Re: [PATCH] MATCH: Make zero_one_valued_p non-recusive fully
On Mon, Sep 18, 2023 at 11:04:16AM +0200, Richard Biener via Gcc-patches wrote: > > Note genmatch should warn (or error out) if this gets detected so I filed > > PR 111446 > > which I will be looking into next week or the week after so we don't run > > into > > this issue again. > > > > PR tree-optimization/111442 > > > > gcc/ChangeLog: > > > > * match.pd (zero_one_valued_p): Have the bit_and match not be > > recusive. s/recusive/recursive/g s/recusion/recursion/g > > diff --git a/gcc/match.pd b/gcc/match.pd > > index 887665633d4..773c3810f51 100644 > > --- a/gcc/match.pd > > +++ b/gcc/match.pd > > @@ -2183,8 +2183,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > > > > /* (a&1) is always [0,1] too. This is useful again when > > the range is not known. */ > > +/* Note this can't be recusive due to VN handling of equivalents, > > + VN and would cause an infinite recusion. */ > > (match zero_one_valued_p > > - (bit_and:c@0 @1 zero_one_valued_p)) > > + (bit_and:c@0 @1 integer_onep) > > + (if (INTEGRAL_TYPE_P (type > > > > /* A conversion from an zero_one_valued_p is still a [0,1]. > > This is useful when the range of a variable is not known */ > > diff --git a/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c > > b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c > > new file mode 100644 > > index 000..5814ee938de > > --- /dev/null > > +++ b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c > > @@ -0,0 +1,13 @@ > > + > > +int *a, b; > > +int main() { > > + int d = 1, e; > > + if (d) > > +e = a ? 0 % 0 : 0; > > + if (d) > > +a = > > + d = -1; > > + b = d & e; > > + b = 2 * e ^ 1; > > + return 0; > > +} > > -- > > 2.31.1 > > Jakub
Re: [PATCH] MATCH: Make zero_one_valued_p non-recusive fully
On Sun, Sep 17, 2023 at 11:41 PM Andrew Pinski via Gcc-patches wrote: > > So it turns out VN can't handle any kind of recusion for match. In this > case we have `b = a & -1` and we try to match a as being zero_one_valued_p > and VN returns b as being the value and we just go into an infinite loop at > this point. Huh, interesting. Must be because we return an available expression for the b, a & -1 equivalency class. Otherwise I'd have expected you get 'a'. > > OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. OK. Richard. > Note genmatch should warn (or error out) if this gets detected so I filed PR > 111446 > which I will be looking into next week or the week after so we don't run into > this issue again. > > PR tree-optimization/111442 > > gcc/ChangeLog: > > * match.pd (zero_one_valued_p): Have the bit_and match not be > recusive. > > gcc/testsuite/ChangeLog: > > * gcc.c-torture/compile/pr111442-1.c: New test. > --- > gcc/match.pd | 5 - > gcc/testsuite/gcc.c-torture/compile/pr111442-1.c | 13 + > 2 files changed, 17 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr111442-1.c > > diff --git a/gcc/match.pd b/gcc/match.pd > index 887665633d4..773c3810f51 100644 > --- a/gcc/match.pd > +++ b/gcc/match.pd > @@ -2183,8 +2183,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > > /* (a&1) is always [0,1] too. This is useful again when > the range is not known. */ > +/* Note this can't be recusive due to VN handling of equivalents, > + VN and would cause an infinite recusion. */ > (match zero_one_valued_p > - (bit_and:c@0 @1 zero_one_valued_p)) > + (bit_and:c@0 @1 integer_onep) > + (if (INTEGRAL_TYPE_P (type > > /* A conversion from an zero_one_valued_p is still a [0,1]. > This is useful when the range of a variable is not known */ > diff --git a/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c > b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c > new file mode 100644 > index 000..5814ee938de > --- /dev/null > +++ b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c > @@ -0,0 +1,13 @@ > + > +int *a, b; > +int main() { > + int d = 1, e; > + if (d) > +e = a ? 0 % 0 : 0; > + if (d) > +a = > + d = -1; > + b = d & e; > + b = 2 * e ^ 1; > + return 0; > +} > -- > 2.31.1 >
[PATCH] MATCH: Make zero_one_valued_p non-recusive fully
So it turns out VN can't handle any kind of recusion for match. In this case we have `b = a & -1` and we try to match a as being zero_one_valued_p and VN returns b as being the value and we just go into an infinite loop at this point. OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. Note genmatch should warn (or error out) if this gets detected so I filed PR 111446 which I will be looking into next week or the week after so we don't run into this issue again. PR tree-optimization/111442 gcc/ChangeLog: * match.pd (zero_one_valued_p): Have the bit_and match not be recusive. gcc/testsuite/ChangeLog: * gcc.c-torture/compile/pr111442-1.c: New test. --- gcc/match.pd | 5 - gcc/testsuite/gcc.c-torture/compile/pr111442-1.c | 13 + 2 files changed, 17 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr111442-1.c diff --git a/gcc/match.pd b/gcc/match.pd index 887665633d4..773c3810f51 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -2183,8 +2183,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* (a&1) is always [0,1] too. This is useful again when the range is not known. */ +/* Note this can't be recusive due to VN handling of equivalents, + VN and would cause an infinite recusion. */ (match zero_one_valued_p - (bit_and:c@0 @1 zero_one_valued_p)) + (bit_and:c@0 @1 integer_onep) + (if (INTEGRAL_TYPE_P (type /* A conversion from an zero_one_valued_p is still a [0,1]. This is useful when the range of a variable is not known */ diff --git a/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c new file mode 100644 index 000..5814ee938de --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr111442-1.c @@ -0,0 +1,13 @@ + +int *a, b; +int main() { + int d = 1, e; + if (d) +e = a ? 0 % 0 : 0; + if (d) +a = + d = -1; + b = d & e; + b = 2 * e ^ 1; + return 0; +} -- 2.31.1