100 Commits

Author SHA1 Message Date
David Majnemer
4a45f0871a New EH representation for MSVC compatibility
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support.  Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Differential Revision: http://reviews.llvm.org/D11097

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243766 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-31 17:58:14 +00:00
Sanjay Patel
7a641cc940 move DAGCombiner's allowableAlignment() helper function into the TLI
Making allowableAlignment() more accessible was suggested as a predecessor patch
for D10662, so I've pulled it into TargetLowering. This let's us remove 4 instances
of duplicate logic in LegalizeDAG.

There's a subtle functional change in the implementation: the existing 
allowableAlignment() code was using getPrefTypeAlignment() when checking 
alignment with the DataLayout and assumed that was fast. In this implementation,
we use getABITypeAlignment() and assume that is fast. See the TODO comment or the
discussion in the Phab review for future improvements in this implementation
(don't use the data layout at all).

There are no regression test changes from this difference, and I'm not sure how to
expose it via a test. I think we actually do want to provide the 'Fast' param when
checking this from DAGCombiner::MergeConsecutiveStores(). Ie, we shouldn't merge 
stores if the new stores are not going to be fast. But that change will require 
fixing allowsMisalignedMemoryAccess() overrides as noted in D10662.

Differential Revision: http://reviews.llvm.org/D10905



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243549 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-29 18:24:18 +00:00
James Molloy
acd275a629 [Codegen] Add intrinsics 'absdiff' and corresponding SDNodes for absolute difference operation
This adds new intrinsics "*absdiff" for absolute difference ops to facilitate efficient code generation for "sum of absolute differences" operation.
The patch also contains the introduction of corresponding SDNodes and basic legalization support.Sanity of the generated code is tested on X86.

This is 1st of the three patches.

Patch by Shahid Asghar-ahmad!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242409 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 15:22:46 +00:00
Mehdi Amini
9c5961b7ba Move most user of TargetMachine::getDataLayout to the Module one
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.

This patch is quite boring overall, except for some uglyness in
ASMPrinter which has a getDataLayout function but has some clients
that use it without a Module (llmv-dsymutil, llvm-dwarfdump), so
some methods are taking a DataLayout as parameter.

Reviewers: echristo

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

Differential Revision: http://reviews.llvm.org/D11090

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242386 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 06:11:10 +00:00
David Majnemer
eddf9e2057 Revert the new EH instructions
This reverts commits r241888-r241891, I didn't mean to commit them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241893 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-10 07:15:17 +00:00
David Majnemer
751c4be705 New EH representation for MSVC compatibility
Summary:
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support.  Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Reviewers: rnk, JosephTremoulet, reames, nlewycky, rjmccall

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11041

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241888 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-10 07:00:44 +00:00
Mehdi Amini
cdc323b2b7 Re-instate the EVT parameter to getScalarShiftAmountTy() for OOT user
A documentation for this function would be nice by the way.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241807 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 15:12:23 +00:00
Mehdi Amini
0e496c884c Make isLegalAddressingMode() taking DataLayout as an argument
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/D11040

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241778 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 02:09:40 +00:00
Mehdi Amini
027a9f4561 Make getByValTypeAlignment() taking DataLayout as an argument
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: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11038

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241777 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 02:09:28 +00:00
Mehdi Amini
29a2d864d4 Make TargetLowering::getShiftAmountTy() taking DataLayout as an argument
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/D11037

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241776 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 02:09:20 +00:00
Mehdi Amini
f29cc18dcb Make TargetLowering::getPointerTy() taking DataLayout as an argument
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, ted, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11028

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241775 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 02:09:04 +00:00
Mehdi Amini
103bdfccee Redirect DataLayout from TargetMachine to Module in ComputeValueVTs()
Summary:
Avoid using the TargetMachine owned DataLayout and use the Module owned
one instead. This requires passing the DataLayout up the stack to
ComputeValueVTs().

