(1)' instruction
sequence is interpreted by the unwinding code in libgcc. To make sure these
occur as a pair, as with other pairings interpreted by the linker, fuse the two
instructions into one instruction (for code generation only).

In the future, we might wish to do this by emitting CFI directives instead,
but this solution is simpler, and mirrors what GCC does. Additional discussion
on this point is contained in the PR.

Fixes PR22015.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224788 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 22:29:40 +00:00
Hal Finkel
2bea947207 [PowerPC] Don't mark the return-address slot as immutable
It is tempting to mark the fixed stack slot used to store the return address as
immutable when lowering @llvm.returnaddress(i32 0). Unfortunately, within the
function, it is not completely immutable: it is written during the function
prologue. When using post-RA instruction scheduling, the prologue instructions
are available for scheduling, and we're not free to interchange the order of a
particular store in the prologue with loads from that stack location.

Fixes PR21976.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224761 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 09:45:06 +00:00
Hal Finkel
775294d183 [PowerPC] Don't attempt a 64-bit pow2 division on PPC32
In r224033, in moving the signed power-of-2 division expansion into
BuildSDIVPow2, I accidentally made it possible to attempt the lowering for a
64-bit division on PPC32. This later asserts.

Fixes PR21928.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224758 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 08:38:50 +00:00
Hal Finkel
0b19b561e0 [PowerPC] Handle cmp op promotion for SELECT[_CC] nodes in PPCTL::DAGCombineExtBoolTrunc
PPCTargetLowering::DAGCombineExtBoolTrunc contains logic to remove unwanted
truncations and extensions when dealing with nodes of the form:
  zext(binary-ops(binary-ops(trunc(x), trunc(y)), ...)

There was a FIXME in the implementation (now removed) regarding the fact that
the function would abort the transformations if any of the non-output operands
of a SELECT or SELECT_CC node would need to be promoted (because they were
also output operands, for example). As a result, we continued to generate
unnecessary zero-extends for code such as this:

  unsigned foo(unsigned a, unsigned b) {
    return  (a <= b) ? a : b;
  }

which would produce:

  cmplw 0, 3, 4
  isel 3, 4, 3, 1
  rldicl 3, 3, 0, 32
  blr

and now we produce:

  cmplw 0, 3, 4
  isel 3, 4, 3, 1
  blr

which is better in the obvious way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224213 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-14 05:53:19 +00:00
Hal Finkel
31f6bdbbbe [PowerPC] Implement BuildSDIVPow2, lower i64 pow2 sdiv using sradi
PPCISelDAGToDAG contained existing code to lower i32 sdiv by a power-of-2 using
srawi/addze, but did not implement the i64 case. DAGCombine now contains a
callback specifically designed for this purpose (BuildSDIVPow2), and part of
the logic has been moved to an implementation of that callback. Doing this
lowering using BuildSDIVPow2 likely does not matter, compared to handling
everything in PPCISelDAGToDAG, for the positive divisor case, but the negative
divisor case, which generates an additional negation, can potentially benefit
from additional folding from DAGCombine. Now, both the i32 and the i64 cases
have been implemented.

Fixes PR20732.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224033 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-11 18:37:52 +00:00
Bill Schmidt
b900895384 [PowerPC 1/4] Little-endian adjustments for VSX loads/stores
This patch addresses the inherent big-endian bias in the lxvd2x,
lxvw4x, stxvd2x, and stxvw4x instructions.  These instructions load
vector elements into registers left-to-right (with the first element
loaded into the high-order bits of the register), regardless of the
endian setting of the processor.  However, these are the only
vector memory instructions that permit unaligned storage accesses, so
we want to use them for little-endian.

To make this work, a lxvd2x or lxvw4x is replaced with an lxvd2x
followed by an xxswapd, which swaps the doublewords.  This works for
lxvw4x as well as lxvd2x, because for lxvw4x on an LE system the
vector elements are in LE order (right-to-left) within each
doubleword.  (Thus after lxvw2x of a <4 x float> the elements will
appear as 1, 0, 3, 2.  Following the swap, they will appear as 3, 2,
0, 1, as desired.)   For stores, an stxvd2x or stxvw4x is replaced
with an stxvd2x preceded by an xxswapd.

Introduction of extra swap instructions provides correctness, but
obviously is not ideal from a performance perspective.  Future patches
will address this with optimizations to remove most of the introduced
swaps, which have proven effective in other implementations.

