This takes the existing static function hasLiveCondCodeDef and makes it a member function of the X86InstrInfo class. This is a useful utility function that an upcoming change would like to use. NFC.
Patch by: Kevin B. Smith
Differential Revision: http://reviews.llvm.org/D12371
llvm-svn: 246073
This is a 'no functional change intended' patch. It removes one FIXME, but adds several more.
Motivation: the FeatureFastUAMem attribute may be too general. It is used to determine if any
sized misaligned memory access under 32-bytes is 'fast'. From the added FIXME comments, however,
you can see that we're not consistent about this. Changing the name of the attribute makes it
clearer to see the logic holes.
Changing this to a 'slow' attribute also means we don't have to add an explicit 'fast' attribute
to new chips; fast unaligned accesses have been standard for several generations of CPUs now.
Differential Revision: http://reviews.llvm.org/D12154
llvm-svn: 245729
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
NaCl's sandbox doesn't allow PUSHF/POPF out of security concerns (priviledged emulators have forgotten to mask system bits in the past, and EFLAGS's DF bit is a constant source of hilarity). Commit r220529 fixed PR20376 by saving cmpxchg's flags result using EFLAGS, this commit now generated LAHF/SAHF instead, for all of x86 (not just NaCl) because it leads to an overall performance gain over PUSHF/POPF.
As with the previous patch this code generation is pretty bad because it occurs very later, after register allocation, and in many cases it rematerializes flags which were already available (e.g. already in a register through SETE). Fortunately it's somewhat rare that this code needs to fire.
I did [[ https://github.com/jfbastien/benchmark-x86-flags | a bit of benchmarking ]], the results on an Intel Haswell E5-2690 CPU at 2.9GHz are:
| Time per call (ms) | Runtime (ms) | Benchmark |
| 0.000012514 | 6257 | sete.i386 |
| 0.000012810 | 6405 | sete.i386-fast |
| 0.000010456 | 5228 | sete.x86-64 |
| 0.000010496 | 5248 | sete.x86-64-fast |
| 0.000012906 | 6453 | lahf-sahf.i386 |
| 0.000013236 | 6618 | lahf-sahf.i386-fast |
| 0.000010580 | 5290 | lahf-sahf.x86-64 |
| 0.000010304 | 5152 | lahf-sahf.x86-64-fast |
| 0.000028056 | 14028 | pushf-popf.i386 |
| 0.000027160 | 13580 | pushf-popf.i386-fast |
| 0.000023810 | 11905 | pushf-popf.x86-64 |
| 0.000026468 | 13234 | pushf-popf.x86-64-fast |
Clearly `PUSHF`/`POPF` are suboptimal. It doesn't really seems to be worth teaching LLVM about individual flags, at least not for this purpose.
Reviewers: rnk, jvoung, t.p.northover
Subscribers: llvm-commits
Differential revision: http://reviews.llvm.org/D6629
llvm-svn: 244503
This commit implements the initial serialization of the machine operand target
flags. It extends the 'TargetInstrInfo' class to add two new methods that help
to provide text based serialization for the target flags.
This commit can serialize only the X86 target flags, and the target flags for
the other targets will be serialized in the follow-up commits.
Reviewers: Duncan P. N. Exon Smith
llvm-svn: 244185
Create wrapper methods in the Function class for the OptimizeForSize and MinSize
attributes. We want to hide the logic of "or'ing" them together when optimizing
just for size (-Os).
Currently, we are not consistent about this and rely on a front-end to always set
OptimizeForSize (-Os) if MinSize (-Oz) is on. Thus, there are 18 FIXME changes here
that should be added as follow-on patches with regression tests.
This patch is NFC-intended: it just replaces existing direct accesses of the attributes
by the equivalent wrapper call.
Differential Revision: http://reviews.llvm.org/D11734
llvm-svn: 243994
In the commentary for D11660, I wasn't sure if it was alright to create new
integer machine instructions without also creating the implicit EFLAGS operand.
From what I can see, the implicit operand is always created by the MachineInstrBuilder
based on the instruction type, so we don't have to do that explicitly. However, in
reviewing the debug output, I noticed that the operand was not marked as 'dead'.
The machine combiner should do that to preserve future optimization opportunities
that may be checking for that dead EFLAGS operand themselves.
Differential Revision: http://reviews.llvm.org/D11696
llvm-svn: 243990
Add i16, i32, i64 imul machine instructions to the list of reassociation
candidates.
