As reported on PR26235, we don't currently make use of the VBROADCASTF128/VBROADCASTI128 instructions (or the AVX512 equivalents) to load+splat a 128-bit vector to both lanes of a 256-bit vector.
This patch enables lowering from subvector insertion/concatenation patterns and auto-upgrades the llvm.x86.avx.vbroadcastf128.pd.256 / llvm.x86.avx.vbroadcastf128.ps.256 intrinsics to match.
We could possibly investigate using VBROADCASTF128/VBROADCASTI128 to load repeated constants as well (similar to how we already do for scalar broadcasts).
Differential Revision: https://reviews.llvm.org/D22460
llvm-svn: 276281
classifyLEAReg() deals with switching operands from 32bit to 64bit in
order to use a LEA64_32 instruction (for three address code goodness).
It currently performs a liveness analysis to determine the kill/undef
flag for the newly added operand. This should not be necessary:
- If the previous operand had a kill flag, then the 32bit part of the
register gets killed, this will kill the super register as well.
- If the previous operand had an undef flag then we didn't care what
value we read, just use the same flag on the new operand.
(No matter what an operand with an undef flag won't affect liveness)
This makes the code independent of the presence of kill flags because it
avoids a call to MachineBasicBlock::computeRegisterLiveness().
Differential Revision: http://reviews.llvm.org/D22283
llvm-svn: 276222
This patch adds costs for the vectorized implementations of CTPOP, the default values were seriously underestimating the cost of these and was encouraging vectorization on targets where serialized use of POPCNT would be much better.
Differential Revision: https://reviews.llvm.org/D22456
llvm-svn: 276104
D20859 and D20860 attempted to replace the SSE (V)CVTTPS2DQ and VCVTTPD2DQ truncating conversions with generic IR instead.
It turns out that the behaviour of these intrinsics is different enough from generic IR that this will cause problems, INF/NAN/out of range values are guaranteed to result in a 0x80000000 value - which plays havoc with constant folding which converts them to either zero or UNDEF. This is also an issue with the scalar implementations (which were already generic IR and what I was trying to match).
This patch changes both scalar and packed versions back to using x86-specific builtins.
It also deals with the other scalar conversion cases that are runtime rounding mode dependent and can have similar issues with constant folding.
A companion clang patch is at D22105
Differential Revision: https://reviews.llvm.org/D22106
llvm-svn: 275981
The following condition expression ( a >> n) & 1 is converted to "bt a, n" instruction. It works on all intel targets.
But on AVX-512 it was broken because the expression is modified to (truncate (a >>n) to i1).
I added the new sequence (truncate (a >>n) to i1) to the BT pattern.
Differential Revision: https://reviews.llvm.org/D22354
llvm-svn: 275950
This mostly just works.
Vectorcall rets are still not supported.
The win64_eh test change is because fast isel doesn't use rsi for temporary
computations, so it doesn't need to be pushed. The test case I'm changing was
originally added to test pushes, but by now there are other test cases in that
file exercising that code path.
https://reviews.llvm.org/D22422
llvm-svn: 275607
Summary:
Instead, we take a single flags arg (a bitset).
Also add a default 0 alignment, and change the order of arguments so the
alignment comes before the flags.
This greatly simplifies many callsites, and fixes a bug in
AMDGPUISelLowering, wherein the order of the args to getLoad was
inverted. It also greatly simplifies the process of adding another flag
to getLoad.
Reviewers: chandlerc, tstellarAMD
Subscribers: jholewinski, arsenm, jyknight, dsanders, nemanjai, llvm-commits
Differential Revision: http://reviews.llvm.org/D22249
llvm-svn: 275592
Summary:
Previously we took an unsigned.
Hooray for type-safety.
Reviewers: chandlerc
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D22282
llvm-svn: 275591
As discussed on PR28136, lowerShuffleAsRepeatedMaskAndLanePermute was attempting to match repeated masks at the 128-bit level and then permute the resultant lanes at the 128-bit (AVX1) or 64-bit (AVX2) sub-lane level.
This change allows us to create the repeated masks at the sub-lane level (and then concat them together to create a 128-bit repeated mask) and then select which sub-lane to permute. This has no effect on the AVX1 codegen.
Fixes PR28136.
llvm-svn: 275543
This improves the situation discussed in D19228 where we were forcing VPERMPD/VPERMQ where VPERM2F128/VPERM2I128 would have been better.
This was incorrectly reverted in rL275421 during triage of PR28552.
llvm-svn: 275497
We were able to assemble, but not disassemble.
Note that fixupRMValue was truncating EA_REG_BND0-3 because we hit
the uint8_t max. The control registers were already squarely above
it, but I don't think they ever go in .r/m, only in .reg.
I also did notice an extra REX.W in our encoding, but I think that's
fine.
llvm-svn: 275427
stdcall is callee-pop like thiscall, so the thiscall changes already did most
of the work for this. This change only opts stdcall in and adds tests.
llvm-svn: 275414
This improves the situation discussed in D19228 where we were forcing VPERMPD/VPERMQ where VPERM2F128/VPERM2I128 would have been better.
llvm-svn: 275411
Primarily this is to allow blend with zero instead of having to use vperm2f128, but we can use this in the future to deal with AVX512 cases where we need to keep the original element size to correctly fold masked operations.
llvm-svn: 275406
Summary:
In this patch we implement the following parts of XRay:
- Supporting a function attribute named 'function-instrument' which currently only supports 'xray-always'. We should be able to use this attribute for other instrumentation approaches.
- Supporting a function attribute named 'xray-instruction-threshold' used to determine whether a function is instrumented with a minimum number of instructions (IR instruction counts).
- X86-specific nop sleds as described in the white paper.
- A machine function pass that adds the different instrumentation marker instructions at a very late stage.
- A way of identifying which return opcode is considered "normal" for each architecture.
There are some caveats here:
1) We don't handle PATCHABLE_RET in platforms other than x86_64 yet -- this means if IR used PATCHABLE_RET directly instead of a normal ret, instruction lowering for that platform might do the wrong thing. We think this should be handled at instruction selection time to by default be unpacked for platforms where XRay is not availble yet.
2) The generated section for X86 is different from what is described from the white paper for the sole reason that LLVM allows us to do this neatly. We're taking the opportunity to deviate from the white paper from this perspective to allow us to get richer information from the runtime library.
Reviewers: sanjoy, eugenis, kcc, pcc, echristo, rnk
Subscribers: niravd, majnemer, atrick, rnk, emaste, bmakam, mcrosier, mehdi_amini, llvm-commits
Differential Revision: http://reviews.llvm.org/D19904
llvm-svn: 275367
This happens to make X86CallFrameOptimization in -O0 / FastISel builds as well,
but it's not clear if the pass should run in that setup.
http://reviews.llvm.org/D22314
llvm-svn: 275320
We know that pcmp produces all-ones/all-zeros bitmasks, so we can use that behavior to avoid unnecessary constant loading.
One could argue that load+and is actually a better solution for some CPUs (Intel big cores) because shifts don't have the
same throughput potential as load+and on those cores, but that should be handled as a CPU-specific later transformation if
it ever comes up. Removing the load is the more general x86 optimization. Note that the uneven usage of vpbroadcast in the
test cases is filed as PR28505:
https://llvm.org/bugs/show_bug.cgi?id=28505
Differential Revision: http://reviews.llvm.org/D22225
llvm-svn: 275276
These patterns just extracted the source down to 128-bits to use the instructions. AVX512 seems to have blindly copied them over for VLX, but did not create similar patterns for 512-bit sources. So I'm hoping the backend can't actually produce these cases.
llvm-svn: 275240
With r274952 and r275201 in place there are no cases left where a
forward liveness analysis yields different results than a backward one.
So we can remove the forward stepping logic.
Differential Revision: http://reviews.llvm.org/D22083
llvm-svn: 275204
Avoid implicit conversions from MachineInstrBundleIterator to
MachineInstr*, mainly by preferring MachineInstr& over MachineInstr* and
using range-based for loops.
llvm-svn: 275149
Make some AVX and AVX512 cast costs more precise.
Based on part of a patch by Elena Demikhovsky (D15604).
Differential Revision: http://reviews.llvm.org/D22064
llvm-svn: 275106
This bug (llvm.org/PR28124) was introduced by r237977, which refactored
the tail call sequence to be generated in two passes instead of one.
Unfortunately, the stack adjustment produced by the first pass was not
recognized by X86FrameLowering::mergeSPUpdates() in all cases, causing
code such as the following, which clobbers the return address, to be
generated:
popl %edi
popl %edi
pushl %eax
jmp tailcallee # TAILCALL
To fix the problem, the entire stack adjustment is performed in
X86ExpandPseudo::ExpandMI() for tail calls.
