Clamp the selector using the actual number of elements 2w instead of the
fixed value 0x1f. So we can simply compare the clamped selector and w
to generate the mask for blending.
gcc/
* config/loongarch/loongarch.cc (loongarch_expand_vec_perm_1):
Clamp the selector using the twice of actual number of elements.
Compare the clamped selector with the element number to get the
blending mask.
---
gcc/config/loongarch/loongarch.cc | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/gcc/config/loongarch/loongarch.cc
b/gcc/config/loongarch/loongarch.cc
index 9e9d6cfc75f..4e32b23b6db 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -9095,10 +9095,13 @@ loongarch_expand_vec_perm_1 (rtx operands[])
w = GET_MODE_NUNITS (mode);
/* If we are using xvshuf.*, clamp the selector to avoid unpredictable
- output. */
- if (maskmode != V8SImode && maskmode != V4DImode)
+ output; if we need to blend two shuf results for the final result,
+ also clamp it so we can use xvslei to generate the bitmask for
+ the blending. */
+ if ((maskmode != V8SImode && maskmode != V4DImode)
+ || !one_operand_shuffle)
{
- rtx t = gen_const_vec_duplicate (maskmode, GEN_INT (0x1f));
+ rtx t = gen_const_vec_duplicate (maskmode, GEN_INT (2 * w - 1));
mask = expand_binop (maskmode, and_optab, mask, t, NULL_RTX, false,
OPTAB_DIRECT);
}
@@ -9211,18 +9214,13 @@ merge_two:
/* Then merge them together. The key is whether any given control
element contained a bit set that indicates the second word. */
rtx xops[6];
- mask = operands[3];
- vt = GEN_INT (w);
- vt = gen_const_vec_duplicate (maskmode, vt);
- vt = force_reg (maskmode, vt);
- mask = expand_simple_binop (maskmode, AND, mask, vt,
- NULL_RTX, 0, OPTAB_DIRECT);
+ vt = gen_const_vec_duplicate (maskmode, GEN_INT (w - 1));
if (GET_MODE (target) != mode)
target = gen_reg_rtx (mode);
xops[0] = target;
- xops[1] = gen_lowpart (mode, t2);
- xops[2] = gen_lowpart (mode, t1);
- xops[3] = gen_rtx_EQ (maskmode, mask, vt);
+ xops[1] = gen_lowpart (mode, t1);
+ xops[2] = gen_lowpart (mode, t2);
+ xops[3] = gen_rtx_LEU (maskmode, mask, vt);
xops[4] = mask;
xops[5] = vt;
--
2.51.2
