forked from OSchip/llvm-project
d8399d12cd
Encode them directly as an imm argument to G_INTRINSIC*. Since now intrinsics can now define what parameters are required to be immediates, avoid using registers for them. Intrinsics could potentially want a constant that isn't a legal register type. Also, since G_CONSTANT is subject to CSE and legalization, transforms could potentially obscure the value (and create extra work for the selector). The register bank of a G_CONSTANT is also meaningful, so this could throw off future folding and legalization logic for AMDGPU. This will be much more convenient to work with than needing to call getConstantVRegVal and checking if it may have failed for every constant intrinsic parameter. AMDGPU has quite a lot of intrinsics wth immarg operands, many of which need inspection during lowering. Having to find the value in a register is going to add a lot of boilerplate and waste compile time. SelectionDAG has always provided TargetConstant for constants which should not be legalized or materialized in a register. The distinction between Constant and TargetConstant was somewhat fuzzy, and there was no automatic way to force usage of TargetConstant for certain intrinsic parameters. They were both ultimately ConstantSDNode, and it was inconsistently used. It was quite easy to mis-select an instruction requiring an immediate. For SelectionDAG, start emitting TargetConstant for these arguments, and using timm to match them. Most of the work here is to cleanup target handling of constants. Some targets process intrinsics through intermediate custom nodes, which need to preserve TargetConstant usage to match the intrinsic expectation. Pattern inputs now need to distinguish whether a constant is merely compatible with an operand or whether it is mandatory. The GlobalISelEmitter needs to treat timm as a special case of a leaf node, simlar to MachineBasicBlock operands. This should also enable handling of patterns for some G_* instructions with immediates, like G_FENCE or G_EXTRACT. This does include a workaround for a crash in GlobalISelEmitter when ARM tries to uses "imm" in an output with a "timm" pattern source. llvm-svn: 372285 |
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|---|---|---|
| clang | ||
| clang-tools-extra | ||
| compiler-rt | ||
| debuginfo-tests | ||
| libc | ||
| libclc | ||
| libcxx | ||
| libcxxabi | ||
| libunwind | ||
| lld | ||
| lldb | ||
| llgo | ||
| llvm | ||
| openmp | ||
| parallel-libs | ||
| polly | ||
| pstl | ||
| .arcconfig | ||
| .clang-format | ||
| .clang-tidy | ||
| .git-blame-ignore-revs | ||
| .gitignore | ||
| README.md | ||
README.md
The LLVM Compiler Infrastructure
This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments.