The original code could create a bitcast from f64 to i64 and back
on 32-bit targets. This was only working because getBitcast was
able to fold the casts away to avoid leaving the illegal i64 type.
Now we handle the scalar case directly by broadcasting using the
scalar type as the element type. Then bitcasting to the final VT.
This works since we ensure the scalar type is the same size as
the final VT element type. No more casts to i64.
For the vector case, we cast to VT or subvector of VT. And then
do the broadcast.
I think this all matches what we generated before, just in a more
readable way.
Previously we tried to promote these to xmm/ymm/zmm by promoting
in the X86CallingConv.td file. But this breaks when we run out
of xmm/ymm/zmm registers and need to fall back to memory. We end
up trying to create a non-sensical scalar to vector. This lead
to an assertion. The new tests in avx512-calling-conv.ll all
trigger this assertion.
Since we really want to treat these types like we do on avx2,
it seems better to promote them before the calling convention
code gets involved. Except when the calling convention is one
that passes the vXi1 type in a k register.
The changes in avx512-regcall-Mask.ll are because we indicated
that xmm/ymm/zmm types should be passed indirectly for the
Win64 ABI before we go to the common lines that promoted the
vXi1 types. This caused the promoted types to be picked up by
the default calling convention code. Now we promote them earlier
so they get passed indirectly as though they were xmm/ymm/zmm.
Differential Revision: https://reviews.llvm.org/D75154
If we would emit a VBROADCAST node, we can instead directly emit
a VBROADCAST_LOAD. This allows us to get rid of the special case
to use an f64 load on 32-bit targets for vXi64.
I believe there is more cleanup we can do later in this function,
but I'll do that in follow ups.
If we go with D75412, we no longer depend on the scalar type directly. So we don't need to avoid using i64. We already have AVX1 fallback patterns with i32 and i64 scalar types so we don't need to avoid using integer types on AVX1.
Differential Revision: https://reviews.llvm.org/D75413
Also add a DAG combine to combine different sized broadcasts from
constant pool to avoid a regression.
Differential Revision: https://reviews.llvm.org/D75412
The build_vector needs to be the only user of the data, but the
chain will likely have another use. So we can't make sure the
build_vector is the only user of the node.
These AddToWorklist calls were added in 84cd968f75.
It's possible the SimplifyDemandedBits/SimplifyDemandedVectorElts
triggered CSE that deleted N. Detect that and avoid adding N
to the worklist.
Fixes PR45067.
Previously this code was called into two ways, either a FrameIndexSDNode
was passed in StackSlot. Or a load node was passed in the argument
called StackSlot. This was determined by a dyn_cast to FrameIndexSDNode.
In the case of a load, we had to go find the real pointer from
operand 0 and cast the node to MemSDNode to find the pointer info.
For the stack slot case, the code assumed that the stack slot
was perfectly aligned despite not being the creator of the slot.
This commit modifies the interface to make the caller responsible
for passing all of the required information to avoid all the
guess work and reverse engineering.
I'm not aware of any issues with the original code after an
earlier commit to fix the alignment of one of the stack objects.
This is just clean up to make the code less surprising.
This node reads the rounding control which means it needs to be ordered properly with operations that change the rounding control. So it needs to be chained to maintain order.
This patch adds a chain input and output to the node and connects it to the chain in SelectionDAGBuilder. I've update all in-tree targets to connect their chain through their lowering code.
Differential Revision: https://reviews.llvm.org/D75132
Instead add it when we make the machine nodes during instruction
selections.
This makes this ISD node closer to ISD::MGATHER. Trying to see
if we remove the X86 specific ones.
I'm hoping to begin improving shuffle combining across different vector sizes, but before that we must ensure that all existing getTargetShuffleInputs calls must bail if the inputs aren't the same size.
The gather intrinsics use a floating point mask when the result
type is FP. But we call DemandedBits on the mask assuming its an
integer type. We also use integer types when we create it from
generic IR. So add a bitcast to the intrinsic path to guarantee
the integer type.
Leave the gather/scatter subclasses, but make them inherit from
MemIntrinsicSDNode and delete their constructor and destructor.
This way we can still have the getIndex, getMask, etc. convenience
functions.
