[Bug rtl-optimization/113597] [14 Regression] aarch64: Significant code quality regression since r14-8346-ga98d5130a6dcff

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113597

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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  Attachment #57214|0                           |1
        is obsolete|                            |

--- Comment #13 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 57252
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57252&action=edit
prototype fix

Note when I extended the patch to also cover a PARM_DECL base to extent
coverage I see

FAIL: gcc.dg/torture/pr70421.c   -O1  execution test
FAIL: gcc.dg/torture/pr70421.c   -O2  execution test
FAIL: gcc.dg/torture/pr70421.c   -O3 -g  execution test
FAIL: gcc.dg/torture/pr70421.c   -Os  execution test
FAIL: gcc.dg/torture/pr70421.c   -O2 -flto -fno-use-linker-plugin
-flto-partitio
n=none  execution test
FAIL: gcc.dg/torture/pr70421.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-obje
cts  execution test

on x86_64.  It seems that arg_base_value isn't the correct thing to use
but it eventually should have been unique_base_value (UNIQUE_BASE_VALUE_ARGP)?
I'm not sure whether all the different unique base values mean we'll not
be able to derive exactly those classes from MEM_EXPRs.