The following fixes a bug in genmatch exposed by adding :s flags to
the (X & C2) >> C1 into (X >> C1) & (C2 >> C1) transform which
hurts PR66948. We were not properly handling captures of captures
resulting from (convert?:s (bit_and:s ...)) when the convert is
dropped.
This also causes quite some bugs in generic-match.c code generation
with respect to required TREE_SIDE_EFFECTS checks and omit-one-operand
calls. Thus I am also backporting this to the 4.5 branch (a single
patter is affected there).
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk
and branch.
Richard.
2015-07-21 Richard Biener <rguent...@suse.de>
PR tree-optimization/66948
* genmatch.c (capture_info::walk_match): Also recurse to
captures. Properly compute expr state from captures of
captures.
* match.pd: Add single-use guards to
(X & C2) >> C1 into (X >> C1) & (C2 >> C1) transform.
Index: gcc/genmatch.c
===================================================================
*** gcc/genmatch.c (revision 226028)
--- gcc/genmatch.c (working copy)
*************** capture_info::walk_match (operand *o, un
*** 1622,1638 ****
{
if (capture *c = dyn_cast <capture *> (o))
{
! info[c->where].toplevel_msk |= 1 << toplevel_arg;
! info[c->where].force_no_side_effects_p |= conditional_p;
! info[c->where].cond_expr_cond_p |= cond_expr_cond_p;
! /* Mark expr (non-leaf) captures and recurse. */
expr *e;
if (c->what
&& (e = dyn_cast <expr *> (c->what)))
{
! info[c->where].expr_p = true;
! info[c->where].force_single_use |= e->force_single_use;
! walk_match (c->what, toplevel_arg, conditional_p, false);
}
}
else if (expr *e = dyn_cast <expr *> (o))
--- 1622,1649 ----
{
if (capture *c = dyn_cast <capture *> (o))
{
! unsigned where = c->where;
! info[where].toplevel_msk |= 1 << toplevel_arg;
! info[where].force_no_side_effects_p |= conditional_p;
! info[where].cond_expr_cond_p |= cond_expr_cond_p;
! if (!c->what)
! return;
! /* Recurse to exprs and captures. */
! if (is_a <capture *> (c->what)
! || is_a <expr *> (c->what))
! walk_match (c->what, toplevel_arg, conditional_p, false);
! /* We need to look past multiple captures to find a captured
! expression as with conditional converts two captures
! can be collapsed onto the same expression. */
! while (c->what && is_a <capture *> (c->what))
! c = as_a <capture *> (c->what);
! /* Mark expr (non-leaf) captures and forced single-use exprs. */
expr *e;
if (c->what
&& (e = dyn_cast <expr *> (c->what)))
{
! info[where].expr_p = true;
! info[where].force_single_use |= e->force_single_use;
}
}
else if (expr *e = dyn_cast <expr *> (o))
Index: gcc/match.pd
===================================================================
*** gcc/match.pd (revision 226028)
--- gcc/match.pd (working copy)
*************** (define_operator_list CBRT BUILT_IN_CBRT
*** 1052,1058 ****
(X & C2) >> C1 into (X >> C1) & (C2 >> C1). */
(for shift (lshift rshift)
(simplify
! (shift (convert? (bit_and @0 INTEGER_CST@2)) INTEGER_CST@1)
(if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
(with { tree mask = int_const_binop (shift, fold_convert (type, @2), @1); }
(bit_and (shift (convert @0) @1) { mask; })))))
--- 1052,1058 ----
(X & C2) >> C1 into (X >> C1) & (C2 >> C1). */
(for shift (lshift rshift)
(simplify
! (shift (convert?:s (bit_and:s @0 INTEGER_CST@2)) INTEGER_CST@1)
(if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
(with { tree mask = int_const_binop (shift, fold_convert (type, @2), @1); }
(bit_and (shift (convert @0) @1) { mask; })))))