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, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11019

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241773 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 01:57:34 +00:00
Mehdi Amini
7bcdaa6978 Remove IsLittleEndian from TargetLowering and redirect to DataLayout
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: llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11017

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241655 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-08 01:00:38 +00:00
Sanjay Patel
7472456fe9 add a cl::opt override for TargetLoweringBase's JumpIsExpensive
This patch is not intended to change existing codegen behavior for any target. 
It just exposes the JumpIsExpensive setting on the command-line to allow for
easier testing and emergency overrides.

Also, change the existing regression test to use FileCheck, explicitly specify
the jump-is-expensive option, and use more precise checks.

Differential Revision: http://reviews.llvm.org/D10846



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241179 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-01 18:10:20 +00:00
Daniel Sanders
128f072d3b Eliminate additional redundant copies of Triple objects. NFC.
Subscribers: rafael, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D10654

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240540 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 13:25:57 +00:00
Matt Arsenault
5f3a6430d6 Add address space argument to isLegalAddressingMode
This is important because of different addressing modes
depending on the address space for GPU targets.

This only adds the argument, and does not update
any of the uses to provide the correct address space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238723 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-01 05:31:59 +00:00
James Molloy
4fa71b66a8 Add SDNodes for umin, umax, smin and smax.
This adds new SDNodes for signed/unsigned min/max. These nodes are built from
select/icmp pairs matched at SDAGBuilder stage.

This patch adds the nodes, as well as legalization support and sets them to
be "expand" for all targets.

NFC for now; this will be tested when I switch AArch64 to using these new
nodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237423 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 09:03:15 +00:00
Ahmed Bougacha
d8b3f0d785 [CodeGen] Use standard -not gnueabi- naming for f16 libcalls on Darwin.
Other targets probably should as well.  Since r237161, compiler-rt has
both, but I don't see why anything other than gnueabi would use a
gnueabi naming scheme.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237324 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-14 01:00:51 +00:00
Jan Vesely
42eeb1d91f CodeGen: Default overflow operations to expand so we don't have to assume targets are lying
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
Reviewed-by: ab
Differential Revision: http://reviews.llvm.org/D9265

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236119 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 16:30:46 +00:00
Pirama Arumuga Nainar
5c1c08cd1f Add support to promote f16 to f32
Summary:
This patch adds legalization support to operate on FP16 as a load/store type
and do operations on it as floats.

Tests for ARM are added to test/CodeGen/ARM/fp16-promote.ll

Reviewers: srhines, t.p.northover

Differential Revision: http://reviews.llvm.org/D8755

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235215 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-17 18:36:25 +00:00
Ahmed Bougacha
44c1c890e4 [CodeGen] "PromoteInteger" f32 to f64 doesn't make sense.
The original f32->f64 promotion logic was refactored into roughly the
currently shape in r37781. However, starting with r132263, the
legalizer has been split into different kinds, and the previous
"Promote" (which did the right thing) was search-and-replace'd into
"PromoteInteger". The divide gradually deepened, with type legalization
("PromoteInteger") being separated from ops legalization
("Promote", which still works for floating point ops).

Fast-forward to today: there's no in-tree target with legal f64 but
illegal f32 (rather: no tests were harmed in the making of this patch).

With such a target, i.e., if you trick the legalizer into going through
the PromoteInteger path for FP, you get the expected brokenness.
For instance, there's no PromoteIntRes_FADD (the name itself sounds
wrong), so we'll just hit some assert in the PromoteInteger path.

Don't pretend we can promote f32 to f64. Instead, always soften.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233464 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-28 01:22:37 +00:00
Ahmed Bougacha
aff96c9829 Deduplicate a bunch of setOpActions into an MVT range-for. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233330 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-26 23:21:03 +00:00
Ahmed Bougacha
5cb4112882 [CodeGen] Don't pretend we can expand f16 libcalls.
We used to mark a bunch of libm nodes as Expand for f16.  There are no
libcalls we can use for those, so we eventually just hit an unhelpful
llvm_unreachable in ExpandFPLibCall.

