[Bug c++/120089] [15/16 regression] GCC miscompiles VK-GL-CTS on aarch64 with -O3

[sjames at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120089

--- Comment #1 from Sam James <sjames at gcc dot gnu.org> ---
$ git diff --word-diff --no-index <(g++ p.cxx -O2 -o p-O2 && ./p-O2) <(g++
p.cxx -O3 -o p-O3 && ./p-O3)
diff --git a/dev/fd/63 b/dev/fd/62
--- a/dev/fd/63
+++ b/dev/fd/62
@@ -1 +1 @@
0 0 0 0 0 0 0 0 0 0 64 191 0 0 96 191 0 0 96 191 0 0 32 191 0 0 32 191 0 0 32
191 0 0 128 190 0 0 96 191 0 0 192 190 0 0 32 191 0 0 0 190 0 0 32 191 0 0 128
62 0 0 96 191 0 0 0 62 0 0 32 191 0 0 192 62 0 0 32 191 0 0 64 63 0 0 96 191 0
0 32 63 0 0 32 191 0 0 [-96 63-]{+192 62+} 0 0 [-32 191-]{+96 63+} 0 0 64 [-191
0 0 192 190-]{+63+} 0 0 [-96 191-]{+32 63+} 0 0 {+32 63+} 0[-190-] 0 {+96 63+}
0[-32 191-] 0 {+96 63+} 0 0 [-190-]{+96 63+} 0 0 128 190 0 0 192 190 0 0 192
190 0 0 0 190 0 0 0 190 0 0 0 190 0 0 128 62 0 0 192 190 0 0 0 62 0 0 0 190 0 0
192 62 0 0 0 190 0 0 64 63 0 0 192 190 0 0 32 63 0 0 0 190 0 0 96 63 0 0 0 190
0 0 64 191 0 0 0 62 0 0 96 191 0 0 192 62 0 0 32 191 0 0 192 62 0 0 128 190 0 0
0 62 0 0 192 190 0 0 192 62 0 0 0 190 0 0 192 62 0 0 128 62 0 0 0 62 0 0 0 62 0
0 192 62 0 0 192 62 0 0 192 62 0 0 64 63 0 0 0 62 0 0 32 63 0 0 192 62 0 0 96
63 0 0 192 62 0 0 64 191 0 0 32 63 0 0 96 191 0 0 96 63 0 0 32 191 0 0 96 63 0
0 128 190 0 0 32 63 0 0 192 190 0 0 96 63 0 0 0 190 0 0 96 63 0 0 128 62 0 0 32
63 0 0 0 62 0 0 96 63 0 0[-192 62-] 0 0[-96 63-] 0 0[-64 63-] 0 0[-32 63-] 0
0[-32 63-] 0 0[-96 63-] 0 0[-96 63-] 0 0 [-96 63-]{+0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0+}