If a simplication occurs the operand will be added to the worklist.
But since the demanded mask was based on N, we need to make sure
we revisit N in case there are more simplifications to be done.
Returning SDValue(N, 0) as we do, only tells DAG combine that
something changed, but that won't make it add anything to the
worklist.
Found while playing around with using VEXTRACT_STORE in more cases.
But I guess this doesn't affect any of our existing tests.
We can use MOVLPS which will load 64 bits, but we need a v4f32
result type. We already have isel patterns for this.
The code here is a little hacky. We can probably improve it with
more isel patterns.
This is similar to using movd which we do for sse2 targets.
I've added a DAG combine for VEXTRACT_STORE to use SimplifyDemandedVectorElts
to clean up some artifacts from type legalization.
Similar to what do for other operations that use a subset of bits.
Allows us to remove a pattern that shrinks a load. Which was
incorrect if the load was volatile.
At this point in the code we know that Op1 or Op2 is
all ones. Y points to the other operand. In the case that
Op2 is zero, Op1 must be all ones and Y is Op2. The OR
ORs Y into Res. But if Y is 0 the OR will be folded away by
getNode so we don't need to check for it.
The combineSelect code was casting to i64 without any check that
i64 was legal. This can break after type legalization.
It also required splitting the mmx register on 32-bit targets.
It's not clear that this makes sense. Instead switch to using
a cmov pseudo like we do for XMM/YMM/ZMM.
The motivating case is seen in "splat4_v8f32_load_store" and based on code in PR42024:
https://bugs.llvm.org/show_bug.cgi?id=42024
(I haven't stepped through the v8i32 sibling test yet to see why that diverged.)
There are other potential improvements visible like allowing scalarization or vector
narrowing.
Differential Revision: https://reviews.llvm.org/D74909
There's a lot of old leftover code in LowerBRCOND. Especially
the detecting or AND or OR of X86ISD::SETCC nodes. Those were
needed before LegalizeDAG was changed to visit nodes before
their operands.
It also relied on reversing the output of LowerSETCC to find the
flags producing node to use for the X86ISD::BRCOND node.
Rather than using LowerSETCC this patch uses emitFlagsForSetcc to
handle the integer ISD::SETCC case. This gives the flag producer
and the comparison code to use directly. I've removed the addTest
flag and just produce a X86ISD::BRCOND and return immediately.
Floating point ISD::SETCC case is just an X86ISD::FCMP with special
care for OEQ and UNE derived from the previous code. I've left
f128 out so it will emit a test. And LowerSETCC will be called
later to produce a libcall and X86ISD::SETCC. We have combines
that can merge the test and X86ISD::SETCC.
We need to handle two cases for overflow ops. Either they are used
directly or they have a seteq 0 or setne 1 to invert the overflow.
The old code did not handle the setne 1 case, but I think some
other combines were making up for it.
If we fail to find a condition, we'll wrap an AND with 1 on the
original condition and tell emitFlagsForSetcc to emit a compare
with 0. This will pickup the LowerAndToBT and or the EmitTest case.
I kept the isTruncWithZeroHighBitsInput call, but we might be able
to fold that in to emitFlagsForSetcc.
Differential Revision: https://reviews.llvm.org/D74750
Only handle power of 2 element count for simplicity. Not sure what to do with vXf64->vXf16 fp_round to avoid double rounding
Differential Revision: https://reviews.llvm.org/D74886
We only need to split after type legalization. If we're before
we can just use a wide store and type legalization will split it.
Add a v128i1 test to exercise it post type legalization.
On some targets, like SPARC, forming overflow ops is only profitable if
the math result is used: https://godbolt.org/z/DxSmdB
This patch adds a new MathUsed parameter to allow the targets
to make the decision and defaults to only allowing it
if the math result is used. That is the conservative choice.
This patch also updates AArch64ISelLowering, X86ISelLowering,
ARMISelLowering.h, SystemZISelLowering.h to allow forming overflow
ops if the math result is not used. On those targets using the
overflow intrinsic for the overflow check only generates better code.
Reviewers: nikic, RKSimon, lebedev.ri, spatel
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D74722
LoweSELECT will detect the constant inputs and convert to scalar
selects, but we can do it directly here.