The introduction of the swaps is performed during lowering of LOAD,
STORE, INTRINSIC_W_CHAIN, and INTRINSIC_VOID operations.  The latter
are used to translate intrinsics that specify the VSX loads and stores
directly into equivalent sequences for little endian.  Thus code that
uses vec_vsx_ld and vec_vsx_st does not have to be modified to be
ported from BE to LE.

We introduce new PPCISD opcodes for LXVD2X, STXVD2X, and XXSWAPD for
use during this lowering step.  In PPCInstrVSX.td, we add new SDType
and SDNode definitions for these (PPClxvd2x, PPCstxvd2x, PPCxxswapd).
These are recognized during instruction selection and mapped to the
correct instructions.

Several tests that were written to use -mcpu=pwr7 or pwr8 are modified
to disable VSX on LE variants because code generation changes with
this and subsequent patches in this set.  I chose to include all of
these in the first patch than try to rigorously sort out which tests
were broken by one or another of the patches.  Sorry about that.

The new test vsx-ldst-builtin-le.ll, and the changes to vsx-ldst.ll,
are disabled until LE support is enabled because of breakages that
occur as noted in those tests.  They are re-enabled in patch 4/4.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223783 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 16:35:51 +00:00
Hal Finkel
b849e04d2b [PowerPC] Don't use a non-allocatable register to implement the 'cc' alias
GCC accepts 'cc' as an alias for 'cr0', and we need to do the same when
processing inline asm constraints. This had previously been implemented using a
non-allocatable register, named 'cc', that was listed as an alias of 'cr0', but
the infrastructure does not seem to support this properly (neither the register
allocator nor the scheduler properly accounts for the alias). Instead, we can
just process this as a naming alias inside of the inline asm
constraint-processing code, so we'll do that instead.

There are two regression tests, one where the post-RA scheduler did the wrong
thing with the non-allocatable alias, and one where the register allocator did
the wrong thing. Fixes PR21742.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223708 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-08 22:54:22 +00:00
Hal Finkel
cf988bca67 [PowerPC] Print all inline-asm consts as signed numbers
Almost all immediates in PowerPC assembly (both 32-bit and 64-bit) are signed
numbers, and it is important that we print them as such. To make sure that
happens, we change PPCTargetLowering::LowerAsmOperandForConstraint so that it
does all intermediate checks on a signed-extended int64_t value, and then
creates the resulting target constant using MVT::i64. This will ensure that all
negative values are printed as negative values (mirroring what is done in other
backends to achieve the same sign-extension effect).

This came up in the context of inline assembly like this:
  "add%I2   %0,%0,%2", ..., "Ir"(-1ll)
where we used to print:
  addi   3,3,4294967295
and gcc would print:
  addi   3,3,-1
and gas accepts both forms, but our builtin assembler (correctly) does not. Now
we print -1 like gcc does.

While here, I replaced a bunch of custom integer checks with isInt<16> and
friends from MathExtras.h.

Thanks to Paul Hargrove for the bug report.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223220 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 09:37:50 +00:00
Hal Finkel
1dce7b19a0 [PowerPC] Fix readcyclecounter to be custom expanded for all 32-bit targets
We need to use the custom expansion of readcyclecounter on all 32-bit targets
(even those with 64-bit registers). This should fix the ppc64 buildbot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223182 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 00:19:17 +00:00
Hal Finkel
1855b261db [PowerPC] Implement readcyclecounter for PPC32
We've long supported readcyclecounter on PPC64, but it is easier there (the
read of the 64-bit time-base register can be accomplished via a single
instruction). This now provides an implementation for PPC32 as well. On PPC32,
the time-base register is still 64 bits, but can only be read 32 bits at a time
via two separate SPRs. The ISA manual explains how to do this properly (it
involves re-reading the upper bits and looping if the counter has wrapped while
being read).

This requires PPC to implement a custom integer splitting legalization for the
READCYCLECOUNTER node, turning it into a target-specific SDAG node, which then
gets turned into a pseudo-instruction, which is then expanded to the necessary
sequence (which has three SPR reads, the comparison and the branch).

