re PR target/43698 (Wrong use of ARMv6 REV instruction for endian bytewapping…

re PR target/43698 (Wrong use of ARMv6 REV instruction for endian bytewapping with -Os or -O2 optimizations)

Fix PR target/43698

2010-07-22  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>

	PR target/43698
	* config/arm/arm.md: Split arm_rev into *arm_rev
	and *thumb1_rev. Set *arm_rev to be predicable.

2010-07-22  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>

	PR target/43698
	* gcc.target/arm/pr43698.c: New test.

From-SVN: r162404

gcc/ChangeLog

+2010-07-22  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
+
+ 	PR target/43698
+	* config/arm/arm.md: Split arm_rev into *arm_rev
+	and *thumb1_rev. Set *arm_rev to be predicable.
+
 2010-07-22  Iain Sandoe  <iains@gcc.gnu.org>
 
 	* config/darwin.h (LINK_COMMAND_SPEC): Split into...

gcc/config/arm/arm.md

@@ -11305,15 +11305,21 @@
    (set_attr "length" "4")]
 )
 
-(define_insn "arm_rev"
+(define_insn "*arm_rev"
   [(set (match_operand:SI 0 "s_register_operand" "=r")
 	(bswap:SI (match_operand:SI 1 "s_register_operand" "r")))]
-  "TARGET_EITHER && arm_arch6"
-  "rev\t%0, %1"
-  [(set (attr "length")
-        (if_then_else (eq_attr "is_thumb" "yes")
-		      (const_int 2)
-		      (const_int 4)))]
+  "TARGET_32BIT && arm_arch6"
+  "rev%?\t%0, %1"
+  [(set_attr "predicable" "yes")
+   (set_attr "length" "4")]
+)
+
+(define_insn "*thumb1_rev"
+  [(set (match_operand:SI 0 "s_register_operand" "=l")
+	(bswap:SI (match_operand:SI 1 "s_register_operand" "l")))]
+  "TARGET_THUMB1 && arm_arch6"
+   "rev\t%0, %1"
+  [(set_attr "length" "2")]
 )
 
 (define_expand "arm_legacy_rev"

gcc/testsuite/ChangeLog

+2010-07-22  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
+
+	PR target/43698
+	* gcc.target/arm/pr43698.c: New test.
+
 2010-07-21  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/44929

gcc/testsuite/gcc.target/arm/pr43698.c

+/* { dg-do run } */
+/* { dg-options "-Os -march=armv7-a" } */
+#include <stdint.h>
+#include <stdlib.h>
+
+
+char do_reverse_endian = 0;
+
+#  define bswap_32(x) \
+  ((((x) & 0xff000000) >> 24) | \
+   (((x) & 0x00ff0000) >>  8) | \
+   (((x) & 0x0000ff00) <<  8) | \
+   (((x) & 0x000000ff) << 24))
+
+#define EGET(X) \
+  (__extension__ ({ \
+      uint64_t __res; \
+      if (!do_reverse_endian) {    __res = (X); \
+      } else if (sizeof(X) == 4) { __res = bswap_32((X)); \
+      } \
+      __res; \
+    }))
+
+void __attribute__((noinline)) X(char **phdr, char **data, int *phoff)
+{
+  *phdr = *data + EGET(*phoff);
+}
+
+int main()
+{
+  char *phdr;
+  char *data = (char *)0x40164000;
+  int phoff = 0x34;
+  X(&phdr, &data, &phoff);
+  if (phdr != (char *)0x40164034)
+    abort ();
+  exit (0);
+}