Commit Graph

1781 Commits

Author SHA1 Message Date
Kit Barton 7c80f98b69 [PPC] Remove Darwin support from POWER backend.
This patch issues an error message if Darwin ABI is attempted with the PPC
backend. It also cleans up existing test cases, either converting the test to
use an alternative triple or removing the test if the coverage is no longer
needed.

Updated Tests
-------------
The majority of test cases were updated to use a different triple that does not
include the Darwin ABI. Many tests were also updated to use FileCheck, in place
of grep.

Deleted Tests
-------------
llvm/test/tools/dsymutil/PowerPC/sibling.test was originally added to test
specific functionality of dsymutil using an object file created with an old
version of llvm-gcc for a Powerbook G4. After a discussion with @JDevlieghere he
suggested removing the test.

llvm/test/CodeGen/PowerPC/combine_loads_from_build_pair.ll was converted from a
PPC test to a SystemZ test, as the behavior is also reproducible there.

All other tests that were deleted were specific to the darwin/ppc ABI and no
longer necessary.

Phabricator Review: https://reviews.llvm.org/D50988

llvm-svn: 340795
2018-08-28 01:18:29 +00:00
Nemanja Ivanovic 5d06f17b8a [PowerPC] Revert commit r339779
This commit has caused failures in some internal benchmarks. Temporarily
reverting this patch until the issue can be diagnosed and fixed.

llvm-svn: 340740
2018-08-27 13:20:42 +00:00
Nemanja Ivanovic f2588a28a8 [PowerPC] Recommit r340016 after fixing the reported issue
The internal benchmark failure reported by Google was due to a missing
check for the result type for the sign-extend and shift DAG. This commit
adds the check and re-commits the patch.

llvm-svn: 340734
2018-08-27 11:20:27 +00:00
Stefan Pintilie f384606799 [PowerPC] Emit xscpsgndp instead of xxlor when copying floating point scalar registers for P9
This patch will address using the xscpsgndp instruction to copy floating point
scalar registers instead of the xxlor (specifically XXLORf) instruction that is
currently used. Additionally, this patch of utilizing xscpsgndp will apply to
P9, while pre-P9 will still use xxlor.

Patch by amyk

Differential Revision: https://reviews.llvm.org/D50004

llvm-svn: 340643
2018-08-24 20:00:24 +00:00
Stefan Pintilie 892fc6b7f2 [Exception Handling] Unwind tables are required for all functions that have an EH personality.
This patch is for defect:
https://bugs.llvm.org/show_bug.cgi?id=32611

Functions may require unwind tables even if they are marked with the attribute
nounwind. Any function with an EH personality may require an unwind table.

Differential Revision: https://reviews.llvm.org/D50987

llvm-svn: 340641
2018-08-24 19:38:29 +00:00
Stefan Pintilie bddd7d8b7b [PowerPC] Change Test Options [NFC]
Patch by amyk

llvm-svn: 340639
2018-08-24 19:24:20 +00:00
Stefan Pintilie 7cb44f2470 Revert "[Exception Handling] Unwind tables are required for all functions that have an EH personality."
This reverts commit rL340614.
Previous commit broke some llvm-cfi-verify tests.

llvm-svn: 340625
2018-08-24 17:27:35 +00:00
Stefan Pintilie 36f31617d3 [Exception Handling] Unwind tables are required for all functions that have an EH personality.
This patch is for defect:
https://bugs.llvm.org/show_bug.cgi?id=32611

Functions may require unwind tables even if they are marked with the attribute
nounwind. Any function with an EH personality may require an unwind table.

Differential Revision: https://reviews.llvm.org/D50987

llvm-svn: 340614
2018-08-24 15:51:47 +00:00
Eric Christopher 3dc594c1e6 Temporarily Revert "[PowerPC] Generate Power9 extswsli extend sign and shift immediate instruction" due to it causing a compiler crash on valid.
This reverts commit r340016, testcase forthcoming.

llvm-svn: 340315
2018-08-21 18:35:08 +00:00
QingShan Zhang f8f9af7ba5 [PowerPC] Add a peephole post RA to transform the inst that fed by add
If the arch is P8, we will select XFLOAD to load the floating point, and then, expand it to vsx and non-vsx X-form instruction post RA. This patch is trying to convert the X-form to D-form if it meets the requirement that one operand of the x-form inst is the special Zero register, and another operand fed by add inst. i.e.
y = add imm, reg
LFDX. 0, y
-->
LFD imm(reg)

Reviewers: Nemanjai
Differential Revision: https://reviews.llvm.org/D49007

llvm-svn: 340149
2018-08-20 02:52:55 +00:00
Stefan Pintilie 39869ccf51 [PowerPC] Generate lxsd instead of the ld->mtvsrd sequence for vector loads
This patch addresses:

- Implementation within PPCISelLowering.cpp to check if we should use direct
load into vector instructions (such as lxsd/lfd ) when the scalar_to_vector
function is used; which will allow us to catch as many cases of the
scalar_to_vector uses as possible to translate the ld->mtvsrd sequence into
lxsd.

