> From: Jakub Jelinek [mailto:ja...@redhat.com] > > n->size = n1.size; > > + for (i = 0, mask = 0xff; i < n->size; i++, mask <<= 8) > > This should be mask <<= BITS_PER_UNIT for consistency.
Indeed.
>
> And, as has been said earlier, the testcase should be a runtime testcase
> (in gcc.c-torture/execute/), probably with
> __attribute__((noinline, noclone)) on the function, where main calls the
> function with a couple of different values, verifies the result and aborts
> if it is incorrect.
Done as well. This should also solve the problem of aarch64 (and potentially
others) missing as the test will be executed by all platform.
>
> Jakub
Since it seems Exchange is unable to keep formatting of patches (or I am unable
to configure it correctly), I put the new patch in attachment in addition to
reproducing it below.
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 748805e..b6d7d93 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2014-03-07 Thomas Preud'homme <thomas.preudho...@arm.com>
+
+ PR tree-optimization/60454
+ * tree-ssa-math-opts.c (find_bswap_1): Fix bswap detection.
+
2014-02-23 David Holsgrove <david.holsgr...@xilinx.com>
* config/microblaze/microblaze.md: Correct ashrsi_reg / lshrsi_reg names
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f3c0c85..b95b2b3 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2014-03-10 Thomas Preud'homme <thomas.preudho...@arm.com>
+
+ PR tree-optimization/60454
+ * gcc.c-torture/execute/pr60454.c (fake_swap32): Testcase to track
+ regression of PR60454.
+
2014-02-23 David Holsgrove <david.holsgr...@xilinx.com>
* gcc/testsuite/gcc.target/microblaze/others/mem_reload.c: New test.
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr60454.c
b/gcc/testsuite/gcc.c-torture/execute/pr60454.c
new file mode 100644
index 0000000..e5fbd8f
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr60454.c
@@ -0,0 +1,25 @@
+#include <stdint.h>
+
+#define __fake_const_swab32(x) ((uint32_t)( \
+ (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) | \
+ (((uint32_t)(x) & (uint32_t)0x0000ff00UL) << 8) | \
+ (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 8) | \
+ (((uint32_t)(x) & (uint32_t)0x0000ff00UL) ) | \
+ (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24)))
+
+/* Previous version of bswap optimization would detect byte swap when none
+ happen. This test aims at catching such wrong detection to avoid
+ regressions. */
+
+uint32_t
+fake_swap32 (uint32_t in) __attribute__ ((noinline, noclone))
+{
+ return __fake_const_swab32 (in);
+}
+
+int main(void)
+{
+ if (fake_swap32 (0x12345678) != 0x78567E12)
+ abort ();
+ return 0;
+}
diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c
index 8e372ed..9ff857c 100644
--- a/gcc/tree-ssa-math-opts.c
+++ b/gcc/tree-ssa-math-opts.c
@@ -1801,7 +1801,9 @@ find_bswap_1 (gimple stmt, struct symbolic_number *n, int
limit)
if (rhs_class == GIMPLE_BINARY_RHS)
{
+ int i;
struct symbolic_number n1, n2;
+ unsigned HOST_WIDEST_INT mask;
tree source_expr2;
if (code != BIT_IOR_EXPR)
@@ -1827,6 +1829,15 @@ find_bswap_1 (gimple stmt, struct symbolic_number *n,
int limit)
return NULL_TREE;
n->size = n1.size;
+ for (i = 0, mask = 0xff; i < n->size; i++, mask <<= BITS_PER_UNIT)
+ {
+ unsigned HOST_WIDEST_INT masked1, masked2;
+
+ masked1 = n1.n & mask;
+ masked2 = n2.n & mask;
+ if (masked1 && masked2 && masked1 != masked2)
+ return NULL_TREE;
+ }
n->n = n1.n | n2.n;
if (!verify_symbolic_number_p (n, stmt))
incorrect_detection_v1.3.diff
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