I might remove some of the code from LowerSELECT and move it to
DAG combine so doing this explicitly will make us less dependent
on it happening in lowering.
This patch enables the debug entry values feature.
- Remove the (CC1) experimental -femit-debug-entry-values option
- Enable it for x86, arm and aarch64 targets
- Resolve the test failures
- Leave the llc experimental option for targets that do not
support the CallSiteInfo yet
Differential Revision: https://reviews.llvm.org/D73534
This helps this transform occur earlier so we can fold the not
with setcc. If we delay it until after type legalization we might
have introduced instructions to widen the mask if the vselect was
widened. This can prevent the not from making it to the setcc.
We could of course add more DAG combines to handle that, but
moving this earlier is easier.
D73835 will make IRBuilder no longer trivially copyable. This patch
deletes the copy constructor in advance, to separate out the breakage.
Currently, the IRBuilder copy constructor is usually used by accident,
not by intention. In rG7c362b25d7a9 I've fixed a number of cases where
functions accepted IRBuilder rather than IRBuilder &, thus performing
an unnecessary copy. In rG5f7b92b1b4d6 I've fixed cases where an
IRBuilder was copied, while an InsertPointGuard should have been used
instead.
The only non-trivial use of the copy constructor is the
getIRBForDbgInsertion() helper, for which I separated construction and
setting of the insertion point in this patch.
Differential Revision: https://reviews.llvm.org/D74693
Both of those functions only have a single caller starting
at LowerSETCC. Just handle floating point directly in LowerSETCC.
This removes the need to pass Chain and IsSignaling all the way
down.
The unseen logic diff occurs because MayFoldLoad() is defined like this:
static bool MayFoldLoad(SDValue Op) {
return Op.hasOneUse() && ISD::isNormalLoad(Op.getNode());
}
The test diffs here all seem ok to me on screen/paper, but it's hard to know
if that will lead to universally better perf for all targets. For example,
if a target implements broadcast from mem as multiple uops, we would have to
weigh the potential reduction of instructions and register pressure vs.
possible increase in number of uops. I don't know if we can make a truly
informed decision on this at compile-time.
The motivating case that I'm looking at in PR42024:
https://bugs.llvm.org/show_bug.cgi?id=42024
...resembles the diff in extract-concat.ll, but we're not going to change the
larger example there without at least 1 other fix.
Differential Revision: https://reviews.llvm.org/D74088
Without PSHUFB we are better using ROTL (expanding to OR(SHL,SRL)) than using the generic v16i8 shuffle lowering - but if we can widen to v8i16 or more then the existing shuffles are still the better option.
REAPPLIED: Original commit rG11c16e71598d was reverted at rGde1d90299b16 as it wasn't accounting for later lowering. This version emits ROTLI or the OR(VSHLI/VSRLI) directly to avoid the issue.
If we widen the compare we might trigger a spurious exception from
the garbage data.
We have two choices here. Explicitly force the upper bits to zero.
Or use a legacy VEX vcmpps/pd instruction and convert the XMM/YMM
result to mask register.
I've chosen to go with the second option. I'm not sure which is
really best. In some cases we could get rid of the zeroing since
the producing instruction probably already zeroed it. But we lose
the ability to fold a load. So which is best is dependent on
surrounding code.
Differential Revision: https://reviews.llvm.org/D74522
Summary:
This was a very odd API, where you had to pass a flag into a zext
function to say whether the extended bits really were zero or not. All
callers passed in a literal true or false.
I think it's much clearer to make the function name reflect the
operation being performed on the value we're tracking (rather than on
the KnownBits Zero and One fields), so zext means the value is being
zero extended and new function anyext means the value is being extended
with unknown bits.
NFC.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74482
This has a really interesting side effect in that it improves some UMAX/UMIN reduction code which had redundant XOR(SHUFFLE(XOR(X,SIGNMASK)),SIGNMASK) patterns - the getNegatibleCost recognises it as FNEG(SHUFFLE(FNEG(X))).... We have a lot of FNEG patterns bitcasted to the integer domain for XOR signbit twiddling which is similar to what we do to allow UMAX/UMIN to be lowered using SMAX/SMIN.
