Commit Graph

494 Commits

Author SHA1 Message Date
Andrea Di Biagio 77f62652c1 Reapply r249121 : "[FastISel][x86] Teach how to select SSE2/AVX bitcasts between 128/256-bit vector types."
This patch teaches FastIsel the following two things:
1) On SSE2, no instructions are needed for bitcasts between 128-bit vector types;
2) On AVX, no instructions are needed for bitcasts between 256-bit vector types.

Example:

  %1 = bitcast <4 x i31> %V to <2 x i64>

Before (-fast-isel -fast-isel-abort=1):

  FastIsel miss: %1 = bitcast <4 x i31> %V to <2 x i64>

Now we don't fall back to SelectionDAG and we correctly fold that computation
propagating the register associated to %V.

Originally reviewed here: http://reviews.llvm.org/D13347

llvm-svn: 249147
2015-10-02 16:08:05 +00:00
Andrea Di Biagio 45874e67a1 Revert: [FastISel][x86] Teach how to select SSE2/AVX bitcasts between 128/256-bit vector types.
r249121 caused a Clang test failure (avx2-buitins.c).
Revert r249121 while I keep investigating on the reason why that test failed.

llvm-svn: 249124
2015-10-02 13:06:19 +00:00
Andrea Di Biagio cb33456122 [FastISel][x86] Teach how to select SSE2/AVX bitcasts between 128/256-bit vector types.
This patch teaches FastIsel the following two things:
1) On SSE2, no instructions are needed for bitcasts between 128-bit vector types;
2) On AVX, no instructions are needed for bitcasts between 256-bit vector types.

Example:

  %1 = bitcast <4 x i31> %V to <2 x i64>

Before (-fast-isel -fast-isel-abort=1):

  FastIsel miss: %1 = bitcast <4 x i31> %V to <2 x i64>

Now we don't fall back to SelectionDAG and we correctly fold that computation
propagating the register associated to %V.

Differential Revision: http://reviews.llvm.org/D13347

llvm-svn: 249121
2015-10-02 12:45:37 +00:00
Jeroen Ketema 740f9d79ca Arguments spilled on the stack before a function call may have
alignment requirements, for example in the case of vectors.
These requirements are exploited by the code generator by using
move instructions that have similar alignment requirements, e.g.,
movaps on x86.

Although the code generator properly aligns the arguments with
respect to the displacement of the stack pointer it computes,
the displacement itself may cause misalignment. For example if
we have

%3 = load <16 x float>, <16 x float>* %1, align 64
call void @bar(<16 x float> %3, i32 0)

the x86 back-end emits:

movaps  32(%ecx), %xmm2
movaps  (%ecx), %xmm0
movaps  16(%ecx), %xmm1
movaps  48(%ecx), %xmm3
subl    $20, %esp       <-- if %esp was 16-byte aligned before this instruction, it no longer will be afterwards 
movaps  %xmm3, (%esp)   <-- movaps requires 16-byte alignment, while %esp is not aligned as such.
movl    $0, 16(%esp)
calll   __bar

To solve this, we need to make sure that the computed value with which
the stack pointer is changed is a multiple af the maximal alignment seen
during its computation. With this change we get proper alignment:

subl    $32, %esp
movaps  %xmm3, (%esp)

Differential Revision: http://reviews.llvm.org/D12337

llvm-svn: 248786
2015-09-29 10:12:57 +00:00
Matthias Braun 818c78d0cc X86: Fix FastISel SSESelect register class
X86FastISel has been using the wrong register class for VBLENDVPS which
produces a VR128 and needs an extra copy to the target register. The
problem was already hit by the existing test cases when using
> llvm-lit -Dllc="llc -verify-machineinstr"

llvm-svn: 246461
2015-08-31 18:25:11 +00:00
Matthias Braun 17af607796 FastISel: Factor out common code; NFC intended
This should be no functional change but for the record: For three cases
in X86FastISel this will change the order in which the FalseMBB and
TrueMBB of a conditional branch is addedd to the successor/predecessor
lists.

llvm-svn: 245997
2015-08-26 01:38:00 +00:00
Alex Lorenz e40c8a2b26 PseudoSourceValue: Replace global manager with a manager in a machine function.
This commit removes the global manager variable which is responsible for
storing and allocating pseudo source values and instead it introduces a new
manager class named 'PseudoSourceValueManager'. Machine functions now own an
instance of the pseudo source value manager class.

