This patch extends D107904's introduction of vector-predicated (VP)
operation legalization to include vector splitting.
When the result of a binary VP operation needs splitting, all of its
operands are split in kind. The two operands and the mask are split as
usual, and the vector-length parameter EVL is "split" such that the low
and high halves each execute the correct number of elements.
Tests have been added to the RISC-V target to show splitting several
scenarios for fixed- and scalable-vector types. Without support for
`umax` (e.g. in the `B` extension) the generated code starts to branch.
Ideally a cost model would prevent their insertion in the first place.
Through these tests many opportunities for better codegen can be seen:
combining known-undef VP operations and for constant-folding operations
on `ISD::VSCALE`, to name but a few.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D107957
I believe, the profitability reasoning here is correct
"sub"reg is already located within the 0'th subreg of wider reg,
so if we have suvector insertion at index 0 into undef,
then it's always free do to.
After this, D109065 finally avoids the regression in D108382.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D109074
This adds lowering of the llvm.fptosi.sat and llvm.fptoui.sat intinsics,
selecting a VCVT instruction which under MVE will inherently perform the
saturate.
Differential Revision: https://reviews.llvm.org/D107865
Currently, the truncate selection dag node is expanded as a bitwise AND plus compare to 1. This change enables scalar comparison in the pattern if the truncate node is uniform.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D108925
With opaque pointers, no actual bitcasts will be present. Instead,
there will be a mismatch between the call FunctionType and the
function ValueType. Change the code to collect CallBases
specifically (rather than general Uses) and compare these types.
RAUW is no longer performed, as there would no longer be any
bitcasts that can be RAUWd.
Differential Revision: https://reviews.llvm.org/D108880
If the true and false values are the same, we don't need a SELECT_CC.
This would normally be folded before a select is legalized to
select_cc. The test case exploits the late legalization of vscale
to trigger a case where they become identical after legalization.
This works around an issue found on a test case in D107957. In that
case the true/false values were both eventually 0 and the select was
used by a vector AVL operand. The select_cc got expanded to control
flow and a phi, but the phi inputs were both copies from X0. MachineIR
optimizations simplified this to a single copy from X0 going into the
vector instruction. This became the input of a vsetvli after vsetvli
insertion. Then register coalescing folded the copy into the vsetvli.
X0 as the source of a vsetvli is a special encoding and should not be
created by coalesing. We need to fix our vsetvli handling to make sure
this can never happen any other way, but removing the unneeded select
is still a worthwhile optimization.
Previously extra wide v4f32 to v4f64 extending loads would be legalized to v2f32
to v2f64 extending loads, which would then be scalarized by legalization. (v2f32
to v2f64 extending loads not produced by legalization were already being emitted
correctly.) Instead, mark v2f32 to v2f64 extending loads as legal and explicitly
lower them using promote_low. This regresses the addressing modes supported for
the extloads not produced by legalization, but that's a fine trade off for now.
Differential Revision: https://reviews.llvm.org/D108496
When we have an any-extending FPR bank load, none of the tablegen patterns
match and we fall back to the C++ selector. Like with the truncating stores
that were fixed recently, the C++ wasn't able to handle it and ended up
generating invalid copies between different size regclasses.
This change adds handling for this case, splitting the load into a regular
load and a SUBREG_TO_REG to extend it into the original wide destination reg.
While initializing the LDS pointers within entry basic block of kernel(s), make
sure that the entry basic block is split after alloca instructions.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D108971
When RA eliminated a dead def it can either immediately delete
the instruction itself or replace it with KILL to defer the
actual removal. If this instruction has a virtual register use
killing the register it will shrink the LI of the use. However,
if the LI covers the instruction and extends beyond it the
shrink will not happen. In fact that is impossible to shrink
such use because of the KILL still using it.
If later the LI of the use will be split at the KILL and the
KILL itself is eliminated after that point the new live segment
ends up at an invalid slot index.
This extremely rare condition was hit after D106408 which has
enabled rematerialization of such instructions. The replacement
with KILL is only done for rematerialized defs which became dead
and such rematerialization did not generally happen before.
