This change adds support for correctly lowering the `__scoped` Clang
builtins, and corresponding scoped LLVM instructions. These were
previously unconditionally lowered to Device scope, which is possibly incorrect.
Furthermore, the default / implicit scope is changed from Device (an
OpenCL assumption) to AllSvmDevices (aka System), since the SPIR-V BE is not
OpenCL specific / can ingest IR coming from other language front-ends. OpenCL
defaulting to Device scope is now reflected in the front-end handling of atomic
ops, which seems preferable.
This PR contains changes in virtual register processing aimed to improve
correctness of emitted MIR between passes from the perspective of
MachineVerifier. This potentially helps to detect previously missed
flaws in code emission and harden the test suite. As a measure of
correctness and usefulness of this PR we may use a mode with expensive
checks set on, and MachineVerifier reports problems in the test suite.
In order to satisfy Machine Verifier requirements to MIR correctness not
only a rework of usage of virtual registers' types and classes is
required, but also corrections into pre-legalizer and instruction
selection logics. Namely, the following changes are introduced:
* scalar virtual registers have proper bit width,
* detect register class by SPIR-V type,
* add a superclass for id virtual register classes,
* fix Tablegen rules used for instruction selection,
* fixes of minor existed issues (missed flag for proper representation
of a null constant for OpenCL vs. HLSL, wrong usage of integer virtual
registers as a synonym of any non-type virtual register).
Print OpConstant floats as formatted decimal floating points, with
special case exceptions to print infinity and NaN as hexfloats.
This change follows from the fixes in
https://github.com/llvm/llvm-project/pull/66686 to correct how
constant values are printed generally.
Differential Revision: https://reviews.llvm.org/D159376
Previously, the SPIR-V instruction printer was always printing the first
operand of an `OpConstant`'s literal value as one of the fixed operands.
This is incorrect for 64-bit values, where the first operand is actually
the value's lower-order word and should be combined with the following
higher-order word before printing.
This change fixes that issue by waiting to print the last fixed operand
of `OpConstant` instructions until the variadic operands are ready to be
printed, then using `NumFixedOps - 1` as the starting operand index for
the literal value operands.
Depends on D156049
