From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 3 May 2005 12:58:11 +0000 (+0200)
Subject: re PR target/21297 (buf[i+i]=0 stores buf[i] when -O2)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=85b583d30a6f23f17bddcabfd700239ca9e10299;p=gcc.git

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 7aecc48dc7f..8fa6e4cad63 100644
--- 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 110b23301a6..ea10926bda7 100644
--- 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 ede71cb4e1b..b6b3ce69aed 100644
--- 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
index 00000000000..eedcb6a3173
--- /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;
+}