This commit also modifies the 'get...' methods in the 'MachinePointerInfo'
class to construct pseudo source values using the instance of the pseudo
source value manager object from the machine function.

This commit updates calls to the 'get...' methods from the 'MachinePointerInfo'
class in a lot of different files because those calls now need to pass in a
reference to a machine function to those methods.

This change will make it easier to serialize pseudo source values as it will
enable me to transform the mips specific MipsCallEntry PseudoSourceValue
subclass into two target independent subclasses.

Reviewers: Akira Hatanaka
llvm-svn: 244693
2015-08-11 23:09:45 +00:00
Mehdi Amini 44ede33a69 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>
llvm-svn: 241775
2015-07-09 02:09:04 +00:00
Mehdi Amini 56228dabfa 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>
llvm-svn: 241773
2015-07-09 01:57:34 +00:00
Peter Collingbourne 6a9d1774d0 IR: Do not consider available_externally linkage to be linker-weak.
From the linker's perspective, an available_externally global is equivalent
to an external declaration (per isDeclarationForLinker()), so it is incorrect
to consider it to be a weak definition.

Also clean up some logic in the dead argument elimination pass and clarify
its comments to better explain how its behavior depends on linkage,
introduce GlobalValue::isStrongDefinitionForLinker() and start using
it throughout the optimizers and backend.

Differential Revision: http://reviews.llvm.org/D10941

llvm-svn: 241413
2015-07-05 20:52:35 +00:00
Rafael Espindola ce4c2bc1d6 Use MCSymbols for FastISel.
The summary is that it moves the mangling earlier and replaces a few
calls to .addExternalSymbol with addSym.

I originally wanted to replace all the uses of addExternalSymbol with
addSym, but noticed it was a lot of work and doesn't need to be done
all at once.

llvm-svn: 240395
2015-06-23 12:21:54 +00:00
Keno Fischer e70b31fc1b [InstrInfo] Refactor foldOperandImpl to thread through InsertPt. NFC
Summary:
This was a longstanding FIXME and is a necessary precursor to cases
where foldOperandImpl may have to create more than one instruction
(e.g. to constrain a register class). This is the split out NFC changes from
D6262.

Reviewers: pete, ributzka, uweigand, mcrosier

Reviewed By: mcrosier

Subscribers: mcrosier, ted, llvm-commits

Differential Revision: http://reviews.llvm.org/D10174

llvm-svn: 239336
2015-06-08 20:09:58 +00:00
Matthias Braun e41e146c16 CodeGen: Use mop_iterator instead of MIOperands/ConstMIOperands
MIOperands/ConstMIOperands are classes iterating over the MachineOperand
of a MachineInstr, however MachineInstr::mop_iterator does the same
thing.

I assume these two iterators exist to have a uniform interface to
iterate over the operands of a machine instruction bundle and a single
machine instruction. However in practice I find it more confusing to have 2
different iterator classes, so this patch transforms (nearly all) the
code to use mop_iterators.

The only exception being MIOperands::anlayzePhysReg() and
MIOperands::analyzeVirtReg() still needing an equivalent, I leave that
as an exercise for the next patch.

Differential Revision: http://reviews.llvm.org/D9932

This version is slightly modified from the proposed revision in that it
introduces MachineInstr::getOperandNo to avoid the extra counting
variable in the few loops that previously used MIOperands::getOperandNo.

llvm-svn: 238539
2015-05-29 02:56:46 +00:00
Eric Christopher 824f42f209 Migrate existing backends that care about software floating point
to use the information in the module rather than TargetOptions.

We've had and clang has used the use-soft-float attribute for some
time now so have the backends set a subtarget feature based on
a particular function now that subtargets are created based on
functions and function attributes.

For the one middle end soft float check go ahead and create
an overloadable TargetLowering::useSoftFloat function that
just checks the TargetSubtargetInfo in all cases.

