RISC-V: Add vector fmin/fmax expanders.

RISC-V: Add vector fmin/fmax expanders.

This patch adds expanders for fmin and fmax.  As per RISC-V V Spec 1.0
vfmin/vfmax are IEEE 754-2019 compliant which differs from IEEE 754-2008
that fmin/fmax require (particularly in the signaling-NaN handling).
Therefore the pattern conditions include a !HONOR_SNANS.

gcc/ChangeLog:

	* config/riscv/autovec.md (<ieee_fmaxmin_op><mode>3): fmax/fmin
	expanders.
	(cond_<ieee_fmaxmin_op><mode>): Ditto.
	(cond_len_<ieee_fmaxmin_op><mode>): Ditto.
	(reduc_fmax_scal_<mode>): Ditto.
	(reduc_fmin_scal_<mode>): Ditto.
	* config/riscv/riscv-v.cc (needs_fp_rounding): Add fmin/fmax.
	* config/riscv/vector-iterators.md (fmin): New UNSPEC.
	(UNSPEC_VFMIN): Ditto.
	* config/riscv/vector.md (@pred_<ieee_fmaxmin_op><mode>): Add
	UNSPEC insn patterns.
	(@pred_<ieee_fmaxmin_op><mode>_scalar): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/cond/cond_fmax-1.c: Remove
	-ffast-math.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax-4.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_run-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_run-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_run-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_run-4.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin-4.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_run-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_run-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_run-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_run-4.c: Ditto.
	* gcc.target/riscv/rvv/autovec/binop/fmax-1.c: New test.
	* gcc.target/riscv/rvv/autovec/binop/fmax_run-1.c: New test.
	* gcc.target/riscv/rvv/autovec/binop/fmax_zvfh-1.c: New test.
	* gcc.target/riscv/rvv/autovec/binop/fmax_zvfh_run-1.c: New test.
	* gcc.target/riscv/rvv/autovec/binop/fmin-1.c: New test.
	* gcc.target/riscv/rvv/autovec/binop/fmin_run-1.c: New test.
	* gcc.target/riscv/rvv/autovec/binop/fmin_zvfh-1.c: New test.
	* gcc.target/riscv/rvv/autovec/binop/fmin_zvfh_run-1.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_zvfh-1.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_zvfh-2.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_zvfh-3.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_zvfh-4.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_zvfh_run-1.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_zvfh_run-2.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_zvfh_run-3.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmax_zvfh_run-4.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_zvfh-1.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_zvfh-2.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_zvfh-3.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_zvfh-4.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_zvfh_run-1.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_zvfh_run-2.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_zvfh_run-3.c: New test.
	* gcc.target/riscv/rvv/autovec/cond/cond_fmin_zvfh_run-4.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc-10.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc_run-10.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc_zvfh-10.c: New test.
	* gcc.target/riscv/rvv/autovec/reduc/reduc_zvfh_run-10.c: New test.