Summary:
Use X86ISD::VFPROUND in the instruction isel patterns. Add new patterns for ISD::FP_ROUND to maintain support for fptrunc in IR.
In the process I found a couple duplicate isel patterns which I also deleted in this patch.
Reviewers: RKSimon, spatel
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D56991
llvm-svn: 351762
This causes a couple of changes in the upgrade tests as signed/unsigned eq/ne are equivalent and we constant fold true/false codes, these changes are the same as what we already do for avx512 cmp/ucmp.
Noticed while cleaning up vector integer comparison costs for PR40376.
llvm-svn: 351697
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llvm-svn: 351636
This sends these intrinsics through isel in a much more normal way. This should allow addressing mode matching in isel to make better use of the displacement field.
llvm-svn: 351583
This sends these intrinsics through isel in a much more normal way. This should allow addressing mode matching in isel to make better use of the displacement field.
Differential Revision: https://reviews.llvm.org/D56827
llvm-svn: 351570
Previously we used ISD::SHL and ISD::SRL to represent these in SelectionDAG. ISD::SHL/SRL interpret an out of range shift amount as undefined behavior and will constant fold to undef. While the intrinsics are defined to return 0 for out of range shift amounts. A previous patch added a special node for VPSRAV to produce all sign bits.
This was previously believed safe because undefs frequently get turned into 0 either from the constant pool or a desire to not have a false register dependency. But undef is treated specially in some optimizations. For example, its ignored in detection of vector splats. So if the ISD::SHL/SRL can be constant folded and all of the elements with in bounds shift amounts are the same, we might fold it to single element broadcast from the constant pool. This would not put 0s in the elements with out of bounds shift amounts.
We do have an existing InstCombine optimization to use shl/lshr when the shift amounts are all constant and in bounds. That should prevent some loss of constant folding from this change.
Patch by zhutianyang and Craig Topper
Differential Revision: https://reviews.llvm.org/D56695
llvm-svn: 351381
This cleans up the duplication we have with both intrinsic isel patterns and vselect isel patterns. This should also allow the intrinsics to get SimplifyDemandedBits support for the condition.
I've switched the canonical pattern in isel to use the X86ISD::BLENDV node instead of VSELECT. Since it always seemed weird to move from BLENDV with its relaxed rules on condition bits to VSELECT which has strict rules about all bits of the condition element being the same. Its more correct to go from VSELECT to BLENDV.
Differential Revision: https://reviews.llvm.org/D56771
llvm-svn: 351380
We're trying to have the vXi1 types in IR as much as possible. This prevents the need for bitcasts when the producer of the mask was already a vXi1 value like an icmp. The bitcasts can be subject to code motion and interfere with basic block at a time isel in bad ways.
llvm-svn: 351275
In keeping with our general direction of having the vXi1 type present in IR, this patch converts the mask argument for avx512 gather to vXi1. This can avoid k-register to GPR to k-register transitions late in codegen.
I left the existing intrinsics behind because they have many out of tree users such as ISPC. They generate their own code and don't go through the autoupgrade path which only works for bitcode and ll parsing. Ideally we will get them to migrate to target independent intrinsics, but it might be easier for them to migrate to these new intrinsics.
I'll work on scatter and gatherpf/scatterpf next.
Differential Revision: https://reviews.llvm.org/D56527
llvm-svn: 351234
We can't represent this properly with vselect like we normally do. We also have to update the instruction definition to use a VK2WM mask instead of VK4WM to represent this.
Fixes another case from PR34877
llvm-svn: 351018
We can't represent this properly with vselect like we normally do. We also have to update the instruction definition to use a VK2WM mask instead of VK4WM to represent this.
Fixes another case from PR34877.
llvm-svn: 351017
The 128-bit input produces 64-bits of output and fills the upper 64-bits with 0. The mask only applies to the lower elements. But we can't represent this with a vselect like we normally do.
This also avoids the need to have a special X86ISD::SELECT when avx512bw isn't enabled since vselect v8i16 isn't legal there.
Fixes another instruction for PR34877.
llvm-svn: 350994
We can't properly represent this with a vselect since the upper elements of the result are supposed to be zeroed regardless of the mask.
This also reuses the new nodes even when the result type fits in 128 bits if the input is q/d and the result is w/b since vselect w/b using k-register condition isn't legal without avx512bw. Currently we're doing this even when avx512bw is enabled, but I might change that.
This fixes some of PR34877
llvm-svn: 350985
Migrate the X86 backend from X86ISD opcodes ADDS and SUBS to generic
ISD opcodes SADDSAT and SSUBSAT. This also improves scodegen for
@llvm.sadd.sat() and @llvm.ssub.sat() intrinsics.
This is a followup to D55787 and part of PR40056.
Differential Revision: https://reviews.llvm.org/D55833
llvm-svn: 349520
Both intrinsics do the exact same thing so we really only need one.
Earlier in the 8.0 cycle we changed the signature of this intrinsic without renaming it. But it looks difficult to get the autoupgrade code to allow me to merge the intrinsics and change the signature at the same time. So I've renamed the intrinsic slightly for the new merged intrinsic. I'm skipping autoupgrading from the previous new to 8.0 signature. I've also renamed the subborrow for consistency.
llvm-svn: 348737
Previously we had to take the carry in and add -1 to it to set the carry flag so we could use it with ADC/SBB. But if we know its 0 then we don't need to bother.