- Test cases to exhibit the behaviour of emitting lxsd/lfd.

Patch by amyk

Differential revision: https://reviews.llvm.org/D49698

llvm-svn: 340037
2018-08-17 15:15:26 +00:00
Nemanja Ivanovic 39751276b0 [PowerPC] Generate Power9 extswsli extend sign and shift immediate instruction
Add a DAG combine for the PowerPC code generator to generate the Power9 extswsli
extend sign and shift immediate instruction.

Patch by RolandF.

Differential revision: https://reviews.llvm.org/D49879

llvm-svn: 340016
2018-08-17 12:35:44 +00:00
Eli Friedman 73e8a784e6 [SelectionDAG] Improve the legalisation lowering of UMULO.
There is no way in the universe, that doing a full-width division in
software will be faster than doing overflowing multiplication in
software in the first place, especially given that this same full-width
multiplication needs to be done anyway.

This patch replaces the previous implementation with a direct lowering
into an overflowing multiplication algorithm based on half-width
operations.

Correctness of the algorithm was verified by exhaustively checking the
output of this algorithm for overflowing multiplication of 16 bit
integers against an obviously correct widening multiplication. Baring
any oversights introduced by porting the algorithm to DAG, confidence in
correctness of this algorithm is extremely high.

Following table shows the change in both t = runtime and s = space. The
change is expressed as a multiplier of original, so anything under 1 is
“better” and anything above 1 is worse.

+-------+-----------+-----------+-------------+-------------+
| Arch  | u64*u64 t | u64*u64 s | u128*u128 t | u128*u128 s |
+-------+-----------+-----------+-------------+-------------+
|   X64 |     -     |     -     |    ~0.5     |    ~0.64    |
|  i686 |   ~0.5    |   ~0.6666 |    ~0.05    |    ~0.9     |
| armv7 |     -     |   ~0.75   |      -      |    ~1.4     |
+-------+-----------+-----------+-------------+-------------+

Performance numbers have been collected by running overflowing
multiplication in a loop under `perf` on two x86_64 (one Intel Haswell,
other AMD Ryzen) based machines. Size numbers have been collected by
looking at the size of function containing an overflowing multiply in
a loop.

All in all, it can be seen that both performance and size has improved
except in the case of armv7 where code size has regressed for 128-bit
multiply. u128*u128 overflowing multiply on 32-bit platforms seem to
benefit from this change a lot, taking only 5% of the time compared to
original algorithm to calculate the same thing.

The final benefit of this change is that LLVM is now capable of lowering
the overflowing unsigned multiply for integers of any bit-width as long
as the target is capable of lowering regular multiplication for the same
bit-width. Previously, 128-bit overflowing multiply was the widest
possible.

Patch by Simonas Kazlauskas!

Differential Revision: https://reviews.llvm.org/D50310

llvm-svn: 339922
2018-08-16 18:39:39 +00:00
Nemanja Ivanovic 5b9a4f8ee5 [PowerPC] Enhance the selection(ISD::VSELECT) of vector type
To make ISD::VSELECT available(legal) so long as there are altivec instruction,
otherwise it's default behavior is expanding.
Use xxsel to match vselect if vsx is open, or use vsel.

In order to do not write many patterns in td file, promote (for vector it's
bitcast) all other type into v4i32 and only pattern match vselect of v4i32 into
vsel or xxsel.

Patch by wuzish
Differential revision: https://reviews.llvm.org/D49531

llvm-svn: 339779
2018-08-15 15:30:36 +00:00
Nemanja Ivanovic 8b4bd09e22 [PowerPC] Don't run BV DAG Combine before legalization if it assumes legal types
When trying to combine a DAG that builds a vector out of sign-extensions of
vector extracts, the code assumes legal input types. Due to that, we have to
disable this combine prior to legalization.
In some cases, the DAG will look slightly different after legalization so
account for that in the matching code.