Instead, just ignore them altogether.  If nothing else changes, we'll
then get the more descriptive and pleasant "Cannot select" fatal error.

There's an argument to be made for consistency, but f16 is already
special in all the good ways, and as long as there's no f16 support in
the ops expander (this patch), as well as the Soften/Expand float
legalizers (which, when hit, will currently segfault), I think there's
no point in even pretending we can legalize any of this.

This shouldn't affect anything that's not already broken.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233328 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-26 22:44:58 +00:00
Mehdi Amini
529919ff31 DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 02:37:25 +00:00
Benjamin Kramer
f74b5c6198 SDAG: Merge the meat of two ExpandAtomic implementations.
The copies already diverged, don't let them become any worse. Reduce
redundancy in code with a little macro metaprogramming.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231401 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-05 20:04:29 +00:00
Eric Christopher
7b1d76b9e5 Add a comment above findRepresentativeClass explaining why it's
where it is so that future generations can understand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231111 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 19:47:14 +00:00
Eric Christopher
a01bc6a59f Remove an argument-less call to getSubtargetImpl from TargetLoweringBase.
This required plumbing a TargetRegisterInfo through computeRegisterProperties
and into findRepresentativeClass which uses it for register class
iteration. This required passing a subtarget into a few target specific
initializations of TargetLowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230583 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-26 00:00:24 +00:00
Eric Christopher
b97b892db1 Move TargetLoweringBase::getTypeConversion to the .cpp file from
the .h file. It's used in only one place (other than recursively)
and there's no need to include it everywhere.

Saves almost 900k from total llvm object file size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230561 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 22:41:30 +00:00
Matt Arsenault
4bacfe2095 Add generic fmad DAG node.
This allows sharing of FMA forming combines to work
with instructions that have the same semantics as a separate
multiply and add.

This is expand by default, and only formed post legalization
so it shouldn't have much impact on targets that do not want it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230070 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 22:10:33 +00:00
Eric Christopher
04bcc11905 Move DataLayout back to the TargetMachine from TargetSubtargetInfo
derived classes.

Since global data alignment, layout, and mangling is often based on the
DataLayout, move it to the TargetMachine. This ensures that global
data is going to be layed out and mangled consistently if the subtarget
changes on a per function basis. Prior to this all targets(*) have
had subtarget dependent code moved out and onto the TargetMachine.

*One target hasn't been migrated as part of this change: R600. The
R600 port has, as a subtarget feature, the size of pointers and
this affects global data layout. I've currently hacked in a FIXME
to enable progress, but the port needs to be updated to either pass
the 64-bitness to the TargetMachine, or fix the DataLayout to
avoid subtarget dependent features.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227113 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 19:03:15 +00:00
Matt Arsenault
7c06364dc0 R600: Implement getRecipEstimate
This requires a new hook to prevent expanding sqrt in terms
of rsqrt and reciprocal. v_rcp_f32, v_rsq_f32, and v_sqrt_f32 are
all the same rate, so this expansion would just double the number
of instructions and cycles.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225828 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 20:53:23 +00:00
Ahmed Bougacha
8065738154 [CodeGen] Use MVT iterator_ranges in legality loops. NFC intended.
A few loops do trickier things than just iterating on an MVT subset,
so I'll leave them be for now.
Follow-up of r225387.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225392 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-07 21:27:10 +00:00
Quentin Colombet
1e2604dccc [CodeGenPrepare] Reapply r224351 with a fix for the assertion failure:
The type promotion helper does not support vector type, so when make
such it does not kick in in such cases.

Original commit message:
[CodeGenPrepare] Move sign/zero extensions near loads using type promotion.

This patch extends the optimization in CodeGenPrepare that moves a sign/zero
extension near a load when the target can combine them. The optimization may
promote any operations between the extension and the load to make that possible.