A new bit of logic is needed to handle integer instructions: they have an
implicit EFLAGS operand, so we have to make sure it's dead in order to do
any reassociation with integer ops.
Differential Revision: http://reviews.llvm.org/D11660
llvm-svn: 243756
This is a follow-up to the FIXME that was added with D7474 ( http://reviews.llvm.org/rL229531 ).
I thought this load folding bug had been made hard-to-hit, but it turns out to be very easy
when targeting 32-bit x86 and causes a miscompile/crash in Wine:
https://bugs.winehq.org/show_bug.cgi?id=38826https://llvm.org/bugs/show_bug.cgi?id=22371#c25
The quick fix is to simply remove the scalar FP logical instructions from the load folding table
in X86InstrInfo, but that causes us to miss load folds that should be possible when lowering fabs,
fneg, fcopysign. So the majority of this patch is altering those lowerings to use *vector* FP
logical instructions (because that's all x86 gives us anyway). That lets us do the load folding
legally.
Differential Revision: http://reviews.llvm.org/D11477
llvm-svn: 243361
Adds pushes to the folding tables.
This also required a fix to the TD definition, since the memory forms of
the push instructions did not have the right mayLoad/mayStore flags.
Differential Revision: http://reviews.llvm.org/D11340
llvm-svn: 243010
canFoldMemoryOperand is not actually used anywhere in the codebase - all existing users instead call foldMemoryOperand directly when they wish to fold and can correctly deduce what they need from the return value.
This patch removes the canFoldMemoryOperand base function and the target implementations; only x86 had a real (bit-rotted) implementation, although AMDGPU had a preparatory stub that had never needed to be completed.
Differential Revision: http://reviews.llvm.org/D11331
llvm-svn: 242638
MOVSDto64rr and MOV64toSDrr are defined to convert between FR64 (%xmm)
<-> GR64 registers, not VR64 (%mm) <-> GR64. This is wrong.
I found this by inspection and could not find a suitable testcase for it
since (1) we don't handle MMX bitcasts in Peephole optimizer as to
generate COPYs that (2) could be expanded back to the appropriate x86
instruction in ExpandPostRA.
Switch to use the appropriate instructions: MMX_MOVD64from64rr and
MMX_MOVD64to64rr here.
llvm-svn: 242191
Extend the reassociation optimization of http://reviews.llvm.org/rL240361 (D10460)
to SSE scalar FP SP adds in addition to AVX scalar FP SP adds.
With the 'switch' in place, we can trivially add other opcodes and test cases in
future patches.
Differential Revision: http://reviews.llvm.org/D10975
llvm-svn: 241515
Currently ( D10321, http://reviews.llvm.org/rL239486 ), we can use the machine combiner pass
to reassociate the following sequence to reduce the critical path:
A = ? op ?
B = A op X
C = B op Y
-->
A = ? op ?
B = X op Y
C = A op B
'op' is currently limited to x86 AVX scalar FP adds (with fast-math on), but in theory, it could
be any associative math/logic op (see TODO in code comment).
This patch generalizes the pattern match to ignore the instruction that defines 'A'. So instead of
a sequence of 3 adds, we now only need to find 2 dependent adds and decide if it's worth
reassociating them.
This generalization has a compile-time cost because we can now match more instruction sequences
and we rely more heavily on the machine combiner to discard sequences where reassociation doesn't
improve the critical path.
For example, in the new test case:
A = M div N
B = A add X
C = B add Y
We'll match 2 reassociation patterns, but this transform doesn't reduce the critical path:
A = M div N
B = A add Y
C = B add X
We need the combiner to reject that pattern but select this:
A = M div N
B = X add Y
C = B add A
Differential Revision: http://reviews.llvm.org/D10460
llvm-svn: 240361
The _Int instructions are special, in that they operate on the full
VR128 instead of FR32. The load folding then looks at MOVSS, at the
user, and bails out when it sees a size mismatch.
What we really know is that the rm_Int instructions don't load the
higher lanes, so folding is fine.
This happens for the straightforward intrinsic code, e.g.:
_mm_add_ss(a, _mm_load_ss(p));
Fixes PR23349.
Differential Revision: http://reviews.llvm.org/D10554
llvm-svn: 240326
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
Summary:
NFC: no one uses AnalyzeBranchPredicate yet.
Add TargetInstrInfo::AnalyzeBranchPredicate and implement for x86. A
later change adding support for page-fault based implicit null checks
depends on this.
