https://gcc.gnu.org/g:4b618758b2bfe6d64932301fd4a77a8fc982b1b4
commit r16-6399-g4b618758b2bfe6d64932301fd4a77a8fc982b1b4 Author: Jeff Law <[email protected]> Date: Fri Dec 26 15:24:56 2025 -0700 [RISC-V][PR target/123283] Wrap naked REG operands with a USE. I was in the process of testing this patch when Andreas filed PR123283. What's going on is we have patterns in sync.md which have naked operands: (define_insn "subword_atomic_fetch_strong_<atomic_optab>" [(set (match_operand:SI 0 "register_operand" "=&r") ;; old value at mem (match_operand:SI 1 "memory_operand" "+A")) ;; mem location (set (match_dup 1) (unspec_volatile:SI [(any_atomic:SI (match_dup 1) (match_operand:SI 2 "arith_operand" "rI")) ;; value for op (match_operand:SI 3 "const_int_operand")] ;; model UNSPEC_SYNC_OLD_OP_SUBWORD)) (match_operand:SI 4 "arith_operand" "rI") ;; mask (match_operand:SI 5 "arith_operand" "rI") ;; not_mask (clobber (match_scratch:SI 6 "=&r")) ;; tmp_1 (clobber (match_scratch:SI 7 "=&r"))] ;; tmp_2 Note carefully operands #4 and #5 and the fact they are a toplevel construct as opposed to being an operand of another RTX. That's a no-no. They need to be wrapped with a USE. I spot-checked sync.md and found a few more instances. Fixing the set I found fixed the testsuite regressions I was seeing and also fixes the mis-compilation of libgo. Bootstrapped and regression tested on my BPI and Pioneer. It's also clean on the riscv64-elf and riscv32-elf targets in my tester. PR target/123283 gcc/ * config/riscv/sync.md (subword_atomic_fetch_strong_nand): Add USEs for naked operands that might be pseudos. (subword_atomic_fetch_strong_<atomic_optab>): Likewise. (subword_atomic_exchange_strong): Likewise. (subword_atomic_cas_strong): Likewise. Diff: --- gcc/config/riscv/sync.md | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/gcc/config/riscv/sync.md b/gcc/config/riscv/sync.md index bc8a562b1cda..2c906cf2ffb8 100644 --- a/gcc/config/riscv/sync.md +++ b/gcc/config/riscv/sync.md @@ -210,8 +210,8 @@ (match_operand:SI 2 "arith_operand" "rI")) ;; value for op (match_operand:SI 3 "const_int_operand")] ;; model UNSPEC_SYNC_OLD_OP_SUBWORD)) - (match_operand:SI 4 "arith_operand" "rI") ;; mask - (match_operand:SI 5 "arith_operand" "rI") ;; not_mask + (use (match_operand:SI 4 "arith_operand" "rI")) ;; mask + (use (match_operand:SI 5 "arith_operand" "rI")) ;; not_mask (clobber (match_scratch:SI 6 "=&r")) ;; tmp_1 (clobber (match_scratch:SI 7 "=&r"))] ;; tmp_2 "TARGET_ZALRSC && TARGET_INLINE_SUBWORD_ATOMIC" @@ -277,8 +277,8 @@ (match_operand:SI 2 "arith_operand" "rI"))) ;; value for op (match_operand:SI 3 "const_int_operand")] ;; mask UNSPEC_SYNC_OLD_OP_SUBWORD)) - (match_operand:SI 4 "arith_operand" "rI") ;; mask - (match_operand:SI 5 "arith_operand" "rI") ;; not_mask + (use (match_operand:SI 4 "arith_operand" "rI")) ;; mask + (use (match_operand:SI 5 "arith_operand" "rI")) ;; not_mask (clobber (match_scratch:SI 6 "=&r")) ;; tmp_1 (clobber (match_scratch:SI 7 "=&r"))] ;; tmp_2 "TARGET_ZALRSC && TARGET_INLINE_SUBWORD_ATOMIC" @@ -512,7 +512,7 @@ [(match_operand:SI 2 "arith_operand" "rI") ;; value (match_operand:SI 3 "const_int_operand")] ;; model UNSPEC_SYNC_EXCHANGE_SUBWORD)) - (match_operand:SI 4 "arith_operand" "rI") ;; not_mask + (use (match_operand:SI 4 "arith_operand" "rI")) ;; not_mask (clobber (match_scratch:SI 5 "=&r"))] ;; tmp_1 "TARGET_ZALRSC && TARGET_INLINE_SUBWORD_ATOMIC" { @@ -785,10 +785,10 @@ (unspec_volatile:SI [(match_operand:SI 2 "reg_or_0_operand" "rJ") ;; expected value (match_operand:SI 3 "arith_operand" "rI")] ;; desired value UNSPEC_COMPARE_AND_SWAP_SUBWORD)) - (match_operand:SI 4 "const_int_operand") ;; model - (match_operand:SI 5 "arith_operand" "rI") ;; mask - (match_operand:SI 6 "arith_operand" "rI") ;; not_mask - (clobber (match_scratch:SI 7 "=&r"))] ;; tmp_1 + (match_operand:SI 4 "const_int_operand") ;; model + (use (match_operand:SI 5 "arith_operand" "rI")) ;; mask + (use (match_operand:SI 6 "arith_operand" "rI")) ;; not_mask + (clobber (match_scratch:SI 7 "=&r"))] ;; tmp_1 "TARGET_ZALRSC && TARGET_INLINE_SUBWORD_ATOMIC" { return "1:\;"
