[Bug target/78556] New: config/rs6000/rs6000.c:6217:36: runtime error: left shift of negative value -12301

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78556

            Bug ID: 78556
           Summary: config/rs6000/rs6000.c:6217:36: runtime error: left
                    shift of negative value -12301
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
  Target Milestone: ---
              Host: powerpc64le-unknown-linux-gnu
            Target: powerpc64le-unknown-linux-gnu
             Build: powerpc64le-unknown-linux-gnu

On powerpc64le-unknown-linux-gnu during bootstrap-ubsan:

config/rs6000/rs6000.c:6217:36: runtime error: left shift of negative value
-12301

I will test:

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 6c28e6a..1ec43c7 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -6214,7 +6214,7 @@ vspltis_constant (rtx op, unsigned step, unsigned copies)
       bitsize /= 2;
       small_val = splat_val >> bitsize;
       mask >>= bitsize;
-      if (splat_val != ((small_val << bitsize) | (small_val & mask)))
+      if (splat_val != ((UINTVAL (small_val) << bitsize) | (small_val &
mask)))
        return false;
       splat_val = small_val;
     }