[amdgcn] Fix ambiguous .md attribute uses

[amdgcn] Fix ambiguous .md attribute uses

This patch is part of a series that fixes ambiguous attribute
uses in .md files, i.e. cases in which attributes didn't use
<ITER:ATTR> to specify an iterator, and in which <ATTR> could
have different values depending on the iterator chosen.

I think this is a genuine bugfix for the case in which the 1REG_MODE
and 1REG_ALT are different, since previously we would use the 1REG_MODE
for both the comparison and the select, even though the operands being
compared are 1REG_ALT rather than 1REG_MODE.

2019-07-06  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/gcn/gcn-valu.md
	(vcond<VEC_1REG_MODE:mode><VEC_1REG_ALT:mode>): Use
	gen_vec_cmp<VEC_1REG_ALT:mode>di rather than (implicitly)
	gen_vec_cmp<VEC_1REG_MODE:mode>di.  Explicitly use
	gen_vcond_mask_<VEC_1REG_MODE:mode>di.
	(vcond<VEC_1REG_MODE:mode><VEC_1REG_ALT:mode>_exec): Likewise,
	but using the _exec comparison patterns.
	(vcondu<VEC_1REG_INT_MODE:mode><VEC_1REG_INT_ALT:mode>): Use
	gen_vec_cmp<VEC_1REG_INT_ALT:mode>di rather than (implicitly)
	gen_vec_cmp<VEC_1REG_INT_MODE:mode>di.  Explicitly use
	gen_vcond_mask_<VEC_1REG_INT_MODE:mode>di.
	(vcondu<VEC_1REG_INT_MODE:mode><VEC_1REG_INT_ALT:mode>_exec): Likewise,
	but using the _exec comparison patterns.

From-SVN: r273159