[PATCH] D134282: [CGP] Add generic TargetLowering::shouldAlignPointerArgs() implementation

[Alexander Richardson via Phabricator via llvm-commits]

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This function was added for ARM targets, but aligning global/stack pointer
arguments passed to memcpy/memmove/memset can improve code size and
performance for all targets that don't have fast unaligned accesses.
This adds a generic implementation that adjusts the alignment to pointer
size if unaligned accesses are slow.
Review D134168 <https://reviews.llvm.org/D134168> suggests that this significantly improves performance on
synthetic benchmarks such as Dhrystone on RV32 as it avoids memcpy() calls.

TODO: It should also improve performance for other benchmarks, would be
good to get some numbers.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D134282

Files:
  llvm/include/llvm/CodeGen/TargetLowering.h
  llvm/lib/CodeGen/CodeGenPrepare.cpp
  llvm/lib/CodeGen/TargetLoweringBase.cpp
  llvm/lib/Target/ARM/ARMISelLowering.cpp
  llvm/lib/Target/ARM/ARMISelLowering.h
  llvm/test/CodeGen/BPF/rodata_5.ll
  llvm/test/CodeGen/RISCV/memcpy-inline.ll
  llvm/test/CodeGen/WebAssembly/bulk-memory64.ll
  llvm/test/CodeGen/X86/GlobalISel/x86_64-irtranslator-struct-return.ll
  llvm/test/CodeGen/X86/load-local-v4i5.ll
  llvm/test/Transforms/CodeGenPrepare/RISCV/adjust-memintrin-alignment.ll

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