With D24253 we can now use SelectionDAG::SignBitIsZero with vector operations.
This patch uses SelectionDAG::SignBitIsZero to recognise that a zero sign bit means that we can use a sitofp instead of a uitofp (which is not directly support on pre-AVX512 hardware).
While AVX512 does provide support for uitofp, the conversion to sitofp should not cause any regressions.
Differential Revision: https://reviews.llvm.org/D24343
llvm-svn: 281852
Until AVX512DQ we only support i64/vXi64 sitofp conversion as scalars.
This patch sees if the sign bit extends far enough that we can truncate to a i32 type and then perform sitofp without loss of precision.
Differential Revision: https://reviews.llvm.org/D24345
llvm-svn: 281502
The REX prefix should be used on indirect jmps, but not direct ones.
For direct jumps, the unwinder looks at the offset to determine if
it's inside the current function.
Differential Revision: https://reviews.llvm.org/D24359
llvm-svn: 281003
The patch is to fix PR30298, which is caused by rL272694. The solution is to
bail out if the target has no SSE2.
Differential Revision: https://reviews.llvm.org/D24288
llvm-svn: 280837
The previous commit (r280368 - https://reviews.llvm.org/D23313) does not cover AVX-512F, KNL set.
FNEG(x) operation is lowered to (bitcast (vpxor (bitcast x), (bitcast constfp(0x80000000))).
It happens because FP XOR is not supported for 512-bit data types on KNL and we use integer XOR instead.
I added pattern match for integer XOR.
Differential Revision: https://reviews.llvm.org/D24221
llvm-svn: 280785
We need to bitcast the index operand to a floating point type so that it matches the result type. If not then the passthru part of the DAG will be a bitcast from the index's original type to the destination type. This makes it very difficult to match. The other option would be to add 5 sets of patterns for every other possible type.
llvm-svn: 280696
Prior to this, we could generate a vector_shuffle from an IR shuffle when the
size of the result was exactly the sum of the sizes of the input vectors.
If the output vector was narrower - e.g. a <12 x i8> being formed by a shuffle
with two <8 x i8> inputs - we would lower the shuffle to a sequence of extracts
and inserts.
Instead, we can form a larger vector_shuffle, and then extract a subvector
of the right size - e.g. shuffle the two <8 x i8> inputs into a <16 x i8>
and then extract a <12 x i8>.
This also includes a target-specific X86 combine that in the presence of
AVX2 combines:
(vector_shuffle <mask> (concat_vectors t1, undef)
(concat_vectors t2, undef))
into:
(vector_shuffle <mask> (concat_vectors t1, t2), undef)
in cases where this allows us to form VPERMD/VPERMQ.
(This is not a separate commit, as that pattern does not appear without
the DAGBuilder change.)
llvm-svn: 280418
Over eager combing prevents the correct folding of writemasks.
At the moment this occurs for ALL EVEX shuffles, in the future we need to check that the user of the root shuffle is a VSELECT that can fold to a writemask.
llvm-svn: 279934
Previously we weren't creating masked logical operations if bitcasts appeared between the logic operation and the select. The IR optimizers can move bitcasts across logic operations and create these cases. To minimize the number of cases we need to handle, this change promotes all logic ops to an i64 vector type just like when only SSE or AVX is available.
Unfortunately, this also has the consequence of making it difficult to select unmasked VPANDD/VPORD/VPXORD in all the cases it was previously used. This is the cause of most of the test change. This shouldn't result in any functional change though.
llvm-svn: 279929
This reverts most of r274613 (AKA r274626) and its follow-ups (r276347, r277289),
due to miscompiles in the test suite. The FastISel change was left in, because
it apparently fixes an unrelated issue.
(Recommit of r279782 which was broken due to a bad merge.)
This fixes 4 out of the 5 test failures in PR29112.
llvm-svn: 279788
This reverts most of r274613 and its follow-ups (r276347, r277289), due to
miscompiles in the test suite. The FastISel change was left in, because it
apparently fixes an unrelated issue.
This fixes 4 out of the 5 test failures in PR29112.
llvm-svn: 279782
Fix VPAVG detection to require AVX512BW, not AVX512F for 512-bit widths,
and change associated asserts to assert in the right direction...
This fixes PR29111.
llvm-svn: 279755
Includes adding more general support for the pattern: VZEXT_MOVL(VZEXT_LOAD(ptr)) -> VZEXT_LOAD(ptr)
This has unearthed a couple of latent poor codegen issues (MINSS/MAXSS scalar load folding and MOVDDUP/BROADCAST load folding patterns), which will be fixed shortly.
