https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116240
--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-14 branch has been updated by Kito Cheng <k...@gcc.gnu.org>: https://gcc.gnu.org/g:86b0f63adb0815b407050514333384dcb7ac640d commit r14-11569-g86b0f63adb0815b407050514333384dcb7ac640d Author: Jeff Law <j...@ventanamicro.com> Date: Thu Aug 8 07:42:26 2024 -0600 [RISC-V][PR target/116240] Ensure object is a comparison before extracting arguments This was supposed to go out the door yesterday, but I kept getting interrupted. The target bits for rtx costing can't assume the rtl they're given actually matches a target pattern. It's just kind of inherent in how the costing routines get called in various places. In this particular case we're trying to cost a conditional move: (set (dest) (if_then_else (cond) (true) (false)) On the RISC-V port the backend only allows actual conditionals for COND. So something like (eq (reg) (const_int 0)). In the costing code for if-then-else we did something like (XEXP (XEXP (cond, 0), 0))) Which fails miserably if COND is a terminal node like (reg) rather than (ne (reg) (const_int 0) So this patch tightens up the RTL scanning to ensure that we have a comparison before we start looking at the comparison's arguments. Run through my tester without incident, but I'll wait for the pre-commit tester to run through a cycle before pushing to the trunk. Jeff ps. We probably could support a naked REG for the condition and internally convert it to (ne (reg) (const_int 0)), but I don't think it likely happens with any regularity. PR target/116240 gcc/ * config/riscv/riscv.cc (riscv_rtx_costs): Ensure object is a comparison before looking at its arguments. gcc/testsuite * gcc.target/riscv/pr116240.c: New test.
