[Bug target/65416] xtensa: memory allocated by alloca is used before the stack pointer is updated

[jcmvbkbc at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65416

jcmvbkbc at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-06-12
           Assignee|unassigned at gcc dot gnu.org      |jcmvbkbc at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from jcmvbkbc at gcc dot gnu.org ---
Created attachment 44261
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44261&action=edit
minimized reproducer source for gcc-8.1

cc1 -funsigned-char -fno-builtin -fno-asm -fmerge-all-constants -std=gnu99
-fno-stack-protector -Os -fstrict-aliasing -mlongcalls -mauto-litpools
-fno-omit-frame-pointer -fdump-tree-all ldso.i

produces assembly with the same pattern in it:

        addi    a8, sp, -16
        l32i.n  a10, a5, 4
        s32i.n  a9, a8, 0
        l32i.n  a9, a5, 8
        movsp   sp, a8

Configured with: ../gcc/configure --target=xtensa-buildroot-linux-uclibc
--disable-shared --disable-libssp --disable-libisl --enable-languages=c
--enable-debug CFLAGS='-O0 -g3' CXXFLAGS='-O0 -g3' LDFLAGS=-g3