[RFC/PATCH 00/11] Fix up some unexpected empty split conditions

[Kewen Lin]

Hi all,

define_insn_and_split should avoid to use empty split condition
if the condition for define_insn isn't empty, otherwise it can
sometimes result in unexpected consequence, since the split
will always be done even if the insn condition doesn't hold.

To avoid forgetting to add "&& 1" onto split condition, as
Segher suggested in thread[1], this series is to add the check
and raise an error if it catches the unexpected cases.  With
this new check, we have to fix up some existing
define_insn_and_split which are detected as error.  I hope all
these places are not intentional to be kept as blank.

Any comments are highly appreciated.

BR,
Kewen

[1] https://gcc.gnu.org/pipermail/gcc-patches/2021-March/566970.html

Kewen Lin (11):
  gen: Emit error msg for empty split condition
  arc: Update unexpected empty split condition
  arm: Update unexpected empty split condition
  cris: Update unexpected empty split condition
  h8300: Update unexpected empty split condition
  i386: Update unexpected empty split condition
  m68k: Update unexpected empty split condition
  mips: Update unexpected empty split condition
  or1k: Update unexpected empty split condition
  sh: Update unexpected empty split condition
  sparc: Update unexpected empty split condition

 gcc/config/arc/arc.md        |  2 +-
 gcc/config/arm/vfp.md        |  4 ++--
 gcc/config/cris/cris.md      |  2 +-
 gcc/config/h8300/combiner.md |  2 +-
 gcc/config/i386/i386.md      |  6 +++---
 gcc/config/i386/sse.md       |  8 ++++----
 gcc/config/m68k/m68k.md      |  6 +++---
 gcc/config/mips/mips.md      |  6 +++---
 gcc/config/or1k/or1k.md      |  2 +-
 gcc/config/sh/sh.md          |  2 +-
 gcc/config/sparc/sparc.md    | 12 ++++++------
 gcc/gensupport.c             |  3 +++
 12 files changed, 29 insertions(+), 26 deletions(-)

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2.17.1