Differential Revision: https://reviews.llvm.org/D74231
The isNegatibleForFree/getNegatedExpression methods currently rely on a raw char value to indicate whether a negation is beneficial or not.
This patch replaces the char return value with an NegatibleCost enum to more clearly demonstrate what is implied.
It also renames isNegatibleForFree to getNegatibleCost to more accurately reflect whats going on.
Differential Revision: https://reviews.llvm.org/D74221
This patch enables the debug entry values feature.
- Remove the (CC1) experimental -femit-debug-entry-values option
- Enable it for x86, arm and aarch64 targets
- Resolve the test failures
- Leave the llc experimental option for targets that do not
support the CallSiteInfo yet
Differential Revision: https://reviews.llvm.org/D73534
This adds a strict version of FP16_TO_FP and FP_TO_FP16 and uses
them to implement soft promotion for the half type. This is
enough to provide basic support for __fp16 with strictfp.
Add the necessary X86 support to use VCVTPS2PH/VCVTPH2PS when F16C
is enabled.
We aren't doing a good job of optimizing AVX512 outside of this code. So remove the bail out for AVX512 and replace with a FIXME. This at least gets us the AVX2 codegen.
Differential Revision: https://reviews.llvm.org/D74431
Without PSHUFB we are better using ROTL (expanding to OR(SHL,SRL)) than using the generic v16i8 shuffle lowering - but if we can widen to v8i16 or more then the existing shuffles are still the better option.
We need to use vector instructions for these operations. Previously
we handled this with isel patterns that used extra instructions
and copies to handle the the conversions.
Now we use custom lowering to emit the conversions. This allows
them to be pattern matched and optimized on their own. For
example we can now emit vpextrw to store the result if its going
directly to memory.
I've forced the upper elements to VCVTPHS2PS to zero to keep some
code similar. Zeroes will be needed for strictfp. I've added a
DAG combine for (fp16_to_fp (fp_to_fp16 X)) to avoid extra
instructions in between to be closer to the previous codegen.
This is a step towards strictfp support for f16 conversions.
Non-AVX512BW targets failed to concatenate 256-bit shifts back to 512-bits (split during 512-bit shuffle lowering as they don't have v32i16/v64i8 types).
As noted on PR44379, we didn't attempt to lower vector shuffles using bit rotations on XOP/AVX512F targets.
This patch lowers to uniform ISD:ROTL nodes - ROTR isn't supported by XOP and they are interchangeable for constant values anyway.
There might be cases where targets without ISD:ROTL support would benefit from this (expanding to SRL+SHL+OR), which I'll investigate in a future patch.
REAPPLIED rGe82e17d4d4ca after reversion at rG39eade73a567 - fixed offset matching in matchShuffleAsBitRotate.
As noted on PR44379, we didn't attempt to lower vector shuffles using bit rotations on XOP/AVX512F targets.
This patch lowers to uniform ISD:ROTL nodes - ROTR isn't supported by XOP and they are interchangeable for constant values anyway.
There might be cases where targets without ISD:ROTL support would benefit from this (expanding to SRL+SHL+OR), which I'll investigate in a future patch.
Also, non-AVX512BW targets fail to concatenate 256-bit rotations back to 512-bits (split during shuffle lowering as they don't have v32i16/v64i8 types).
---
Internal shuffle tests indicate theres a bug somewhere that I haven't been able to track down yet.
Fix issue mentioned on rGe82e17d4d4ca - non-AVX512BW targets failed to concatenate 256-bit rotations back to 512-bits (split during shuffle lowering as they don't have v32i16/v64i8 types).
As noted on PR44379, we didn't attempt to lower vector shuffles using bit rotations on XOP/AVX512F targets.
This patch lowers to uniform ISD:ROTL nodes - ROTR isn't supported by XOP and they are interchangeable for constant values anyway.
There might be cases where targets without ISD:ROTL support would benefit from this (expanding to SRL+SHL+OR), which I'll investigate in a future patch.
Also, non-AVX512BW targets fail to concatenate 256-bit rotations back to 512-bits (split during shuffle lowering as they don't have v32i16/v64i8 types).
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a3 with proper LiveIn
declaration, better option handling and more portable testing.
