| Message ID | alpine.LSU.2.11.1412011400000.5894@zhemvz.fhfr.qr |
|---|---|
| State | New |
| Headers | show |
On Mon, 1 Dec 2014, Richard Biener wrote: > The following fixes PR64126. > > Bootstrapped and tested on x86_64-unknown-linux-gnu, applied. > > Richard. > > 2014-12-01 Richard Biener <rguenther@suse.de> > > PR middle-end/64126 > * match.pd: Allow conversions in ~A + 1 -> -A, add -A - 1 -> ~A > and -1 - A -> ~A. > * fold-const.c (fold_binary_loc): Remove transforms here. > > Index: gcc/match.pd > =================================================================== > --- gcc/match.pd (revision 218144) > +++ gcc/match.pd (working copy) > @@ -484,8 +522,22 @@ (define_operator_list inverted_tcc_compa > > /* ~A + 1 -> -A */ > (simplify > - (plus (bit_not @0) integer_each_onep) > - (negate @0)) > + (plus (convert? (bit_not @0)) integer_each_onep) > + (if (tree_nop_conversion_p (type, TREE_TYPE (@0))) > + (negate (convert @0)))) > + > + /* -A - 1 -> ~A */ > + (simplify > + (minus (convert? (negate @0)) integer_each_onep) > + (if (!TYPE_OVERFLOW_TRAPS (type) I don't understand why TYPE_OVERFLOW_TRAPS is tested for this one but not the others. > + && tree_nop_conversion_p (type, TREE_TYPE (@0))) > + (bit_not (convert @0)))) > + > + /* -1 - A -> ~A */ > + (simplify > + (minus integer_all_onesp @0) > + (if (TREE_CODE (type) != COMPLEX_TYPE) > + (bit_not @0))) It should also be true for COMPLEX_TYPE where integer_all_onesp tests for -1-i. (I know you are just copying from fold-const)
On Mon, 1 Dec 2014, Marc Glisse wrote: > On Mon, 1 Dec 2014, Richard Biener wrote: > > > The following fixes PR64126. > > > > Bootstrapped and tested on x86_64-unknown-linux-gnu, applied. > > > > Richard. > > > > 2014-12-01 Richard Biener <rguenther@suse.de> > > > > PR middle-end/64126 > > * match.pd: Allow conversions in ~A + 1 -> -A, add -A - 1 -> ~A > > and -1 - A -> ~A. > > * fold-const.c (fold_binary_loc): Remove transforms here. > > > > Index: gcc/match.pd > > =================================================================== > > --- gcc/match.pd (revision 218144) > > +++ gcc/match.pd (working copy) > > @@ -484,8 +522,22 @@ (define_operator_list inverted_tcc_compa > > > > /* ~A + 1 -> -A */ > > (simplify > > - (plus (bit_not @0) integer_each_onep) > > - (negate @0)) > > + (plus (convert? (bit_not @0)) integer_each_onep) > > + (if (tree_nop_conversion_p (type, TREE_TYPE (@0))) > > + (negate (convert @0)))) > > + > > + /* -A - 1 -> ~A */ > > + (simplify > > + (minus (convert? (negate @0)) integer_each_onep) > > + (if (!TYPE_OVERFLOW_TRAPS (type) > > I don't understand why TYPE_OVERFLOW_TRAPS is tested for this one but not the > others. No idea - I just copied from fold-const.c. The whole -ftrapv and now -fsanitize=overflow stuff is just very inconsistently checked. > > + && tree_nop_conversion_p (type, TREE_TYPE (@0))) > > + (bit_not (convert @0)))) > > + > > + /* -1 - A -> ~A */ > > + (simplify > > + (minus integer_all_onesp @0) > > + (if (TREE_CODE (type) != COMPLEX_TYPE) > > + (bit_not @0))) > > It should also be true for COMPLEX_TYPE where integer_all_onesp tests for > -1-i. Yeah, I have no idea why it was disabled for complex. Maybe expansion doesn't deal with ~complex properly (on some targets?). Not sure. Didn't bother to investigate as ... > (I know you are just copying from fold-const) ... I was just copying from fold-const.c ;) Richard.
Index: gcc/match.pd =================================================================== --- gcc/match.pd (revision 218144) +++ gcc/match.pd (working copy) @@ -484,8 +522,22 @@ (define_operator_list inverted_tcc_compa /* ~A + 1 -> -A */ (simplify - (plus (bit_not @0) integer_each_onep) - (negate @0)) + (plus (convert? (bit_not @0)) integer_each_onep) + (if (tree_nop_conversion_p (type, TREE_TYPE (@0))) + (negate (convert @0)))) + + /* -A - 1 -> ~A */ + (simplify + (minus (convert? (negate @0)) integer_each_onep) + (if (!TYPE_OVERFLOW_TRAPS (type) + && tree_nop_conversion_p (type, TREE_TYPE (@0))) + (bit_not (convert @0)))) + + /* -1 - A -> ~A */ + (simplify + (minus integer_all_onesp @0) + (if (TREE_CODE (type) != COMPLEX_TYPE) + (bit_not @0))) /* (T)(P + A) - (T)P -> (T) A */ (for add (plus pointer_plus) Index: gcc/fold-const.c =================================================================== --- gcc/fold-const.c (revision 218144) +++ gcc/fold-const.c (working copy) @@ -10391,19 +10475,6 @@ fold_binary_loc (location_t loc, negate_expr (arg1)), fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0))); - /* Convert -A - 1 to ~A. */ - if (TREE_CODE (arg0) == NEGATE_EXPR - && integer_each_onep (arg1) - && !TYPE_OVERFLOW_TRAPS (type)) - return fold_build1_loc (loc, BIT_NOT_EXPR, type, - fold_convert_loc (loc, type, - TREE_OPERAND (arg0, 0))); - - /* Convert -1 - A to ~A. */ - if (TREE_CODE (type) != COMPLEX_TYPE - && integer_all_onesp (arg0)) - return fold_build1_loc (loc, BIT_NOT_EXPR, type, op1); - /* X - (X / Y) * Y is X % Y. */ if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))