PR rtl-optimization/49799

	* combine.c (make_compound_operation): Check if the bit field is valid
	before change it to bit field extraction.

	* gcc.dg/pr49799.c: New test case.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@176911 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c304e82..0b70415 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2011-07-29  Wei Guozhi  <carrot@google.com>
+
+       PR rtl-optimization/49799
+       * combine.c (make_compound_operation): Check if the bit field is valid
+       before change it to bit field extraction.
+
 2011-07-29  Bernd Schmidt  <bernds@codesourcery.com>
 
        PR rtl-optimization/49891

diff --git a/gcc/combine.c b/gcc/combine.c
index 4dbf022..b5cf245 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -7787,6 +7787,7 @@ make_compound_operation (rtx x, enum rtx_code in_code)
          && GET_CODE (lhs) == ASHIFT
          && CONST_INT_P (XEXP (lhs, 1))
          && INTVAL (rhs) >= INTVAL (XEXP (lhs, 1))
+         && INTVAL (XEXP (lhs, 1)) >= 0
          && INTVAL (rhs) < mode_width)
        {
          new_rtx = make_compound_operation (XEXP (lhs, 0), next_code);

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 85daf9f..d5e61cb 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-07-29  Wei Guozhi  <carrot@google.com>
+
+       PR rtl-optimization/49799
+       * gcc.dg/pr49799.c: New test case.
+
 2011-07-22  Sebastian Pop  <sebastian.pop@amd.com>
 
        PR middle-end/48648

diff --git a/gcc/testsuite/gcc.dg/pr49799.c b/gcc/testsuite/gcc.dg/pr49799.c
new file mode 100644 (file)
index 0000000..61ac261
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr49799.c
@@ -0,0 +1,25 @@
+/* PR rtl-optimization/49799 */
+/* { dg-do assemble } */
+/* { dg-options "-O2 -w" } */
+
+static __inline int bar(int a)
+{
+    int tmp;
+
+    if (a <= 0) a ^= 0xFFFFFFFF;
+
+    return tmp - 1;
+}
+
+void foo(short *K)
+{
+    short tmp;
+    short *pptr, P[14];
+
+    pptr = P;
+    tmp = bar(*K);
+    *pptr = (*K << tmp) >> 16;
+
+    if (*P < tmp)
+        *K++ = 0;
+}