I thought this issue should be fixed when we implement those implication rules correctly? Does march=rv32imaf_zca/mabi=ilp32 still not able select march=rv32imac/mabi=ilp32 still happen after this[1] patch?
[1] https://github.com/gcc-mirror/gcc/commit/42ce61eaefc4db70e2e7ea2d8ef091daa458eb48 On Wed, May 28, 2025 at 4:04 PM <yunze...@linux.alibaba.com> wrote: > > From: Yunze Zhu <yunze...@linux.alibaba.com> > > Currently when choosing multilib set for target like > march=rv32imaf_zca/mabi=ilp32, > gnu toolchain reports "Cannot find suitable multilib set". > This is because in current dependent extension zca implies c when has > combinations of extensions: Zca, F_Zca_Zcf or FD_Zca_Zcf_Zcd, > and f_zca is not one of these combinations and therefore extension c can not > be implied, > and multilib set march=rv32imac/mabi=ilp32 cannot be selected. > The most accurate method to fix this problem is changing multilib in > MULTILIB_REQUIRED: march=rv32imac/mabi=ilp32 > to an equivalent one: march=rv32ima_zca/mabi=ilp32. > However, this method may cause compatibility issues with multilib path in > previos toolchain. > There is an alternative method that add an extra check in multilib selection > functions, > which checks whether c extension in multilibs is subset of zc* extensions in > arch string. > By this method not only totally matched multilib sets but equivalent multilib > subsets could be selected. > > gcc/ChangeLog: > > * common/config/riscv/riscv-common.cc > (riscv_subset_list::match_score_inc_p): New Function. > * config/riscv/riscv-subset.h: New Function. > --- > gcc/common/config/riscv/riscv-common.cc | 27 +++++++++++++++++++++++++ > gcc/config/riscv/riscv-subset.h | 2 ++ > 2 files changed, 29 insertions(+) > > diff --git a/gcc/common/config/riscv/riscv-common.cc > b/gcc/common/config/riscv/riscv-common.cc > index a6d8763f032..f43899bb413 100644 > --- a/gcc/common/config/riscv/riscv-common.cc > +++ b/gcc/common/config/riscv/riscv-common.cc > @@ -412,12 +412,39 @@ riscv_subset_list::match_score (riscv_subset_list > *list) const > for (s = list->m_head; s != NULL; s = s->next) > if (this->lookup (s->name.c_str ()) != NULL) > score++; > + else if (this->match_score_inc_p (s->name.c_str (), list)) > + score++; > else > return 0; > > return score; > } > > +/* Check if given extension is equivalent to one or group of extensions > +in given subset list. */ > +bool > +riscv_subset_list::match_score_inc_p (std::string name, > + riscv_subset_list *multilib) const > +{ > + if (name.compare ("c") != 0 || this->lookup ("zca") == NULL) > + return false; > + > + /* Check equivalent requirment when having d extension in multilib. */ > + if (multilib->lookup ("d") != NULL) > + { > + if (multilib->xlen () == 32) > + return this->lookup ("zcf") != NULL && this->lookup ("zcd") != NULL; > + else > + return this->lookup ("zcd") != NULL; > + } > + > + /* Check equivalent requirment when having f extension in multilib. */ > + if (multilib->lookup ("f") != NULL && multilib->xlen () == 32) > + return this->lookup ("zcf") != NULL; > + > + return true; > +} > + > /* Get the rank for single-letter subsets, lower value meaning higher > priority. */ > > diff --git a/gcc/config/riscv/riscv-subset.h b/gcc/config/riscv/riscv-subset.h > index c5d9fab4de9..f80210cd755 100644 > --- a/gcc/config/riscv/riscv-subset.h > +++ b/gcc/config/riscv/riscv-subset.h > @@ -114,6 +114,8 @@ public: > > int match_score (riscv_subset_list *) const; > > + bool match_score_inc_p (std::string, riscv_subset_list *) const; > + > void set_loc (location_t); > > void set_allow_adding_dup (bool v) { m_allow_adding_dup = v; } > -- > 2.47.1 >