This is a fix for https://bugs.llvm.org/show_bug.cgi?id=38087

Differential Revision: https://reviews.llvm.org/D49080

llvm-svn: 339769
2018-08-15 12:58:13 +00:00
Sanjay Patel 15d1501aae [SelectionDAG] try harder to convert funnel shift to rotate
Similar to rL337966 - if the DAGCombiner's rotate matching was 
working as expected, I don't think we'd see any test diffs here.

AArch only goes right, and PPC only goes left. 
x86 has both, so no diffs there.

Differential Revision: https://reviews.llvm.org/D50091

llvm-svn: 339359
2018-08-09 17:26:22 +00:00
Zaara Syeda b2595b988b [PowerPC] Improve codegen for vector loads using scalar_to_vector
This patch aims to improve the codegen for vector loads involving the
scalar_to_vector (load X) sequence. Initially, ld->mv instructions were used
for scalar_to_vector (load X), so this patch allows scalar_to_vector (load X)
to utilize:

LXSD and LXSDX for i64 and f64
LXSIWAX for i32 (sign extension to i64)
LXSIWZX for i32 and f64

Committing on behalf of Amy Kwan.
Differential Revision: https://reviews.llvm.org/D48950

llvm-svn: 339260
2018-08-08 15:20:43 +00:00
Nemanja Ivanovic e1a525ed06 [PowerPC] Do not round values prior to converting to integer
Adding the FP_ROUND nodes when combining FP_TO_[SU]INT of elements
feeding a BUILD_VECTOR into an FP_TO_[SU]INT of the built vector
loses precision. This patch removes the code that adds these nodes
to true f64 operands. It also adds patterns required to ensure
the code is still vectorized rather than converting individual
elements and inserting into a vector.

Fixes https://bugs.llvm.org/show_bug.cgi?id=38342

Differential Revision: https://reviews.llvm.org/D50121

llvm-svn: 338658
2018-08-02 00:03:22 +00:00
Sanjay Patel 8aac22e06a [SelectionDAG] fix bug in translating funnel shift with non-power-of-2 type
The bug is visible in the constant-folded x86 tests. We can't use the
negated shift amount when the type is not power-of-2:
https://rise4fun.com/Alive/US1r

...so in that case, use the regular lowering that includes a select
to guard against a shift-by-bitwidth. This path is improved by only
calculating the modulo shift amount once now.

Also, improve the rotate (with power-of-2 size) lowering to use
a negate rather than subtract from bitwidth. This improves the
codegen whether we have a rotate instruction or not (although
we can still see that we're not matching to a legal rotate in
all cases).

llvm-svn: 338592
2018-08-01 17:17:08 +00:00
Sanjay Patel 9f807f44b1 [DAGCombiner] transform sub-of-shifted-signbit to add
This is exchanging a sub-of-1 with add-of-minus-1:
https://rise4fun.com/Alive/plKAH

This is another step towards improving select-of-constants codegen (see D48970).

x86 is the motivating target, and those diffs all appear to be wins. PPC and AArch64 look neutral.
I've limited this to early combining (!LegalOperations) in case a target wants to reverse it, but
I think canonicalizing to 'add' is more likely to produce further transforms because we have more
folds for 'add'.

Differential Revision: https://reviews.llvm.org/D49924

llvm-svn: 338317
2018-07-30 22:21:37 +00:00
Sanjay Patel 06c7d5aef6 [AArch64, PowerPC, x86] add more signbit math tests; NFC
The tests with a constant sub operand were added with rL338143,
but the potential transform doesn't have that requirement, so
adding more tests with variable operands.

llvm-svn: 338150
2018-07-27 18:31:21 +00:00
Sanjay Patel efac39eef6 [AArch64, PowerPC, x86] add more signbit math tests; NFC
llvm-svn: 338143
2018-07-27 18:12:29 +00:00
Sanjay Patel c7abb416dc [DAGCombiner] fold 'not' with signbit math
This is a follow-up suggested in D48970. 

Alive proofs:
https://rise4fun.com/Alive/sII

We can eliminate an instruction in the usual select-of-constants 
to bit hack transform by adjusting the add/sub with constant.
This is always a win. 

There are more transforms that are likely wins, but they may need 
target hooks in case some targets do not benefit. 