Patch by Magnus Lång <margnus1@gmail.com>
Differential Revision: http://reviews.llvm.org/D21325
llvm-svn: 275103
It is an optimization pass, and should not run at -O0. Especially since Fast RA
will not do the required register coalescing anyway, so it's a loss even from
the optimization standpoint.
This also works around (but doesn't quite fix) PR28489.
llvm-svn: 275099
At present the only shuffle with a variable mask we recognise is PSHUFB, which influences if its worth the cost of mask creation/loading of a combined target shuffle with a variable mask. This change sets up the infrastructure to support other shuffles in the future but has no effect yet.
llvm-svn: 275059
Calls to matchVectorShuffleAsInsertPS only need to ensure the inputs are 128-bit vectors. Only lowerVectorShuffleAsInsertPS needs to ensure that they are v4f32.
llvm-svn: 275028
Until we have a better way to extract constants through bitcasted build vectors (and how to handle undefs of partial lanes etc.) at least accept build vectors that are all zeroes.
llvm-svn: 274833
xorl + setcc is generally the preferred sequence due to the partial register
stall setcc + movzbl suffers from. As a bonus, it also encodes one byte smaller.
This fixes PR28146.
The original commit tried inserting an 8bit-subreg into a GR32 (not GR32_ABCD)
which was not appreciated by fast regalloc on 32-bit.
llvm-svn: 274802
xorl + setcc is generally the preferred sequence due to the partial register
stall setcc + movzbl suffers from. As a bonus, it also encodes one byte smaller.
This fixes PR28146.
Differential Revision: http://reviews.llvm.org/D21774
llvm-svn: 274692
This is "cvtdq2ps" which does not appear to be particularly slow on any CPU
according to Agner's tables. Choosing "5" as a cost here as suggested in:
https://llvm.org/bugs/show_bug.cgi?id=21356
...but it seems very conservative given that the instruction is fully pipelined,
and I think these costs are supposed to model throughput.
Note that related costs are also most likely too high, but this fixes PR21356
and partly fixes PR28434.
llvm-svn: 274658
Cast cost tables are now sorted, for each cast type, lexicographically on
[source base type, source vector width, dest base type, base vector width].
llvm-svn: 274653
We were checking for 2 insertions (which is caught earlier in the pattern matching loop) instead of the case where we have no insertions.
Turns out this code never fires as we always try to lower to insertps after trying to lower to blendps, which would catch these cases - I'm about to make some changes to support combining to insertps which could cause this to fire so I don't want to remove it.
llvm-svn: 274648
The patch removes redundant kmov instructions (not all, we still have a lot of work here) and redundant "and" instructions after "setcc".
I use "AssertZero" marker between X86ISD::SETCC node and "truncate" to eliminate extra "and $1" instruction.
I also changed zext, aext and trunc patterns in the .td file. It allows to remove extra "kmov" instruictions.
This patch fixes https://llvm.org/bugs/show_bug.cgi?id=28173.
Fast ISEL mode is not supported correctly for AVX-512. ICMP/FCMP scalar instruction should return result in k-reg. It will be fixed in one of the next patches. I redirected handling of "cmp" to the DAG builder mode. (The code looks worse in one specific test case, but without this fix the new patch fails).
Differential revision: http://reviews.llvm.org/D21956
llvm-svn: 274613
This patch adds support for including the avx512 mask register information in the mask/maskz versions of shuffle instruction comments.
This initial version just adds support for MOVDDUP/MOVSHDUP/MOVSLDUP to reduce the mass of test regenerations, other shuffle instructions can be added in due course.
Differential Revision: http://reviews.llvm.org/D21953
llvm-svn: 274459
Summary: The code generation should be independent of the debug info.
Reviewers: zansari, davidxl, mkuper, majnemer
Subscribers: majnemer, llvm-commits
Differential Revision: http://reviews.llvm.org/D21911
llvm-svn: 274357
For the most part this simplifies all callers. There were two places in X86 that needed an explicit makeArrayRef to shorten a statically sized array.
llvm-svn: 274337
Change all the methods in LiveVariables that expect non-null
MachineInstr* to take MachineInstr& and update the call sites. This
clarifies the API, and designs away a class of iterator to pointer
implicit conversions.
llvm-svn: 274319
This is a mechanical change to make TargetLowering API take MachineInstr&
(instead of MachineInstr*), since the argument is expected to be a valid
MachineInstr. In one case, changed a parameter from MachineInstr* to
MachineBasicBlock::iterator, since it was used as an insertion point.