Although this optimization may be beneficial for all targets, in particular
AArch64, this is enabled for X86 only as I have not benchmarked it for other
targets yet.


** Context **

Most targets feature extended loads, i.e., loads that perform a zero or sign
extension for free. In that context it is interesting to expose such pattern in
CodeGenPrepare so that the instruction selection pass can form such loads.
Sometimes, this pattern is blocked because of instructions between the load and
the extension. When those instructions are promotable to the extended type, we
can expose this pattern.


** Motivating Example **

Let us consider an example:
define void @foo(i8* %addr1, i32* %addr2, i8 %a, i32 %b) {
  %ld = load i8* %addr1
  %zextld = zext i8 %ld to i32
  %ld2 = load i32* %addr2
  %add = add nsw i32 %ld2, %zextld
  %sextadd = sext i32 %add to i64
  %zexta = zext i8 %a to i32
  %addza = add nsw i32 %zexta, %zextld
  %sextaddza = sext i32 %addza to i64
  %addb = add nsw i32 %b, %zextld
  %sextaddb = sext i32 %addb to i64
  call void @dummy(i64 %sextadd, i64 %sextaddza, i64 %sextaddb)
  ret void
}

As it is, this IR generates the following assembly on x86_64:
[...]
  movzbl  (%rdi), %eax   # zero-extended load
  movl  (%rsi), %es      # plain load
  addl  %eax, %esi       # 32-bit add
  movslq  %esi, %rdi     # sign extend the result of add
  movzbl  %dl, %edx      # zero extend the first argument
  addl  %eax, %edx       # 32-bit add
  movslq  %edx, %rsi     # sign extend the result of add
  addl  %eax, %ecx       # 32-bit add
  movslq  %ecx, %rdx     # sign extend the result of add
[...]
The throughput of this sequence is 7.45 cycles on Ivy Bridge according to IACA.

Now, by promoting the additions to form more extended loads we would generate:
[...]
  movzbl  (%rdi), %eax   # zero-extended load
  movslq  (%rsi), %rdi   # sign-extended load
  addq  %rax, %rdi       # 64-bit add
  movzbl  %dl, %esi      # zero extend the first argument
  addq  %rax, %rsi       # 64-bit add
  movslq  %ecx, %rdx     # sign extend the second argument
  addq  %rax, %rdx       # 64-bit add
[...]
The throughput of this sequence is 6.15 cycles on Ivy Bridge according to IACA.

This kind of sequences happen a lot on code using 32-bit indexes on 64-bit
architectures.

Note: The throughput numbers are similar on Sandy Bridge and Haswell.


** Proposed Solution **

To avoid the penalty of all these sign/zero extensions, we merge them in the
loads at the beginning of the chain of computation by promoting all the chain of
computation on the extended type. The promotion is done if and only if we do not
introduce new extensions, i.e., if we do not degrade the code quality.
To achieve this, we extend the existing “move ext to load” optimization with the
promotion mechanism introduced to match larger patterns for addressing mode
(r200947).
The idea of this extension is to perform the following transformation:
ext(promotableInst1(...(promotableInstN(load))))
=>
promotedInst1(...(promotedInstN(ext(load))))

The promotion mechanism in that optimization is enabled by a new TargetLowering
switch, which is off by default. In other words, by default, the optimization
performs the “move ext to load” optimization as it was before this patch.


** Performance **

Configuration: x86_64: Ivy Bridge fixed at 2900MHz running OS X 10.10.
Tested Optimization Levels: O3/Os
Tests: llvm-testsuite + externals.
Results:
- No regression beside noise.
- Improvements:
CINT2006/473.astar:  ~2%
Benchmarks/PAQ8p: ~2%
Misc/perlin: ~3%

The results are consistent for both O3 and Os.

