[PATCH] D75903: [AArch64][CodeGen] Fixing stack alignment of HFA arguments on AArch64 PCS

[Lucas Prates via Phabricator via llvm-commits]

pratlucas created this revision.
Herald added subscribers: llvm-commits, cfe-commits, danielkiss, hiraditya, kristof.beyls.
Herald added projects: clang, LLVM.
pratlucas added a child revision: D75904: [ARM][CodeGen] Fixing stack alignment of HFA arguments on AArch32 PCS.
pratlucas added reviewers: t.p.northover, rnk, olista01, bogner.

Properly complying with AArch64 PCS on the handling of over-aligned HFA
arguments when those are placed on the stack. AAPCS64 specifies that the
stacked argument address should be rounded up to the Natural Alignment
of the argument before the argument is copied to memory.

Over alignment information extracted from language attributes on clang
was not properly propagated to the backend for those arguments, as it
does not map to the backend's base type alignments. As the standard also
specifies that, when placed in registers, a single FP register should be
allocated for each individual HFA element, type coercion is no suitable
for capturing the alignment constraints.

This patch fixes the alignment of these arguments by capturing their
stack alignment requirements in an IR argument attribute, making sure
this information is available for the calling convention lowering stage.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D75903

Files:
  clang/include/clang/CodeGen/CGFunctionInfo.h
  clang/lib/CodeGen/CGCall.cpp
  clang/lib/CodeGen/TargetInfo.cpp
  clang/test/CodeGen/aarch64-args-hfa.c
  clang/test/CodeGen/arm64-arguments.c
  llvm/docs/LangRef.rst
  llvm/include/llvm/CodeGen/TargetCallingConv.h
  llvm/include/llvm/CodeGen/TargetLowering.h
  llvm/include/llvm/IR/Argument.h
  llvm/include/llvm/IR/Attributes.h
  llvm/include/llvm/IR/Attributes.td
  llvm/include/llvm/IR/Function.h
  llvm/include/llvm/IR/InstrTypes.h
  llvm/lib/AsmParser/LLParser.cpp
  llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
  llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
  llvm/lib/IR/Attributes.cpp
  llvm/lib/IR/Function.cpp
  llvm/lib/IR/Verifier.cpp
  llvm/lib/Target/AArch64/AArch64CallingConvention.cpp
  llvm/test/Bitcode/compatibility.ll
  llvm/test/CodeGen/AArch64/arm64-abi-hfa-args.ll

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