The patch deletes an instruction immediately if it is a result
of rematerialization and has such use. An alternative would be
to prohibit a split at a KILL instruction, but it looks like it
is better to split a live range rather then keeping a killed
instruction just in case it can be rematerialized further.
Fixes PR51655.
Differential Revision: https://reviews.llvm.org/D108951
Similar to D108842, D108844, D108926, D108928, and D108936.
__has_builtin(builtin_mul_overflow) returns true for 32b RISCV targets,
but Clang is deferring to compiler RT when encountering long long types.
If the semantics of __has_builtin mean "the compiler resolves these,
always" then we shouldn't conditionally emit a libcall.
Link: https://bugs.llvm.org/show_bug.cgi?id=28629
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D108939
Similar to D108842, D108844, and D108926.
__has_builtin(builtin_mul_overflow) returns true for 32b PPC targets,
but Clang is deferring to compiler RT when encountering long long types.
This breaks ppc44x_defconfig + CONFIG_BLK_DEV_NBD=y builds of the Linux
kernel that are using builtin_mul_overflow with these types for these
targets.
If the semantics of __has_builtin mean "the compiler resolves these,
always" then we shouldn't conditionally emit a libcall.
This will still need to be worked around in the Linux kernel in order to
continue to support these builds of the Linux kernel for this
target with older releases of clang.
Link: https://bugs.llvm.org/show_bug.cgi?id=28629
Link: https://github.com/ClangBuiltLinux/linux/issues/1438
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D108936
As noted in the comments in D108227, using G_FPTOSI produces wrong results for
G_ISNAN. Drop the G_FPTOSI and perform the operation on integer types.
Elsewhere in LLVM, a bitcast would be the appropriate choice (as it is in SDAG).
GlobalISel does not distinguish between integer and FP types, so a bitcast would
be meaningless here.
This is an improvement over D107852. We don't need to enumerate specific
function names; we can just check for `noreturn` attribute. This also
requires us to make sure `__resumeExeption` and `emscripten_longjmp`
have `noreturn` attribute too; one of them is a JS function and the
other calls a JS function so Clang does not have a way to deduce they
don't return.
This is effectively NFC, because I'm not sure if there is an additional
case this case covers; if we add a custom function call that has
`noreturn` attribute, it will be processed within the SjLj handling and
turned into `__invoke` call. So this really applies to some special
functions like `emscripten_longjmp`.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D108955
There are three kinds of "rethrowing" BBs in this pass:
1. In Emscripten SjLj, after a possibly longjmping function call, we
check if the thrown longjmp corresponds to one of setjmps within the
current function. If not, we rethrow the longjmp by calling
`emscripten_longjmp`.
2. In Emscripten EH, after a possibly throwing function call, we check
if the thrown exception corresponds to the current `catch` clauses.
If not, we rethrow the exception by calling `__resumeException`.
3. When both Emscripten EH and SjLj are used, when we check for an
exception after a possibly throwing function call, it is possible
that we get not an exception but a longjmp. In this case, we
shouldn't swallow it; we should rethrow the longjmp by calling
`emscripten_longjmp`.
4. When both Emscripten EH and SjLj are used, when we check for a
longjmp after a possibly longjmping function call, it is possible
that we get not a longjmp but an exception. In this case, we
shouldn't swallot it; we should rethrow the exception by calling
`__resumeException`.
Case 1 is in Emscripten SjLj, 2 is in Emscripten EH, and 3 and 4 are
relevant when both Emscripten EH and SjLj are used. 3 and 4 were first
implemented in D106525.
We create BBs for 1, 3, and 4 in this pass. We create those BBs for
every throwing/longjmping function call, along with other BBs that
contain condition checks. What this CL does is to create a single BB
within a function for each of 1, 3, and 4 cases. These BBs are exiting
BBs in the function and thus don't have successors, so easy to be shared
between calls.
