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* [Bug target/115289] New: PPC: Document the machine constraint 'Y' and make it non-internal @ 2024-05-30 7:27 mpe+gcc at ellerman dot id.au 2024-05-30 14:29 ` [Bug target/115289] " segher at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: mpe+gcc at ellerman dot id.au @ 2024-05-30 7:27 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115289 Bug ID: 115289 Summary: PPC: Document the machine constraint 'Y' and make it non-internal Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: mpe+gcc at ellerman dot id.au Target Milestone: --- Please document the "Y" inline asm constraint for powerpc. It's needed to correctly pass arbitrary pointer arguments to inline asm using a DS-form instruction. The Linux Kernel plans to use the constraint, see: https://lore.kernel.org/linuxppc-dev/20240529123029.146953-1-mpe@ellerman.id.au/ A minimal reproducer for the problem seen in the kernel is below. $ cat test.c struct { long a; long b; short c; char d[8]; } e; void f(void) { unsigned long v = 0; unsigned long *g = (unsigned long *)&e.d; asm goto("std%X0 %1,%0 # put_user\n" : "=m"(*g) : "r"(v) : : out); out: } $ gcc-14 -Wall -nostdinc -O2 -c -o test.o test.c /tmp/ccsSkWJz.s: Assembler messages: /tmp/ccsSkWJz.s:21: Error: operand out of domain (18 is not a multiple of 4) ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/115289] PPC: Document the machine constraint 'Y' and make it non-internal 2024-05-30 7:27 [Bug target/115289] New: PPC: Document the machine constraint 'Y' and make it non-internal mpe+gcc at ellerman dot id.au @ 2024-05-30 14:29 ` segher at gcc dot gnu.org 2024-05-31 16:09 ` segher at gcc dot gnu.org 2024-05-31 16:17 ` segher at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: segher at gcc dot gnu.org @ 2024-05-30 14:29 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115289 Segher Boessenkool <segher at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever confirmed|0 |1 Last reconfirmed| |2024-05-30 --- Comment #1 from Segher Boessenkool <segher at gcc dot gnu.org> --- Yup. Thanks for the report! Note that you usually want "YZ", not just "Y", so that things always work (with just "Y" reloading does not always work). ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/115289] PPC: Document the machine constraint 'Y' and make it non-internal 2024-05-30 7:27 [Bug target/115289] New: PPC: Document the machine constraint 'Y' and make it non-internal mpe+gcc at ellerman dot id.au 2024-05-30 14:29 ` [Bug target/115289] " segher at gcc dot gnu.org @ 2024-05-31 16:09 ` segher at gcc dot gnu.org 2024-05-31 16:17 ` segher at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: segher at gcc dot gnu.org @ 2024-05-31 16:09 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115289 --- Comment #2 from Segher Boessenkool <segher at gcc dot gnu.org> --- Note that the testcase isn't valid C (you cannot validly access an array of char as a long int), but the problem is there anyway. I'll try to write a better testcase. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/115289] PPC: Document the machine constraint 'Y' and make it non-internal 2024-05-30 7:27 [Bug target/115289] New: PPC: Document the machine constraint 'Y' and make it non-internal mpe+gcc at ellerman dot id.au 2024-05-30 14:29 ` [Bug target/115289] " segher at gcc dot gnu.org 2024-05-31 16:09 ` segher at gcc dot gnu.org @ 2024-05-31 16:17 ` segher at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: segher at gcc dot gnu.org @ 2024-05-31 16:17 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115289 --- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> --- This needs backports all the way back to GCC 10 (well, as far back as we can go, anyway :-) ). ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-05-31 16:17 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2024-05-30 7:27 [Bug target/115289] New: PPC: Document the machine constraint 'Y' and make it non-internal mpe+gcc at ellerman dot id.au 2024-05-30 14:29 ` [Bug target/115289] " segher at gcc dot gnu.org 2024-05-31 16:09 ` segher at gcc dot gnu.org 2024-05-31 16:17 ` segher at gcc dot gnu.org
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