i386: Fix up _mm_min_ss etc. handling of zeros and NaNs [PR116738]

i386: Fix up _mm_min_ss etc. handling of zeros and NaNs [PR116738]

min/max patterns for intrinsics which on x86 result in the second
input operand if the two operands are both zeros or one or both of them
are a NaN shouldn't use SMIN/SMAX RTL, because that is similarly to
MIN_EXPR/MAX_EXPR undefined what will be the result in those cases.

The following patch adds an expander which uses either a new pattern with
UNSPEC_IEEE_M{AX,IN} or use the S{MIN,MAX} representation of the same.

2024-09-20  Uros Bizjak  <ubizjak@gmail.com>
	    Jakub Jelinek  <jakub@redhat.com>

	PR target/116738
	* config/i386/subst.md (mask_scalar_operand_arg34,
	mask_scalar_expand_op3, round_saeonly_scalar_mask_arg3): New
	subst attributes.
	* config/i386/sse.md
	(<sse>_vm<code><mode>3<mask_scalar_name><round_saeonly_scalar_name>):
	Change from define_insn to define_expand, rename the old define_insn
	to ...
	(*<sse>_vm<code><mode>3<mask_scalar_name><round_saeonly_scalar_name>):
	... this.
	(<sse>_ieee_vm<ieee_maxmin><mode>3<mask_scalar_name><round_saeonly_scalar_name>):
	New define_insn.

	* gcc.target/i386/sse-pr116738.c: New test.