Kewen Lin <li...@linux.ibm.com> writes: > 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.
I wonder whether we should instead redefine the semantics of define_insn_and_split so that the split condition is always applied on top of the insn condition. It's rare for a define_insn_and_split to have independent insn and split conditions, so at the moment, we're making the common case hard. Thanks, Richard > 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(-)
