Hi James,
Thanks for your review and useful comments.
>> If you could try to keep one reply chain for each patch series
Will keep that in mind for sure :-)
>> Very minor, but what is wrong with:
>> int matches[16][2] = {0};
Done.
>> nummatches is unused.
Removed.
>> This search algorithm is tough to follow
Updated as per your comments.
>> Put braces round this and write it as two statements
Done.
>> Move your new code above the part-variable case.
Done.
>> c is unused.
Removed.
Bootstrapped and Regression tested on aarch64-thunder-linux.
Please review the patch and let us know if any comments or suggestions.
Thanks,
Naveen
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index bce490f..239ba72 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -11707,6 +11707,57 @@ aarch64_expand_vector_init (rtx target, rtx vals)
return;
}
+ enum insn_code icode = optab_handler (vec_set_optab, mode);
+ gcc_assert (icode != CODE_FOR_nothing);
+
+ /* If there are only variable elements, try to optimize
+ the insertion using dup for the most common element
+ followed by insertions. */
+
+ /* The algorithm will fill matches[*][0] with the earliest matching element,
+ and matches[X][1] with the count of duplicate elements (if X is the
+ earliest element which has duplicates). */
+
+ if (n_var == n_elts && n_elts <= 16)
+ {
+ int matches[16][2] = {0};
+ for (int i = 0; i < n_elts; i++)
+ {
+ for (int j = 0; j <= i; j++)
+ {
+ if (rtx_equal_p (XVECEXP (vals, 0, i), XVECEXP (vals, 0, j)))
+ {
+ matches[i][0] = j;
+ matches[j][1]++;
+ break;
+ }
+ }
+ }
+ int maxelement = 0;
+ int maxv = 0;
+ for (int i = 0; i < n_elts; i++)
+ if (matches[i][1] > maxv)
+ {
+ maxelement = i;
+ maxv = matches[i][1];
+ }
+
+ /* Create a duplicate of the most common element. */
+ rtx x = copy_to_mode_reg (inner_mode, XVECEXP (vals, 0, maxelement));
+ aarch64_emit_move (target, gen_rtx_VEC_DUPLICATE (mode, x));
+
+ /* Insert the rest. */
+ for (int i = 0; i < n_elts; i++)
+ {
+ rtx x = XVECEXP (vals, 0, i);
+ if (matches[i][0] == maxelement)
+ continue;
+ x = copy_to_mode_reg (inner_mode, x);
+ emit_insn (GEN_FCN (icode) (target, x, GEN_INT (i)));
+ }
+ return;
+ }
+
/* Initialise a vector which is part-variable. We want to first try
to build those lanes which are constant in the most efficient way we
can. */
@@ -11740,10 +11791,6 @@ aarch64_expand_vector_init (rtx target, rtx vals)
}
/* Insert the variable lanes directly. */
-
- enum insn_code icode = optab_handler (vec_set_optab, mode);
- gcc_assert (icode != CODE_FOR_nothing);
-
for (int i = 0; i < n_elts; i++)
{
rtx x = XVECEXP (vals, 0, i);
diff --git a/gcc/testsuite/gcc.target/aarch64/pr71663.c b/gcc/testsuite/gcc.target/aarch64/pr71663.c
new file mode 100644
index 0000000..65f368d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr71663.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#define vector __attribute__((vector_size(16)))
+
+vector float combine (float a, float b, float d)
+{
+ return (vector float) { a, b, a, d };
+}
+
+/* { dg-final { scan-assembler-not "movi\t" } } */
+/* { dg-final { scan-assembler-not "orr\t" } } */
+/* { dg-final { scan-assembler-times "ins\t" 2 } } */
+/* { dg-final { scan-assembler-times "dup\t" 1 } } */