Reviewers: reames, ab, atrick
Reviewed By: atrick
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10200
llvm-svn: 239742
Summary:
TargetInstrInfo::getLdStBaseRegImmOfs to
TargetInstrInfo::getMemOpBaseRegImmOfs and implement for x86. The
implementation only handles a few easy cases now and will be made more
sophisticated in the future.
This is NFCI: the only user of `getLdStBaseRegImmOfs` (now
`getmemOpBaseRegImmOfs`) is `LoadClusterMotion` and `LoadClusterMotion`
is disabled for x86.
Reviewers: reames, ab, MatzeB, atrick
Reviewed By: MatzeB, atrick
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10199
llvm-svn: 239741
This will use Itinieraries if available, but will also work if just a
MCSchedModel is available.
Differential Revision: http://reviews.llvm.org/D10428
llvm-svn: 239658
This is a reimplementation of D9780 at the machine instruction level rather than the DAG.
Use the MachineCombiner pass to reassociate scalar single-precision AVX additions (just a
starting point; see the TODO comments) to increase ILP when it's safe to do so.
The code is closely based on the existing MachineCombiner optimization that is implemented
for AArch64.
This patch should not cause the kind of spilling tragedy that led to the reversion of r236031.
Differential Revision: http://reviews.llvm.org/D10321
llvm-svn: 239486
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
Implemented DAG lowering for all these forms.
Added tests for DAG lowering and encoding.
Differential Revision: http://reviews.llvm.org/D10310
llvm-svn: 239300
Finish the job that was abandoned in D6958 following the refactoring in
http://reviews.llvm.org/rL230221:
1. Uncomment the intrinsic def for the AVX r_Int instruction.
2. Add missing r_Int entries to the load folding tables; there are already
tests that check these in "test/Codegen/X86/fold-load-unops.ll", so I
haven't added any more in this patch.
3. Add patterns to solve PR21507 ( https://llvm.org/bugs/show_bug.cgi?id=21507 ).
So instead of this:
movaps %xmm0, %xmm1
rcpss %xmm1, %xmm1
movss %xmm1, %xmm0
We should now get:
rcpss %xmm0, %xmm0
And instead of this:
vsqrtss %xmm0, %xmm0, %xmm1
vblendps $1, %xmm1, %xmm0, %xmm0 ## xmm0 = xmm1[0],xmm0[1,2,3]
We should now get:
vsqrtss %xmm0, %xmm0, %xmm0
Differential Revision: http://reviews.llvm.org/D9504
llvm-svn: 236740
We don't need codegen-only intrinsic instructions for the vector forms of these instructions.
This makes the reciprocal estimate instruction lowering identical to how we handle normal
square roots: (V)SQRTPS / (V)SQRTPD.
No existing regression tests fail with this patch.
Differential Revision: http://reviews.llvm.org/D9301
llvm-svn: 236013
This is a 1-line patch (with a TODO for AVX because that will affect
even more regression tests) that lets us substitute the appropriate
64-bit store for the float/double/int domains.
It's not clear to me exactly what the difference is between the 0xD6 (MOVPQI2QImr) and
0x7E (MOVSDto64mr) opcodes, but this is apparently the right choice.
Differential Revision: http://reviews.llvm.org/D8691
llvm-svn: 235014
All of the cases were just appending from random access iterators to a
vector. Using insert/append can grow the vector to the perfect size
directly and moves the growing out of the loop. No intended functionalty
change.
llvm-svn: 230845
Reapply r230248.
Teach the peephole optimizer to work with MMX instructions by adding
entries into the foldable tables. This covers folding opportunities not
handled during isel.
llvm-svn: 230499
Teach the peephole optimizer to work with MMX instructions by adding
entries into the foldable tables. This covers folding opportunities not
handled during isel.
llvm-svn: 230226
Change the memory operands in sse12_fp_packed_scalar_logical_alias from scalars to vectors.
That's what the hardware packed logical FP instructions define: 128-bit memory operands.
There are no scalar versions of these instructions...because this is x86.
Generating the wrong code (folding a scalar load into a 128-bit load) is still possible
using the peephole optimization pass and the load folding tables. We won't completely
solve this bug until we either fix the lowering in fabs/fneg/fcopysign and any other
places where scalar FP logic is created or fix the load folding in foldMemoryOperandImpl()
to make sure it isn't changing the size of the load.
Differential Revision: http://reviews.llvm.org/D7474
llvm-svn: 229531
Patch to allow XOP instructions (integer comparison and integer multiply-add) to be commuted. The comparison instructions sometimes require the compare mode to be flipped but the remaining instructions can use default commutation modes.
