mailing list of musl libc
 help / color / mirror / code / Atom feed
From: Rich Felker <>
Subject: [musl] Draft riscv64 TLSDESC implementation
Date: Tue, 22 Aug 2023 13:38:21 -0400	[thread overview]
Message-ID: <> (raw)

[-- Attachment #1: Type: text/plain, Size: 509 bytes --]

The psABI work is not finalized, but based on the current status of, I think
the attached is a valid (but untested) implementation of TLSDESC for
riscv64. Actually activating it requires also adding the relocation
type macro to riscv64/reloc.h.

If any rv folks could look it over and make sure I haven't made any
stupid asm errors or missed any obvious optimizations, that would help
to quickly get this merged when the psABI is finalized.


[-- Attachment #2: tlsdesc.s --]
[-- Type: text/plain, Size: 590 bytes --]

.global __tlsdesc_static
.hidden __tlsdesc_static
.type __tlsdesc_static,%function
	ld a0,8(a0)
	jr t0

.global __tlsdesc_dynamic
.hidden __tlsdesc_dynamic
.type __tlsdesc_dynamic,%function
	add sp,sp,-8
	sd t1,(sp)
	sd t2,8(sp)

	ld t2,-8(tp) # t2=dtv

	ld a0,8(a0)  # a0=&{modidx,off}
	ld t1,8(a0)  # t1=off
	ld a0,(a0)   # a0=modidx
	sll a0,a0,3  # a0=8*modidx

	add a0,a0,t2 # a0=dtv+8*modidx
	ld a0,(a0)   # a0=dtv[modidx]
	add a0,a0,t1 # a0=dtv[modidx]+off
	sub a0,a0,tp # a0=dtv[modidx]+off-tp

	ld t1,(sp)
	ld t2,8(sp)
	add sp,sp,8
	jr t0

                 reply	other threads:[~2023-08-22 17:38 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).