Ok, what about the following patch and associated ChangeLog entries?
2014-06-24 Thomas Preud'homme <[email protected]>
PR tree-optimization/61375
* tree-ssa-math-opts.c (find_bswap_or_nop_1): Cancel optimization if
symbolic number cannot be represented in an unsigned HOST_WIDE_INT.
(execute_optimize_bswap): Cancel optimization if CHAR_BIT != 8.
2014-06-24 Thomas Preud'homme <[email protected]>
PR tree-optimization/61375
* gcc.c-torture/execute/pr61375-1.c: New test.
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr61375.c
b/gcc/testsuite/gcc.c-torture/execute/pr61375.c
new file mode 100644
index 0000000..6fb4693
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr61375.c
@@ -0,0 +1,35 @@
+#ifdef __UINT64_TYPE__
+typedef __UINT64_TYPE__ uint64_t;
+#else
+typedef unsigned long long uint64_t;
+#endif
+
+#ifndef __SIZEOF_INT128__
+#define __int128 long long
+#endif
+
+/* Some version of bswap optimization would ICE when analyzing a mask constant
+ too big for an HOST_WIDE_INT (PR61375). */
+
+__attribute__ ((noinline, noclone)) uint64_t
+uint128_central_bitsi_ior (unsigned __int128 in1, uint64_t in2)
+{
+ __int128 mask = (__int128)0xffff << 56;
+ return ((in1 & mask) >> 56) | in2;
+}
+
+int
+main (int argc)
+{
+ __int128 in = 1;
+#ifdef __SIZEOF_INT128__
+ in <<= 64;
+#endif
+ if (sizeof (uint64_t) * __CHAR_BIT__ != 64)
+ return 0;
+ if (sizeof (unsigned __int128) * __CHAR_BIT__ != 128)
+ return 0;
+ if (uint128_central_bitsi_ior (in, 2) != 0x102)
+ __builtin_abort ();
+ return 0;
+}
diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c
index 9ff857c..045bf48 100644
--- a/gcc/tree-ssa-math-opts.c
+++ b/gcc/tree-ssa-math-opts.c
@@ -1740,6 +1740,8 @@ find_bswap_1 (gimple stmt, struct symbolic_number *n, int
limit)
n->size = TYPE_PRECISION (TREE_TYPE (rhs1));
if (n->size % BITS_PER_UNIT != 0)
return NULL_TREE;
+ if (n->size > HOST_BITS_PER_WIDEST_INT)
+ return NULL_TREE;
n->size /= BITS_PER_UNIT;
n->n = (sizeof (HOST_WIDEST_INT) < 8 ? 0 :
(unsigned HOST_WIDEST_INT)0x08070605 << 32 | 0x04030201);
@@ -1781,6 +1783,8 @@ find_bswap_1 (gimple stmt, struct symbolic_number *n, int
limit)
type_size = TYPE_PRECISION (gimple_expr_type (stmt));
if (type_size % BITS_PER_UNIT != 0)
return NULL_TREE;
+ if (type_size > (int) HOST_BITS_PER_WIDEST_INT)
+ return NULL_TREE;
if (type_size / BITS_PER_UNIT < (int)(sizeof (HOST_WIDEST_INT)))
{
@@ -1911,7 +1915,7 @@ execute_optimize_bswap (void)
bool changed = false;
tree bswap16_type = NULL_TREE, bswap32_type = NULL_TREE, bswap64_type =
NULL_TREE;
- if (BITS_PER_UNIT != 8)
+ if (BITS_PER_UNIT != 8 || CHAR_BIT != 8)
return 0;
if (sizeof (HOST_WIDEST_INT) < 8)
Is this ok for 4.8 and 4.9 branches?
Best regards,
Thomas