Differential Revision: https://reviews.llvm.org/D68720
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a3 with proper LiveIn
declaration, better option handling and more portable testing.
Differential Revision: https://reviews.llvm.org/D68720
Remove code from LegalizeTypes that allowed this to work.
We were already using BUILD_PAIR for this in some places so this
standardizes on a single way to do this.
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a3 with better option
handling and more portable testing
Differential Revision: https://reviews.llvm.org/D68720
This hasn't been used for years, its original implementation, D35700, had bugs that caused the reversion of most of the code, and since then x86 shuffle lowering/combining has handled most cases and can deal with the rest as well.
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a3 with correct option
flags set.
Differential Revision: https://reviews.llvm.org/D68720
This reverts commit 39f50da2a3.
The -fstack-clash-protection is being passed to the linker too, which
is not intended.
Reverting and fixing that in a later commit.
Summary: This patch introduces an API for MemOp in order to simplify and tighten the client code.
Reviewers: courbet
Subscribers: arsenm, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jsji, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73964
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
Differential Revision: https://reviews.llvm.org/D68720
X86 uses i8 for shift amounts. This code can fail on a 32-bit target
if it runs after type legalization.
This code was copied from AArch64 and modified for X86, but the
shift amount wasn't changed to the correct type for X86.
Fixes PR44812
If we don't have cmov, X87 compares write to FPSW and we need to
move the bits to EFLAGS to use as JCC/SETCC/CMOV conditions.
Previously this was done by calling ConvertCmpIfNecessary in
multiple places which would emit the extra code for the FNSTSW,
a shift, a truncate, and a SAHF instructions. Isel would then
select trunc+X86ISD::CMP to a FUCOM instruction that produces FPSW.
This patch centralizes all of the handling into a single custom
isel handler. This allows us to remove ConvertCmpIfNecessary and
a couple target specific ISD opcodes.
Differential Revision: https://reviews.llvm.org/D73863
Same for any_extend though we don't have coverage for that.
The test changes are because isel didn't check one use of the
setcc_carry. So in isel we would end up with two different
sized setcc_carry instructions. And since it clobbers
the flags we would need to recreate the flags for the second
instruction.
This code handles additional uses by truncating the new wide
setcc_carry back to the original size for those uses.
lrint/llrint are defined as rounding using the current rounding
mode. Numbers that can't be converted raise FE_INVALID and an
implementation defined value is returned. They may also write to
errno.
I believe this means we can use cvtss2si/cvtsd2si or fist to
convert as long as -fno-math-errno is passed on the command line.
Clang will leave them as libcalls if errno is enabled so they
won't become ISD::LRINT/LLRINT in SelectionDAG.
For 64-bit results on a 32-bit target we can't use cvtss2si/cvtsd2si
but we can use fist since it can write to a 64-bit memory location.
Though maybe we could consider using vcvtps2qq/vcvtpd2qq on avx512dq
targets?
gcc also does this optimization.
I think we might be able to do this with STRICT_LRINT/LLRINT as
well, but I've left that for future work.
Differential Revision: https://reviews.llvm.org/D73859
The CATCHPAD node mostly existed to be selected into the EH_RESTORE
instruction, which sets the frame back up when 32-bit Windows exceptions
return to the parent function. However, creating this MachineInstr early
increases the risk that other passes will come along and insert
instructions that use the stack before ESP and EBP are restored. That
happened in PR44697.
Instead of representing these in the instruction stream early, delay it
until PEI. Mark the blocks where this needs to happen as EHPads, but not
funclet entry blocks. Passes after PEI have to be careful not to hoist
instructions that can use stack across frame setup instructions, so this
should be relatively reliable.
Fixes PR44697
Reviewed By: hans
Differential Revision: https://reviews.llvm.org/D73752
This time with correct types for the data result from the SUB.
Original commit message:
Our normal lowering for ISD::SETCC uses X86ISD::SUB to enable
CSE unless the RHS is 0. optimizeCompareInstr called by the peephole
pass can turn subs with unused results into cmps to clean this up.
This commit makes other places that create X86ISD::CMP have the
same behavior.
