re PR target/21297 (buf[i+i]=0 stores buf[i] when -O2)

	PR target/21297
	* config/i386/i386.c (legitimize_address): When canonicalizing
	ASHIFT into MULT, multiply by 1 << shift_count instead of
	1 << log2 (shift_count).

	* gcc.c-torture/execute/20050502-2.c: New test.

From-SVN: r99156

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7aecc48dc7f91f12df5c31581271483e8a3facee..8fa6e4cad63794d3c721e38794e8bd245c6f726d 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2005-05-03  Jakub Jelinek  <jakub@redhat.com>
+
+       PR target/21297
+       * config/i386/i386.c (legitimize_address): When canonicalizing
+       ASHIFT into MULT, multiply by 1 << shift_count instead of
+       1 << log2 (shift_count).
+
 2005-05-03  Andrew MacLeod  <amacleod@redhat.com>
 
        * lambda-code.c (gcc_loop_to_lambda_loop, 

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 110b23301a69c1e0dbfd5fffddb5897381141835..ea10926bda73aa825b56170d322d026c1e7b11ee 100644 (file)
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -5902,9 +5902,10 @@ legitimize_address (rtx x, rtx oldx ATTRIBUTE_UNUSED, enum machine_mode mode)
   /* Canonicalize shifts by 0, 1, 2, 3 into multiply */
   if (GET_CODE (x) == ASHIFT
       && GET_CODE (XEXP (x, 1)) == CONST_INT
-      && (log = (unsigned) exact_log2 (INTVAL (XEXP (x, 1)))) < 4)
+      && (unsigned HOST_WIDE_INT) INTVAL (XEXP (x, 1)) < 4)
     {
       changed = 1;
+      log = INTVAL (XEXP (x, 1));
       x = gen_rtx_MULT (Pmode, force_reg (Pmode, XEXP (x, 0)),
                        GEN_INT (1 << log));
     }
@@ -5915,9 +5916,10 @@ legitimize_address (rtx x, rtx oldx ATTRIBUTE_UNUSED, enum machine_mode mode)
 
       if (GET_CODE (XEXP (x, 0)) == ASHIFT
          && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
-         && (log = (unsigned) exact_log2 (INTVAL (XEXP (XEXP (x, 0), 1)))) < 4)
+         && (unsigned HOST_WIDE_INT) INTVAL (XEXP (XEXP (x, 0), 1)) < 4)
        {
          changed = 1;
+         log = INTVAL (XEXP (XEXP (x, 0), 1));
          XEXP (x, 0) = gen_rtx_MULT (Pmode,
                                      force_reg (Pmode, XEXP (XEXP (x, 0), 0)),
                                      GEN_INT (1 << log));
@@ -5925,9 +5927,10 @@ legitimize_address (rtx x, rtx oldx ATTRIBUTE_UNUSED, enum machine_mode mode)
 
       if (GET_CODE (XEXP (x, 1)) == ASHIFT
          && GET_CODE (XEXP (XEXP (x, 1), 1)) == CONST_INT
-         && (log = (unsigned) exact_log2 (INTVAL (XEXP (XEXP (x, 1), 1)))) < 4)
+         && (unsigned HOST_WIDE_INT) INTVAL (XEXP (XEXP (x, 1), 1)) < 4)
        {
          changed = 1;
+         log = INTVAL (XEXP (XEXP (x, 1), 1));
          XEXP (x, 1) = gen_rtx_MULT (Pmode,
                                      force_reg (Pmode, XEXP (XEXP (x, 1), 0)),
                                      GEN_INT (1 << log));

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ede71cb4e1bf149024ce3599d495745b23937be7..b6b3ce69aed9de2d8befe51567248e869c8368e9 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2005-05-03  Jakub Jelinek  <jakub@redhat.com>
+
+       PR target/21297
+       * gcc.c-torture/execute/20050502-2.c: New test.
+
 2005-05-03  Uros Bizjak  <uros@kss-loka.si>
 
        PR middle-end/21282

diff --git a/gcc/testsuite/gcc.c-torture/execute/20050502-2.c b/gcc/testsuite/gcc.c-torture/execute/20050502-2.c
new file mode 100644 (file)
index 0000000..eedcb6a
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20050502-2.c
@@ -0,0 +1,34 @@
+/* PR target/21297 */
+typedef __SIZE_TYPE__ size_t;
+extern int memcmp (const char *, const char *, size_t);
+extern void abort ();
+
+void
+foo (char *x)
+{
+  int i;
+  for (i = 0; i < 2; i++);
+  x[i + i] = '\0';
+}
+
+void
+bar (char *x)
+{
+  int i;
+  for (i = 0; i < 2; i++);
+  x[i + i + i + i] = '\0';
+}
+
+int
+main (void)
+{
+  char x[] = "IJKLMNOPQR";
+  foo (x);
+  if (memcmp (x, "IJKL\0NOPQR", sizeof x) != 0)
+    abort ();
+  x[4] = 'M';
+  bar (x);
+  if (memcmp (x, "IJKLMNOP\0R", sizeof x) != 0)
+    abort ();
+  return 0;
+}