Commit Graph

19 Commits

Author SHA1 Message Date
Adam Nemet 709e3046ee [LoopDataPrefetch] Add TTI to limit the number of iterations to prefetch ahead
Summary:
It can hurt performance to prefetch ahead too much.  Be conservative for
now and don't prefetch ahead more than 3 iterations on Cyclone.

Reviewers: hfinkel

Subscribers: llvm-commits, mzolotukhin

Differential Revision: http://reviews.llvm.org/D17949

llvm-svn: 263772
2016-03-18 00:27:43 +00:00
Adam Nemet 6d8beeca53 [LoopDataPrefetch/Aarch64] Allow selective prefetching of large-strided accesses
Summary:
And use this TTI for Cyclone.  As it was explained in the original RFC
(http://thread.gmane.org/gmane.comp.compilers.llvm.devel/92758), the HW
prefetcher work up to 2KB strides.

I am also adding tests for this and the previous change (D17943):

* Cyclone prefetching accesses with a large stride
* Cyclone not prefetching accesses with a small stride
* Generic Aarch64 subtarget not prefetching either

Reviewers: hfinkel

Subscribers: aemerson, rengolin, llvm-commits, mzolotukhin

Differential Revision: http://reviews.llvm.org/D17945

llvm-svn: 263771
2016-03-18 00:27:38 +00:00
Adam Nemet 53e758fc55 [Aarch64] Add pass LoopDataPrefetch for Cyclone
Summary:
This wires up the pass for Cyclone but keeps it off for now because we
need a few more TTIs.

The getPrefetchMinStride value is not very well tuned right now but it
works well with CFP2006/433.milc which motivated this.

Tests will be added as part of the upcoming large-stride prefetching
patch.

Reviewers: t.p.northover

Subscribers: llvm-commits, aemerson, hfinkel, rengolin

Differential Revision: http://reviews.llvm.org/D17943

llvm-svn: 263770
2016-03-18 00:27:29 +00:00
Eric Christopher a4e5d3cf8e constify the Function parameter to the TTI creation callback and
propagate to all callers/users/etc.

llvm-svn: 247864
2015-09-16 23:38:13 +00:00
Silviu Baranga 755ec0e027 [AArch64] Turn on by default interleaved access vectorization
Summary:
This change turns on by default interleaved access vectorization
for AArch64.

We also clean up some tests which were spedifically enabling this
behaviour.

Reviewers: rengolin

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D12149

llvm-svn: 246542
2015-09-01 11:26:46 +00:00
Chandler Carruth 93205eb966 [TTI] Make the cost APIs in TargetTransformInfo consistently use 'int'
rather than 'unsigned' for their costs.

For something like costs in particular there is a natural "negative"
value, that of savings or saved cost. As a consequence, there is a lot
of code that subtracts or creates negative values based on cost, all of
which is prone to awkwardness or bugs when dealing with an unsigned
type. Similarly, we *never* want these values to wrap, as that would
cause Very Bad code generation (likely percieved as an infinite loop as
we try to emit over 2^32 instructions or some such insanity).

All around 'int' seems a much better fit for these basic metrics. I've
added asserts to ensure that at least the TTI interface never returns
negative numbers here. If we ever have a use case for negative numbers,
we can remove this, but this way a bug where someone used '-1' to
produce a 'very large' cost will be caught by the assert.

This passes all tests, and is also UBSan clean.

No functional change intended.

Differential Revision: http://reviews.llvm.org/D11741

llvm-svn: 244080
2015-08-05 18:08:10 +00:00
Mehdi Amini 5010ebf181 Make TargetTransformInfo keeping a reference to the Module DataLayout
DataLayout is no longer optional. It was initialized with or without
a DataLayout, and the DataLayout when supplied could have been the
one from the TargetMachine.

Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11021

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241774
2015-07-09 02:08:42 +00:00
Hao Liu 7ec8ee3119 [AArch64] Lower interleaved memory accesses to ldN/stN intrinsics. This patch also adds a function to calculate the cost of interleaved memory accesses.
E.g. Lower an interleaved load:
        %wide.vec = load <8 x i32>, <8 x i32>* %ptr
        %v0 = shuffle %wide.vec, undef, <0, 2, 4, 6>
        %v1 = shuffle %wide.vec, undef, <1, 3, 5, 7>
     into:
        %ld2 = { <4 x i32>, <4 x i32> } call llvm.aarch64.neon.ld2(%ptr)
        %vec0 = extractelement { <4 x i32>, <4 x i32> } %ld2, i32 0
        %vec1 = extractelement { <4 x i32>, <4 x i32> } %ld2, i32 1

E.g. Lower an interleaved store:
        %i.vec = shuffle <8 x i32> %v0, <8 x i32> %v1, <0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 11>
        store <12 x i32> %i.vec, <12 x i32>* %ptr
     into:
        %sub.v0 = shuffle <8 x i32> %v0, <8 x i32> v1, <0, 1, 2, 3>
        %sub.v1 = shuffle <8 x i32> %v0, <8 x i32> v1, <4, 5, 6, 7>
        %sub.v2 = shuffle <8 x i32> %v0, <8 x i32> v1, <8, 9, 10, 11>
        call void llvm.aarch64.neon.st3(%sub.v0, %sub.v1, %sub.v2, %ptr)

Differential Revision: http://reviews.llvm.org/D10533

llvm-svn: 240754
2015-06-26 02:32:07 +00:00
Hao Liu d0ca8d7edd [AArch64] Revert r239711 again. We need to discuss how to share code between AArch64 and ARM backend.
llvm-svn: 239713
2015-06-15 01:56:40 +00:00
Hao Liu cb070e3833 [AArch64] Match interleaved memory accesses into ldN/stN instructions.
Re-commit after adding "-aarch64-neon-syntax=generic" to fix the failure on OS X.
This patch was firstly committed in r239514, then reverted in r239544 because of a syntax incompatible failure on OS X.

llvm-svn: 239711
2015-06-15 01:35:49 +00:00
Rafael Espindola 65d37e64a9 This reverts commit r239529 and r239514.
Revert "[AArch64] Match interleaved memory accesses into ldN/stN instructions."
Revert "Fixing MSVC 2013 build error."

The  test/CodeGen/AArch64/aarch64-interleaved-accesses.ll test was failing on OS X.

llvm-svn: 239544
2015-06-11 17:30:33 +00:00
Hao Liu 4566d18e89 [AArch64] Match interleaved memory accesses into ldN/stN instructions.
Add a pass AArch64InterleavedAccess to identify and match interleaved memory accesses. This pass transforms an interleaved load/store into ldN/stN intrinsic. As Loop Vectorizor disables optimization on interleaved accesses by default, this optimization is also disabled by default. To enable it by "-aarch64-interleaved-access-opt=true"

E.g. Transform an interleaved load (Factor = 2):
       %wide.vec = load <8 x i32>, <8 x i32>* %ptr
       %v0 = shuffle %wide.vec, undef, <0, 2, 4, 6>  ; Extract even elements
       %v1 = shuffle %wide.vec, undef, <1, 3, 5, 7>  ; Extract odd elements
     Into:
       %ld2 = { <4 x i32>, <4 x i32> } call aarch64.neon.ld2(%ptr)
       %v0 = extractelement { <4 x i32>, <4 x i32> } %ld2, i32 0
       %v1 = extractelement { <4 x i32>, <4 x i32> } %ld2, i32 1

E.g. Transform an interleaved store (Factor = 2):
       %i.vec = shuffle %v0, %v1, <0, 4, 1, 5, 2, 6, 3, 7>  ; Interleaved vec
       store <8 x i32> %i.vec, <8 x i32>* %ptr
     Into:
       %v0 = shuffle %i.vec, undef, <0, 1, 2, 3>
       %v1 = shuffle %i.vec, undef, <4, 5, 6, 7>
       call void aarch64.neon.st2(%v0, %v1, %ptr)

llvm-svn: 239514
2015-06-11 09:05:02 +00:00
Wei Mi 062c74484d [X86] Disable loop unrolling in loop vectorization pass when VF is 1.
The patch disabled unrolling in loop vectorization pass when VF==1 on x86 architecture,
by setting MaxInterleaveFactor to 1. Unrolling in loop vectorization pass may introduce
the cost of overflow check, memory boundary check and extra prologue/epilogue code when
regular unroller will unroll the loop another time. Disable it when VF==1 remove the
unnecessary cost on x86. The same can be done for other platforms after verifying
interleaving/memory bound checking to be not perf critical on those platforms.

