MaskRay marked 2 inline comments as done.
MaskRay added a subscriber: bsdjhb.
MaskRay added inline comments.
================
Comment at: llvm/lib/Target/RISCV/RISCVExpandPseudoInsts.cpp:680
+ if (MF->getTarget().isPositionIndependent() ||
+ MF->getTarget().getCodeModel() != CodeModel::Small) {
const auto &STI = MF->getSubtarget<RISCVSubtarget>();
----------------
jrtc27 wrote:
> This is confusing and differs from when you invoke the assembler manually,
> even via the Clang driver with the right code model specified. Any `la`s
> there will be assembled as `AUIPC`/`ADDI`. I am of the view it was a mistake
> to make `la`'s behaviour conditional on PICness and it should have always
> used the GOT, but this is what we have.
> I am of the view it was a mistake to make la's behaviour conditional on
> PICness and it should have always used the GOT, but this is what we have.
I agree with you. `la`'s behavior should not be conditional on PIC. RISC-V
probably should have a GOT relaxation mechanism. See my comment at
https://github.com/riscv/riscv-elf-psabi-doc/issues/126
================
Comment at: llvm/lib/Target/TargetMachine.cpp:192
return false;
+ // RISC-V non-small code models prefer avoiding copy relocations.
+ if (TT.isRISCV() && getCodeModel() != CodeModel::Small)
----------------
jrtc27 wrote:
> Are we sure we want to do this and take the performance hit over GCC due to
> the extra level of indirection on every single extern global access? If this
> is the solution to take for extern weak, I think we should limit it to just
> that and have a separate discussion about non-extern-weak.
I'd like to know more about `-mcmodel=medany -fno-pic`'s use cases. I guess
@bsdjhb's FreeBSD kernel use case can probably be met by `-mcmodel=medany
-fpie`.
I think there is no precedent which differs extern-strong and extern-weak. If
GOT relaxation works, we can make this unconditional.
// RISC-V prefer avoiding copy relocations.
if (TT.isRISCV()
return false;
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D72056/new/
https://reviews.llvm.org/D72056
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