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[lld] [ELF/AArch64] Simplify AArch64 isRelRelative
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Authored by zatrazz on Mar 10 2016, 1:34 AM.

Details

Reviewers
ruiu
rafael
Summary

This patch simplifies the isRelRelative for AArch64 to just handle the
cases where it is not relative, instead of list all the relocations
that is. It also adds more testing for shared objects creation.

Diff Detail

Event Timeline

zatrazz updated this revision to Diff 50247.Mar 10 2016, 1:34 AM
zatrazz retitled this revision from to [lld] [ELF/AArch64] Simplify AArch64 isRelRelative.
zatrazz updated this object.
zatrazz added reviewers: ruiu, rafael.
zatrazz set the repository for this revision to rL LLVM.
zatrazz added a project: lld.
zatrazz added subscribers: llvm-commits, grimar, rengolin, emaste.
rafael edited edge metadata.Mar 10 2016, 8:43 AM
rafael added a subscriber: rafael.
bool AArch64TargetInfo::isRelRelative(uint32_t Type) const {
  • return Type == R_AARCH64_PREL32 || Type == R_AARCH64_ADR_PREL_PG_HI21 ||
  • Type == R_AARCH64_LDST8_ABS_LO12_NC ||
  • Type == R_AARCH64_LDST32_ABS_LO12_NC ||
  • Type == R_AARCH64_LDST64_ABS_LO12_NC ||
  • Type == R_AARCH64_ADD_ABS_LO12_NC || Type == R_AARCH64_CALL26; + switch (Type) { + default: + return true; + case R_AARCH64_ABS64: + case R_AARCH64_ADR_GOT_PAGE: + case R_AARCH64_LD64_GOT_LO12_NC: + return !Config->Shared;

I don't think this makes sense. The relocations have different
definitions depending on -shared? If not, how come they become
relative or not depending on -shared?

Cheers,
Rafael

bool AArch64TargetInfo::isRelRelative(uint32_t Type) const {
  • return Type == R_AARCH64_PREL32 || Type == R_AARCH64_ADR_PREL_PG_HI21 ||
  • Type == R_AARCH64_LDST8_ABS_LO12_NC ||
  • Type == R_AARCH64_LDST32_ABS_LO12_NC ||
  • Type == R_AARCH64_LDST64_ABS_LO12_NC ||
  • Type == R_AARCH64_ADD_ABS_LO12_NC || Type == R_AARCH64_CALL26; + switch (Type) { + default: + return true; + case R_AARCH64_ABS64: + case R_AARCH64_ADR_GOT_PAGE: + case R_AARCH64_LD64_GOT_LO12_NC: + return !Config->Shared;

I don't think this makes sense. The relocations have different
definitions depending on -shared? If not, how come they become
relative or not depending on -shared?

Cheers,
Rafael

They do have different semantics depending if the code is position independent (which it is not only shared, but also PIE executables) and this method is used to define whether we will emit or not a dynamic relocation. If you check, gold is doing pretty much this in its local scan.

zatrazz abandoned this revision.Mar 21 2016, 2:12 PM