<rdar://problem/18310086>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224402 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 01:36:17 +00:00
Reid Kleckner
0c7f4e46b6 Revert "[CodeGenPrepare] Move sign/zero extensions near loads using type promotion."
This reverts commit r224351. It causes assertion failures when building
ICU.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224397 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 00:29:23 +00:00
Quentin Colombet
93b6e016b1 [CodeGenPrepare] Move sign/zero extensions near loads using type promotion.
This patch extends the optimization in CodeGenPrepare that moves a sign/zero
extension near a load when the target can combine them. The optimization may
promote any operations between the extension and the load to make that possible.

Although this optimization may be beneficial for all targets, in particular
AArch64, this is enabled for X86 only as I have not benchmarked it for other
targets yet.


** Context **

Most targets feature extended loads, i.e., loads that perform a zero or sign
extension for free. In that context it is interesting to expose such pattern in
CodeGenPrepare so that the instruction selection pass can form such loads.
Sometimes, this pattern is blocked because of instructions between the load and
the extension. When those instructions are promotable to the extended type, we
can expose this pattern.


** Motivating Example **

Let us consider an example:
define void @foo(i8* %addr1, i32* %addr2, i8 %a, i32 %b) {
  %ld = load i8* %addr1
  %zextld = zext i8 %ld to i32
  %ld2 = load i32* %addr2
  %add = add nsw i32 %ld2, %zextld
  %sextadd = sext i32 %add to i64
  %zexta = zext i8 %a to i32
  %addza = add nsw i32 %zexta, %zextld
  %sextaddza = sext i32 %addza to i64
  %addb = add nsw i32 %b, %zextld
  %sextaddb = sext i32 %addb to i64
  call void @dummy(i64 %sextadd, i64 %sextaddza, i64 %sextaddb)
  ret void
}

As it is, this IR generates the following assembly on x86_64:
[...]
  movzbl  (%rdi), %eax   # zero-extended load
  movl  (%rsi), %es      # plain load
  addl  %eax, %esi       # 32-bit add
  movslq  %esi, %rdi     # sign extend the result of add
  movzbl  %dl, %edx      # zero extend the first argument
  addl  %eax, %edx       # 32-bit add
  movslq  %edx, %rsi     # sign extend the result of add
  addl  %eax, %ecx       # 32-bit add
  movslq  %ecx, %rdx     # sign extend the result of add
[...]
The throughput of this sequence is 7.45 cycles on Ivy Bridge according to IACA.

Now, by promoting the additions to form more extended loads we would generate:
[...]
  movzbl  (%rdi), %eax   # zero-extended load
  movslq  (%rsi), %rdi   # sign-extended load
  addq  %rax, %rdi       # 64-bit add
  movzbl  %dl, %esi      # zero extend the first argument
  addq  %rax, %rsi       # 64-bit add
  movslq  %ecx, %rdx     # sign extend the second argument
  addq  %rax, %rdx       # 64-bit add
[...]
The throughput of this sequence is 6.15 cycles on Ivy Bridge according to IACA.

This kind of sequences happen a lot on code using 32-bit indexes on 64-bit
architectures.

Note: The throughput numbers are similar on Sandy Bridge and Haswell.


** Proposed Solution **

To avoid the penalty of all these sign/zero extensions, we merge them in the
loads at the beginning of the chain of computation by promoting all the chain of
computation on the extended type. The promotion is done if and only if we do not
introduce new extensions, i.e., if we do not degrade the code quality.
To achieve this, we extend the existing “move ext to load” optimization with the
promotion mechanism introduced to match larger patterns for addressing mode
(r200947).
The idea of this extension is to perform the following transformation:
ext(promotableInst1(...(promotableInstN(load))))
=>
promotedInst1(...(promotedInstN(ext(load))))

The promotion mechanism in that optimization is enabled by a new TargetLowering
switch, which is off by default. In other words, by default, the optimization
performs the “move ext to load” optimization as it was before this patch.