Also remove the command line option that hard codes whether or
not soft-float is set by using the attribute for all of the
target specific test cases - for the generic just go ahead and
add the attribute in the one case that showed up.

llvm-svn: 237079
2015-05-12 01:26:05 +00:00
Pete Cooper 7f7c9f1dad [X86] Fast-ISel was incorrectly always killing the source of a truncate.
A trunc from i32 to i1 on x86_64 generates an instruction such as

%vreg19<def> = COPY %vreg9:sub_8bit<kill>; GR8:%vreg19 GR32:%vreg9

However, the copy here should only have the kill flag on the 32-bit path, not the 64-bit one.
Otherwise, we are killing the source of the truncate which could be used later in the program.

llvm-svn: 236890
2015-05-08 18:29:42 +00:00
Pete Cooper d31583ddfb [x86] Fix register class of folded load index reg.
When folding a load in to another instruction, we need to fix the class of the index register
Otherwise, it could be something like GR64 not GR64_NOSP and would fail the machine verifier.

llvm-svn: 236644
2015-05-06 21:37:19 +00:00
Pete Cooper d0dae3e577 [X86 fast-isel] Constrain the index reg class to not include SP.
The index reg on instructions with complex address modes is a GPR64_NOSP.  Constrain it to appease the machine verifier.

llvm-svn: 236557
2015-05-05 23:41:53 +00:00
Andrea Di Biagio 98c367093d [X86][FastIsel] Fix assertion failure when selecting int-to-double conversion (PR23273).
This fixes a regression introduced at revision 231243.
The target-independent selection algorithm in FastISel knows how to select
a SINT_TO_FP if the target is SSE but not AVX. That is because on X86, the
tablegen'd 'fastEmit' functions know how to select CVTSI2SSrr and CVTSI2SDrr.

Method X86FastISel::X86SelectSIToFP was therefore working under the
wrong assumption that the target was AVX. That assumption was incorrect since
we can have a target that is neither AVX nor SSE.

So, rather than asserting for the presence of AVX, we should have had an
early exit from 'X86SelectSIToFP' if the target was not AVX.
This patch fixes the issue replacing the invalid assertion with an early exit.

Thanks to Dimitry Andric for reporting this problem and for providing a small
reproducible testcase. Added test pr23273.ll.

llvm-svn: 235295
2015-04-20 11:56:59 +00:00
Duncan P. N. Exon Smith 3bef6a3803 CodeGen: Assert that inlined-at locations agree
As a follow-up to r234021, assert that a debug info intrinsic variable's
`MDLocalVariable::getInlinedAt()` always matches the
`MDLocation::getInlinedAt()` of its `!dbg` attachment.

The goal here is to get rid of `MDLocalVariable::getInlinedAt()`
entirely (PR22778), but I'll let these assertions bake for a while
first.

If you have an out-of-tree backend that just broke, you're probably
attaching the wrong `DebugLoc` to a `DBG_VALUE` instruction.  The one
you want is the location that was attached to the corresponding
`@llvm.dbg.declare` or `@llvm.dbg.value` call that you started with.

llvm-svn: 234038
2015-04-03 19:20:26 +00:00
Andrea Di Biagio 8f7feec5fd [X86][FastIsel] Teach how to select vector load instructions.
This patch teaches fast-isel how to select 128-bit vector load instructions.
Added test CodeGen/X86/fast-isel-vecload.ll

Differential Revision: http://reviews.llvm.org/D8605

llvm-svn: 233270
2015-03-26 11:29:02 +00:00
Rafael Espindola 933f51af54 Use the i8 immediate cmp instructions when possible.
llvm-svn: 232378
2015-03-16 14:25:08 +00:00
Rafael Espindola 19141f2711 Don't repeat names in comments and clang-format this function.
llvm-svn: 232375
2015-03-16 14:05:49 +00:00
Eric Christopher 9deb75d176 Have getCallPreservedMask and getThisCallPreservedMask take a
MachineFunction argument so that we can grab subtarget specific
features off of it.

llvm-svn: 231979
2015-03-11 22:42:13 +00:00
Sanjay Patel 302404b277 [AVX] Lower / fast-isel scalar FP selects into VBLENDV instructions (PR22483)
This patch reduces code size for all AVX targets and increases speed for some chips.

SSE 4.1 introduced the useless (see code comments) 2-register form of BLENDV and
only in the packed float/double flavors.

AVX subsequently made the instruction useful by adding a 4-register operand form.

So we just need to paper over the lack of scalar forms of this instruction, complicate
the code to choose float or double forms, and use blendv on scalars since all FP is in
xmm registers anyway.