This is another step towards making up for canonicalizing to 
select-of-constants in rL331486.

llvm-svn: 338132
2018-07-27 16:42:55 +00:00
Sanjay Patel 60c04b961e [PowerPC] add more tests for signbit math; NFC
llvm-svn: 338130
2018-07-27 16:22:18 +00:00
Sanjay Patel 215dcbf4db [SelectionDAG] try to convert funnel shift directly to rotate if legal
If the DAGCombiner's rotate matching was working as expected, 
I don't think we'd see any test diffs here. 

This sidesteps the issue of custom lowering for rotates raised in PR38243:
https://bugs.llvm.org/show_bug.cgi?id=38243
...by only dealing with legal operations.

llvm-svn: 337966
2018-07-25 21:38:30 +00:00
Sanjay Patel f94c4c84e6 [AArch, PowerPC] add more tests for legal rotate ops; NFC
llvm-svn: 337964
2018-07-25 21:25:50 +00:00
Stefan Pintilie 0c122d5a41 [Power9] Code Cleanup - Remove needsAggressiveScheduling()
As we already return true from needsAggressiveScheduling() for the most recent
hardware it would be cleaner to just return true for all PowerPC hardware.

Differential Revision: https://reviews.llvm.org/D48663

llvm-svn: 337488
2018-07-19 19:34:18 +00:00
Justin Hibbits d52990c71b Introduce codegen for the Signal Processing Engine
Summary:
The Signal Processing Engine (SPE) is found on NXP/Freescale e500v1,
e500v2, and several e200 cores.  This adds support targeting the e500v2,
as this is more common than the e500v1, and is in SoCs still on the
market.

This patch is very intrusive because the SPE is binary incompatible with
the traditional FPU.  After discussing with others, the cleanest
solution was to make both SPE and FPU features on top of a base PowerPC
subset, so all FPU instructions are now wrapped with HasFPU predicates.

Supported by this are:
* Code generation following the SPE ABI at the LLVM IR level (calling
conventions)
* Single- and Double-precision math at the level supported by the APU.

Still to do:
* Vector operations
* SPE intrinsics

As this changes the Callee-saved register list order, one test, which
tests the precise generated code, was updated to account for the new
register order.

Reviewed by: nemanjai
Differential Revision: https://reviews.llvm.org/D44830

llvm-svn: 337347
2018-07-18 04:25:10 +00:00
Sanjay Patel c71adc8040 [Intrinsics] define funnel shift IR intrinsics + DAG builder support
As discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123292.html
http://lists.llvm.org/pipermail/llvm-dev/2018-July/124400.html

We want to add rotate intrinsics because the IR expansion of that pattern is 4+ instructions, 
and we can lose pieces of the pattern before it gets to the backend. Generalizing the operation 
by allowing 2 different input values (plus the 3rd shift/rotate amount) gives us a "funnel shift" 
operation which may also be a single hardware instruction.

Initially, I thought we needed to define new DAG nodes for these ops, and I spent time working 
on that (much larger patch), but then I concluded that we don't need it. At least as a first 
step, we have all of the backend support necessary to match these ops...because it was required. 
And shepherding these through the IR optimizer is the primary concern, so the IR intrinsics are 
likely all that we'll ever need.

There was also a question about converting the intrinsics to the existing ROTL/ROTR DAG nodes
(along with improving the oversized shift documentation). Again, I don't think that's strictly 
necessary (as the test results here prove). That can be an efficiency improvement as a small 
follow-up patch.

So all we're left with is documentation, definition of the IR intrinsics, and DAG builder support. 

Differential Revision: https://reviews.llvm.org/D49242

llvm-svn: 337221
2018-07-16 22:59:31 +00:00
Sanjay Patel a41c886c55 [DAGCombiner] extend(ifpositive(X)) -> shift-right (not X)
This is almost the same as an existing IR canonicalization in instcombine, 
so I'm assuming this is a good early generic DAG combine too.

The motivation comes from reduced bit-hacking for select-of-constants in IR 
after rL331486. We want to restore that functionality in the DAG as noted in
the commit comments for that change and the llvm-dev discussion here:
http://lists.llvm.org/pipermail/llvm-dev/2018-July/124433.html

The PPC and AArch tests show that those targets are already doing something 
similar. x86 will be neutral in the minimal case and generally better when 
this pattern is extended with other ops as shown in the signbit-shift.ll tests.

Note the asymmetry: we don't include the (extend (ifneg X)) transform because 
it already exists in SimplifySelectCC(), and that is verified in the later 
unchanged tests in the signbit-shift.ll files. Without the 'not' op, the 
general transform to use a shift is always a win because that's a single 
instruction.