This code matches (zext (trunc (setcc_carry))) -> (and (setcc_carry), 1)
but the code never checks what type we're truncating too. An and
mask of 1 would only make sense if the trunc was to MVT::i1, but
we didn't check for that.
I believe this code is a leftover from when i1 was a legal type.
Our normal lowering for ISD::SETCC uses X86ISD::SUB to enable
CSE unless the RHS is 0. optimizeCompareInstr called by the peephole
pass can turn subs with unused results into cmps to clean this up.
This commit makes other places that create X86ISD::CMP have the
same behavior.
We were creating two with different operand orders, and then only
using one of them.
Instead just swap the operands when needed and create a single node.
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: arsenm, dschuff, jyknight, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73885
We only need to call this on floating point comparisons. In this
case these are known to be integer compares. One of them even
has a SUB opcode instead of CMP.
Summary: This is a first step before changing the types to llvm::Align and introduce functions to ease client code.
Reviewers: courbet
Subscribers: arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73785
ISD::FROUND is defined to round to nearest with ties rounding
away from 0. This mode isn't supported in hardware on X86.
But as long as we aren't compiling with trapping math, we can
emulate this with floor(X + copysign(nextafter(0.5, 0.0), X)).
We have to use nextafter to avoid some corner cases that adding
0.5 would have. For example, if X is nextafter(0.5, 0.0) it should
round to 0.0, but adding 0.5 would need one extra bit of mantissa
than can be stored so it rounds to 1.0. Adding nextafter(0.5, 0.0)
instead will just increase the exponent by 1 and leave the mantissa
as all 1s. This would be nextafter(1.0, 0.0) which will floor to 0.0.
Techically this requires -fno-trapping-math which isn't our default.
But if we care about exceptions we should be using constrained
intrinsics. Constrained intrinsics would use STRICT_FROUND which
won't go through this code.
Fixes PR42195.
Differential Revision: https://reviews.llvm.org/D73607
This code needs to map from the FPCW 2-bit encoding for rounding mode to the 2-bit encoding defined for FLT_ROUNDS. The previous implementation did some clever swapping of bits and adding 1 modulo 4 to do the mapping.
This patch instead uses an 8-bit immediate as a lookup table of four 2-bit values. Then we use the 2-bit FPCW encoding to index the lookup table by using a right shift and an AND. This requires extracting the 2-bit value from FPCW and multipying it by 2 to make it usable as a shift amount. But still results in less code.
Differential Revision: https://reviews.llvm.org/D73599
Summary: X86 has instructions to calculate fma and fneg at the same time. But we combine the fneg and fma only when fneg is the source operand under strict FP.
Reviewers: craig.topper, andrew.w.kaylor, uweigand, RKSimon, LiuChen3
Subscribers: LuoYuanke, llvm-commits, cfe-commits, jdoerfert, hiraditya
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72824
Pull out combineTargetShuffle code added in rG3fd5d1c6e7db into a helper function and extend it to handle shufps(shufps(load(),x),y) and shufps(y,shufps(load(),x)) cases as well.
Every case in the switch had a string version of themselves. Two
of them had a typo that used : instead of ::
By using a macro we can automate the string creation and avoid
the possibility of typos like this.
This is similar to what is done on the AMDGPU target.
I believe for STRICT_FP I need to use a STRICT_FP_EXTEND for the extending to f80 for returning f32/f64 in 32-bit mode when SSE is enabled. The STRICT_FP_EXTEND node requires a Chain. I need to get that node onto the chain before any CopyToRegs are emitted. This is because all the CopyToRegs are glued and chained together. So I can't put a STRICT_FP_EXTEND on the chain between the glued nodes without also glueing the STRICT_ FP_EXTEND.
This patch moves all the extend creation to a first pass and then creates the copytoregs and fills out RetOps in a second pass.
Differential Revision: https://reviews.llvm.org/D72665
Summary:
This is a follow up on https://reviews.llvm.org/D71473#inline-647262.
There's a caveat here that `Align(1)` relies on the compiler understanding of `Log2_64` implementation to produce good code. One could use `Align()` as a replacement but I believe it is less clear that the alignment is one in that case.
Reviewers: xbolva00, courbet, bollu
Subscribers: arsenm, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, Jim, kerbowa, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73099
Craig Topper