Thanks to Paul Hargrove for pointing out to me that this was still unimplemented.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223161 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-02 22:01:00 +00:00
Hal Finkel
5d6f185653 [PowerPC] Implement combineRepeatedFPDivisors
This does not matter on newer cores (where we can use reciprocal estimates in
fast-math mode anyway), but for older cores this allows us to generate better
fast-math code where we have multiple FDIVs with a common divisor.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222710 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-24 23:45:21 +00:00
Craig Topper
e0ed7df6b0 Remove a bunch of unnecessary typecasts to 'const TargetRegisterClass *'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222509 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-21 05:58:21 +00:00
David Blaikie
5401ba7099 Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 07:49:26 +00:00
Aditya Nandakumar
365df40768 We can get the TLOF from the TargetMachine - so constructor no longer requires TargetLoweringObjectFile to be passed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221926 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 21:29:21 +00:00
Aditya Nandakumar
847729d19a This patch changes the ownership of TLOF from TargetLoweringBase to TargetMachine so that different subtargets could share the TLOF effectively
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221878 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 09:26:31 +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
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
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
Ulrich Weigand
8a9c531e9a [PowerPC] Load BlockAddress values from the TOC in 64-bit SVR4 code
Since block address values can be larger than 2GB in 64-bit code, they
cannot be loaded simply using an @l / @ha pair, but instead must be
loaded from the TOC, just like GlobalAddress, ConstantPool, and
JumpTable values are.

The commit also fixes a bug in PPCLinuxAsmPrinter::doFinalization where
temporary labels could not be used as TOC values, since code would
attempt (and fail) to use GetOrCreateSymbol to create a symbol of the
same name as the temporary label.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220959 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-31 10:33:14 +00:00
Sanjay Patel
a46f06efe2 Use rsqrt (X86) to speed up reciprocal square root calcs
This is a first step for generating SSE rsqrt instructions for
reciprocal square root calcs when fast-math is allowed.

For now, be conservative and only enable this for AMD btver2
where performance improves significantly - for example, 29%
on llvm/projects/test-suite/SingleSource/Benchmarks/BenchmarkGame/n-body.c
(if we convert the data type to single-precision float).

This patch adds a two constant version of the Newton-Raphson
refinement algorithm to DAGCombiner that can be selected by any target
via a parameter returned by getRsqrtEstimate()..

See PR20900 for more details:
http://llvm.org/bugs/show_bug.cgi?id=20900

Differential Revision: http://reviews.llvm.org/D5658



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220570 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-24 17:02:16 +00:00
Bill Schmidt
55321cd8a7 [PATCH] Support select-cc for VSFRC when VSX is enabled
A previous patch enabled SELECT_VSRC and SELECT_CC_VSRC for VSX to
handle <2 x double> cases.  This patch adds SELECT_VSFRC and
SELECT_CC_VSFRC to allow use of all 64 vector-scalar registers for the
f64 type when VSX is enabled.  The changes are analogous to those in
the previous patch.  I've added a new variant to vsx.ll to test the
code generation.

(I also cleaned up a little formatting in PPCInstrVSX.td from the
previous patch.)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220395 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 16:58:20 +00:00
Bill Schmidt
013cbf2f1a [PowerPC] Support select-cc for VSX
The tests test/CodeGen/Generic/select-cc.ll and
test/CodeGen/PowerPC/select-cc.ll both fail with VSX enabled.  The
problem is that the lowering logic for the SELECT and SELECT_CC
operations doesn't currently support the VSX registers.  This patch
fixes that.

In lib/Target/PowerPC/PPCInstrInfo.td, we have pseudos to handle this
for other register classes.  Similar pseudos are added in
PPCInstrVSX.td (they must be there, because the "vsrc" register class
definition appears there) for the VSRC register class.  The
SELECT_VSRC pseudo is then used in pattern matching for SELECT_CC.

The rest of the patch just adds logic for SELECT_VSRC wherever similar
logic appears for SELECT_VRRC.

There are no new test cases because the existing tests above test
this, along with a variant in test/CodeGen/PowerPC/vsx.ll.

After discussion with Hal, a future patch will add similar _VSFRC
variants to override f64 type handling (currently using F8RC).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220385 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 13:13:40 +00:00
Bill Schmidt
b76f5ba103 [PowerPC] Enable use of lxvw4x/stxvw4x in VSX code generation
Currently the VSX support enables use of lxvd2x and stxvd2x for 2x64
types, but does not yet use lxvw4x and stxvw4x for 4x32 types.  This
patch adds that support.

As with lxvd2x/stxvd2x, this involves straightforward overriding of
the patterns normally recognized for lvx/stvx, with preference given
to the VSX patterns when VSX is enabled.

In addition, the logic for permitting misaligned memory accesses is
modified so that v4r32 and v4i32 are treated the same as v2f64 and
v2i64 when VSX is enabled.  Finally, the DAG generation for unaligned
loads is changed to just use a normal LOAD (which will become lxvw4x)
on P8 and later hardware, where unaligned loads are preferred over
lvsl/lvx/lvx/vperm.