This should go a long way towards fixing PR24545.
llvm-svn: 348727
Summary:
As discussed in D52304 / IRC, we now have pattern matching for
'bit extract' in two places - tablegen and `X86DAGToDAGISel`.
There are 4 patterns.
And we will have a problem with `x & (-1 >> (32 - y))` pattern.
* If the mask is one-use, then it is always unfolded into `x << (32 - y) >> (32 - y)` first.
Thus, the existing test coverage is already broken.
* If it is not one-use, then it is not unfolded, and is matched as BZHI.
* If it is not one-use, we will not match it as BEXTR. And if it is one-use, it will have been unfolded already.
So we will either not handle that pattern for BEXTR, or not have test coverage for it.
This is bad.
As discussed with @craig.topper, let's unify this matching, and do everything in `X86DAGToDAGISel`.
Then we will not have code duplication, and will have proper test coverage.
This indeed does not affect any tests, and this is great.
It means that for these two patterns, the `X86DAGToDAGISel` is identical to the tablegen version.
Please review carefully, i'm not fully sure about that intrinsic change, and introduction of the new `X86ISD` opcode.
Reviewers: craig.topper, RKSimon, spatel
Reviewed By: craig.topper
Subscribers: llvm-commits, craig.topper
Differential Revision: https://reviews.llvm.org/D53164
llvm-svn: 344904
We should represent the store directly in IR instead. This gives the middle end a chance to remove it if it can see a load from the same address.
Differential Revision: https://reviews.llvm.org/D51769
llvm-svn: 341677
These are intrinsics for supporting kadd builtins in clang. These builtins are already in gcc to implement intrinsics from icc. Though they are missing from the Intel Intrinsics Guide.
This instruction adds two mask registers together as if they were scalar rather than a vXi1. We might be able to get away with a bitcast to scalar and a normal add instruction, but that would require DAG combine smarts in the backend to recoqnize add+bitcast. For now I'd prefer to go with the easiest implementation so we can get these builtins in to clang with good codegen.
Differential Revision: https://reviews.llvm.org/D51370
llvm-svn: 340869
AVX512 added new versions of these intrinsics that take a rounding mode. If the rounding mode is 4 the new intrinsics are equivalent to the old intrinsics.
The AVX512 intrinsics were being lowered to ISD opcodes, but the legacy SSE intrinsics were left as intrinsics. This resulted in the AVX512 instructions needing separate patterns for the ISD opcodes and the legacy SSE intrinsics.
Now we convert SSE intrinsics and AVX512 intrinsics with rounding mode 4 to the same ISD opcode so we can share the isel patterns.
llvm-svn: 339749
Summary: This revision improves previous version (rL330322) which has been reverted due to crashes.
This is the patch that lowers x86 intrinsics to native IR
in order to enable optimizations. The patch also includes folding
of previously missing saturation patterns so that IR emits the same
machine instructions as the intrinsics.
Reviewers: craig.topper, spatel, RKSimon
Reviewed By: craig.topper
Subscribers: mike.dvoretsky, DavidKreitzer, sroland, llvm-commits
Differential Revision: https://reviews.llvm.org/D46179
llvm-svn: 339650
This converts them to what clang is now using for codegen. Unfortunately, there seem to be a few kinks to work out still. I'll try to address with follow up patches.
llvm-svn: 336871
This allows us to handle masking in a very similar way to the default rounding version that uses llvm.fma.
I had to add new rounding mode CodeGenOnly instructions to support isel when we can't find a movss to grab the upper bits from to use the b_Int instruction.
Fast-isel tests have been updated to match new clang codegen.
We are currently having trouble folding fneg into the new intrinsic. I'm going to correct that in a follow up patch to keep the size of this one down.
A future patch will also remove the old intrinsics.
llvm-svn: 336506
The intrinsics can be implemented with a f32/f64 llvm.fma intrinsic and an insert into a zero vector.
There are a couple regressions here due to SelectionDAG not being able to pull an fneg through an extract_vector_elt. I'm not super worried about this though as InstCombine should be able to do it before we get to SelectionDAG.
llvm-svn: 336416
This upgrades all of the intrinsics to use fneg instructions to convert fma into fmsub/fnmsub/fnmadd/fmsubadd. And uses a select instruction for masking.
This matches how clang uses the intrinsics these days.
llvm-svn: 336409
There's a regression in here due to inability to combine fneg inputs of X86ISD::FMSUB/FNMSUB/FNMADD nodes.
More removals to come, but I wanted to stop and fix the regression that showed up in this first.
llvm-svn: 336303
I think the intrinsics named 'avx512.mask.' should refer to the previous behavior of taking a mask argument in the intrinsic instead of using a 'select' or 'and' instruction in IR to accomplish the masking. This is more consistent with the goal that eventually we will have no intrinsics that have masking builtin. When we reach that goal, we should have no intrinsics named "avx512.mask".
llvm-svn: 335744