Alive proofs:
https://rise4fun.com/Alive/ysli

Name: if pos, get -1
  %c = icmp sgt i16 %x, -1
  %r = sext i1 %c to i16
  =>
  %n = xor i16 %x, -1
  %r = ashr i16 %n, 15

Name: if pos, get 1
  %c = icmp sgt i16 %x, -1
  %r = zext i1 %c to i16
  =>
  %n = xor i16 %x, -1
  %r = lshr i16 %n, 15

Differential Revision: https://reviews.llvm.org/D48970

llvm-svn: 337130
2018-07-15 16:27:07 +00:00
Nemanja Ivanovic 080c35050e [PowerPC] Materialize more constants with CR-field set in late peephole
Revision r322373 fixed a bug in how we materialize constants when the CR-field
needs to be set.

However the fix is overly conservative. It will only do the transform if
AND-ing the input with the new constant produces the same new constant.
This is of course correct, but not necessarily required.

If there are no futher uses of the constant, the constant can be changed.
If there are no uses of the GPR result, the final result of the materialization
isn't important other than it needs to compare to zero correctly (lt, gt, eq).

Differential revision: https://reviews.llvm.org/D42109

llvm-svn: 337008
2018-07-13 15:21:03 +00:00
Stefan Pintilie 94259ba13a [PowerPC] [NFC] Update __float128 tests
Add the two options -ppc-vsr-nums-as-vr and -ppc-asm-full-reg-names to
the __float128 tests. Then modify the tests as required.

llvm-svn: 336940
2018-07-12 20:18:57 +00:00
Joel E. Denny 9fa9c9368d [FileCheck] Add -allow-deprecated-dag-overlap to failing llvm tests
See https://reviews.llvm.org/D47106 for details.

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D47171

This commit drops that patch's changes to:

  llvm/test/CodeGen/NVPTX/f16x2-instructions.ll
  llvm/test/CodeGen/NVPTX/param-load-store.ll

For some reason, the dos line endings there prevent me from commiting
via the monorepo.  A follow-up commit (not via the monorepo) will
finish the patch.

llvm-svn: 336843
2018-07-11 20:25:49 +00:00
Stefan Pintilie b9d01aa29e [Power9] Add remaining __flaot128 builtin support for FMA round to odd
Implement this as it is done on GCC:

__float128 a, b, c, d;
a = __builtin_fmaf128_round_to_odd (b, c, d);         // generates xsmaddqpo
a = __builtin_fmaf128_round_to_odd (b, c, -d);        // generates xsmsubqpo
a = - __builtin_fmaf128_round_to_odd (b, c, d);       // generates xsnmaddqpo
a = - __builtin_fmaf128_round_to_odd (b, c, -d);      // generates xsnmsubpqp

Differential Revision: https://reviews.llvm.org/D48218

llvm-svn: 336754
2018-07-11 01:42:22 +00:00
Stefan Pintilie 133acb22bb [Power9] Add __float128 builtins for Rounding Operations
Added __float128 support for a number of rounding operations:

trunc
rint
nearbyint
round
floor
ceil

Differential Revision: https://reviews.llvm.org/D48415

llvm-svn: 336601
2018-07-09 20:38:40 +00:00
Stefan Pintilie 58e3e0a827 [Power9] [LLVM] Add __float128 support for trunc to double round to odd
Add support for this builtin:
double builtin_truncf128_round_to_odd(float128)

Differential Revision: https://reviews.llvm.org/D48483

llvm-svn: 336595
2018-07-09 20:09:22 +00:00
Stefan Pintilie 83a5fe146e [Power9] Add __float128 builtins for Round To Odd
GCC has builtins for these round to odd instructions:

__float128 __builtin_sqrtf128_round_to_odd (__float128)
__float128 __builtin_{add,sub,mul,div}f128_round_to_odd (__float128, __float128)
__float128 __builtin_fmaf128_round_to_odd (__float128, __float128, __float128)

Differential Revision: https://reviews.llvm.org/D47550

llvm-svn: 336578
2018-07-09 18:50:06 +00:00
Stefan Pintilie 3d76326d24 [Power9] Add __float128 support for compare operations
Added handling for the select f128.

Differential Revision: https://reviews.llvm.org/D48294

llvm-svn: 336548
2018-07-09 13:36:14 +00:00
Stefan Pintilie b351f09c9e [Power9] Add __float128 library call for frem
Power 9 does not have a hardware instruction for frem but we can call fmodf128.

