From 681143b9b94d7f1c88a7c34e2250865c31191959 Mon Sep 17 00:00:00 2001
From: Uros Bizjak <ubizjak@gmail.com>
Date: Sun, 13 Jun 2021 21:50:51 +0200
Subject: [PATCH] i386: Improve variable permutation insn avoidance [PR101021]
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Emit constant permutation insn directly from expand_vec_perm_shufb.
2021-06-13 Uroš Bizjak <ubizjak@gmail.com>
gcc/
PR target/101021
* config/i386/i386-expand.c (expand_vec_perm_pshufb):
Emit constant permutation insn directly from here.
---
gcc/config/i386/i386-expand.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index 2fa3a18dc6af..6e33f6f81962 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -17593,13 +17593,16 @@ expand_vec_perm_pshufb (struct expand_vec_perm_d *d)
return false;
}
- /* Try to avoid variable permutation instruction. */
- if (canonicalize_vector_int_perm (d, &nd) && expand_vec_perm_1 (&nd))
- return false;
-
if (d->testing_p)
return true;
+ /* Try to avoid variable permutation instruction. */
+ if (canonicalize_vector_int_perm (d, &nd) && expand_vec_perm_1 (&nd))
+ {
+ emit_move_insn (d->target, gen_lowpart (d->vmode, nd.target));
+ return true;
+ }
+
if (vmode == V8SImode)
for (i = 0; i < 8; ++i)
rperm[i] = GEN_INT ((d->perm[i * nelt / 8] * 8 / nelt) & 7);
--
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