As a side effect, this removes a bunch of MachineInstr* to
MachineBasicBlock::iterator implicit conversions, a necessary step
toward fixing PR26753.
llvm-svn: 274287
This is mostly a mechanical change to make TargetInstrInfo API take
MachineInstr& (instead of MachineInstr* or MachineBasicBlock::iterator)
when the argument is expected to be a valid MachineInstr. This is a
general API improvement.
Although it would be possible to do this one function at a time, that
would demand a quadratic amount of churn since many of these functions
call each other. Instead I've done everything as a block and just
updated what was necessary.
This is mostly mechanical fixes: adding and removing `*` and `&`
operators. The only non-mechanical change is to split
ARMBaseInstrInfo::getOperandLatencyImpl out from
ARMBaseInstrInfo::getOperandLatency. Previously, the latter took a
`MachineInstr*` which it updated to the instruction bundle leader; now,
the latter calls the former either with the same `MachineInstr&` or the
bundle leader.
As a side effect, this removes a bunch of MachineInstr* to
MachineBasicBlock::iterator implicit conversions, a necessary step
toward fixing PR26753.
Note: I updated WebAssembly, Lanai, and AVR (despite being
off-by-default) since it turned out to be easy. I couldn't run tests
for AVR since llc doesn't link with it turned on.
llvm-svn: 274189
[x86] (PR15455) While (ins|outs)[bwld] instructions do not take %dx as a
memory operand, various unofficial references do and objdump
disassembles to this format. Extend special treatment of
similar (in|out)[bwld] operations.
Reviewers: craig.topper, rnk, ab
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D18837
llvm-svn: 274152
When lowering two blended PACKUS, we used to disregard the types
of the PACKUS inputs, indiscriminately generating a v16i8 PACKUS.
This leads to non-selectable things like:
(v16i8 (PACKUS (v4i32 v0), (v4i32 v1)))
Instead, check that the PACKUSes have the same type, and use that
as the final result type.
llvm-svn: 274138
Summary: LLVM assumes that large clearance will hide the partial register spill penalty. But in our experiment, 16 clearance is too small. As the inserted XOR is normally fairly cheap, we should have a higher clearance threshold to aggressively insert XORs that is necessary to break partial register dependency.
Reviewers: wmi, davidxl, stoklund, zansari, myatsina, RKSimon, DavidKreitzer, mkuper, joerg, spatel
Subscribers: davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D21560
llvm-svn: 274068
The original implementation attempted to zero registers using
XOR %foo, %foo. This is problematic because it constitutes a
read-modify-write of a register which might not be defined.
Instead, use MOV32r0 to avoid these problems; expandPostRAPseudo does
the right thing here.
llvm-svn: 274024
AVX1 can only broadcast vectors as floats/doubles, so for 256-bit vectors we insert bitcasts if we are shuffling v8i32/v4i64 types. Unfortunately the presence of these bitcasts prevents the current broadcast lowering code from peeking through cases where we have concatenated / extracted vectors to create the 256-bit vectors.
This patch allows us to peek through bitcasts as long as the number of elements doesn't change (i.e. element bitwidth is the same) so the broadcast index is not affected.
Note this bitcast peek is different from the stage later on which doesn't care about the type and is just trying to find a load node.
As we're being more aggressive with bitcasts, we also need to ensure that the broadcast type is correctly bitcasted
Differential Revision: http://reviews.llvm.org/D21660
llvm-svn: 274013
This patch allows target shuffles to be combined to single input immediate permute instructions - (V)PSHUFD/VPERMILPD/VPERMILPS - allowing more general pattern matching than what we current do and improves the likelihood of memory folding compared to existing patterns which tend to reuse the input in multiple arguments.
Further permute instructions (V)PSHUFLW/(V)PSHUFHW/(V)PERMQ/(V)PERMPD may be added in the future but its proven tricky to create tests cases for them so far. (V)PSHUFLW/(V)PSHUFHW is already handled quite well in combineTargetShuffle so it may be that removing some of that code may allow us to perform more of the combining in one place without duplication.
Differential Revision: http://reviews.llvm.org/D21148
llvm-svn: 273999
AVX1 can only broadcast vectors as floats/doubles, so for 256-bit vectors we insert bitcasts if we are shuffling v8i32/v4i64 types. Unfortunately the presence of these bitcasts prevents the current broadcast lowering code from peeking through cases where we have concatenated / extracted vectors to create the 256-bit vectors.
This patch allows us to peek through bitcasts as long as the number of elements doesn't change (i.e. element bitwidth is the same) so the broadcast index is not affected.