Its also reduced a couple of tests so that they no longer reach the instruction threshold necessary to be combined to PSHUFB (see PR26183).
llvm-svn: 279646
Consecutive load matching (EltsFromConsecutiveLoads) currently uses VZEXT_LOAD (load scalar into lowest element and zero uppers) for vXi64 / vXf64 vectors only.
For vXi32 / vXf32 vectors it instead creates a scalar load, SCALAR_TO_VECTOR and finally VZEXT_MOVL (zero upper vector elements), relying on tablegen patterns to match this into an equivalent of VZEXT_LOAD.
This patch adds the VZEXT_LOAD patterns for vXi32 / vXf32 vectors directly and updates EltsFromConsecutiveLoads to use this.
This has proven necessary to allow us to easily make VZEXT_MOVL a full member of the target shuffle set - without this change the call to combineShuffle (which is the main caller of EltsFromConsecutiveLoads) tended to recursively recreate VZEXT_MOVL nodes......
Differential Revision: https://reviews.llvm.org/D23673
llvm-svn: 279619
As discussed on PR26491, we are missing the opportunity to make use of the smaller MOVHLPS instruction because we set both arguments of a SHUFPD when using it to lower a single input shuffle.
This patch sets the lowered argument to UNDEF if that shuffle element is undefined. This in turn makes it easier for target shuffle combining to decode UNDEF shuffle elements, allowing combines to MOVHLPS to occur.
A fix to match against MOVHPD stores was necessary as well.
This builds on the improved MOVLHPS/MOVHLPS lowering and memory folding support added in D16956
Adding similar support for SHUFPS will have to wait until have better support for target combining of binary shuffles.
Differential Revision: https://reviews.llvm.org/D23027
llvm-svn: 279430
This doesn't change tests codegen as we already combined to blend+zero which is what we lower VZEXT_MOVL to on SSE41+ targets, but it does put us in a better position when we improve shuffling for optsize.
llvm-svn: 279273
INSERTPS doesn't fit well with our shuffle mask canonicalization, so we need to attempt both the original mask and the commuted mask to more likely get a match
llvm-svn: 279230
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.
llvm-svn: 278902
1. Use shuffle to insert element i1 into vector. The previous implementation was incorrect ( dest_bit OR src_bit , it doesn't clear the bit if src_bit=0 )
2. Improve shuffle i1 vector, use CVT2MASK if supported instead TRUNCATE.
Differential Revision: http://reviews.llvm.org/D23347
llvm-svn: 278623
Currently X86ISelLowering has a similar transformation for sexts:
sext(add_nsw(x, C)) --> add(sext(x), C_sext)
In this change I extend this code to handle zexts as well.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D23359
llvm-svn: 278520
The PALIGNR target shuffle decode was not taking into account that DecodePALIGNRMask (rather oddly) expects the operands to be in reverse order, nor was it detecting unary patterns, causing combines to combine with the incorrect input.
The cgbuiltin, auto upgrade and instruction comments code correctly swap the operands so are not affected.
llvm-svn: 278494
The previous implementation (not custom) doesn't enforce zeroing off upper bits. The assumption is that i1 PRODUCER (truncate and extractelement) must zero all upper bits, so i1 CONSUMER instructions ( test, zext, save, etc) can be done without additional zeroing.
Make extractelement i1 lowering custom for all vector i1.
Differential Revision: http://reviews.llvm.org/D23246
llvm-svn: 278328
isUndefOrEqual and isUndefOrInRange treated all -ve shuffle mask values as UNDEF, now it has to be SM_SentinelUndef (-1)
We already have asserts to check that lowered SHUFFLE_VECTOR indices are in the range -1 <= index < 2*masksize (or masksize for unary shuffles)
llvm-svn: 278218
This reverts commit r278048. Something changed between the last time I
built this--it takes awhile on my ridiculously slow and ancient
computer--and now that broke this.
llvm-svn: 278053
Summary:
Based on two patches by Michael Mueller.
This is a target attribute that causes a function marked with it to be
emitted as "hotpatchable". This particular mechanism was originally
devised by Microsoft for patching their binaries (which they are
constantly updating to stay ahead of crackers, script kiddies, and other
ne'er-do-wells on the Internet), but is now commonly abused by Windows
programs to hook API functions.
This mechanism is target-specific. For x86, a two-byte no-op instruction
is emitted at the function's entry point; the entry point must be
immediately preceded by 64 (32-bit) or 128 (64-bit) bytes of padding.
This padding is where the patch code is written. The two byte no-op is
then overwritten with a short jump into this code. The no-op is usually
a `movl %edi, %edi` instruction; this is used as a magic value
indicating that this is a hotpatchable function.
