From: Tobias Burnus <tobias@codesourcery.com>
To: <newlib@sourceware.org>
Subject: [PATCH] amdgcn: Use __builtin_gcn_ in libc/machine/amdgcn/getreent.c
Date: Tue, 22 Nov 2022 17:59:38 +0100 [thread overview]
Message-ID: <3975025a-2aa8-910b-1a2e-575c047d5b46@codesourcery.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 560 bytes --]
This patch replaces some more hard-coded register use and
coded internal implementation choices by compiler builtins –
added in this case of GCC 13 (mainline). #if conditions are
used to use the builtins if (and only if) they are available
in the used compiler.
Thanks,
Tobias
-----------------
Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
[-- Attachment #2: 0001-amdgcn-Use-__builtin_gcn_-in-libc-machine-amdgcn-get.patch --]
[-- Type: text/x-patch, Size: 2773 bytes --]
From 611559a7939c29afeda6bb585fb6ba846e5a8b0e Mon Sep 17 00:00:00 2001
From: Tobias Burnus <tobias@codesourcery.com>
Date: Tue, 22 Nov 2022 14:53:48 +0100
Subject: [PATCH] amdgcn: Use __builtin_gcn_ in libc/machine/amdgcn/getreent.c
Call __builtin_gcn_get_stack_limit and __builtin_gcn_first_call_this_thread_p
to reduce dependency on some register/layout assumptions by using the new
GCC mainline (GCC 13) builtins, if they are available. If not, the existing
code is used.
---
newlib/libc/machine/amdgcn/getreent.c | 38 ++++++++++++++++++++-------
1 file changed, 29 insertions(+), 9 deletions(-)
diff --git a/newlib/libc/machine/amdgcn/getreent.c b/newlib/libc/machine/amdgcn/getreent.c
index be7d2edc9..ef731f649 100644
--- a/newlib/libc/machine/amdgcn/getreent.c
+++ b/newlib/libc/machine/amdgcn/getreent.c
@@ -29,22 +29,42 @@ typedef struct hsa_kernel_dispatch_packet_s {
struct _reent *
__getreent (void)
{
- /* Place the reent data at the top of the stack allocation.
- s[0:1] contains a 48-bit private segment base address.
+ /* Place the reent data at the top of the stack allocation. */
+ struct data {
+ int marker;
+ struct _reent reent;
+ } *data;
+
+#if defined(__has_builtin) \
+ && __has_builtin(__builtin_gcn_get_stack_limit) \
+ && __has_builtin(__builtin_gcn_first_call_this_thread_p)
+ unsigned long addr = (((unsigned long) __builtin_gcn_get_stack_limit()
+ - sizeof(struct data)) & ~7);
+ data = (struct data *)addr;
+
+ register long sp asm("s16");
+
+ if (sp >= addr)
+ goto stackoverflow;
+ if (__builtin_gcn_first_call_this_thread_p())
+ {
+ data->marker = 12345;
+ __builtin_memset (&data->reent, 0, sizeof(struct _reent));
+ _REENT_INIT_PTR_ZEROED (&data->reent);
+ }
+ else if (data->marker != 12345)
+ goto stackoverflow;
+#else
+ /* s[0:1] contains a 48-bit private segment base address.
s11 contains the offset to the base of the stack.
s[4:5] contains the dispatch pointer.
-
+
WARNING: this code will break if s[0:1] is ever used for anything! */
const register unsigned long buffer_descriptor asm("s0");
unsigned long private_segment = buffer_descriptor & 0x0000ffffffffffff;
const register unsigned int stack_offset asm("s11");
const register hsa_kernel_dispatch_packet_t *dispatch_ptr asm("s4");
- struct data {
- int marker;
- struct _reent reent;
- } *data;
-
unsigned long stack_base = private_segment + stack_offset;
unsigned long stack_end = stack_base + dispatch_ptr->private_segment_size * 64;
unsigned long addr = (stack_end - sizeof(struct data)) & ~7;
@@ -69,7 +89,7 @@ __getreent (void)
}
else if (data->marker != 12345)
goto stackoverflow;
-
+#endif
return &data->reent;
--
2.25.1
next reply other threads:[~2022-11-22 16:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-22 16:59 Tobias Burnus [this message]
2022-11-22 23:08 ` Jeff Johnston
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:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3975025a-2aa8-910b-1a2e-575c047d5b46@codesourcery.com \
--to=tobias@codesourcery.com \
--cc=newlib@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* 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.
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 read-only IMAP folder(s) and NNTP newsgroup(s).