This gives us an approximately 50% speed up for a blendv microbenchmark sequence
on SandyBridge and Haswell:
blendv : 29.73 cycles/iter
logic : 43.15 cycles/iter

No new test cases with this patch because:

1. fast-isel-select-sse.ll tests the positive side for regular X86 lowering and fast-isel
2. sse-minmax.ll and fp-select-cmp-and.ll confirm that we're not firing for scalar selects without AVX
3. fp-select-cmp-and.ll and logical-load-fold.ll confirm that we're not firing for scalar selects with constants.

http://llvm.org/bugs/show_bug.cgi?id=22483

Differential Revision: http://reviews.llvm.org/D8063

llvm-svn: 231408
2015-03-05 21:46:54 +00:00
Andrea Di Biagio df93ccf49a [X86][FastISel] Simplify the logic in method X86SelectSIToFP.
The target-independent selection algorithm in FastISel already knows how
to select a SINT_TO_FP if the target is SSE but not AVX.

On targets that have SSE but not AVX, the tablegen'd 'fastEmit' functions
for ISD::SINT_TO_FP know how to select instruction X86::CVTSI2SSrr
(for an i32 to f32 conversion) and X86::CVTSI2SDrr (for an i32 to f64
conversion).

This patch simplifies the logic in method X86SelectSIToFP knowing that
the code would not be reachable if the subtarget doesn't have AVX.
No functional change intended.

llvm-svn: 231243
2015-03-04 14:23:25 +00:00
Tim Northover 3b6b7ca2bc CodeGen: convert CCState interface to using ArrayRefs
Everyone except R600 was manually passing the length of a static array
at each callsite, calculated in a variety of interesting ways. Far
easier to let ArrayRef handle that.

There should be no functional change, but out of tree targets may have
to tweak their calls as with these examples.

llvm-svn: 230118
2015-02-21 02:11:17 +00:00
Andrea Di Biagio 7035178aeb [X86][FastIsel] Teach how to select float-half conversion intrinsics.
This patch teaches X86FastISel how to select intrinsic 'convert_from_fp16' and
intrinsic 'convert_to_fp16'.
If the target has F16C, we can select VCVTPS2PHrr for a float-half conversion,
and VCVTPH2PSrr for a half-float conversion.

Differential Revision: http://reviews.llvm.org/D7673

llvm-svn: 230043
2015-02-20 19:37:14 +00:00
Andrea Di Biagio e7b58ee555 [X86][FastIsel] Teach how to select scalar integer to float/double conversions.
This patch teaches fast-isel how to select a (V)CVTSI2SSrr for an integer to 
float conversion, and how to select a (V)CVTSI2SDrr for an integer to double
conversion.

Added test 'fast-isel-int-float-conversion.ll'.

Differential Revision: http://reviews.llvm.org/D7698

llvm-svn: 229589
2015-02-17 23:40:58 +00:00
David Majnemer ca19485f08 X86: @llvm.frameaddress should defer to SelectionDAG for Win CFI
llvm-svn: 228754
2015-02-10 22:00:34 +00:00
Andrea Di Biagio 62622d2396 [X86][FastIsel] Avoid introducing legacy SSE instructions if the target has AVX.
This patch teaches X86FastISel how to select AVX instructions for scalar
float/double convert operations.

Before this patch, X86FastISel always selected legacy SSE instructions
for FPExt (from float to double) and FPTrunc (from double to float).

For example:
\code
  define double @foo(float %f) {
    %conv = fpext float %f to double
    ret double %conv
  }
\end code

Before (with -mattr=+avx -fast-isel) X86FastIsel selected a CVTSS2SDrr which is
legacy SSE:
  cvtss2sd %xmm0, %xmm0

With this patch, X86FastIsel selects a VCVTSS2SDrr instead:
  vcvtss2sd %xmm0, %xmm0, %xmm0

Added test fast-isel-fptrunc-fpext.ll to check both the register-register and
the register-memory float/double conversion variants.

