[Bug rtl-optimization/63906] New: [5 Regression] lra_remat mis-compiles glibc on aarch64

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63906

            Bug ID: 63906
           Summary: [5 Regression] lra_remat mis-compiles glibc on aarch64
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: blocker
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
            Target: aarch64-linux-gnu

I don't have much information yet but I wanted to file this so I don't lose
track of it.

With lra_remat turned on, we get a crash inside dl_main.

   0x000000400080386c <dl_main+5604>:   ldr     x2, [x3,w0,uxtw #3]
=> 0x0000004000803870 <dl_main+5608>:   ldrb    w1, [x2,#788]
(gdb) p $x2
$1 = 0