On Sat, Oct 22, 2022 at 8:19 PM Richard Henderson <richard.hender...@linaro.org> wrote: > > We were matching a signed 13-bit range, not a 12-bit range. > Expand the commentary within the function and be explicit > about all of the ranges. > > Reported-by: LIU Zhiwei <zhiwei_...@linux.alibaba.com> > Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
Thanks! Applied to riscv-to-apply.next Alistair > --- > tcg/riscv/tcg-target.c.inc | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) > > diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc > index 1cdaf7b57b..2a84c57bec 100644 > --- a/tcg/riscv/tcg-target.c.inc > +++ b/tcg/riscv/tcg-target.c.inc > @@ -154,13 +154,26 @@ static bool tcg_target_const_match(int64_t val, TCGType > type, int ct) > if ((ct & TCG_CT_CONST_ZERO) && val == 0) { > return 1; > } > - if ((ct & TCG_CT_CONST_S12) && val == sextreg(val, 0, 12)) { > + /* > + * Sign extended from 12 bits: [-0x800, 0x7ff]. > + * Used for most arithmetic, as this is the isa field. > + */ > + if ((ct & TCG_CT_CONST_S12) && val >= -0x800 && val <= 0x7ff) { > return 1; > } > - if ((ct & TCG_CT_CONST_N12) && -val == sextreg(-val, 0, 12)) { > + /* > + * Sign extended from 12 bits, negated: [-0x7ff, 0x800]. > + * Used for subtraction, where a constant must be handled by ADDI. > + */ > + if ((ct & TCG_CT_CONST_N12) && val >= -0x7ff && val <= 0x800) { > return 1; > } > - if ((ct & TCG_CT_CONST_M12) && val >= -0xfff && val <= 0xfff) { > + /* > + * Sign extended from 12 bits, +/- matching: [-0x7ff, 0x7ff]. > + * Used by addsub2, which may need the negative operation, > + * and requires the modified constant to be representable. > + */ > + if ((ct & TCG_CT_CONST_M12) && val >= -0x7ff && val <= 0x7ff) { > return 1; > } > return 0; > -- > 2.34.1 > >