RISC-V: Combine vec_duplicate + vmadd.vv to vmadd.vx on GR2VR cost

This patch would like to combine the vec_duplicate + vmadd.vv to the
vmadd.vx.  From example as below code.  The related pattern will depend
on the cost of vec_duplicate from GR2VR.  Then the late-combine will
take action if the cost of GR2VR is zero, and reject the combination
if the GR2VR cost is greater than zero.

Assume we have example code like below, GR2VR cost is 0.

Before this patch:
  11   │     beq a3,zero,.L8
  12   │     vsetvli a5,zero,e32,m1,ta,ma
  13   │     vmv.v.x v2,a2
  ...
  16   │ .L3:
  17   │     vsetvli a5,a3,e32,m1,ta,ma
  ...
  22   │     vmadd.vv v1,v2,v3
  ...
  25   │     bne a3,zero,.L3

After this patch:
  11   │     beq a3,zero,.L8
  ...
  14   │ .L3:
  15   │     vsetvli a5,a3,e32,m1,ta,ma
  ...
  20   │     vmadd.vx v1,a2,v3
  ...
  23   │     bne a3,zero,.L3

gcc/ChangeLog:

	* config/riscv/autovec-opt.md (*vmacc_vx_<mode>): Rename to
	handle both the macc and madd.
	(*mul_plus_vx_<mode>): Add madd pattern.
	* config/riscv/vector.md (@pred_mul_plus_vx_<mode>): Rename to
	handle both the macc and madd.
	(*pred_macc_<mode>_scalar_undef): Remove.
	(*pred_nmsac_<mode>_scalar_undef): Remove.
	(*pred_mul_plus_vx<mode>_undef): Add new pattern to handle
	both the vmacc and vmadd.
	(@pred_mul_plus_vx<mode>): Ditto.

Signed-off-by: Pan Li <pan2.li@intel.com>

0 files changed, 0 insertions, 0 deletions