This patch also sets the SSE domains of all the XOP instructions.
Differential Revision: http://reviews.llvm.org/D7646
llvm-svn: 229267
Canonicalize access to function attributes to use the simpler API.
getAttributes().getAttribute(AttributeSet::FunctionIndex, Kind)
=> getFnAttribute(Kind)
getAttributes().hasAttribute(AttributeSet::FunctionIndex, Kind)
=> hasFnAttribute(Kind)
llvm-svn: 229214
Added most of the missing vector folding patterns for AVX2 (as well as fixing the vpermpd and verpmq patterns)
Differential Revision: http://reviews.llvm.org/D7492
llvm-svn: 228688
This patch adds the complete AMD Bulldozer XOP instruction set to the memory folding pattern tables for stack folding, etc.
Note: Many of the XOP instructions have multiple table entries as it can fold loads from different sources.
Differential Revision: http://reviews.llvm.org/D7484
llvm-svn: 228685
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
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
MSDN's x64 software conventions page says that this is one of the fixed
list of legal epilogues:
https://msdn.microsoft.com/en-us/library/tawsa7cb.aspx
Presumably this is how the unwinder distinguishes epilogue jumps from
in-function control flow.
Also normalize the way we place "## TAILCALL" comments on such jumps.
llvm-svn: 227611
For ordered, unordered, equal and not-equal tests, packed float and double comparison instructions can be safely commuted without affecting the results. This patch checks the comparison mode of the (v)cmpps + (v)cmppd instructions and commutes the result if it can.
Differential Revision: http://reviews.llvm.org/D7178
llvm-svn: 227145
Patch to allow (v)pclmulqdq to be commuted - swaps the src registers and inverts the immediate (low/high) src mask.
Differential Revision: http://reviews.llvm.org/D7180
llvm-svn: 227141
Minor tweak now that D7042 is complete, we can enable stack folding for (V)MOVDDUP and do proper testing.
Added missing AVX ymm folding patterns and fixed alignment for AVX VMOVSLDUP / VMOVSHDUP.
llvm-svn: 226873
Added most of the missing integer vector folding patterns for SSE (to SSE42) and AVX1.
The most useful of these are probably the i32/i64 extraction, i8/i16/i32/i64 insertions, zero/sign extension, unsigned saturation subtractions, i64 subtractions and the variable mask blends (pblendvb) - others include CLMUL, SSE42 string comparisons and bit tests.
Differential Revision: http://reviews.llvm.org/D7094
llvm-svn: 226745
Now that we can create much more exhaustive X86 memory folding tests, this patch adds the missing AVX1/F16C floating point instruction stack foldings we can easily test for including the scalar intrinsics (add, div, max, min, mul, sub), conversions float/int to double, half precision conversions, rounding, dot product and bit test. The patch also adds a couple of obviously missing SSE instructions (more to follow once we have full SSE testing).
Now that scalar folding is working it broke a very old test (2006-10-07-ScalarSSEMiscompile.ll) - this test appears to make no sense as its trying to ensure that a scalar subtraction isn't folded as it 'would zero the top elts of the loaded vector' - this test just appears to be wrong to me.
Differential Revision: http://reviews.llvm.org/D7055
llvm-svn: 226513
A pass that adds random noops to X86 binaries to introduce diversity with the goal of increasing security against most return-oriented programming attacks.
Command line options:
-noop-insertion // Enable noop insertion.
-noop-insertion-percentage=X // X% of assembly instructions will have a noop prepended (default: 50%, requires -noop-insertion)
-max-noops-per-instruction=X // Randomly generate X noops per instruction. ie. roll the dice X times with probability set above (default: 1). This doesn't guarantee X noop instructions.
In addition, the following 'quick switch' in clang enables basic diversity using default settings (currently: noop insertion and schedule randomization; it is intended to be extended in the future).
-fdiversify
This is the llvm part of the patch.
clang part: D3393
http://reviews.llvm.org/D3392
Patch by Stephen Crane (@rinon)
llvm-svn: 225908
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
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
Added RegOp2MemOpTable4 to transform 4th operand from register to memory in merge-masked versions of instructions.
Added lowering tests.
llvm-svn: 224516
Added a missing memory folding relationship for the (V)CVTPD2PS instruction - we can safely fold these for stack reloads.
Differential Revision: http://reviews.llvm.org/D6663
llvm-svn: 224383
Sanjay Patel