Note this bitcast peek is different from the stage later on which doesn't care about the type and is just trying to find a load node.
Differential Revision: http://reviews.llvm.org/D21660
llvm-svn: 273848
Memory references were not being propagated for this folded load. This
prevented optimizations like LICM from hoisting the load.
Added test to verify that this allows LICM to proceed.
llvm-svn: 273617
X86FrameLowering::adjustForHiPEPrologue() contains a hard-coded offset
into an Erlang Runtime System-internal data structure (the PCB). As the
layout of this data structure is prone to change, this poses problems
for maintaining compatibility.
To address this problem, the compiler can produce this information as
module-level named metadata. For example (where P_NSP_LIMIT is the
offending offset):
!hipe.literals = !{ !2, !3, !4 }
!2 = !{ !"P_NSP_LIMIT", i32 152 }
!3 = !{ !"X86_LEAF_WORDS", i32 24 }
!4 = !{ !"AMD64_LEAF_WORDS", i32 24 }
Patch by Magnus Lang
Differential Revision: http://reviews.llvm.org/D20363
llvm-svn: 273593
The setCallee function will set the number of fixed arguments based
on the size of the argument list. The FixedArgs parameter was often
explicitly set to 0, leading to a lack of consistent value for non-
vararg functions.
Differential Revision: http://reviews.llvm.org/D20376
llvm-svn: 273403
Summary:
Fix the computation of the offsets present in the scopetable when using the
SEH (__except_handler4).
This patch added an intrinsic to track the position of the allocation on the
stack of the EHGuard. This position is needed when producing the ScopeTable.
```
struct _EH4_SCOPETABLE {
DWORD GSCookieOffset;
DWORD GSCookieXOROffset;
DWORD EHCookieOffset;
DWORD EHCookieXOROffset;
_EH4_SCOPETABLE_RECORD ScopeRecord[1];
};
struct _EH4_SCOPETABLE_RECORD {
DWORD EnclosingLevel;
long (*FilterFunc)();
union {
void (*HandlerAddress)();
void (*FinallyFunc)();
};
};
```
The code to generate the EHCookie is added in `X86WinEHState.cpp`.
Which is adding these instructions when using SEH4.
```
Lfunc_begin0:
# BB#0: # %entry
pushl %ebp
movl %esp, %ebp
pushl %ebx
pushl %edi
pushl %esi
subl $28, %esp
movl %ebp, %eax <<-- Loading FramePtr
movl %esp, -36(%ebp)
movl $-2, -16(%ebp)
movl $L__ehtable$use_except_handler4_ssp, %ecx
xorl ___security_cookie, %ecx
movl %ecx, -20(%ebp)
xorl ___security_cookie, %eax <<-- XOR FramePtr and Cookie
movl %eax, -40(%ebp) <<-- Storing EHGuard
leal -28(%ebp), %eax
movl $__except_handler4, -24(%ebp)
movl %fs:0, %ecx
movl %ecx, -28(%ebp)
movl %eax, %fs:0
movl $0, -16(%ebp)
calll _may_throw_or_crash
LBB1_1: # %cont
movl -28(%ebp), %eax
movl %eax, %fs:0
addl $28, %esp
popl %esi
popl %edi
popl %ebx
popl %ebp
retl
```
And the corresponding offset is computed:
```
Luse_except_handler4_ssp$parent_frame_offset = -36
.p2align 2
L__ehtable$use_except_handler4_ssp:
.long -2 # GSCookieOffset
.long 0 # GSCookieXOROffset
.long -40 # EHCookieOffset <<----
.long 0 # EHCookieXOROffset
.long -2 # ToState
.long _catchall_filt # FilterFunction
.long LBB1_2 # ExceptionHandler
```
Clang is not yet producing function using SEH4, but it's a work in progress.
This patch is a step toward having a valid implementation of SEH4.
Unfortunately, it is not yet fully working. The EH registration block is not
allocated at the right offset on the stack.
Reviewers: rnk, majnemer
Subscribers: llvm-commits, chrisha
Differential Revision: http://reviews.llvm.org/D21231
llvm-svn: 273281
The main difference is that StubDynamicNoPIC is gone. The
dynamic-no-pic mode as the name implies is simply not pic. It is just
conservative about what it assumes to be dso local.
llvm-svn: 273222
The BSWAP of vector types is quite efficiently implemented using vector shuffles on SSE/AVX targets, we should reflect the typical cost of this to encourage vectorization.
