[PATCH] D92293: [RISCVAsmParser] Allow a SymbolRef operand to be a complex expression

[Fangrui Song via Phabricator via llvm-commits]

MaskRay marked 2 inline comments as done.
MaskRay added inline comments.


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Comment at: llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp:1862
+  MCFixup Fixup;
+  if (Expr->evaluateAsRelocatable(Res, nullptr, &Fixup))
+    return Res.getRefKind() == RISCVMCExpr::VK_RISCV_None;
----------------
jrtc27 wrote:
> MaskRay wrote:
> > jrtc27 wrote:
> > > Should we not be passing the assembler pointer? I don't remember when exactly RISC-V needs it, but RISC-V is pickier due to supporting linker relaxation.
> > We don't need it here. Passing the pointer can enable more aggressive constant folding, but this appears to be fine for now.
> Then we might as well? It's lying around in the target streamer's streamer (maybe elsewhere is more accessible too, this area of the MC layer gets a bit twisty-turny-maze).
We can't provide it. MCAsmLayout is constructed in MCAssembler::Finish, a very late stage (and only when MCObjectStreamer is used). The AsmParser code should work for both -filetype=asm and -filetype=obj.

The simplification here makes sense. If we find it overly restrictive in the future, we can consider deleting it (most other targets don't have such rigid checks - but the diagnostics will become worse " operand must be a bare symbol name" -> something in the relocation emission stage


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  https://reviews.llvm.org/D92293/new/

https://reviews.llvm.org/D92293