The names of BBs created are:
Case 1: `call.em.longjmp`
Case 3: `rethrow.exn`
Case 4: `rethrow.longjmp`
For the case 2 we don't currently create BBs; we only replace the
existing `resume` instruction with `call @__resumeException`. And Clang
already creates only a single `resume` BB per function and reuses it,
so we don't need to optimize this case.
Not sure what are good benchmarks for EH/SjLj, but this decreases the
size of the object file for `grfmt_jpeg.bc` (presumably from opencv) we
got from one of our users by 8.9%. Even after running `wasm-opt -O4` on
them, there is still 4.8% improvement.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D108945
In D87099, the mangler learned to quote export directives that contain
special characters. Only alhpanumerical characters as well as
'_', '$', '.' and '@' were exmpt from this quoting. However, at least
binutils considers an unquoted '.' to be syntax and object files
containing such symbols will cause errors during linking. Fix that
by removing '.' from the list of allowed exemptions.
Differential Revision: https://reviews.llvm.org/D100359
Instead of splitting off the fp16 to float conversion and generating
a libcall, we should split the operation into fp16 to float and float
to integer operations. This will allow the float to integer conversion
to go through any custom handling the target has. If the target doesn't
have custom handling then we should come back to ExpandIntRes_FP_TO_SINT/
ExpandIntRes_FP_TO_UINT automatically to create the libcall.
This avoids generating libcalls on 32-bit X86. These library functions may
not exist in 32-bit libgcc. At least for LLVM, we never generate them when
hardware floating point instructions are available.
Differential Revision: https://reviews.llvm.org/D108933
When expanding a SMULFIXSAT ISD node (usually originating from
a smul.fix.sat intrinsic) we've applied some optimizations for
the special case when the scale is zero. The idea has been that
it would be cheaper to use an SMULO instruction (if legal) to
perform the multiplication and at the same time detect any overflow.
And in case of overflow we could use some SELECT:s to replace the
result with the saturated min/max value. The only tricky part
is to know if we overflowed on the min or max value, i.e. if the
product is positive or negative. Unfortunately the implementation
has been incorrect as it has looked at the product returned by the
SMULO to determine the sign of the product. In case of overflow that
product is truncated and won't give us the correct sign bit.
This patch is adding an extra XOR of the multiplication operands,
which is used to determine the sign of the non truncated product.
This patch fixes PR51677.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D108938
It looks like this array was missed in 4276d4a8d08b7640eb57cabf6988a5cf65b228b6
Fixed tests that expected `elements` to be empty or depeneded on the order of the empty DINode.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D107024
The check for whether a rotate is possible occurs before the
memory legality checks for the integer type. So it's possible we
decide we can use a rotate, but then fail the legality checks. If
that happens we should not fall back to a vector type. This triggers
an assertion in the rotate handling when it finds a vector type
instead of an integer type.
In theory we could use a shufflevector in place of the rotate, but
right now I'd just like to fix the crash.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D108839
PowerPC can model these instructions, so we don't need this flag set.
Reviewed By: shchenz, jsji
Differential Revision: https://reviews.llvm.org/D71983
A new kind BTF_KIND_TAG is added to .BTF to encode
btf_tag attributes. The format looks like
CommonType.name : attribute string
CommonType.type : attached to a struct/union/func/var.
CommonType.info : encoding BTF_KIND_TAG
kflag == 1 to indicate the attribute is
for CommonType.type, or kflag == 0
for struct/union member or func argument.
one uint32_t : to encode which member/argument starting from 0.
If one particular type or member/argument has more than one attribute,
multiple BTF_KIND_TAG will be generated.
Differential Revision: https://reviews.llvm.org/D106622
If the icmp is in a different block, then the register for the icmp
operand may not be initialized, as it nominally does not have
cross-block uses. Add a check that the icmp is in the same block
as the branch, which should be the common case.
This matches what X86 FastISel does:
5b6b090cf2/llvm/lib/Target/X86/X86FastISel.cpp (L1648)
The "not" transform that could have a similar issue is dropped
entirely, because it is currently dead: The incoming value is
a branch or select condition of type i1, but this code requires
an i32 to trigger.
Fixes https://bugs.llvm.org/show_bug.cgi?id=51651.