Differential Revision: http://reviews.llvm.org/D21521
llvm-svn: 273217
Fix for PR27726 - sitofp i64 to fp128 was loading the merged load i64 to a x87 register preventing legalization for conversion to fp128.
Added 32-bit tests for fp128 cast/conversions.
llvm-svn: 273210
We currently only allow exact matches of shuffle mask patterns during target shuffle combining.
This patch relaxes this to permit SM_SentinelUndef in the combined shuffle to always be accepted as well as allowing exact matching of the SM_SentinelZero value.
I've adjusted some tests that were requiring exact shuffle masks to now include undef values.
Differential Revision: http://reviews.llvm.org/D21495
llvm-svn: 273119
Summary:
... into getFrameIndexReferencePreferSP. This change folds the
fail-then-retry logic into getFrameIndexReferencePreferSP.
There is a non-functional but behaviorial change in WinException --
earlier if `getFrameIndexReferenceFromSP` failed we'd trip an assert,
but now we'll silently use the (wrong) offset from the base pointer. I
could not write the assert I'd like to write ("FrameReg ==
StackRegister", like I've done in X86FrameLowering) since there is no
easy way to get to the stack register from WinException (happy to be
proven wrong here). One solution to this is to add a `bool
OnlyStackPointer` parameter to `getFrameIndexReferenceFromSP` that
asserts if it could not satisfy its promise of returning an offset from
a stack pointer, but that seems overkill.
Reviewers: rnk
Subscribers: sanjoy, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D21427
llvm-svn: 272938
... instead of explicitly conditioning on NDEBUG. Also use an easier to
read conditional expression.
(Addresses post-commit review from David Blaikie.)
llvm-svn: 272762
Summary:
... when the offset is not statically known.
Prioritize addresses relative to the stack pointer in the stackmap, but
fallback gracefully to other modes of addressing if the offset to the
stack pointer is not a known constant.
Patch by Oscar Blumberg!
Reviewers: sanjoy
Subscribers: llvm-commits, majnemer, rnk, sanjoy, thanm
Differential Revision: http://reviews.llvm.org/D21259
llvm-svn: 272756
Nearly all the changes to this pass have been done while maintaining and
updating other parts of LLVM. LLVM has had another pass, SROA, which
has superseded ScalarReplAggregates for quite some time.
Differential Revision: http://reviews.llvm.org/D21316
llvm-svn: 272737
For <N x i32> type mul, pmuludq will be used for targets without SSE41, which
often introduces many extra pack and unpack instructions in vectorized loop
body because pmuludq generates <N/2 x i64> type value. However when the operands
of <N x i32> mul are extended from smaller size values like i8 and i16, the type
of mul may be shrunk to use pmullw + pmulhw/pmulhuw instead of pmuludq, which
generates better code. For targets with SSE41, pmulld is supported so no
shrinking is needed.
Differential Revision: http://reviews.llvm.org/D20931
llvm-svn: 272694
Summary:
The "-Werror=enum-compare" shows that the statement is using two different enums:
enumeral mismatch in conditional expression: 'llvm::X86ISD::NodeType' vs 'llvm::ISD::NodeType'
A follow-up fix on D21235.
Reviewers: klimek
Subscribers: spatel, cfe-commits
Differential Revision: http://reviews.llvm.org/D21278
llvm-svn: 272539
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.
llvm-svn: 272512
This patch is intended to solve:
https://llvm.org/bugs/show_bug.cgi?id=28044
By changing the definition of X86ISD::CMPP to use float types, we allow it to be created
and pass legalization for an SSE1-only target where v4i32 is not legal.
The motivational trail for this change includes:
https://llvm.org/bugs/show_bug.cgi?id=28001
and eventually makes this trigger:
http://reviews.llvm.org/D21190
Ie, after this step, we should be free to have Clang generate FP compare IR instead of x86
intrinsics for SSE C packed compare intrinsics. (We can auto-upgrade and remove the LLVM
sse.cmp intrinsics as a follow-up step.) Once we're generating vector IR instead of x86
intrinsics, a big pile of generic optimizations can trigger.
Differential Revision: http://reviews.llvm.org/D21235
llvm-svn: 272511
PSHUFB can speed up BITREVERSE of byte vectors by performing LUT on the low/high nibbles separately and ORing the results. Wider integer vector types are already BSWAP'd beforehand so also make use of this approach.
llvm-svn: 272477
These are byte shift instructions and it will make shuffle combining a lot more straightforward if we can assume a vXi8 vector of bytes so decoded shuffle masks match the return type's number of elements
llvm-svn: 272468
The costs are somewhat hand-wavy, but should be much closer to the truth
than what we get from BasicTTI.
