RISC-V: Support non-SLP unordered reduction

This patch add reduc_*_scal to support reduction auto-vectorization.

Use COND_LEN_* + reduc_*_scal to support unordered non-SLP auto-vectorization.

Consider this following case:
int __attribute__((noipa))
and_loop (int32_t * __restrict x,
int32_t n, int res)
{
  for (int i = 0; i < n; ++i)
    res &= x[i];
  return res;
}

ASM:
and_loop:
	ble	a1,zero,.L4
	vsetvli	a3,zero,e32,m1,ta,ma
	vmv.v.i	v1,-1
.L3:
	vsetvli	a5,a1,e32,m1,tu,ma       ------------> MUST BE "TU".
	slli	a4,a5,2
	sub	a1,a1,a5
	vle32.v	v2,0(a0)
	add	a0,a0,a4
	vand.vv	v1,v2,v1
	bne	a1,zero,.L3
	vsetivli	zero,1,e32,m1,ta,ma
	vmv.v.i	v2,-1
	vsetvli	a3,zero,e32,m1,ta,ma
	vredand.vs	v1,v1,v2
	vmv.x.s	a5,v1
	and	a0,a2,a5
	ret
.L4:
	mv	a0,a2
	ret

Fix bug of VSETVL PASS which is caused by reduction testcase.

SLP reduction and floating-point in-order reduction are not supported yet.

gcc/ChangeLog:

	* config/riscv/autovec.md (reduc_plus_scal_<mode>): New pattern.
	(reduc_smax_scal_<mode>): Ditto.
	(reduc_umax_scal_<mode>): Ditto.
	(reduc_smin_scal_<mode>): Ditto.
	(reduc_umin_scal_<mode>): Ditto.
	(reduc_and_scal_<mode>): Ditto.
	(reduc_ior_scal_<mode>): Ditto.
	(reduc_xor_scal_<mode>): Ditto.
	* config/riscv/riscv-protos.h (enum insn_type): Add reduction.
	(expand_reduction): New function.
	* config/riscv/riscv-v.cc (emit_vlmax_reduction_insn): Ditto.
	(emit_vlmax_fp_reduction_insn): Ditto.
	(get_m1_mode): Ditto.
	(expand_cond_len_binop): Fix name.
	(expand_reduction): New function
	* config/riscv/riscv-vsetvl.cc (gen_vsetvl_pat): Fix VSETVL BUG.
	(validate_change_or_fail): New function.
	(change_insn): Fix VSETVL BUG.
	(change_vsetvl_insn): Ditto.
	(pass_vsetvl::backward_demand_fusion): Ditto.
	(pass_vsetvl::df_post_optimization): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/rvv.exp: Add reduction tests.
	* gcc.target/riscv/rvv/autovec/reduc/reduc-1.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc-2.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc-3.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc-4.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc_run-1.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc_run-2.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc_run-3.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc_run-4.c: New test.

0 files changed, 0 insertions, 0 deletions