A number of tests now generate the VSX loads/stores instead of
lvx/stvx, so this patch adds VSX variants to those tests.  I've also
added <4 x float> tests to the vsx.ll test case, and created a
vsx-p8.ll test case to be used for testing code generation for the
P8Vector feature.  For now, that simply tests the unaligned load/store
behavior.

This has been tested along with a temporary patch to enable the VSX
and P8Vector features, with no new regressions encountered with or
without the temporary patch applied.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220047 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-17 15:13:38 +00:00
Robin Morisset
2b1874cbd4 [Power] Improve the expansion of atomic loads/stores
Summary:
Atomic loads and store of up to the native size (32 bits, or 64 for PPC64)
can be lowered to a simple load or store instruction (as the synchronization
is already handled by AtomicExpand, and the atomicity is guaranteed thanks to
the alignment requirements of atomic accesses). This is exactly what this patch
does. Previously, these were implemented by complex
load-linked/store-conditional loops.. an obvious performance problem.

For example, this patch turns
```
define void @store_i8_unordered(i8* %mem) {
  store atomic i8 42, i8* %mem unordered, align 1
  ret void
}
```
from
```
_store_i8_unordered:                    ; @store_i8_unordered
; BB#0:
    rlwinm r2, r3, 3, 27, 28
    li r4, 42
    xori r5, r2, 24
    rlwinm r2, r3, 0, 0, 29
    li r3, 255
    slw r4, r4, r5
    slw r3, r3, r5
    and r4, r4, r3
LBB4_1:                                 ; =>This Inner Loop Header: Depth=1
    lwarx r5, 0, r2
    andc r5, r5, r3
    or r5, r4, r5
    stwcx. r5, 0, r2
    bne cr0, LBB4_1
; BB#2:
    blr
```
into
```
_store_i8_unordered:                    ; @store_i8_unordered
; BB#0:
    li r2, 42
    stb r2, 0(r3)
    blr

```
which looks like a pretty clear win to me.

Test Plan:
fixed the tests + new test for indexed accesses + make check-all

Reviewers: jfb, wschmidt, hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5587

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218922 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-02 22:27:07 +00:00
Eric Christopher
300743f74a constify the TargetMachine argument used in the subtarget and
lowering constructors.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218832 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-01 21:36:28 +00:00
Sanjay Patel
cafc85bf1e Split the estimate() interface into separate functions for each type. NFC.
It was hacky to use an opcode as a switch because it won't always match
(rsqrte != sqrte), and it looks like we'll need to add more special casing
per arch than I had hoped for. Eg, x86 will prefer a different NR estimate
implementation. ARM will want to use it's 'step' instructions. There also
don't appear to be any new estimate instructions in any arch in a long,
long time. Altivec vloge and vexpte may have been the first and last in
that field...



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218698 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 20:28:48 +00:00
Sanjay Patel
676af35b38 Refactor reciprocal and reciprocal square root estimate into target-independent functions (part 2).
This is purely refactoring. No functional changes intended. PowerPC is the only target
that is currently using this interface.

The ultimate goal is to allow targets other than PowerPC (certainly X86 and Aarch64) to turn this:

z = y / sqrt(x)

into:

z = y * rsqrte(x)

And:

z = y / x

into:

z = y * rcpe(x)

using whatever HW magic they can use. See http://llvm.org/bugs/show_bug.cgi?id=20900 .

There is one hook in TargetLowering to get the target-specific opcode for an estimate instruction
along with the number of refinement steps needed to make the estimate usable.

Differential Revision: http://reviews.llvm.org/D5484



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218553 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-26 23:01:47 +00:00
Robin Morisset
58bca6e8ec [Power] Use AtomicExpandPass for fence insertion, and use lwsync where appropriate
Summary:
This patch makes use of AtomicExpandPass in Power for inserting fences around
atomic as part of an effort to remove fence insertion from SelectionDAGBuilder.
As a big bonus, it lets us use sync 1 (lightweight sync, often used by the mnemonic
lwsync) instead of sync 0 (heavyweight sync) in many cases.

I also added a test, as there was no test for the barriers emitted by the Power
backend for atomic loads and stores.

Test Plan: new test + make check-all

Reviewers: jfb

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5180

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218331 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-23 20:46:49 +00:00
Sanjay Patel
3e05b40fd0 Refactor reciprocal square root estimate into target-independent function; NFC.
This is purely a plumbing patch. No functional changes intended.

