[GlobalISel][AArch64] Make FP constraint checks consider possible use/def banks

In a few places in getInstrMapping, we check if use/def instructions for the
instruction we're mapping have floating point constraints.

We can improve this check and reduce the number of copies in GISel-compiled code
if we make a couple observations:

- For a def instruction, it only matters if the def instruction must always
  output a value stored on a FPR

- For a use instruction, it only matters if the use instruction must always
  only take in values stored in FPRs

This adds two new functions:

- onlyUsesFP
- onlyDefinesFP

Then we can use those when we're checking the uses/defs instead.

Without this patch, the load, unmerge, store, and select in the added test
would have unnecessary copies.

Differential Revision: https://reviews.llvm.org/D62426

llvm-svn: 361679
3 files changed
tree: dc9443c3659705d18e2562fe67123bf90f5d17d1
  1. .arcconfig
  2. .clang-format
  3. .clang-tidy
  4. .gitignore
  5. README.md
  6. clang-tools-extra/
  7. clang/
  8. compiler-rt/
  9. debuginfo-tests/
  10. libclc/
  11. libcxx/
  12. libcxxabi/
  13. libunwind/
  14. lld/
  15. lldb/
  16. llgo/
  17. llvm/
  18. openmp/
  19. parallel-libs/
  20. polly/
  21. pstl/
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.