Differential Revision: https://reviews.llvm.org/D108840
__has_builtin(__builtin_mul_overflow) returns true for 32b MIPS targets,
but Clang is deferring to compiler RT when encountering `long long`
types. This breaks sanitizer builds of the Linux kernel that are using
__builtin_mul_overflow with these types for these targets.
If the semantics of __has_builtin mean "the compiler resolves these,
always" then we shouldn't conditionally emit a libcall.
This will still need to be worked around in the Linux kernel in order to
continue to support malta_defconfig builds of the Linux kernel for this
target with older releases of clang.
Link: https://bugs.llvm.org/show_bug.cgi?id=28629
Link: https://github.com/ClangBuiltLinux/linux/issues/1438
Reviewed By: rengolin
Differential Revision: https://reviews.llvm.org/D108844
__has_builtin(__builtin_mul_overflow) returns true for 32b ARM targets,
but Clang is deferring to compiler RT when encountering `long long`
types. This breaks sanitizer builds of the Linux kernel that are using
__builtin_mul_overflow with these types for these targets.
If the semantics of __has_builtin mean "the compiler resolves these,
always" then we shouldn't conditionally emit a libcall.
This will still need to be worked around in the Linux kernel in order to
continue to support allmodconfig builds of the Linux kernel for this
target with older releases of clang.
Link: https://bugs.llvm.org/show_bug.cgi?id=28629
Link: https://github.com/ClangBuiltLinux/linux/issues/1438
Reviewed By: rengolin
Differential Revision: https://reviews.llvm.org/D108842
This fixes another reproducer from https://bugs.llvm.org/show_bug.cgi?id=51615
And again, the fix lies not in the code added in D105390
In this case, we completely don't check that the "broadcast-from-mem" we create
can actually fold the load. In this case, it's operand was not a load at all:
```
Combining: t16: v8i32 = vector_shuffle<0,u,u,u,0,u,u,u> t14, undef:v8i32
Creating new node: t29: i32 = undef
RepeatLoad:
t8: i32 = truncate t7
t7: i64 = extract_vector_elt t5, Constant:i64<0>
t5: v2i64,ch = load<(load (s128) from %ir.arg)> t0, t2, undef:i64
t2: i64,ch = CopyFromReg t0, Register:i64 %0
t1: i64 = Register %0
t4: i64 = undef
t3: i64 = Constant<0>
Combining: t15: v8i32 = undef
```
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D108821
This adds an ELEN limit for fixed length vectors. This will scalarize
any elements larger than this. It will also disable some fractional
LMULs. For example, if ELEN=32 then mf8 becomes illegal, i32/f32
vectors can't use any fractional LMULs, i16/f16 can only use mf2,
and i8 can use mf2 and mf4.
We may also need something for the scalable vectors, but that has
interactions with the intrinsics and we can't scalarize a scalable
vector.
Longer term this should come from one of the Zve* features
For vectors that are exactly equal to getMaxSVEVectorSizeInBits, just use
AArch64SVEPredPattern::all, which can enable the use of unpredicated ptrue when available.
TestPlan: check-llvm
Differential Revision: https://reviews.llvm.org/D108706
x86_fp80 format allows values that do not fit any of IEEE-754 category.
Previously they were recognized by intrinsic __builtin_isnan as NaNs.
Now this intrinsic is implemented using instruction FXAM, which
distinguish between NaNs and unsupported values. It can make some
programs behave differently.
As a solution, this fix changes lowering of the intrinsic. If floating
point exceptions are ignored, llvm.isnan is lowered into unordered
comparison, as __buildtin_isnan was implemented earlier. In strictfp
functions the intrinsic is lowered using FXAM, which does not raise
exceptions even for signaling NaN, as required by IEEE-754 and C
standards.
Differential Revision: https://reviews.llvm.org/D108037
Without this change only the preferred fusion opcode is tested
when attempting to combine FMA operations.
If both FMA and FMAD are available then FMA ops formed prior to
legalization will not be merged post legalization as FMAD becomes
the preferred fusion opcode.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D108619