Differential Revision: http://reviews.llvm.org/D21156
llvm-svn: 272406
512-bit VPSLLDQ/VPSRLDQ can only be used for avx512bw targets so lowerVectorShuffleAsShift had to be adjusted to include the subtarget
llvm-svn: 272300
As suggested by clang-tidy's performance-unnecessary-copy-initialization.
This can easily hit lifetime issues, so I audited every change and ran the
tests under asan, which came back clean.
llvm-svn: 272126
Summary:
This patch is adding support for the MSVC buffer security check implementation
The buffer security check is turned on with the '/GS' compiler switch.
* https://msdn.microsoft.com/en-us/library/8dbf701c.aspx
* To be added to clang here: http://reviews.llvm.org/D20347
Some overview of buffer security check feature and implementation:
* https://msdn.microsoft.com/en-us/library/aa290051(VS.71).aspx
* http://www.ksyash.com/2011/01/buffer-overflow-protection-3/
* http://blog.osom.info/2012/02/understanding-vs-c-compilers-buffer.html
For the following example:
```
int example(int offset, int index) {
char buffer[10];
memset(buffer, 0xCC, index);
return buffer[index];
}
```
The MSVC compiler is adding these instructions to perform stack integrity check:
```
push ebp
mov ebp,esp
sub esp,50h
[1] mov eax,dword ptr [__security_cookie (01068024h)]
[2] xor eax,ebp
[3] mov dword ptr [ebp-4],eax
push ebx
push esi
push edi
mov eax,dword ptr [index]
push eax
push 0CCh
lea ecx,[buffer]
push ecx
call _memset (010610B9h)
add esp,0Ch
mov eax,dword ptr [index]
movsx eax,byte ptr buffer[eax]
pop edi
pop esi
pop ebx
[4] mov ecx,dword ptr [ebp-4]
[5] xor ecx,ebp
[6] call @__security_check_cookie@4 (01061276h)
mov esp,ebp
pop ebp
ret
```
The instrumentation above is:
* [1] is loading the global security canary,
* [3] is storing the local computed ([2]) canary to the guard slot,
* [4] is loading the guard slot and ([5]) re-compute the global canary,
* [6] is validating the resulting canary with the '__security_check_cookie' and performs error handling.
Overview of the current stack-protection implementation:
* lib/CodeGen/StackProtector.cpp
* There is a default stack-protection implementation applied on intermediate representation.
* The target can overload 'getIRStackGuard' method if it has a standard location for the stack protector cookie.
* An intrinsic 'Intrinsic::stackprotector' is added to the prologue. It will be expanded by the instruction selection pass (DAG or Fast).
* Basic Blocks are added to every instrumented function to receive the code for handling stack guard validation and errors handling.
* Guard manipulation and comparison are added directly to the intermediate representation.
* lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
* lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
* There is an implementation that adds instrumentation during instruction selection (for better handling of sibbling calls).
* see long comment above 'class StackProtectorDescriptor' declaration.
* The target needs to override 'getSDagStackGuard' to activate SDAG stack protection generation. (note: getIRStackGuard MUST be nullptr).
* 'getSDagStackGuard' returns the appropriate stack guard (security cookie)
* The code is generated by 'SelectionDAGBuilder.cpp' and 'SelectionDAGISel.cpp'.
* include/llvm/Target/TargetLowering.h
* Contains function to retrieve the default Guard 'Value'; should be overriden by each target to select which implementation is used and provide Guard 'Value'.
* lib/Target/X86/X86ISelLowering.cpp
* Contains the x86 specialisation; Guard 'Value' used by the SelectionDAG algorithm.
Function-based Instrumentation:
* The MSVC doesn't inline the stack guard comparison in every function. Instead, a call to '__security_check_cookie' is added to the epilogue before every return instructions.
* To support function-based instrumentation, this patch is
* adding a function to get the function-based check (llvm 'Value', see include/llvm/Target/TargetLowering.h),
* If provided, the stack protection instrumentation won't be inlined and a call to that function will be added to the prologue.
* modifying (SelectionDAGISel.cpp) do avoid producing basic blocks used for inline instrumentation,
* generating the function-based instrumentation during the ISEL pass (SelectionDAGBuilder.cpp),
* if FastISEL (not SelectionDAG), using the fallback which rely on the same function-based implemented over intermediate representation (StackProtector.cpp).
