Maciej W. Rozycki <ma...@orcam.me.uk> 于2024年6月20日周四 01:24写道： > > On Wed, 19 Jun 2024, YunQiang Su wrote: > > > MIPSr6 removes condition trap instructions with imm, so the instruction > > like `teq $2,imm` will be converted to > > li $at, imm > > teq $2, $at > > > > The current version of Gas cannot detect if imm is zero, and output > > teq $2, $0 > > Let's do it in GCC. > > It seems like an output pattern issue with `*conditional_trap_reg<mode>' > insn to me. >
Yes. You are right. We should update `*conditional_trap_reg<mode>'. > > diff --git a/gcc/config/mips/mips.cc b/gcc/config/mips/mips.cc > > index 48924116937..ba1e6214656 100644 > > --- a/gcc/config/mips/mips.cc > > +++ b/gcc/config/mips/mips.cc > > @@ -6026,7 +6026,7 @@ mips_expand_conditional_trap (rtx comparison) > > > > emit_insn (gen_rtx_TRAP_IF (VOIDmode, > > gen_rtx_fmt_ee (code, mode, op0, op1), > > - const0_rtx)); > > + gen_rtx_REG (mode, GP_REG_FIRST))); > > IOW this just papers over the actual issue. > I think that we still need it, as it will make the RTL more easy to understand. I think that we should make the surprise in RTL as less as possible. > FWIW, > > Maciej
