Bootstrapped and tested on x86_64-unknown-linux-gnu.
Richard.
2020-01-09 Richard Biener <rguent...@suse.de>
PR tree-optimization/93040
* gimple-ssa-store-merging.c (find_bswap_or_nop): Raise search limit.
* gcc.dg/optimize-bswaphi-1.c: Amend.
* gcc.dg/optimize-bswapsi-2.c: Likewise.
Index: gcc/gimple-ssa-store-merging.c
===================================================================
--- gcc/gimple-ssa-store-merging.c (revision 280006)
+++ gcc/gimple-ssa-store-merging.c (working copy)
@@ -848,11 +848,11 @@ find_bswap_or_nop (gimple *stmt, struct
{
/* The last parameter determines the depth search limit. It usually
correlates directly to the number n of bytes to be touched. We
- increase that number by log2(n) + 1 here in order to also
+ increase that number by 2 * (log2(n) + 1) here in order to also
cover signed -> unsigned conversions of the src operand as can be seen
in libgcc, and for initial shift/and operation of the src operand. */
int limit = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (gimple_expr_type (stmt)));
- limit += 1 + (int) ceil_log2 ((unsigned HOST_WIDE_INT) limit);
+ limit += 2 * (1 + (int) ceil_log2 ((unsigned HOST_WIDE_INT) limit));
gimple *ins_stmt = find_bswap_or_nop_1 (stmt, n, limit);
if (!ins_stmt)
Index: gcc/testsuite/gcc.dg/optimize-bswaphi-1.c
===================================================================
--- gcc/testsuite/gcc.dg/optimize-bswaphi-1.c (revision 280006)
+++ gcc/testsuite/gcc.dg/optimize-bswaphi-1.c (working copy)
@@ -54,5 +54,11 @@ swap16 (HItype in)
| (((in >> 8) & 0xFF) << 0);
}
-/* { dg-final { scan-tree-dump-times "16 bit load in target endianness found
at" 3 "bswap" } } */
+unsigned short
+get_unaligned_16 (unsigned char *p)
+{
+ return p[0] | (p[1] << 8);
+}
+
+/* { dg-final { scan-tree-dump-times "16 bit load in target endianness found
at" 4 "bswap" } } */
/* { dg-final { scan-tree-dump-times "16 bit bswap implementation found at" 4
"bswap" } } */
Index: gcc/testsuite/gcc.dg/optimize-bswapsi-2.c
===================================================================
--- gcc/testsuite/gcc.dg/optimize-bswapsi-2.c (revision 280006)
+++ gcc/testsuite/gcc.dg/optimize-bswapsi-2.c (working copy)
@@ -44,5 +44,16 @@ uint32_t read_be32_3 (unsigned char *dat
| (*data << 24);
}
-/* { dg-final { scan-tree-dump-times "32 bit load in target endianness found
at" 3 "bswap" } } */
+static inline unsigned short
+get_unaligned_16 (unsigned char *p)
+{
+ return p[0] | (p[1] << 8);
+}
+unsigned int
+get_unaligned_32 (unsigned char *p)
+{
+ return get_unaligned_16 (p) | (get_unaligned_16 (p + 2) << 16);
+}
+
+/* { dg-final { scan-tree-dump-times "32 bit load in target endianness found
at" 4 "bswap" } } */
/* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 3
"bswap" } } */