Modifications
* adding support for MSVC (lib/Target/X86/X86ISelLowering.cpp)
* adding support function-based instrumentation (lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp, .h)
Results
* IR generated instrumentation:
```
clang-cl /GS test.cc /Od /c -mllvm -print-isel-input
```
```
*** Final LLVM Code input to ISel ***
; Function Attrs: nounwind sspstrong
define i32 @"\01?example@@YAHHH@Z"(i32 %offset, i32 %index) #0 {
entry:
%StackGuardSlot = alloca i8* <<<-- Allocated guard slot
%0 = call i8* @llvm.stackguard() <<<-- Loading Stack Guard value
call void @llvm.stackprotector(i8* %0, i8** %StackGuardSlot) <<<-- Prologue intrinsic call (store to Guard slot)
%index.addr = alloca i32, align 4
%offset.addr = alloca i32, align 4
%buffer = alloca [10 x i8], align 1
store i32 %index, i32* %index.addr, align 4
store i32 %offset, i32* %offset.addr, align 4
%arraydecay = getelementptr inbounds [10 x i8], [10 x i8]* %buffer, i32 0, i32 0
%1 = load i32, i32* %index.addr, align 4
call void @llvm.memset.p0i8.i32(i8* %arraydecay, i8 -52, i32 %1, i32 1, i1 false)
%2 = load i32, i32* %index.addr, align 4
%arrayidx = getelementptr inbounds [10 x i8], [10 x i8]* %buffer, i32 0, i32 %2
%3 = load i8, i8* %arrayidx, align 1
%conv = sext i8 %3 to i32
%4 = load volatile i8*, i8** %StackGuardSlot <<<-- Loading Guard slot
call void @__security_check_cookie(i8* %4) <<<-- Epilogue function-based check
ret i32 %conv
}
```
* SelectionDAG generated instrumentation:
```
clang-cl /GS test.cc /O1 /c /FA
```
```
"?example@@YAHHH@Z": # @"\01?example@@YAHHH@Z"
# BB#0: # %entry
pushl %esi
subl $16, %esp
movl ___security_cookie, %eax <<<-- Loading Stack Guard value
movl 28(%esp), %esi
movl %eax, 12(%esp) <<<-- Store to Guard slot
leal 2(%esp), %eax
pushl %esi
pushl $204
pushl %eax
calll _memset
addl $12, %esp
movsbl 2(%esp,%esi), %esi
movl 12(%esp), %ecx <<<-- Loading Guard slot
calll @__security_check_cookie@4 <<<-- Epilogue function-based check
movl %esi, %eax
addl $16, %esp
popl %esi
retl
```
Reviewers: kcc, pcc, eugenis, rnk
Subscribers: majnemer, llvm-commits, hans, thakis, rnk
Differential Revision: http://reviews.llvm.org/D20346
llvm-svn: 272053
Currently the only way to use the (V)MOVNTDQA nontemporal vector loads instructions is through the int_x86_sse41_movntdqa style builtins.
This patch adds support for lowering nontemporal loads from general IR, allowing us to remove the movntdqa builtins in a future patch.
We currently still fold nontemporal loads into suitable instructions, we should probably look at removing this (and nontemporal stores as well) or at least make the target's folding implementation aware that its dealing with a nontemporal memory transaction.
There is also an issue that VMOVNTDQA only acts on 128-bit vectors on pre-AVX2 hardware - so currently a normal ymm load is still used on AVX1 targets.
Differential Review: http://reviews.llvm.org/D20965
llvm-svn: 272011
Currently the only way to use the (V)MOVNTDQA nontemporal vector loads instructions is through the int_x86_sse41_movntdqa style builtins.
This patch adds support for lowering nontemporal loads from general IR, allowing us to remove the movntdqa builtins in a future patch.
We currently still fold nontemporal loads into suitable instructions, we should probably look at removing this (and nontemporal stores as well) or at least make the target's folding implementation aware that its dealing with a nontemporal memory transaction.
There is also an issue that VMOVNTDQA only acts on 128-bit vectors on pre-AVX2 hardware - so currently a normal ymm load is still used on AVX1 targets.
Differential Review: http://reviews.llvm.org/D20965
llvm-svn: 272010
We currently only combine to blend+zero if the target value type has 8 elements or less, but this was missing a lot of cases where the combined mask had been widened.
This change makes it so we use the combined mask to determine the blend value type, allowing us to catch more widened cases.
llvm-svn: 272003
Simon Pilgrim