The ultimate goal is to allow targets other than PowerPC (certainly X86 and Aarch64) to turn this:

z = y / sqrt(x)

into:

z = y * rsqrte(x)

using whatever HW magic they can use. See http://llvm.org/bugs/show_bug.cgi?id=20900 .

The first step is to add a target hook for RSQRTE, take the already target-independent code selfishly hoarded by PPC, and put it into DAGCombiner.

Next steps:

    The code in DAGCombiner::BuildRSQRTE() should be refactored further; tests that exercise that logic need to be added.
    Logic in PPCTargetLowering::BuildRSQRTE() should be hoisted into DAGCombiner.
    X86 and AArch64 overrides for TargetLowering.BuildRSQRTE() should be added.

Differential Revision: http://reviews.llvm.org/D5425



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218219 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-21 15:19:15 +00:00
Hal Finkel
c404e8208c Optionally enable more-aggressive FMA formation in DAGCombine
The heuristic used by DAGCombine to form FMAs checks that the FMUL has only one
use, but this is overly-conservative on some systems. Specifically, if the FMA
and the FADD have the same latency (and the FMA does not compete for resources
with the FMUL any more than the FADD does), there is no need for the
restriction, and furthermore, forming the FMA leaving the FMUL can still allow
for higher overall throughput and decreased critical-path length.

Here we add a new TLI callback, enableAggressiveFMAFusion, false by default, to
elide the hasOneUse check. This is enabled for PowerPC by default, as most
PowerPC systems will benefit.

Patch by Olivier Sallenave, thanks!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218120 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-19 11:42:56 +00:00
Craig Topper
c4e394a333 Use cast to MVT instead of EVT on a couple calls to getSizeInBits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217473 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-10 04:51:36 +00:00
Eric Christopher
d5dd8ce2a5 Reinstate "Nuke the old JIT."
Approved by Jim Grosbach, Lang Hames, Rafael Espindola.

This reinstates commits r215111, 215115, 215116, 215117, 215136.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216982 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 22:28:02 +00:00
Sanjay Patel
d1a09c47d2 name change: isPow2DivCheap -> isPow2SDivCheap
isPow2DivCheap

That name doesn't specify signed or unsigned.

Lazy as I am, I eventually read the function and variable comments. It turns out that this is strictly about signed div. But I discovered that the comments are wrong:

   srl/add/sra

is not the general sequence for signed integer division by power-of-2. We need one more 'sra':

   sra/srl/add/sra

That's the sequence produced in DAGCombiner. The first 'sra' may be removed when dividing by exactly '2', but that's a special case.

This patch corrects the comments, changes the name of the flag bit, and changes the name of the accessor methods.

No functional change intended.

Differential Revision: http://reviews.llvm.org/D5010


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216237 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-21 22:31:48 +00:00
Hal Finkel
5dc48ac04a [PowerPC] Mark fixed-offset byvals as pointed-to by IR values
A byval object, even if allocated at a fixed offset (prescribed by the ABI) is
pointed to by IR values. Most fixed-offset stack objects are not pointed-to by
IR values, so the default is to assume this is not possible. However, we need
to override the default in this case (instruction scheduling can cause
miscompiles otherwise).

Fixes PR20280.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215795 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-16 00:17:05 +00:00
Hal Finkel
bdd8b6bfb9 [PowerPC] Darwin byval arguments are not immutable
On PPC/Darwin, byval arguments occur at fixed stack offsets in the callee's
frame, but are not immutable -- the pointer value is directly available to the
higher-level code as the address of the argument, and the value of the byval
argument can be modified at the IR level.

This is necessary, but not sufficient, to fix PR20280. When PR20280 is fixed in
a follow-up commit, its test case will cover this change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215793 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-16 00:16:29 +00:00
Hal Finkel
e693d3c558 [PowerPC] Implement PPCTargetLowering::getTgtMemIntrinsic
This implements PPCTargetLowering::getTgtMemIntrinsic for Altivec load/store
intrinsics. As with the construction of the MachineMemOperands for the
intrinsic calls used for unaligned load/store lowering, the only slight
complication is that we need to represent a larger memory range than the
loaded/stored value-type size (because the address is rounded down to an
aligned address, and we need to conservatively represent the entire possible
range of the actual access). This required adding an extra size field to
TargetLowering::IntrinsicInfo, and this was done in a way that required no
modifications to other targets (the size defaults to the store size of the
provided memory data type).

