[Bug target/111670] New: H8/300 SX uses incorrect code sequences

[Bug target/111670] New: H8/300 SX uses incorrect code sequences

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111670

            Bug ID: 111670
           Summary: H8/300 SX uses incorrect code sequences
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: law at gcc dot gnu.org
  Target Milestone: ---

The H8/SX port can create sequences like

(set (mem (autoinc (reg sp)) (reg_sp))

Here autoinc is PRE_DECEMENT or PRE_INCREMENT addressing modes.

Which is invalid RTL.

I believe this is the root cause of the following H8/SX failures in the
testsuite:


h8300-sim/-msx/-mint32: gcc.c-torture/execute/920501-6.c   -O1  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/920501-6.c   -Os  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/pr20466-1.c   -O1  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/pr20466-1.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/pr20466-1.c   -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/pr39339.c   -O2 -flto
-fno-use-linker-plugin -flto-partition=none  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/ssad-run.c   -O1  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/ssad-run.c   -Os  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/usad-run.c   -O1  execution test
h8300-sim/-msx/-mint32: gcc.c-torture/execute/usad-run.c   -Os  execution test

I suspect we need to break the "Q" constraint into two variants.  One which
allows autoinc addressing modes and the other does not.

For movsi/movhi  we would use the version which does not allow autoinc
addressing modes and instead use the Z0/ZA approach like the other H8 variants
are using.

I'm not currently working on this.

[Bug target/111670] H8/300 SX uses incorrect code sequences

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111670

Jeffrey A. Law <law at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
             Target|                            |h8300