* tree-ssa-ccp.c (valid_lattice_transition): Clarify comment

	about transition from invariant to known bits.
	(likely_value): Addresses with UNDEFINED components are UNDEFINED.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_7-branch@189679 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index eae42d7..7040eaf 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2012-07-19  Richard Guenther  <rguenther@suse.de>
+           Eric Botcazou  <ebotcazou@adacore.com>
+
+       * tree-ssa-ccp.c (valid_lattice_transition): Clarify comment
+       about transition from invariant to known bits.
+       (likely_value): Addresses with UNDEFINED components are UNDEFINED.
+
 2012-07-19  Jakub Jelinek  <jakub@redhat.com>
 
        PR middle-end/54017

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a35d465..3f4a0dc 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2012-07-19  Richard Guenther  <rguenther@suse.de>
+           Eric Botcazou  <ebotcazou@adacore.com>
+
+       * gnat.dg/loop_optimization11.adb: New testcase.
+       * gnat.dg/loop_optimization11_pkg.ads: Likewise.
+
 2012-07-19  Eric Botcazou  <ebotcazou@adacore.com>
 
        * gnat.dg/discr38.adb: New test.

diff --git a/gcc/testsuite/gnat.dg/loop_optimization11.adb b/gcc/testsuite/gnat.dg/loop_optimization11.adb
new file mode 100644 (file)
index 0000000..e4e27d4
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/loop_optimization11.adb
@@ -0,0 +1,19 @@
+-- { dg-do compile }\r
+-- { dg-options "-O" }\r
+\r
+with Loop_Optimization11_Pkg; use Loop_Optimization11_Pkg;\r
+\r
+procedure Loop_Optimization11 is\r
+   Arr : array (Prot, Mem) of Integer := (others => (others => 0));\r
+begin\r
+   Put_Line (Img (0) & " ");\r
+   for I in Arr'Range (1) loop\r
+      for J in Arr'Range (2) loop\r
+         declare\r
+            Elem : Integer renames Arr (I, J);\r
+         begin\r
+            Put_Line (Img (Elem));\r
+         end;\r
+      end loop;\r
+   end loop;\r
+end;\r

diff --git a/gcc/testsuite/gnat.dg/loop_optimization11_pkg.ads b/gcc/testsuite/gnat.dg/loop_optimization11_pkg.ads
new file mode 100644 (file)
index 0000000..f4248e5
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/loop_optimization11_pkg.ads
@@ -0,0 +1,11 @@
+package Loop_Optimization11_Pkg is\r
+\r
+   function Img (X : Integer) return String;\r
+\r
+   procedure Put_Line (Data : String);\r
+\r
+   type Prot is (Execute, Execute_Read, Execute_Read_Write);\r
+\r
+   type Mem is (Mem_Image, Mem_Mapped, Mem_Private, Unknown);\r
+\r
+end Loop_Optimization11_Pkg;\r

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 4e86b8d..abe50dd 100644 (file)
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -409,7 +409,8 @@ valid_lattice_transition (prop_value_t old_val, prop_value_t new_val)
 
   /* Now both lattice values are CONSTANT.  */
 
-  /* Allow transitioning from &x to &x & ~3.  */
+  /* Allow transitioning from PHI <&x, not executable> == &x
+     to PHI <&x, &y> == common alignment.  */
   if (TREE_CODE (old_val.value) != INTEGER_CST
       && TREE_CODE (new_val.value) == INTEGER_CST)
     return true;
@@ -652,6 +653,11 @@ likely_value (gimple stmt)
             the undefined operand may be promoted.  */
          return UNDEFINED;
 
+       case ADDR_EXPR:
+         /* If any part of an address is UNDEFINED, like the index
+            of an ARRAY_EXPR, then treat the result as UNDEFINED.  */
+         return UNDEFINED;
+
        default:
          ;
        }