This fixes test/CodeGen/PowerPC/unal-altivec-wint.ll (so it can be un-XFAILed).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215512 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-13 01:15:40 +00:00
Joerg Sonnenberger
6f3e49e03c Add low-level option for avoiding float stores from va_start until
soft-float is properly supported.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215221 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-08 16:46:10 +00:00
Eric Christopher
aa5b9c0f6f Temporarily Revert "Nuke the old JIT." as it's not quite ready to
be deleted. This will be reapplied as soon as possible and before
the 3.6 branch date at any rate.

Approved by Jim Grosbach, Lang Hames, Rafael Espindola.

This reverts commits r215111, 215115, 215116, 215117, 215136.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215154 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-07 22:02:54 +00:00
Rafael Espindola
875710a2fd Nuke the old JIT.
I am sure we will be finding bits and pieces of dead code for years to
come, but this is a good start.

Thanks to Lang Hames for making MCJIT a good replacement!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215111 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-07 14:21:18 +00:00
Eric Christopher
41612a9b85 Remove the target machine from CCState. Previously it was only used
to get the subtarget and that's accessible from the MachineFunction
now. This helps clear the way for smaller changes where we getting
a subtarget will require passing in a MachineFunction/Function as
well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214988 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-06 18:45:26 +00:00
Bill Schmidt
bb639a1f96 [PowerPC] Swap arguments and adjust shift count for vsldoi on little endian
Commits r213915 and r214718 fix recognition of shuffle masks for vmrg*
and vpku*um instructions for a little-endian target, by swapping the
input arguments.  The vsldoi instruction requires similar treatment,
and also needs its shift count adjusted for little endian.

Reviewed by Ulrich Weigand.

This is a bug fix candidate for release 3.5 (and hopefully the last of
those for PowerPC).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214923 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-05 20:47:25 +00:00
Eric Christopher
6035518e3b Have MachineFunction cache a pointer to the subtarget to make lookups
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.

Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214838 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-05 02:39:49 +00:00
Bill Schmidt
84fef1f55d [PPC64LE] Fix wrong IR for vec_sld and vec_vsldoi
My original LE implementation of the vsldoi instruction, with its
altivec.h interfaces vec_sld and vec_vsldoi, produces incorrect
shufflevector operations in the LLVM IR.  Correct code is generated
because the back end handles the incorrect shufflevector in a
consistent manner.

This patch and a companion patch for Clang correct this problem by
removing the fixup from altivec.h and the corresponding fixup from the
PowerPC back end.  Several test cases are also modified to reflect the
now-correct LLVM IR.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214800 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 23:21:01 +00:00
Eric Christopher
9f85dccfc6 Remove the TargetMachine forwards for TargetSubtargetInfo based
information and update all callers. No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214781 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 21:25:23 +00:00
Ulrich Weigand
c568629589 [PowerPC] Swap arguments to vpkuhum/vpkuwum on little-endian
In commit r213915, Bill fixed little-endian usage of vmrgh* and vmrgl*
by swapping the input arguments.  As it turns out, the exact same fix
is also required for the vpkuhum/vpkuwum patterns.

This fixes another regression in llvmpipe when vector support is
enabled.

Reviewed by Bill Schmidt.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214718 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 13:53:40 +00:00
Ulrich Weigand
d5e9497c88 [PowerPC] MULHU/MULHS are not legal for vector types
I ran into some test failures where common code changed vector division
by constant into a multiply-high operation (MULHU).  But these are not
implemented by the back-end, so we failed to recognize the insn.

Fixed by marking MULHU/MULHS as Expand for vector types.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214716 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 13:27:12 +00:00
Ulrich Weigand
3b7a193521 [PowerPC] Fix and improve vector comparisons
This patch refactors code generation of vector comparisons.

This fixes a wrong code-gen bug for ISD::SETGE for floating-point types,
and improves generated code for vector comparisons in general.

Specifically, the patch moves all logic deciding how to implement vector
comparisons into getVCmpInst, which gets two extra boolean outputs
indicating to its caller whether its needs to swap the input operands
and/or negate the result of the comparison.  Apart from implementing
these two modifications as directed by getVCmpInst, there is no need
to ever implement vector comparisons in any other manner; in particular,
there is never a need to perform two separate comparisons (e.g. one for
equal and one for greater-than, as code used to do before this patch).

Reviewed by Bill Schmidt.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214714 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 13:13:57 +00:00