Differential Revision: http://reviews.llvm.org/D7438

llvm-svn: 228682
2015-02-10 12:04:41 +00:00
Eric Christopher a1c535b5e8 Migrate to using the subtarget on the machine function and update
all uses.

llvm-svn: 227891
2015-02-02 23:03:45 +00:00
Michael Kuperstein 13fbd45263 [X86] Convert esp-relative movs of function arguments to pushes, step 2
This moves the transformation introduced in r223757 into a separate MI pass.
This allows it to cover many more cases (not only cases where there must be a 
reserved call frame), and perform rudimentary call folding. It still doesn't 
have a heuristic, so it is enabled only for optsize/minsize, with stack 
alignment <= 8, where it ought to be a fairly clear win.

(Re-commit of r227728)

Differential Revision: http://reviews.llvm.org/D6789

llvm-svn: 227752
2015-02-01 16:56:04 +00:00
Michael Kuperstein e86aa9a8a4 Revert r227728 due to bad line endings.
llvm-svn: 227746
2015-02-01 16:15:07 +00:00
Michael Kuperstein bd57186c76 [X86] Convert esp-relative movs of function arguments to pushes, step 2
This moves the transformation introduced in r223757 into a separate MI pass.
This allows it to cover many more cases (not only cases where there must be a 
reserved call frame), and perform rudimentary call folding. It still doesn't 
have a heuristic, so it is enabled only for optsize/minsize, with stack 
alignment <= 8, where it ought to be a fairly clear win.

Differential Revision: http://reviews.llvm.org/D6789

llvm-svn: 227728
2015-02-01 11:44:44 +00:00
David Blaikie 2600c28f9c DebugInfo: Teach Fast ISel to respect the debug location of comparisons in jumps
The use of the DbgLoc in FastISel is probably something we should fix.
It's prone to leaking the wrong location into instructions - we should
have a clear chain of custody from the debug location of an IR
Instruction to that of a MachineInstr to avoid such leakage.

llvm-svn: 227481
2015-01-29 19:09:18 +00:00
Eric Christopher 8b7706517c 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.

llvm-svn: 227113
2015-01-26 19:03:15 +00:00
Michael Kuperstein ada9fa1ca9 [x32] Fast ISel should use LEA64_32r instead of LEA32r to adjust addresses in x32 mode.
llvm-svn: 226661
2015-01-21 14:44:05 +00:00
Craig Topper ddbf51f904 [X86] Make isel select the 2-byte register form of INC/DEC even in non-64-bit mode. Convert to the 1-byte form in non-64-bit mode as part of MCInst lowering.
Overall this seems simpler. It reduces duplication of patterns between both modes and it simplifies the memory folding/unfolding tables as they don't need to create fake instructions just to keep track of 64-bitness.

llvm-svn: 225252
2015-01-06 07:35:50 +00:00
Craig Topper 49758aab94 [X86] Make isel select the shorter form of jump instructions instead of the long form.
The assembler backend will relax to the long form if necessary. This removes a swap from long form to short form in the MCInstLowering code. Selecting the long form used to be required by the old JIT.

llvm-svn: 225242
2015-01-06 04:23:53 +00:00
Keno Fischer fd22c6693b [X86][ISel] Fix a regression I introduced in r224884
The else case ResultReg was not checked for validity.
To my surprise, this case was not hit in any of the
existing test cases. This includes a new test cases
that tests this path.

Also drop the `target triple` declaration from the
original test as suggested by H.J. Lu, because
apparently with it the test won't be run on Linux

llvm-svn: 224901
2014-12-28 15:20:57 +00:00
Keno Fischer 8438b08663 [FastIsel][X86] Fix invalid register replacement for bool args
Summary:
Consider the following IR:

  %3 = load i8* undef
  %4 = trunc i8 %3 to i1
  %5 = call %jl_value_t.0* @foo(..., i1 %4, ...)
  ret %jl_value_t.0* %5

Bools (that are the result of direct truncs) are lowered as whatever
the argument to the trunc was and a "and 1", causing the part of the
MBB responsible for this argument to look something like this:

  %vreg8<def,tied1> = AND8ri %vreg7<kill,tied0>, 1, %EFLAGS<imp-def>; GR8:%vreg8,%vreg7

Later, when the load is lowered, it will insert

  %vreg15<def> = MOV8rm %vreg14, 1, %noreg, 0, %noreg; mem:LD1[undef] GR8:%vreg15 GR64:%vreg14

but remember to (at the end of isel) replace vreg7 by vreg15. Now for
the bug. In fast isel lowering, we mistakenly mark vreg8 as the result
of the load instead of the trunc. This adds a fixup to have
vreg8 replaced by whatever the result of the load is as well, so
we end up with

  %vreg15<def,tied1> = AND8ri %vreg15<kill,tied0>, 1, %EFLAGS<imp-def>; GR8:%vreg15

which is an SSA violation and causes problems later down the road.

