| Message ID | alpine.DEB.2.02.1510291540100.19735@laptop-mg.saclay.inria.fr |
|---|---|
| State | New |
| Headers | show |
On Thu, Oct 29, 2015 at 4:06 PM, Marc Glisse <marc.glisse@inria.fr> wrote: > Hello, > > before we completely forget about it, this fixes the pattern as discussed > around https://gcc.gnu.org/ml/gcc-patches/2015-10/msg01459.html . > > Note that, as seen in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68008#c1 > , we would sometimes like to allow a conversion between trunc_div and mult, > but that's a separate generalization and I did not want to think of the > proper conditions for its validity. > > Bootstrap+regtest on ppc64le-redhat-linux. Ok, can you add a comment why we can't use matching captures before the operand_equal_p? Just in case somebody stumbles across this... Richard. > 2015-10-30 Marc Glisse <marc.glisse@inria.fr> > > * match.pd (X-(X/Y)*Y): Properly handle conversions and > commutativity. > > -- > Marc Glisse > Index: gcc/match.pd > =================================================================== > --- gcc/match.pd (revision 229478) > +++ gcc/match.pd (working copy) > @@ -311,24 +311,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > /* X % -Y is the same as X % Y. */ > (simplify > (trunc_mod @0 (convert? (negate @1))) > (if (!TYPE_UNSIGNED (type) > && !TYPE_OVERFLOW_TRAPS (type) > && tree_nop_conversion_p (type, TREE_TYPE (@1))) > (trunc_mod @0 (convert @1)))) > > /* X - (X / Y) * Y is the same as X % Y. */ > (simplify > - (minus (convert1? @0) (convert2? (mult (trunc_div @0 @1) @1))) > - (if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type)) > - && TYPE_UNSIGNED (TREE_TYPE (@0)) == TYPE_UNSIGNED (type)) > - (trunc_mod (convert @0) (convert @1)))) > + (minus (convert1? @2) (convert2? (mult:c (trunc_div @0 @1) @1))) > + (if (operand_equal_p (@0, @2, 0) > + && (INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))) > + (convert (trunc_mod @0 @1)))) > > /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR, > i.e. "X % C" into "X & (C - 1)", if X and C are positive. > Also optimize A % (C << N) where C is a power of 2, > to A & ((C << N) - 1). */ > (match (power_of_two_cand @1) > INTEGER_CST@1) > (match (power_of_two_cand @1) > (lshift INTEGER_CST@1 @2)) > (for mod (trunc_mod floor_mod) >
Index: gcc/match.pd =================================================================== --- gcc/match.pd (revision 229478) +++ gcc/match.pd (working copy) @@ -311,24 +311,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* X % -Y is the same as X % Y. */ (simplify (trunc_mod @0 (convert? (negate @1))) (if (!TYPE_UNSIGNED (type) && !TYPE_OVERFLOW_TRAPS (type) && tree_nop_conversion_p (type, TREE_TYPE (@1))) (trunc_mod @0 (convert @1)))) /* X - (X / Y) * Y is the same as X % Y. */ (simplify - (minus (convert1? @0) (convert2? (mult (trunc_div @0 @1) @1))) - (if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type)) - && TYPE_UNSIGNED (TREE_TYPE (@0)) == TYPE_UNSIGNED (type)) - (trunc_mod (convert @0) (convert @1)))) + (minus (convert1? @2) (convert2? (mult:c (trunc_div @0 @1) @1))) + (if (operand_equal_p (@0, @2, 0) + && (INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))) + (convert (trunc_mod @0 @1)))) /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR, i.e. "X % C" into "X & (C - 1)", if X and C are positive. Also optimize A % (C << N) where C is a power of 2, to A & ((C << N) - 1). */ (match (power_of_two_cand @1) INTEGER_CST@1) (match (power_of_two_cand @1) (lshift INTEGER_CST@1 @2)) (for mod (trunc_mod floor_mod)