After the PR92818 commit there's one function in the testcase below
remaining not using bit-inserts. The following fixes this.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2019-12-05 Richard Biener <rguent...@suse.de>
PR tree-optimization/92819
* match.pd (VEC_PERM_EXPR -> BIT_INSERT_EXPR): Handle inserts
into the last lane. For two-element vectors try inserting
into the last lane when inserting into the first fails.
* gcc.target/i386/pr92819-1.c: New testcase.
Index: gcc/testsuite/gcc.target/i386/pr92819-1.c
===================================================================
--- gcc/testsuite/gcc.target/i386/pr92819-1.c (nonexistent)
+++ gcc/testsuite/gcc.target/i386/pr92819-1.c (working copy)
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O -msse2 -fdump-tree-forwprop1" } */
+
+typedef double v2df __attribute__((vector_size (16)));
+
+v2df
+foo (v2df x, double *p)
+{
+ return (v2df) { x[0], *p };
+}
+
+v2df
+bar (v2df x, double *p)
+{
+ return (v2df) { *p, x[1] };
+}
+
+/* { dg-final { scan-tree-dump-times "BIT_INSERT_EXPR" 2 "forwprop1" } } */
+/* { dg-final { scan-assembler "movhpd" } } */
+/* { dg-final { scan-assembler "movlpd" } } */
Index: gcc/match.pd
===================================================================
--- gcc/match.pd (revision 278998)
+++ gcc/match.pd (working copy)
@@ -6032,7 +6032,8 @@ (define_operator_list COND_TERNARY
|| TREE_CODE (cop1) == VECTOR_CST
|| TREE_CODE (cop1) == CONSTRUCTOR))
{
- if (sel.series_p (1, 1, nelts + 1, 1))
+ bool insert_first_p = sel.series_p (1, 1, nelts + 1, 1);
+ if (insert_first_p)
{
/* After canonicalizing the first elt to come from the
first vector we only can insert the first elt from
@@ -6041,13 +6042,19 @@ (define_operator_list COND_TERNARY
if ((ins = fold_read_from_vector (cop0, sel[0])))
op0 = op1;
}
- else
+ /* The above can fail for two-element vectors which always
+ appear to insert the first element, so try inserting
+ into the second lane as well. For more than two
+ elements that's wasted time. */
+ if (!insert_first_p || (!ins && maybe_eq (nelts, 2u)))
{
unsigned int encoded_nelts = sel.encoding ().encoded_nelts ();
for (at = 0; at < encoded_nelts; ++at)
if (maybe_ne (sel[at], at))
break;
- if (at < encoded_nelts && sel.series_p (at + 1, 1, at + 1, 1))
+ if (at < encoded_nelts
+ && (known_eq (at + 1, nelts)
+ || sel.series_p (at + 1, 1, at + 1, 1)))
{
if (known_lt (poly_uint64 (sel[at]), nelts))
ins = fold_read_from_vector (cop0, sel[at]);
