[Bug target/85829] New: [8/9 Regression] PARTIAL_REG_DEPENDENCY and MOVX were disabled for Haswell and newer processors

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85829

            Bug ID: 85829
           Summary: [8/9 Regression] PARTIAL_REG_DEPENDENCY and MOVX were
                    disabled for Haswell and newer processors
           Product: gcc
           Version: 8.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: hubicka at ucw dot cz
  Target Milestone: ---
            Target: x86_64-*-*, i?86-*-*

r254152 disabled PARTIAL_REG_DEPENDENCY and MOVX were disabled for Haswell
and newer processors. r258972 restored them for skylake-avx512.  We may need
them back for all Haswell and newer processors.