On 6/28/23 05:55, Juzhe-Zhong wrote:
Similar to vfwmacc. Add combine patterns as follows:
For vfwnmsac:
1. (set (reg) (fma (neg (float_extend (reg))) (float_extend (reg))) (reg) )))
2. (set (reg) (fma (neg (float_extend (reg))) (reg) (reg) )))
For vfwmsac:
1. (set (reg) (fma (float_extend (reg)) (float_extend (reg))) (neg (reg)) )))
2. (set (reg) (fma (float_extend (reg)) (reg) (neg (reg)) )))
For vfwnmacc:
1. (set (reg) (fma (neg (float_extend (reg))) (float_extend (reg))) (neg (reg))
)))
2. (set (reg) (fma (neg (float_extend (reg))) (reg) (neg (reg)) )))
gcc/ChangeLog:
* config/riscv/autovec-opt.md (*double_widen_fnma<mode>): New pattern.
(*single_widen_fnma<mode>): Ditto.
(*double_widen_fms<mode>): Ditto.
(*single_widen_fms<mode>): Ditto.
(*double_widen_fnms<mode>): Ditto.
(*single_widen_fnms<mode>): Ditto.
+
+;; This helps to match ext + fnma.
+(define_insn_and_split "*single_widen_fnma<mode>"
+ [(set (match_operand:VWEXTF 0 "register_operand")
+ (fma:VWEXTF
+ (neg:VWEXTF
+ (float_extend:VWEXTF
+ (match_operand:<V_DOUBLE_TRUNC> 2 "register_operand")))
+ (match_operand:VWEXTF 3 "register_operand")
+ (match_operand:VWEXTF 1 "register_operand")))]
I'd like to understand this better. It looks like it's meant to be a
bridge to another pattern. However, it looks like it would be a 4->1
pattern without needing a bridge. So I'd like to know why that code
isn't working.
Can you send the before/after combine dumps which show this bridge
pattern being used?
The same concern exists with the other bridge patterns, but I don't
think I need to see the before/after for each of them.
Thanks,
Jeff