Reviewers: majnemer, sanjoy, rnk
Subscribers: dberris, llvm-commits
Differential Revision: https://reviews.llvm.org/D19908
llvm-svn: 278048
On modern Intel processors hardware SQRT in many cases is faster than RSQRT
followed by Newton-Raphson refinement. The patch introduces a simple heuristic
to choose between hardware SQRT instruction and Newton-Raphson software
estimation.
The patch treats scalars and vectors differently. The heuristic is that for
scalars the compiler should optimize for latency while for vectors it should
optimize for throughput. It is based on the assumption that throughput bound
code is likely to be vectorized.
Basically, the patch disables scalar NR for big cores and disables NR completely
for Skylake. Firstly, scalar SQRT has shorter latency than NR code in big cores.
Secondly, vector SQRT has been greatly improved in Skylake and has better
throughput compared to NR.
Differential Revision: https://reviews.llvm.org/D21379
llvm-svn: 277725
We currently only support combining target shuffles that consist of a single source input (plus elements known to be undef/zero).
This patch generalizes the recursive combining of the target shuffle to collect all the inputs, merging any duplicates along the way, into a full set of src ops and its shuffle mask.
We uncover a number of cases where we have failed to combine a unary shuffle because the input has been duplicated and separated during lowering.
This will allow us to combine to 2-input shuffles in a future patch.
Differential Revision: https://reviews.llvm.org/D22859
llvm-svn: 277631
As discussed on PR14593, this patch adds support for lowering to SHLD/SHRD from the patterns generated by DAGTypeLegalizer::ExpandShiftWithKnownAmountBit.
Differential Revision: https://reviews.llvm.org/D23000
llvm-svn: 277299
Removed AssertZext node, which was inserted between X86ISD::SETCC and "truncate to i1".
Differential Revision: https://reviews.llvm.org/D22850
llvm-svn: 277289
Up until now, we only had code to match PSADBW patterns that look like what
comes out of the loop vectorizer - a partial reduction inside the loop body
that gets fed into a horizontal operation in a different basic block.
This adds support for straight-line patterns, like those generated by the
SLP vectorizer.
Differential Revision: https://reviews.llvm.org/D22889
llvm-svn: 277219
Support for lowering to VBROADCASTF128 etc. in D22460 was not correctly ensuring that the only users of the 128-bit vector load were the insertions of the vector into the lower/upper subvectors.
llvm-svn: 277214
We currently default to using either generic shuffles or MASK+PACKUS/PACKSS to truncate all integer vectors. For vector comparisons, we know that the result will be either all or zero bits in every element, which can be efficiently truncated by directly using PACKSS to repeatedly halve the size of each element.
Due to the limited input values (-1 or 0) we don't need to account for vector element size, so for simplicity we just use the PACKSS(vXi16,vXi16) implementation in all cases. Additionally for AVX2 PACKSS of 256bit data we must perform a PERMQ shuffle to reorder the data into the correct order. I did investigate performing a single shuffle after all the PACKSS calls but the need to cross 128bit lanes makes this difficult to achieve efficiently.
We avoid performing this on AVX512 as it should have better alternative truncation instructions.
Differential Revision: https://reviews.llvm.org/D22814
llvm-svn: 277132
This places the 132/213/231 form number in front of the SS/SD/PS/PD. Move the Y for 256-bit versions to be after the PS/PD. Change the AVX512 scalar forms to include a Z in the their name. This new format should be consistent with the general naming of instructions.
llvm-svn: 276559
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).
Reapplied with fix for PR28657 - removed intrinsic definitions (clang companion patch to be be submitted shortly).
Differential Revision: https://reviews.llvm.org/D22460
llvm-svn: 276416
Under normal circumstances we prefer the higher performance MOVD to extract the 0'th element of a v8i16 vector instead of PEXTRW.
But as detailed on PR27265, this prevents the SSE41 implementation of PEXTRW from folding the store of the 0'th element. Additionally it prevents us from making use of the fact that the (SSE2) reg-reg version of PEXTRW implicitly zero-extends the i16 element to the i32/i64 destination register.
This patch only preferentially lowers to MOVD if we will not be zero-extending the extracted i16, nor prevent a store from being folded (on SSSE41).
Fix for PR27265.
Differential Revision: https://reviews.llvm.org/D22509
llvm-svn: 276289
As requested on D22509, I've pulled out the v8i16 extraction lowering as the SSE41 and pre-SSE41 implementations are effectively the same.
llvm-svn: 276285
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Elena Demikhovsky