This fixes PR21557.

Test Plan: Test test case from PR21557 is added to the test suite.

Reviewers: ributzka

Reviewed By: ributzka

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6245

llvm-svn: 224884
2014-12-27 13:10:15 +00:00
Jan Wen Voung f547861ba0 Use 32-bit ebp for NaCl64 in a limited case: llvm.frameaddress.
Summary:
Follow up to [x32] "Use ebp/esp as frame and stack pointer":
http://reviews.llvm.org/D4617

In that earlier patch, NaCl64 was made to always use rbp.
That's needed for most cases because rbp should hold a full
64-bit address within the NaCl sandbox so that load/stores
off of rbp don't require sandbox adjustment (zeroing the top
32-bits, then filling those by adding r15).

However, llvm.frameaddress returns a pointer and pointers
are 32-bit for NaCl64. In this case, use ebp instead, which
will make the register copy type check. A similar mechanism
may be needed for llvm.eh.return, but is not added in this change.

Test Plan: test/CodeGen/X86/frameaddr.ll

Reviewers: dschuff, nadav

Subscribers: jfb, llvm-commits

Differential Revision: http://reviews.llvm.org/D6514

llvm-svn: 223510
2014-12-05 20:55:53 +00:00
Michael Liao 5bf9578ce4 [X86] Clean up whitespace as well as minor coding style
llvm-svn: 223339
2014-12-04 05:20:33 +00:00
Craig Topper 61e88f44f9 Remove a bunch of unnecessary typecasts to 'const TargetRegisterClass *'
llvm-svn: 222509
2014-11-21 05:58:21 +00:00
Derek Schuff a54222045e [x86 fast-isel] Materialize allocas with the correct-sized lea for ILP32
Summary:
X86FastISel::fastMaterializeAlloca was incorrectly conditioning its
opcode selection on subtarget bitness rather than pointer size.

Differential Revision: http://reviews.llvm.org/D6136

llvm-svn: 221386
2014-11-05 19:27:21 +00:00
Simon Pilgrim 2f9548a3ef [X86] Memory folding for commutative instructions (updated)
This patch improves support for commutative instructions in the x86 memory folding implementation by attempting to fold a commuted version of the instruction if the original folding fails - if that folding fails as well the instruction is 're-commuted' back to its original order before returning.

Updated version of r219584 (reverted in r219595) - the commutation attempt now explicitly ensures that neither of the commuted source operands are tied to the destination operand / register, which was the source of all the regressions that occurred with the original patch attempt.

Added additional regression test case provided by Joerg Sonnenberger.

Differential Revision: http://reviews.llvm.org/D5818

llvm-svn: 220239
2014-10-20 22:14:22 +00:00
NAKAMURA Takumi 75a0240056 Revert r219584, "[X86] Memory folding for commutative instructions."
It broke i686 selfhosting.

llvm-svn: 219595
2014-10-13 04:17:34 +00:00
Simon Pilgrim 77ac26d279 [X86] Memory folding for commutative instructions.
This patch improves support for commutative instructions in the x86 memory folding implementation by attempting to fold a commuted version of the instruction if the original folding fails - if that folding fails as well the instruction is 're-commuted' back to its original order before returning.

This mainly helps the stack inliner better fold reloads of 3 (or more) operand instructions (VEX encoded SSE etc.) but by performing this in the lowest foldMemoryOperandImpl implementation it also replaces the X86InstrInfo::optimizeLoadInstr version and is now used by FastISel too.

Differential Revision: http://reviews.llvm.org/D5701

llvm-svn: 219584
2014-10-12 10:52:55 +00:00
Adrian Prantl 87b7eb9d0f Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

Note: I accidentally committed a bogus older version of this patch previously.
llvm-svn: 218787
2014-10-01 18:55:02 +00:00
Adrian Prantl b458dc2eee Revert r218778 while investigating buldbot breakage.
"Move the complex address expression out of DIVariable and into an extra"

llvm-svn: 218782
2014-10-01 18:10:54 +00:00