| Message ID | 201103311725.40432.ebotcazou@adacore.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Mar 31, 2011 at 5:25 PM, Eric Botcazou <ebotcazou@adacore.com> wrote: > Hi, > > the ACATS test cc3601a started to fail recently at -O2 after the various tweaks > to the optimizer. This is an assertion failure in the gimplifier invoked from > PRE because of a dangling PLACEHOLDER_EXPR in operand #2 of an ARRAY_REF. > > CCP2 turns the ARRAY_REF: > > D.2774_394 = MEM[(boolean[(size_type) <PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->LB0:<PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->UB0 >= <PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->LB0 ? (size_type) <PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->UB0 : (size_type) <PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->LB0 + -1] *)&ab1][D.2776_392]{lb: D.2758_393 sz: > 1}; > > into: > > D.2774_394 = MEM[(boolean[(size_type) <PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->LB0:<PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->UB0 >= <PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->LB0 ? (size_type) <PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->UB0 : (size_type) <PLACEHOLDER_EXPR struct > opt16__ab___XUP>.P_BOUNDS->LB0 + -1] *)&ab1][D.2776_392]{lb: 0 sz: 1}; > > i.e. it computes that operand #2 is 0. Later PRE re-creates the reference "by > pieces" and explicitly drops the 0: > > if (genop2) > { > /* Drop zero minimum index. */ > if (tree_int_cst_equal (genop2, integer_zero_node)) > genop2 = NULL_TREE; > > so the gimplifier re-populates it, bringing back the PLACEHOLDER_EXPR. > > Fixed by not dropping the 0 in PRE. Tested on i586-suse-linux, OK for the > mainline? Ok. Thanks, Richard. > > 2011-03-31 Eric Botcazou <ebotcazou@adacore.com> > > * tree-ssa-pre.c (create_component_ref_by_pieces_1) <ARRAY_REF>: > Drop a zero minimum index only if it is redundant. > > > 2011-03-31 Eric Botcazou <ebotcazou@adacore.com> > > * gnat.dg/opt16.adb: New test. > > > -- > Eric Botcazou >
Index: tree-ssa-pre.c =================================================================== --- tree-ssa-pre.c (revision 171716) +++ tree-ssa-pre.c (working copy) @@ -2874,8 +2874,10 @@ create_component_ref_by_pieces_1 (basic_ return NULL_TREE; if (genop2) { - /* Drop zero minimum index. */ - if (tree_int_cst_equal (genop2, integer_zero_node)) + tree domain_type = TYPE_DOMAIN (TREE_TYPE (genop0)); + /* Drop zero minimum index if redundant. */ + if (integer_zerop (genop2) + && integer_zerop (TYPE_MIN_VALUE (domain_type))) genop2 = NULL_TREE; else {
Hi, the ACATS test cc3601a started to fail recently at -O2 after the various tweaks to the optimizer. This is an assertion failure in the gimplifier invoked from PRE because of a dangling PLACEHOLDER_EXPR in operand #2 of an ARRAY_REF. CCP2 turns the ARRAY_REF: D.2774_394 = MEM[(boolean[(size_type) <PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->LB0:<PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->UB0 >= <PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->LB0 ? (size_type) <PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->UB0 : (size_type) <PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->LB0 + -1] *)&ab1][D.2776_392]{lb: D.2758_393 sz: 1}; into: D.2774_394 = MEM[(boolean[(size_type) <PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->LB0:<PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->UB0 >= <PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->LB0 ? (size_type) <PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->UB0 : (size_type) <PLACEHOLDER_EXPR struct opt16__ab___XUP>.P_BOUNDS->LB0 + -1] *)&ab1][D.2776_392]{lb: 0 sz: 1}; i.e. it computes that operand #2 is 0. Later PRE re-creates the reference "by pieces" and explicitly drops the 0: if (genop2) { /* Drop zero minimum index. */ if (tree_int_cst_equal (genop2, integer_zero_node)) genop2 = NULL_TREE; so the gimplifier re-populates it, bringing back the PLACEHOLDER_EXPR. Fixed by not dropping the 0 in PRE. Tested on i586-suse-linux, OK for the mainline? 2011-03-31 Eric Botcazou <ebotcazou@adacore.com> * tree-ssa-pre.c (create_component_ref_by_pieces_1) <ARRAY_REF>: Drop a zero minimum index only if it is redundant. 2011-03-31 Eric Botcazou <ebotcazou@adacore.com> * gnat.dg/opt16.adb: New test.