The "new" VEC_PERM_EXPR handling makes it easy to support bswap
for variable-length vectors.
Tested on aarch64-linux-gnu (with and without SVE), aarch64_be-elf
and x86_64-linux-gnu. OK to install?
Richard
2018-08-23 Richard Sandiford <richard.sandif...@arm.com>
gcc/
* tree-vect-stmts.c (vectorizable_bswap): Handle variable-length
vectors.
gcc/testsuite/
* gcc.target/aarch64/sve/bswap_1.c: New test.
* gcc.target/aarch64/sve/bswap_2.c: Likewise.
* gcc.target/aarch64/sve/bswap_3.c: Likewise.
Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c 2018-08-23 09:59:35.245682525 +0100
+++ gcc/tree-vect-stmts.c 2018-08-23 10:07:30.233601466 +0100
@@ -2961,13 +2961,10 @@ vectorizable_bswap (stmt_vec_info stmt_i
vec_info *vinfo = stmt_info->vinfo;
loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
unsigned ncopies;
- unsigned HOST_WIDE_INT nunits, num_bytes;
op = gimple_call_arg (stmt, 0);
vectype = STMT_VINFO_VECTYPE (stmt_info);
-
- if (!TYPE_VECTOR_SUBPARTS (vectype).is_constant (&nunits))
- return false;
+ poly_uint64 nunits = TYPE_VECTOR_SUBPARTS (vectype);
/* Multiple types in SLP are handled by creating the appropriate number of
vectorized stmts for each SLP node. Hence, NCOPIES is always 1 in
@@ -2983,11 +2980,11 @@ vectorizable_bswap (stmt_vec_info stmt_i
if (! char_vectype)
return false;
- if (!TYPE_VECTOR_SUBPARTS (char_vectype).is_constant (&num_bytes))
+ poly_uint64 num_bytes = TYPE_VECTOR_SUBPARTS (char_vectype);
+ unsigned word_bytes;
+ if (!constant_multiple_p (num_bytes, nunits, &word_bytes))
return false;
- unsigned word_bytes = num_bytes / nunits;
-
/* The encoding uses one stepped pattern for each byte in the word. */
vec_perm_builder elts (num_bytes, word_bytes, 3);
for (unsigned i = 0; i < 3; ++i)
Index: gcc/testsuite/gcc.target/aarch64/sve/bswap_1.c
===================================================================
--- /dev/null 2018-07-26 10:26:13.137955424 +0100
+++ gcc/testsuite/gcc.target/aarch64/sve/bswap_1.c 2018-08-23
10:07:30.233601466 +0100
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-vectorize" } */
+
+#include <stdint.h>
+
+void
+f (uint16_t *a, uint16_t *b)
+{
+ for (int i = 0; i < 100; ++i)
+ a[i] = __builtin_bswap16 (b[i]);
+}
+
+/* { dg-final { scan-assembler-times {\trevb\tz[0-9]+\.h, p[0-7]/m,
z[0-9]+\.h\n} 1 { xfail aarch64_big_endian } } } */
Index: gcc/testsuite/gcc.target/aarch64/sve/bswap_2.c
===================================================================
--- /dev/null 2018-07-26 10:26:13.137955424 +0100
+++ gcc/testsuite/gcc.target/aarch64/sve/bswap_2.c 2018-08-23
10:07:30.233601466 +0100
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-vectorize" } */
+
+#include <stdint.h>
+
+void
+f (uint32_t *a, uint32_t *b)
+{
+ for (int i = 0; i < 100; ++i)
+ a[i] = __builtin_bswap32 (b[i]);
+}
+
+/* { dg-final { scan-assembler-times {\trevb\tz[0-9]+\.s, p[0-7]/m,
z[0-9]+\.s\n} 1 { xfail aarch64_big_endian } } } */
Index: gcc/testsuite/gcc.target/aarch64/sve/bswap_3.c
===================================================================
--- /dev/null 2018-07-26 10:26:13.137955424 +0100
+++ gcc/testsuite/gcc.target/aarch64/sve/bswap_3.c 2018-08-23
10:07:30.233601466 +0100
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-vectorize" } */
+
+#include <stdint.h>
+
+void
+f (uint64_t *a, uint64_t *b)
+{
+ for (int i = 0; i < 100; ++i)
+ a[i] = __builtin_bswap64 (b[i]);
+}
+
+/* { dg-final { scan-assembler-times {\trevb\tz[0-9]+\.d, p[0-7]/m,
z[0-9]+\.d\n} 1 { xfail aarch64_big_endian } } } */
