LoongArch: Implement vec_init<M><N> where N is a LSX vector mode

This patch implements more vec_init optabs that can handle two LSX vectors producing a LASX
vector by concatenating them. When an lsx vector is concatenated with an LSX const_vector of
zeroes, the vec_concatz pattern can be used effectively. For example as below

typedef short v8hi __attribute__ ((vector_size (16)));
typedef short v16hi __attribute__ ((vector_size (32)));
v8hi a, b;

v16hi vec_initv16hiv8hi ()
{
 return __builtin_shufflevector (a, b, 0, 8, 1, 9, 2, 10, 3, 11, 4, 12, 5, 13, 6, 14, 7, 15);
}

Before this patch:

vec_initv16hiv8hi:
    addi.d  $r3,$r3,-64
    .cfi_def_cfa_offset 64
    xvrepli.h   $xr0,0
    la.local    $r12,.LANCHOR0
    xvst    $xr0,$r3,0
    xvst    $xr0,$r3,32
    vld $vr0,$r12,0
    vst $vr0,$r3,0
    vld $vr0,$r12,16
    vst $vr0,$r3,32
    xvld    $xr1,$r3,32
    xvld    $xr2,$r3,32
    xvld    $xr0,$r3,0
    xvilvh.h    $xr0,$xr1,$xr0
    xvld    $xr1,$r3,0
    xvilvl.h    $xr1,$xr2,$xr1
    addi.d  $r3,$r3,64
    .cfi_def_cfa_offset 0
    xvpermi.q   $xr0,$xr1,32
    jr  $r1

After this patch:

vec_initv16hiv8hi:
    la.local        $r12,.LANCHOR0
    vld     $vr0,$r12,32
    vld     $vr2,$r12,48
    xvilvh.h        $xr1,$xr2,$xr0
    xvilvl.h        $xr0,$xr2,$xr0
    xvpermi.q       $xr1,$xr0,32
    xvst    $xr1,$r4,0
    jr      $r1

gcc/ChangeLog:

	* config/loongarch/lasx.md (vec_initv32qiv16qi): Rename to ..
	(vec_init<mode><lasxhalf>): .. this, and extend to mode.
	(@vec_concatz<mode>): New insn pattern.
	* config/loongarch/loongarch.cc (loongarch_expand_vector_group_init):
	Handle VALS containing two vectors.

gcc/testsuite/ChangeLog:

	* gcc.target/loongarch/vector/lasx/lasx-vec-init-2.c: New test.

0 files changed, 0 insertions, 0 deletions