This patch defines the i1 type as illegal in the X86 backend for AVX512.
For DAG operations on <N x i1> types (build vector, extract vector element, ...) i8 is used, and should be truncated/extended.
This should produce better scalar code for i1 types since GPRs will be used instead of mask registers.
Differential Revision: https://reviews.llvm.org/D32273
llvm-svn: 303421
We've had several bugs(PR32256, PR32241) recently that resulted from usages of AH/BH/CH/DH either before or after a copy to/from a mask register.
This ultimately occurs because we create COPY_TO_REGCLASS with VK1 and GR8. Then in CopyToFromAsymmetricReg in X86InstrInfo we find a 32-bit super register for the GR8 to emit the KMOV with. But as these tests are demonstrating, its possible for the GR8 register to be a high register and we end up doing an accidental extra or insert from bits 15:8.
I think the best way forward is to stop making copies directly between mask registers and GR8/GR16. Instead I think we should restrict to only copies between mask registers and GR32/GR64 and use EXTRACT_SUBREG/INSERT_SUBREG to handle the conversion from GR32 to GR16/8 or vice versa.
Unfortunately, this complicates fastisel a bit more now to create the subreg extracts where we used to create GR8 copies. We can probably make a helper function to bring down the repitition.
This does result in KMOVD being used for copies when BWI is available because we don't know the original mask register size. This caused a lot of deltas on tests because we have to split the checks for KMOVD vs KMOVW based on BWI.
Differential Revision: https://reviews.llvm.org/D30968
llvm-svn: 298928
select Cond, C +/- 1, C --> add(ext Cond), C -- with a target hook.
This is part of the ongoing process to obsolete D24480. The motivation is to
canonicalize to select IR in InstCombine whenever possible, so we need to have a way to
undo that easily in codegen.
PowerPC is an obvious winner for this kind of transform because it has fast and complete
bit-twiddling abilities but generally lousy conditional execution perf (although this might
have changed in recent implementations).
x86 also sees some wins, but the effect is limited because these transforms already mostly
exist in its target-specific combineSelectOfTwoConstants(). The fact that we see any x86
changes just shows that that code is a mess of special-case holes. We may be able to remove
some of that logic now.
My guess is that other targets will want to enable this hook for most cases. The likely
follow-ups would be to add value type and/or the constants themselves as parameters for the
hook. As the tests in select_const.ll show, we can transform any select-of-constants to
math/logic, but the general transform for any 2 constants needs one more instruction
(multiply or 'and').
ARM is one target that I think may not want this for most cases. I see infinite loops there
because it wants to use selects to enable conditionally executed instructions.
Differential Revision: https://reviews.llvm.org/D30537
llvm-svn: 296977
r289653 added a case where `vselect <cond> <vector1> <all-zeros>`
is transformed to:
`vselect xor(cond, DAG.getConstant(1, DL, CondVT) <all-zeros> <vector1>`
This was not aimed to catch cases where Cond is not a vXi1
mask but it does. Moreover, when Cond type is VxiN (N > 1)
then xor(cond, DAG.getConstant(1, DL, CondVT) != NOT(cond).
This patch changes the above to xor with allones, and avoids
entering the case for non-mask Conds.
llvm-svn: 291745
This fixes selection of KANDN instructions and allows us to remove an extra set of patterns for KNOT and KXNOR.
Reviewers: delena, igorb
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26134
llvm-svn: 285878
Summary:
In the case where of 'select i1 , f32, f32' or select i1, f64, f64 prefer lowering to masked-moves over branches.
Fixes pr30561
Reviewers: igorb, aymanmus, delena
Differential Revision: https://reviews.llvm.org/D25310
llvm-svn: 285196
Previously we were extending to copying the whole ZMM register. The register allocator shouldn't use XMM16-31 or YMM16-31 in this configuration as the instructions to spill them aren't available.
llvm-svn: 280648
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
Optimized lowering of BITCAST node. The BITCAST node can be replaced with COPY_TO_REG instead of KMOV.
It allows to suppress two opposite BITCAST operations and avoid redundant "movs".
Differential Revision: https://reviews.llvm.org/D23247
llvm-svn: 277958
I'm not convinced the patterns for the rm_Int was correct anyway. It had a tied source that should't exist for the unmasked version. The load form of MOVSS always zeros the most significant bits. I've left the patterns off the masked load instructions as I'm not sure what the correct pattern should be and we don't have any tests currently. Nor do we implement masked scalar load intrinsics in clang currently.
llvm-svn: 277098
An identity COPY like this:
%AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.
Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).
llvm-svn: 274952
This re-applies r268760, reverted in r268794.
Fixes http://llvm.org/PR27670
The original imp-defs assertion was way overzealous: forward all
implicit operands, except imp-defs of the new super-reg def (r268787
for GR64, but also possible for GR16->GR32), or imp-uses of the new
super-reg use.
While there, mark the source use as Undef, and add an imp-use of the
old source reg: that should cover any case of dead super-regs.
At the stage the pass runs, flags are unlikely to matter anyway;
still, let's be as correct as possible.
Also add MIR tests for the various interesting cases.
Original commit message:
Codesize is less (16) or equal (8), and we avoid partial
dependencies.
Differential Revision: http://reviews.llvm.org/D19999
llvm-svn: 268831
xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B)) was only being combined at the AfterLegalizeTypes stage, this patch permits the combine to occur anytime before then as well.
The main aim with this to improve the ability to recognise bitmasks that can be converted to shuffles.
I had to modify a number of AVX512 mask tests as the basic bitcast to/from scalar pattern was being stripped out, preventing testing of the mmask bitops. By replacing the bitcasts with loads we can get almost the same result.
Differential Revision: http://reviews.llvm.org/D18944
llvm-svn: 265998
fixed extract-insert i1 element,
load i1, zextload i1 should be with "and $1, %reg" to prevent loading garbage.
added a bunch of new tests.
llvm-svn: 237793
"[x86] Simplify vector selection if condition value type matches vselect value type and true value is all ones or false value is all zeros."
llvm-svn: 221028
This transformation worked if selector is produced by SETCC, however SETCC is needed only if we consider to swap operands. So I replaced SETCC check for this case.
Added tests for vselect of <X x i1> values.
llvm-svn: 220777
Added scalar compare VCMPSS, VCMPSD.
Implemented LowerSELECT for scalar FP operations.
I replaced FSETCCss, FSETCCsd with one node type FSETCCs.
Node extract_vector_elt(v16i1/v8i1, idx) returns an element of type i1.
llvm-svn: 197384
Guy Blank