On 7/29/2026 1:17 AM, Jin Ma wrote:
Add recognition for the following macro-fusion pairs:
RISCV_FUSE_SUB_SEQZ - sub/subw + seqz/snez
RISCV_FUSE_ADD_LD - add type + integer load
RISCV_FUSE_ADD_ST - add type + integer store
RISCV_FUSE_ADD_ANDI - add/addi type + andi type
RISCV_FUSE_ANDI_ADD - andi type + add/addi type
RISCV_FUSE_LOGIC_LOGIC - logic + logic
RISCV_FUSE_SLLI_SRLI - slli/slliw + srli/srliw
RISCV_FUSE_SRLI_ADD - srli/srliw + add type
RISCV_FUSE_PREINDEX_LD - addi type + load
RISCV_FUSE_PREINDEX_ST - addi type + store
RISCV_FUSE_POSTINDEX_LD - load + addi type
RISCV_FUSE_POSTINDEX_ST - store + addi type
RISCV_FUSE_LDST_PAIR_INC - ascending integer load/store pair
RISCV_FUSE_LDST_PAIR_DEC - descending integer load/store pair
RISCV_FUSE_FLDFST_PAIR_INC - ascending FP load/store pair
RISCV_FUSE_FLDFST_PAIR_DEC - descending FP load/store pair
Leave the pairs disabled by default and mark positive checks as XFAIL.
gcc/ChangeLog:
* config/riscv/riscv-fusion.cc: Include insn-attr.h.
(riscv_fusion_same_source_p, riscv_set_is_addw_p,
riscv_set_is_word_add_p, riscv_set_is_addiw_p, riscv_insn_is_mv_li_p,
riscv_insn_is_addi_type_p, riscv_insn_is_nonword_addi_type_p,
riscv_insn_is_add_type_p, riscv_insn_is_add_addi_p,
riscv_insn_is_sub_type_p, riscv_insn_is_andi_type_p,
riscv_insn_is_logical_type_p, riscv_set_is_slli_p,
riscv_set_is_slliw_p, riscv_set_is_srli_p, riscv_set_is_srliw_p,
riscv_set_is_word_shift_p, riscv_fusion_extract_address,
riscv_fusion_load_store, riscv_insn_is_load_store_type_p): New
helper functions.
(riscv_fuse_sub_seqz, riscv_fuse_add_andi, riscv_fuse_add_ldst_1,
riscv_fuse_add_ld, riscv_fuse_add_st, riscv_fuse_andi_add,
riscv_fuse_logic_logic, riscv_fuse_slli_srli, riscv_fuse_srli_add,
riscv_fuse_preindex_ldst_1, riscv_fuse_preindex_ld,
riscv_fuse_preindex_st, riscv_fuse_postindex_ldst_1,
riscv_fuse_postindex_ld, riscv_fuse_postindex_st,
riscv_fuse_ldst_pair_1, riscv_fuse_ldst_pair_inc,
riscv_fuse_ldst_pair_dec, riscv_fuse_fldfst_pair_inc,
riscv_fuse_fldfst_pair_dec): New function implementing the
corresponding RISCV_FUSE_* pair.
(riscv_fusion_table): Add entries for the new pairs.
* config/riscv/riscv-protos.h (enum riscv_fusion_pairs): Add pair
flags.
This is getting pretty large and tedious to try and work through from a
review standpoint. I hate to ask, but can we break this down into
individual cases to aid review?
jeff
