passes.c: Add bswap pass.

2009-06-14  Andreas Krebbel  <Andreas.Krebbel@de.ibm.com>

	* passes.c: Add bswap pass.
	* tree-pass.h: Add pass_optimize_bswap declaration.
	* tree-ssa-math-opts.c: Include diagnostics.h for print_gimple_stmt.
	Include rtl.h, expr.h and optabs.h for optab_handler check.
	(struct symbolic_number, pass_optimize_bswap): New definition.
	(do_shift_rotate, verify_symbolic_number_p): New functions.
	(find_bswap_1, find_bswap, execute_optimize_bswap): New functions.
	(gate_optimize_bswap): New function.
	* tree.c (widest_int_cst_value): New function.
	* tree.h (widest_int_cst_value): Prototype added.

2009-06-14  Andreas Krebbel  <Andreas.Krebbel@de.ibm.com>

	* gcc.dg/optimize-bswap-1.c: New testcase.

From-SVN: r148471

gcc/ChangeLog

+2009-06-14  Andreas Krebbel  <Andreas.Krebbel@de.ibm.com>
+
+	* passes.c: Add bswap pass.
+	* tree-pass.h: Add pass_optimize_bswap declaration.
+	* tree-ssa-math-opts.c: Include diagnostics.h for print_gimple_stmt.
+	Include rtl.h, expr.h and optabs.h for optab_handler check.
+	(struct symbolic_number, pass_optimize_bswap): New definition.
+	(do_shift_rotate, verify_symbolic_number_p): New functions.
+	(find_bswap_1, find_bswap, execute_optimize_bswap): New functions.
+	(gate_optimize_bswap): New function.
+	* tree.c (widest_int_cst_value): New function.
+	* tree.h (widest_int_cst_value): Prototype added.
+
 2009-06-14  Steven Bosscher  <steven@gcc.gnu.org>
 
 	* cfgcleanup.c (old_insns_match_p): Remove code to substitute

gcc/passes.c

@@ -638,6 +638,7 @@ init_optimization_passes (void)
       NEXT_PASS (pass_copy_prop);
       NEXT_PASS (pass_fold_builtins);
       NEXT_PASS (pass_cse_sincos);
+      NEXT_PASS (pass_optimize_bswap);
       NEXT_PASS (pass_split_crit_edges);
       NEXT_PASS (pass_pre);
       NEXT_PASS (pass_sink_code);

gcc/testsuite/ChangeLog

+2009-06-14  Andreas Krebbel  <Andreas.Krebbel@de.ibm.com>
+
+	* gcc.dg/optimize-bswap-1.c: New testcase.
+
 2009-06-14  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/40389

gcc/testsuite/gcc.dg/optimize-bswap-1.c

+/* { dg-do compile } */
+/* { dg-require-effective-target stdint_types } */
+/* { dg-options "-O2 -fdump-tree-bswap" } */
+
+#include <stdint.h>
+
+#define __const_swab32(x) ((uint32_t)(				      \
+        (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) |            \
+        (((uint32_t)(x) & (uint32_t)0x0000ff00UL) <<  8) |            \
+        (((uint32_t)(x) & (uint32_t)0x00ff0000UL) >>  8) |            \
+        (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24)))
+
+#define __const_swab64(x) ((uint64_t)(			                        \
+	(((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) |             \
+	(((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) |		\
+	(((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) |		\
+	(((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) <<  8) |		\
+	(((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >>  8) |		\
+	(((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) |		\
+	(((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) |		\
+	(((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56)))
+
+/* This byte swap implementation is used by the Linux kernel and the
+   GNU C library.  */
+
+uint32_t
+swap32_a (uint32_t in)
+{
+  return __const_swab32 (in);
+}
+
+uint64_t
+swap64 (uint64_t in)
+{
+  return __const_swab64 (in);
+}
+
+/* The OpenSSH byte swap implementation.  */
+uint32_t
+swap32_b (uint32_t in)
+{
+  uint32_t a;
+
+  a = (in << 16) | (in >> 16);
+  a = ((a & 0x00ff00ff) << 8) | ((a & 0xff00ff00) >> 8);
+
+  return a;
+}
+
+/* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 2 "bswap" } } */
+/* { dg-final { scan-tree-dump-times "64 bit bswap implementation found at" 1 "bswap" } } */
+/* { dg-final { cleanup-tree-dump "bswap" } } */

gcc/tree-pass.h

@@ -377,6 +377,7 @@ extern struct gimple_opt_pass pass_late_warn_uninitialized;
 extern struct gimple_opt_pass pass_cse_reciprocals;
 extern struct gimple_opt_pass pass_cse_sincos;
 extern struct gimple_opt_pass pass_convert_to_rsqrt;
+extern struct gimple_opt_pass pass_optimize_bswap;
 extern struct gimple_opt_pass pass_warn_function_return;
 extern struct gimple_opt_pass pass_warn_function_noreturn;
 extern struct gimple_opt_pass pass_cselim;

gcc/tree.c

@@ -8489,6 +8489,35 @@ int_cst_value (const_tree x)
   return val;
 }
 
+/* Return value of a constant X and sign-extend it.  */
+
+HOST_WIDEST_INT
+widest_int_cst_value (const_tree x)
+{
+  unsigned bits = TYPE_PRECISION (TREE_TYPE (x));
+  unsigned HOST_WIDEST_INT val = TREE_INT_CST_LOW (x);
+
+#if HOST_BITS_PER_WIDEST_INT > HOST_BITS_PER_WIDE_INT
+  gcc_assert (HOST_BITS_PER_WIDEST_INT >= 2 * HOST_BITS_PER_WIDE_INT);
+  val |= TREE_INT_CST_HIGH (x) << HOST_BITS_PER_WIDE_INT;
+#else
+  /* Make sure the sign-extended value will fit in a HOST_WIDE_INT.  */
+  gcc_assert (TREE_INT_CST_HIGH (x) == 0
+	      || TREE_INT_CST_HIGH (x) == -1);
+#endif
+
+  if (bits < HOST_BITS_PER_WIDEST_INT)
+    {
+      bool negative = ((val >> (bits - 1)) & 1) != 0;
+      if (negative)
+	val |= (~(unsigned HOST_WIDEST_INT) 0) << (bits - 1) << 1;
+      else
+	val &= ~((~(unsigned HOST_WIDEST_INT) 0) << (bits - 1) << 1);
+    }
+
+  return val;
+}
+
 /* If TYPE is an integral type, return an equivalent type which is
     unsigned iff UNSIGNEDP is true.  If TYPE is not an integral type,
     return TYPE itself.  */

gcc/tree.h

@@ -4868,6 +4868,7 @@ extern tree build_nonstandard_integer_type (unsigned HOST_WIDE_INT, int);
 extern tree build_range_type (tree, tree, tree);
 extern bool subrange_type_for_debug_p (const_tree, tree *, tree *);
 extern HOST_WIDE_INT int_cst_value (const_tree);
+extern HOST_WIDEST_INT widest_int_cst_value (const_tree);
 
 extern bool fields_compatible_p (const_tree, const_tree);
 extern tree find_compatible_field (tree, tree);