The pattern mistakenly believes that fsflags can use immediate numbers, but in fact it does not support it. Immediate numbers should use fsflagsi.
For example: __builtin_riscv_fsflags(4); The following error occurred: /tmp/ccoWdWqT.s: Assembler messages: /tmp/ccoWdWqT.s:14: Error: illegal operands `fsflags 4' gcc/ChangeLog: * config/riscv/riscv.md: Likewise. --- gcc/config/riscv/riscv.md | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md index 4615e811947..1ec85e30d7e 100644 --- a/gcc/config/riscv/riscv.md +++ b/gcc/config/riscv/riscv.md @@ -3074,7 +3074,7 @@ (define_insn "riscv_frcsr" "frcsr\t%0") (define_insn "riscv_fscsr" - [(unspec_volatile [(match_operand:SI 0 "csr_operand" "rK")] UNSPECV_FSCSR)] + [(unspec_volatile [(match_operand:SI 0 "csr_operand" "r")] UNSPECV_FSCSR)] "TARGET_HARD_FLOAT || TARGET_ZFINX" "fscsr\t%0") @@ -3085,9 +3085,11 @@ (define_insn "riscv_frflags" "frflags\t%0") (define_insn "riscv_fsflags" - [(unspec_volatile [(match_operand:SI 0 "csr_operand" "rK")] UNSPECV_FSFLAGS)] + [(unspec_volatile [(match_operand:SI 0 "csr_operand" "r,K")] UNSPECV_FSFLAGS)] "TARGET_HARD_FLOAT || TARGET_ZFINX" - "fsflags\t%0") + "@ + fsflags\t%0 + fsflagsi\t%0") (define_insn "*riscv_fsnvsnan<mode>2" [(unspec_volatile [(match_operand:ANYF 0 "register_operand" "f") -- 2.17.1