force_gimple_operand doesn't really do a "deep" verification
on its input when we ask for a non-simple result here. Instead
it trusts that the CONSTRUCTOR PRE feeds it is valid GIMPLE.
Unfortunately that isn't so if its elements required a conversion.
The following fixes it by merging gimple_convert and its use
in PRE from match-and-simplify (which avoids force_gimple_operand
entirely in PRE). The implementation of gimple_convert is of
course still using fold here.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
Richard.
2014-10-10 Richard Biener <rguent...@suse.de>
PR tree-optimization/63419
* gimple-fold.h (gimple_convert): New function.
* gimple-fold.c (gimple_convert): Likewise.
* tree-ssa-pre.c (create_expression_by_pieces): Use gimple_convert
to split out required conversions early.
* g++.dg/torture/pr63419.C: New testcase.
Index: gcc/gimple-fold.c
===================================================================
*** gcc/gimple-fold.c (revision 216069)
--- gcc/gimple-fold.c (working copy)
*************** rewrite_to_defined_overflow (gimple stmt
*** 5282,5284 ****
--- 5282,5301 ----
return stmts;
}
+
+ /* Return OP converted to TYPE by emitting a conversion statement on SEQ
+ if required using location LOC. Note that OP will be returned
+ unmodified if GIMPLE does not require an explicit conversion between
+ its type and TYPE. */
+
+ tree
+ gimple_convert (gimple_seq *seq, location_t loc, tree type, tree op)
+ {
+ if (useless_type_conversion_p (type, TREE_TYPE (op)))
+ return op;
+ op = fold_convert_loc (loc, type, op);
+ gimple_seq stmts = NULL;
+ op = force_gimple_operand (op, &stmts, true, NULL_TREE);
+ gimple_seq_add_seq_without_update (seq, stmts);
+ return op;
+ }
Index: gcc/gimple-fold.h
===================================================================
*** gcc/gimple-fold.h (revision 216069)
--- gcc/gimple-fold.h (working copy)
*************** extern tree gimple_fold_indirect_ref (tr
*** 45,48 ****
--- 45,55 ----
extern bool arith_code_with_undefined_signed_overflow (tree_code);
extern gimple_seq rewrite_to_defined_overflow (gimple);
+ extern tree gimple_convert (gimple_seq *, location_t, tree, tree);
+ inline tree
+ gimple_convert (gimple_seq *seq, tree type, tree op)
+ {
+ return gimple_convert (seq, UNKNOWN_LOCATION, type, op);
+ }
+
#endif /* GCC_GIMPLE_FOLD_H */
Index: gcc/tree-ssa-pre.c
===================================================================
*** gcc/tree-ssa-pre.c (revision 216069)
--- gcc/tree-ssa-pre.c (working copy)
*************** create_expression_by_pieces (basic_block
*** 2819,2830 ****
if (nary->opcode == POINTER_PLUS_EXPR)
{
if (i == 0)
! genop[i] = fold_convert (nary->type, genop[i]);
else if (i == 1)
! genop[i] = convert_to_ptrofftype (genop[i]);
}
else
! genop[i] = fold_convert (TREE_TYPE (nary->op[i]), genop[i]);
}
if (nary->opcode == CONSTRUCTOR)
{
--- 2819,2833 ----
if (nary->opcode == POINTER_PLUS_EXPR)
{
if (i == 0)
! genop[i] = gimple_convert (&forced_stmts,
! nary->type, genop[i]);
else if (i == 1)
! genop[i] = gimple_convert (&forced_stmts,
! sizetype, genop[i]);
}
else
! genop[i] = gimple_convert (&forced_stmts,
! TREE_TYPE (nary->op[i]), genop[i]);
}
if (nary->opcode == CONSTRUCTOR)
{
*************** create_expression_by_pieces (basic_block
*** 2866,2873 ****
statements.
We have to call unshare_expr because force_gimple_operand may
modify the tree we pass to it. */
! folded = force_gimple_operand (unshare_expr (folded), &forced_stmts,
false, NULL);
/* If we have any intermediate expressions to the value sets, add them
to the value sets and chain them in the instruction stream. */
--- 2869,2878 ----
statements.
We have to call unshare_expr because force_gimple_operand may
modify the tree we pass to it. */
! gimple_seq tem = NULL;
! folded = force_gimple_operand (unshare_expr (folded), &tem,
false, NULL);
+ gimple_seq_add_seq_without_update (&forced_stmts, tem);
/* If we have any intermediate expressions to the value sets, add them
to the value sets and chain them in the instruction stream. */