** Performance **

Configuration: x86_64: Ivy Bridge fixed at 2900MHz running OS X 10.10.
Tested Optimization Levels: O3/Os
Tests: llvm-testsuite + externals.
Results:
- No regression beside noise.
- Improvements:
CINT2006/473.astar:  ~2%
Benchmarks/PAQ8p: ~2%
Misc/perlin: ~3%

The results are consistent for both O3 and Os.

<rdar://problem/18310086>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224351 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 19:09:03 +00:00
Philip Reames
78cc6fcb01 [Statepoints 2/4] Statepoint infrastructure for garbage collection: MI & x86-64 Backend
This is the second patch in a small series.  This patch contains the MachineInstruction and x86-64 backend pieces required to lower Statepoints.  It does not include the code to actually generate the STATEPOINT machine instruction and as a result, the entire patch is currently dead code.  I will be submitting the SelectionDAG parts within the next 24-48 hours.  Since those pieces are by far the most complicated, I wanted to minimize the size of that patch.  That patch will include the tests which exercise the functionality in this patch.  The entire series can be seen as one combined whole in http://reviews.llvm.org/D5683.

The STATEPOINT psuedo node is generated after all gc values are explicitly spilled to stack slots.  The purpose of this node is to wrap an actual call instruction while recording the spill locations of the meta arguments used for garbage collection and other purposes.  The STATEPOINT is modeled as modifing all of those locations to prevent backend optimizations from forwarding the value from before the STATEPOINT to after the STATEPOINT.  (Doing so would break relocation semantics for collectors which wish to relocate roots.)

The implementation of STATEPOINT is closely modeled on PATCHPOINT.  Eventually, much of the code in this patch will be removed.  The long term plan is to merge the functionality provided by statepoints and patchpoints.  Merging their implementations in the backend is likely to be a good starting point.

Reviewed by: atrick, ributzka



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223085 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 22:52:56 +00:00
Simon Pilgrim
1c86b63b9b Target triple OS detection tidyup. NFC
Use Triple::isOS*() helpers where possible.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222960 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-29 19:18:21 +00:00
Craig Topper
cac2f22b32 Replace a couple asserts with static_asserts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222114 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-17 00:26:50 +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
Hao Liu
80021c5cf8 PR20557: Fix the bug that bogus cpu parameter crashes llc on AArch64 backend.
Initial patch by Oleg Ranevskyy.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220945 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-31 02:35:34 +00:00
Matt Arsenault
015776f38c Add minnum / maxnum codegen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220342 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 23:01:01 +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
Pedro Artigas
ef6ddcf87a Added a TLI hook to signal that the target does not have or does not care about
floating point exceptions, added use of flag to fold potentially exception 
raising floating point math in selection DAG. No functionality change, as 
targets have to explicitly ask for this behavior and none does today.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215222 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-08 16:46:53 +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
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
Tim Northover
f8d927f22b CodeGen: emit IR-level f16 conversion intrinsics as fptrunc/fpext
This makes the first stage DAG for @llvm.convert.to.fp16 an fptrunc,
and correspondingly @llvm.convert.from.fp16 an fpext. The legalisation
path is now uniform, regardless of the input IR:

  fptrunc -> FP_TO_FP16 (if f16 illegal) -> libcall
  fpext -> FP16_TO_FP (if f16 illegal) -> libcall

Each target should be able to select the version that best matches its
operations and not be required to duplicate patterns for both fptrunc
and FP_TO_FP16 (for example).

As a result we can remove some redundant AArch64 patterns.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213507 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 09:13:56 +00:00
Tim Northover
0afed03229 CodeGen: soften f16 type by default instead of marking legal.
Actual support for softening f16 operations is still limited, and can be added
when it's needed.  But Soften is much closer to being a useful thing to try
than keeping it Legal when no registers can actually hold such values.

Longer term, we probably want something between Soften and Promote semantics
for most targets, it'll be more efficient to promote the 4 basic operations to
f32 than libcall them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213372 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-18 12:41:46 +00:00