Differential Revision: http://reviews.llvm.org/D9515

llvm-svn: 236613
2015-05-06 17:12:25 +00:00
Chandler Carruth ab5cb36c40 [multiversion] Remove the function parameter from the unrolling
preferences interface on TTI now that all of TTI is per-function.

llvm-svn: 227741
2015-02-01 14:31:23 +00:00
Chandler Carruth c956ab6603 [multiversion] Switch the TTI queries from TargetMachine to Subtarget
now that we have a correct and cached subtarget specific to the
function.

Also, finish providing a cached per-function subtarget in the core
LLVMTargetMachine -- that layer hadn't switched over yet.

The only use of the TargetMachine was to re-lookup a subtarget for
a particular function to work around the fact that TTI was immutable.
Now that it is per-function and we haved a cached subtarget, use it.

This still leaves a few interfaces with real warts on them where we were
passing Function objects through the TTI interface. I'll remove these
and clean their usage up in subsequent commits now that this isn't
necessary.

llvm-svn: 227738
2015-02-01 14:22:17 +00:00
Chandler Carruth c340ca839c [multiversion] Remove the cached TargetMachine pointer from the
intermediate TTI implementation template and instead query up to the
derived class for both the TargetMachine and the TargetLowering.

Most of the derived types had a TLI cached already and there is no need
to store a less precisely typed target machine pointer.

This will in turn make it much cleaner to look up the TLI via
a per-function subtarget instead of the generic subtarget, and it will
pave the way toward pulling the subtarget used for unroll preferences
into the same form once we are *always* using the function to look up
the correct subtarget.

llvm-svn: 227737
2015-02-01 14:01:15 +00:00
Chandler Carruth 8b04c0d26a [multiversion] Switch all of the targets over to use the
TargetIRAnalysis access path directly rather than implementing getTTI.

This even removes getTTI from the interface. It's more efficient for
each target to just register a precise callback that creates their
specific TTI.

As part of this, all of the targets which are building their subtargets
individually per-function now build their TTI instance with the function
and thus look up the correct subtarget and cache it. NVPTX, R600, and
XCore currently don't leverage this functionality, but its trivial for
them to add it now.

llvm-svn: 227735
2015-02-01 13:20:00 +00:00
Chandler Carruth ee642690ea [multiversion] Remove a false freedom to leave the TargetMachine pointer
null.

For some reason some of the original TTI code supported a null target
machine. This seems to have been legacy, and I made matters worse when
refactoring this code by spreading that pattern further through the
various targets.

The TargetMachine can't actually be null, and it doesn't make sense to
support that use case. I've now consistently removed it and removed all
of the code trying to cope with that situation. This is probably good,
as several targets *didn't* cope with it being null despite the null
default argument in their constructors. =]

llvm-svn: 227734
2015-02-01 12:38:24 +00:00
Chandler Carruth 93dcdc47db [PM] Switch the TargetMachine interface from accepting a pass manager
base which it adds a single analysis pass to, to instead return the type
erased TargetTransformInfo object constructed for that TargetMachine.

This removes all of the pass variants for TTI. There is now a single TTI
*pass* in the Analysis layer. All of the Analysis <-> Target
communication is through the TTI's type erased interface itself. While
the diff is large here, it is nothing more that code motion to make
types available in a header file for use in a different source file
within each target.

I've tried to keep all the doxygen comments and file boilerplate in line
with this move, but let me know if I missed anything.

With this in place, the next step to making TTI work with the new pass
manager is to introduce a really simple new-style analysis that produces
a TTI object via a callback into this routine on the target machine.
Once we have that, we'll have the building blocks necessary to accept
a function argument as well.

llvm-svn: 227685
2015-01-31 11:17:59 +00:00