[PATCH] D107280: [RISCV] Lower extern_weak symbols using the GOT for the medany model

Mon May 15 22:33:01 PDT 2023

MaskRay added inline comments.

================
Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:2736
+      // Extern weak symbols must be addressed indirectly as 0 may not be
+      // within 2GiB of PC. This generates the pattern (PseudoLA sym), which
+      // expands to (ld (addi (auipc %got_pcrel_hi(sym)) %pcrel_lo(auipc))).
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MaskRay wrote:
> jrtc27 wrote:
> > MaskRay wrote:
> > > PseudoLGA
> > Already spotted and fixed :)
> `Extern weak symbols, if unresolved, must be addressed indirectly ...`
> 
> `extern_weak` is the IR representation related to the current module. Another TU may provide a definition. The original sentence is imprecise.
Hmm, better wording may be that "An unresolved undefined weak symbol has a value of zero, which may not be within +-2GiB of PC. Use a GOT-generating code sequence so that the zero address is representable." This may feel verbose. Feel free to simplify.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107280/new/

https://reviews.llvm.org/D107280