https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99813
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- I think the bug is in swapped constraints on add<mode>3_poly_1. We have: (define_constraint "Uai" "@internal A constraint that matches a VG-based constant that can be added by a single INC or DEC." (match_operand 0 "aarch64_sve_scalar_inc_dec_immediate")) (define_constraint "Uav" "@internal A constraint that matches a VG-based constant that can be added by a single ADDVL or ADDPL." (match_operand 0 "aarch64_sve_addvl_addpl_immediate")) and *add<mode>3_aarch64 has: Uai,Uav and matching output for those 2 constraints is: * return aarch64_output_sve_scalar_inc_dec (operands[2]); * return aarch64_output_sve_addvl_addpl (operands[2]);" Now, *add<mode>3_poly_1 has: Uav,Uai and matching output for those 2 constraints is: * return aarch64_output_sve_scalar_inc_dec (operands[2]); * return aarch64_output_sve_addvl_addpl (operands[2]); so IMHO, either we need to swap those 2 return lines, or do: --- gcc/config/aarch64/aarch64.md.jj 2021-02-25 23:07:07.851319165 +0100 +++ gcc/config/aarch64/aarch64.md 2021-03-30 11:13:35.994077470 +0200 @@ -2051,7 +2051,7 @@ (match_operand:GPI 0 "register_operand" "=r,r,r,r,r,r,&r") (plus:GPI (match_operand:GPI 1 "register_operand" "%rk,rk,rk,rk,rk,0,rk") - (match_operand:GPI 2 "aarch64_pluslong_or_poly_operand" "I,r,J,Uaa,Uav,Uai,Uat")))] + (match_operand:GPI 2 "aarch64_pluslong_or_poly_operand" "I,r,J,Uaa,Uai,Uav,Uat")))] "TARGET_SVE && operands[0] != stack_pointer_rtx" "@ add\\t%<w>0, %<w>1, %2