re PR middle-end/36988 (ICE in gimple_rhs_has_side_effects, at gimple.c:2369)

2008-08-01  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/36988
	* tree-ssa-ccp.c (ccp_fold): Conversions of constants only
	do not matter if that doesn't change volatile qualification.

	* gcc.c-torture/compile/pr36988.c: New testcase.

From-SVN: r138512

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 03a050b..d22df09 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2008-08-01  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/36988
+       * tree-ssa-ccp.c (ccp_fold): Conversions of constants only
+       do not matter if that doesn't change volatile qualification.
+
 2008-08-01  Paolo Bonzini  <bonzini@gnu.org>
 
        * configure.ac: Do not generate libada-mk.  Do not subst

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index bd823ca..78287a7 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-08-01  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/36988
+       * gcc.c-torture/compile/pr36988.c: New testcase.
+
 2008-08-01  Olivier Hainque  <hainque@adacore.com>
 
        * gnat.dg/raise_from_pure.ad[bs],

diff --git a/gcc/testsuite/gcc.c-torture/compile/pr36988.c b/gcc/testsuite/gcc.c-torture/compile/pr36988.c
new file mode 100644 (file)
index 0000000..44118d5
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr36988.c
@@ -0,0 +1,11 @@
+typedef struct {
+    unsigned char mbxCommand;
+} MAILBOX_t;
+void lpfc_sli_brdrestart(void)
+{
+  volatile unsigned int word0;
+  MAILBOX_t *mb;
+  mb = (MAILBOX_t *) &word0;
+  mb->mbxCommand = 0x1A;
+  __writel((*(unsigned int *) mb));
+}

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 44b5523..b867bba 100644 (file)
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -989,7 +989,13 @@ ccp_fold (gimple stmt)
                 allowed places.  */
               if ((subcode == NOP_EXPR || subcode == CONVERT_EXPR)
                  && ((POINTER_TYPE_P (TREE_TYPE (lhs))
-                      && POINTER_TYPE_P (TREE_TYPE (op0)))
+                      && POINTER_TYPE_P (TREE_TYPE (op0))
+                      /* Do not allow differences in volatile qualification
+                         as this might get us confused as to whether a
+                         propagation destination statement is volatile
+                         or not.  See PR36988.  */
+                      && (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (lhs)))
+                          == TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (op0)))))
                      || useless_type_conversion_p (TREE_TYPE (lhs),
                                                    TREE_TYPE (op0))))
                 return op0;