OK.
Andrew
On 26/05/2023 15:58, Tobias Burnus wrote:
(Update the syntax of the amdgcn commandline option in anticipation of
later patches;
while -m(no-)xnack is in mainline since r12-2396-gaad32a00b7d2b6 (for
PR100208),
-mxsnack (contrary to -msram-ecc) is currently mostly a stub for later
patches
and is documented as such in invoke.texi. Thus, this change should have
no (or
only a minimal) affect on users.)
GCC currently supports for GCN -mxnack / -mno-xnack arguments, matching
+xnack and -xnack when passed to the LLVM linker. However, since V4 the
latter
supports three states, besides on/off there is now also unspecified.
That matches
the semantic of sram(-)ecc, which GCC already implements as 'on'/'off'
and 'any'.
Cf.
https://llvm.org/docs/AMDGPUUsage.html#target-features>> and
https://gcc.gnu.org/onlinedocs/gcc-13.1.0/gcc/AMD-GCN-Options.html>>
The attached patch uses the sram-ecc flag syntax now also for xnack.
Note that currently only 'no' is supported which is ensured via a 'sorry'.
Hence, the default is 'no'. I assume we want to change the default once
XNACK is working - therefore, the documentation does only states the
current
default as a comment.
The changes were picked from the patch "amdgcn: Support XNACK mode" at
-
https://gcc.gnu.org/pipermail/gcc-patches/2022-July/597991.html>> - OG12 0229066ecb24421d48e3e0d56f31c30cc1affdab
- OG13 cbc3dd01de8788587a2b641efcb838058303b5ab
but only includes all changes related to the commandline option changes,
excluding the other changes like those to isns.
It additionally updates invoke.texi (using the wording from -msram-ecc).
(I actually encountered this issue because of the non-updated manual.)
Tested with full bootstrap, regtesting running, but not expecting
surprised.
OK for mainline?
Tobias
PS: For FIJI, "" is passed – that's ensured by NO_XNACK in the ASM_SPEC
and the 'switch' later in output_file_start (unchanged), otherwise 'xnack-'
is used (via the default in gcn.opt for the compiler and via XNACKOPT for
the command line.)
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