For the NEED_EQ_NE_P `riscv_emit_int_compare' is documented to only emit EQ or NE comparisons against zero, however it does not catch incorrect use where a non-equality comparison has been requested and falls through to the general case then. Add a safety guard to catch such a case then.
Arguably the NEED_EQ_NE_P case would best be moved into a function of its own, but let's leave it for a separate cleanup. gcc/ * config/riscv/riscv.cc (riscv_emit_int_compare): Bail out if NEED_EQ_NE_P but the comparison is neither EQ nor NE. --- FWIW the structure of code here clearly shows the NEED_EQ_NE_P case has been bolted on as an afterthought rather than how this piece would look if written from scratch right away. Let's defer any further cleanups at this stage of the development cycle though. --- gcc/config/riscv/riscv.cc | 1 + 1 file changed, 1 insertion(+) gcc-riscv-emit-int-compare-need-eq-ne.diff Index: gcc/gcc/config/riscv/riscv.cc =================================================================== --- gcc.orig/gcc/config/riscv/riscv.cc +++ gcc/gcc/config/riscv/riscv.cc @@ -3779,6 +3779,7 @@ riscv_emit_int_compare (enum rtx_code *c *op1 = const0_rtx; return; } + gcc_unreachable (); } if (splittable_const_int_operand (*op1, VOIDmode))