This PR resolves the issue that SPIR-V Backend uses the notion of a
pointer size of the target, most notably, in legalizer code, but
Tablegen instruction selection in SPIR-V Backend doesn't account for a
pointer size of the target. See
https://github.com/llvm/llvm-project/issues/88723 for a detailed
description. There are 3 test cases attached to the PR that reproduced
the issue, when dealing with spirv32-spirv64 differences, and are
working correctly now with this PR.
This PR contains a series of fixes which are to improve type inference
and instruction selection.
Namely, it includes:
* fix OpSelect to support operands of a pointer type, according to the
SPIR-V specification (previously only integer/float/vectors of integer
or float were supported) -- a new test case is added and existing test
case is updated;
* fix TableGen typo's in definition of register classes and introduce a
new reg class that is a vector of pointers;
* fix usage of a machine function context when there is a need to switch
between different machine functions to infer/validate correct types;
* add usage of TypedPointerType instead of PointerType so that later
stages of type inference are able to distinguish pointer types by their
element types, effectively supporting hierarchy of pointer/pointee types
and avoiding more complicated recursive type matching on level of
machine instructions in favor of direct pointer comparison using LLVM's
`Type *` values;
* extracting detailed information about operand types using known type
rules for some llvm instructions (for instance, by deducing PHI's
operand pointee types if PHI's results type was deducted on previous
stages of type inference), and adding correspondent
`Intrinsic::spv_assign_ptr_type` to keep type info along consequent
passes,
* ensure that OpConstantComposite reuses a constant when it's already
created and available in the same machine function -- otherwise there is
a crash while building a dependency graph, the corresponding test case
is attached,
* implement deduction of function's return type for opaque pointers, a
new test case is attached,
* make 'emit intrinsics' a module pass to resolve function return types
over the module -- first types for all functions of the module must be
calculated, and only after that it's feasible to deduct function return
types on this earlier stage of translation.
This PR is to add vector reduction instructions according to
https://llvm.org/docs/GlobalISel/GenericOpcode.html#vector-reduction-operations
and widen in such a way a range of successful supported conversions,
covering new cases of vector reduction instructions which IRTranslator
is unable to resolve.
By legalizing vector reduction instructions we introduce a new
instruction patterns that should be addressed, including patterns that
are delegated to pre-legalize step. To address this problem, a new pass
is added that is to bring newly generated instructions after
legalization to an aspect required by instruction selection.
Expected overheads for existing cases is minimal, because a new pass is
working only with newly introduced instructions, otherwise it's just a
additional code traverse without any actions.
