Re: [PATCH v2] [PR100106] Reject unaligned subregs when strict alignment is required

["Maciej W. Rozycki" <macro@orcam.me.uk>]

On Thu, 5 May 2022, Alexandre Oliva via Gcc-patches wrote:

> [PR100106] Reject unaligned subregs when strict alignment is required
> 
> From: Alexandre Oliva <oliva@adacore.com>
> 
> The testcase for pr100106, compiled with optimization for 32-bit
> powerpc -mcpu=604 with -mstrict-align expands the initialization of a
> union from a float _Complex value into a load from an SCmode
> constant pool entry, aligned to 4 bytes, into a DImode pseudo,
> requiring 8-byte alignment.

 This has regressed building the `alpha-linux-gnu' target, in libada, as 
from commit d6b756447cd5 including GCC 14 and up to current GCC 15 trunk:

during RTL pass: ira
+===========================GNAT BUG DETECTED==============================+
| 15.0.0 20240610 (experimental) (alpha-linux-gnu) GCC error:              |
| in gen_rtx_SUBREG, at emit-rtl.cc:1032                                   |
| Error detected around g-debpoo.adb:1896:8                                |
| Compiling g-debpoo.adb                                                   |
| Please submit a bug report; see https://gcc.gnu.org/bugs/ .              |
| Use a subject line meaningful to you and us to track the bug.            |
| Include the entire contents of this bug box in the report.               |
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+==========================================================================+

I have filed PR #115459.

  Maciej