The Ada testcase below exposes that we do not properly handle
&a[CONSTANT][UNDEFINED] when initially computing its lattice
value and will ICE if the UNDEFINED value becomes CONSTANT later.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk
(Eric, if you want to do the testing on the branch and do the backport
that would be nice).
Richard.
2012-07-19 Richard Guenther <rguent...@suse.de>
Eric Botcazou <ebotca...@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.
* gnat.dg/loop_optimization11.adb: New testcase.
* gnat.dg/loop_optimization11_pkg.ads: Likewise.
Index: gcc/tree-ssa-ccp.c
===================================================================
*** gcc/tree-ssa-ccp.c (revision 189646)
--- gcc/tree-ssa-ccp.c (working copy)
*************** valid_lattice_transition (prop_value_t o
*** 405,411 ****
/* Now both lattice values are CONSTANT. */
! /* Allow transitioning from &x to &x & ~3. */
if (TREE_CODE (old_val.value) != INTEGER_CST
&& TREE_CODE (new_val.value) == INTEGER_CST)
return true;
--- 405,412 ----
/* Now both lattice values are CONSTANT. */
! /* 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;
*************** likely_value (gimple stmt)
*** 648,653 ****
--- 649,659 ----
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:
;
}
Index: gcc/testsuite/gnat.dg/loop_optimization11.adb
===================================================================
*** gcc/testsuite/gnat.dg/loop_optimization11.adb (revision 0)
--- gcc/testsuite/gnat.dg/loop_optimization11.adb (working copy)
***************
*** 0 ****
--- 1,19 ----
+ -- { dg-do compile }
+ -- { dg-options "-O" }
+
+ with Loop_Optimization11_Pkg; use Loop_Optimization11_Pkg;
+
+ procedure Loop_Optimization11 is
+ Arr : array (Prot, Mem) of Integer := (others => (others => 0));
+ begin
+ Put_Line (Img (0) & " ");
+ for I in Arr'Range (1) loop
+ for J in Arr'Range (2) loop
+ declare
+ Elem : Integer renames Arr (I, J);
+ begin
+ Put_Line (Img (Elem));
+ end;
+ end loop;
+ end loop;
+ end;
Index: gcc/testsuite/gnat.dg/loop_optimization11_pkg.ads
===================================================================
*** gcc/testsuite/gnat.dg/loop_optimization11_pkg.ads (revision 0)
--- gcc/testsuite/gnat.dg/loop_optimization11_pkg.ads (working copy)
***************
*** 0 ****
--- 1,11 ----
+ package Loop_Optimization11_Pkg is
+
+ function Img (X : Integer) return String;
+
+ procedure Put_Line (Data : String);
+
+ type Prot is (Execute, Execute_Read, Execute_Read_Write);
+
+ type Mem is (Mem_Image, Mem_Mapped, Mem_Private, Unknown);
+
+ end Loop_Optimization11_Pkg;
