What about using similar way as vlmul?
# NOTE: diff is based on your patch.
[kitoc@hsinchu02 riscv]$ git diff
diff --git a/gcc/config/riscv/riscv-protos.h b/gcc/config/riscv/riscv-protos.h
index 33f7cb1d670..3cb5c23cb09 100644
--- a/gcc/config/riscv/riscv-protos.h
+++ b/gcc/config/riscv/riscv-protos.h
@@ -345,6 +345,7 @@ enum floating_point_rounding_mode
FRM_DYN = 7, /* Aka 0b111. */
FRM_STATIC_MIN = FRM_RNE,
FRM_STATIC_MAX = FRM_RMM,
+ FRM_NONE = 8,
};
opt_machine_mode vectorize_related_mode (machine_mode, scalar_mode,
diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index d5fb8611d6e..3d5dc0c11be 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -112,6 +112,7 @@ public:
{
m_has_fp_rounding_mode_p = true;
m_fp_rounding_mode = mode;
+ gcc_assert (mode != FRM_NONE);
}
void add_output_operand (rtx x, machine_mode mode)
diff --git a/gcc/config/riscv/vector.md b/gcc/config/riscv/vector.md
index f966f1ba769..c1a7650fe85 100644
--- a/gcc/config/riscv/vector.md
+++ b/gcc/config/riscv/vector.md
@@ -865,9 +865,9 @@ (define_attr "vxrm_mode" "rnu,rne,rdn,rod,none"
(const_string "none")))
;; Defines rounding mode of an floating-point operation.
-(define_attr "frm_mode" "rne,rtz,rdn,rup,rmm,dyn,dyn_exit,dyn_call,none"
+(define_attr "frm_mode" ""
(cond [(eq_attr "type" "vfalu,vfwalu,vfmul,vfdiv,vfwmul,vfdiv,vfwmul")
- (const_string "dyn")]
+ (const_string "FRM_DYN")]
(const_string "none")))
;; -----------------------------------------------------------------