Differential Revision: https://reviews.llvm.org/D48552

llvm-svn: 336406
2018-07-06 02:47:02 +00:00
Lei Huang 5612b90694 [Power9] Add lib calls for float128 operations with no equivalent PPC instructions
Map the following instructions to the proper float128 lib calls:
  pow[i], exp[2], log[2|10], sin, cos, fmin, fmax

Differential Revision: https://reviews.llvm.org/D48544

llvm-svn: 336361
2018-07-05 15:21:37 +00:00
Sanjay Patel bce899ff59 [AArch64, PowerPC, x86] add tests for signbit bit hacks; NFC
llvm-svn: 336348
2018-07-05 13:16:46 +00:00
Lei Huang 66e22c21c3 [Power9] Optimize codgen for conversions of int to float128
Optimize code sequences for integer conversion to fp128 when the integer is a result of:
  * float->int
  * float->long
  * double->int
  * double->long

Differential Revision: https://reviews.llvm.org/D48429

llvm-svn: 336316
2018-07-05 07:46:01 +00:00
Lei Huang 9d70afbb31 [Power9][NFC] add back-end tests for passing homogeneous fp128 aggregates by value
Tests to verify that we are passing fp128 via VSX registers as per ABI.
These are related to clang commit rL336308.

Differential Revision: https://reviews.llvm.org/D48310

llvm-svn: 336314
2018-07-05 06:51:38 +00:00
Lei Huang 5bab646c26 [Power9] Add tests for passing float128 in VSX reg for non-homogenous aggregates
Add missing testcase for rL336310

llvm-svn: 336313
2018-07-05 06:29:28 +00:00
Lei Huang d17c39ccaa [Power9]Legalize and emit code for quad-precision convert from single-precision
Legalize and emit code for quad-precision floating point operation conversion of
single-precision value to quad-precision.

Differential Revision: https://reviews.llvm.org/D47569

llvm-svn: 336307
2018-07-05 04:18:37 +00:00
Lei Huang a26f3be454 [Power9] Implement float128 parameter passing and return values
This patch enable parameter passing and return by value for float128 types.
Passing aggregate/union which contain float128 members will be submitted in
subsequent patches.

Differential Revision: https://reviews.llvm.org/D47552

llvm-svn: 336306
2018-07-05 04:10:15 +00:00
Lei Huang 6270ab6ce4 [Power9]Legalize and emit code for round & convert quad-precision values
Legalize and emit code for round & convert float128 to double precision and
single precision.

Differential Revision: https://reviews.llvm.org/D46997

llvm-svn: 336299
2018-07-04 21:59:16 +00:00
Stefan Pintilie cb4f0c5c07 [PowerPC] Replace the Post RA List Scheduler with the Machine Scheduler
We want to run the Machine Scheduler instead of the List Scheduler after RA.
  Checked with a performance run on a Power 9 machine with SPEC 2006 and while
  some benchmarks improved and others degraded the geomean was slightly improved
  with the Machine Scheduler.

  Differential Revision: https://reviews.llvm.org/D45265

llvm-svn: 336295
2018-07-04 18:54:25 +00:00
Gabor Buella da4a966e1c NFC - Various typo fixes in tests
llvm-svn: 336268
2018-07-04 13:28:39 +00:00
QingShan Zhang 3b2aa2b4b4 [PowerPC] Don't make it as pre-inc candidate if displacement isn't 4's multiple for i64 pre-inc load/store
For the below case, pre-inc prep think it's a good candidate to use pre-inc for the bucket, but 64bit integer load/store update (pre-inc) instruction on Power requires the displacement field should be DS-form (4's multiple). Since it can't satisfy the constraint, we have to do some fix ups later. As below, the original load/stores could be well-form, it makes things worse.

unsigned long long result = 0;
unsigned long long foo(char *p, unsigned long long n) {
  for (unsigned long long i = 0; i < n; i++) {
    unsigned long long x1 = *(unsigned long long *)(p - 50000 + i);
    unsigned long long x2 = *(unsigned long long *)(p - 61024 + i);
    unsigned long long x3 = *(unsigned long long *)(p - 62048 + i);
    unsigned long long x4 = *(unsigned long long *)(p - 64096 + i);
    result *= x1 * x2 * x3 * x4;
  }
  return result;
}

Patch by jedilyn(Kewen Lin).

Differential Revision: https://reviews.llvm.org/D48813 
--This line, and  those below, will be ignored--

M    lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
A    test/CodeGen/PowerPC/preincprep-i64-check.ll

llvm-svn: 336074
2018-07-02 05:46:09 +00:00