[Bug target/128437] [14/15/16/17 Regression] ICE: output_operand: '%&' used without any local dynamic TLS references on x86_64 with -O2 -fPIC -fvisibility=hidden

[ubizjak at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128437

Uroš Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
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           Assignee|unassigned at gcc dot gnu.org      |ubizjak at gmail dot com
             Status|NEW                         |ASSIGNED

--- Comment #14 from Uroš Bizjak <ubizjak at gmail dot com> ---
Created attachment 66089
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=66089&action=edit
Proposed patch

Patch adds ix86_remove_dead_tls_ld_base, called from ix86_reorg (after sched2)
for TARGET_64BIT, which deletes const, nothrow calls whose %rax result is
unused and whose pattern contains UNSPEC_TLS_LD_BASE. Calls whose result is
still used are untouched, so '%&' keeps finding the symbol of the remaining
local-dynamic references.