| Message ID | 20241201015400.2131214-2-quic_apinski@quicinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] gimple-lim: Reuse boolean var when moving PHI | expand |
> Am 01.12.2024 um 02:59 schrieb Andrew Pinski <quic_apinski@quicinc.com>: > > Like r15-5063-g6e84a41622f56c, but this is for the `a != 0` case. > After adding vn_valueize to the handle the `a ==/!= 0` case > of insert_predicates_for_cond, it would go into an infinite loop > as the Value number for a could be the same as what it > is for the whole expression. This avoids that recursion so there is > no infinite loop here. > > Note lim was introducing `bool_var2 = bool_var1 != 0` originally but > with the gimple testcase in -2, there is no dependency on what passes > before hand will do. > > Bootstrapped and tested on x86_64-linux-gnu. Ok Richard > PR tree-optimization/117859 > > gcc/ChangeLog: > > * tree-ssa-sccvn.cc (insert_predicates_for_cond): If the > valueization for the new lhs for `lhs != 0` > is the same as the old ones, don't recurse. > > gcc/testsuite/ChangeLog: > > * gcc.dg/torture/pr117859-1.c: New test. > * gcc.dg/torture/pr117859-2.c: New test. > > Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com> > --- > gcc/testsuite/gcc.dg/torture/pr117859-1.c | 23 ++++++++++ > gcc/testsuite/gcc.dg/torture/pr117859-2.c | 51 +++++++++++++++++++++++ > gcc/tree-ssa-sccvn.cc | 3 +- > 3 files changed, 76 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/gcc.dg/torture/pr117859-1.c > create mode 100644 gcc/testsuite/gcc.dg/torture/pr117859-2.c > > diff --git a/gcc/testsuite/gcc.dg/torture/pr117859-1.c b/gcc/testsuite/gcc.dg/torture/pr117859-1.c > new file mode 100644 > index 00000000000..21e0a26e5ca > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/torture/pr117859-1.c > @@ -0,0 +1,23 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fno-ssa-phiopt -fno-expensive-optimizations" } */ > + > +/* PR tree-optimization/117859 */ > + > +unsigned char a; > +int b, c, d, e, g, h, j, k; > +struct { > + int f : 1; > +} i; > +char l(int m) { return a > 255 >> m ? 0 : m; } > +int main() { > + if (i.f) > + d = b; > + k = e = 1; > + for (; e; e--) > + g = 0; > + h = g ? 1 << g : 1; > + c = h || i.f; > + while (b) > + j = l(k && i.f); > + return 0; > +} > diff --git a/gcc/testsuite/gcc.dg/torture/pr117859-2.c b/gcc/testsuite/gcc.dg/torture/pr117859-2.c > new file mode 100644 > index 00000000000..83549a80d3e > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/torture/pr117859-2.c > @@ -0,0 +1,51 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fgimple" } */ > + > +/* PR tree-optimization/117859 */ > + > +void __GIMPLE (ssa,startwith("pre")) > +m (int p, int b) > +{ > + int _6; > + _Bool _48; > + _Bool _50; > + int _57; > + _Bool _59; > + > + __BB(2): > + _6 = 0; // This needs to be prop'ed to make _48 unconditional > + if (_6 != 0) > + goto __BB5; > + else > + goto __BB14; > + > + __BB(14): > + _48 = p_2(D) != 0; > + goto __BB7; > + > + __BB(5): > + goto __BB7; > + > + __BB(7): > + _59 = __PHI (__BB5: _Literal (_Bool) 1, __BB14: _48); > + if (b_36(D) != 0) > + goto __BB8; > + else > + goto __BB13; > + > + __BB(8): > + _50 = _59 != _Literal (_Bool) 0; // Important being != 0 > + _57 = _50 ? 1 : 0; // can be unused but need around for _50 being used > + goto __BB9; > + > + __BB(9,loop_header(2)): > + if (_59 != _Literal (_Bool) 0) > + goto __BB13; > + else > + goto __BB9; > + > + __BB(13): > + return; > + > + > +} > diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc > index 7ef0bd01d3c..8d74731a891 100644 > --- a/gcc/tree-ssa-sccvn.cc > +++ b/gcc/tree-ssa-sccvn.cc > @@ -7964,7 +7964,8 @@ insert_predicates_for_cond (tree_code code, tree lhs, tree rhs, > edge nf = false_e; > if (code == EQ_EXPR) > std::swap (nt, nf); > - insert_predicates_for_cond (nc, nlhs, nrhs, nt, nf); > + if (lhs != nlhs) > + insert_predicates_for_cond (nc, nlhs, nrhs, nt, nf); > } > /* (a | b) == 0 -> > on true edge assert: a == 0 & b == 0. */ > -- > 2.43.0 >
diff --git a/gcc/testsuite/gcc.dg/torture/pr117859-1.c b/gcc/testsuite/gcc.dg/torture/pr117859-1.c new file mode 100644 index 00000000000..21e0a26e5ca --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr117859-1.c @@ -0,0 +1,23 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-ssa-phiopt -fno-expensive-optimizations" } */ + +/* PR tree-optimization/117859 */ + +unsigned char a; +int b, c, d, e, g, h, j, k; +struct { + int f : 1; +} i; +char l(int m) { return a > 255 >> m ? 0 : m; } +int main() { + if (i.f) + d = b; + k = e = 1; + for (; e; e--) + g = 0; + h = g ? 1 << g : 1; + c = h || i.f; + while (b) + j = l(k && i.f); + return 0; +} diff --git a/gcc/testsuite/gcc.dg/torture/pr117859-2.c b/gcc/testsuite/gcc.dg/torture/pr117859-2.c new file mode 100644 index 00000000000..83549a80d3e --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr117859-2.c @@ -0,0 +1,51 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fgimple" } */ + +/* PR tree-optimization/117859 */ + +void __GIMPLE (ssa,startwith("pre")) +m (int p, int b) +{ + int _6; + _Bool _48; + _Bool _50; + int _57; + _Bool _59; + + __BB(2): + _6 = 0; // This needs to be prop'ed to make _48 unconditional + if (_6 != 0) + goto __BB5; + else + goto __BB14; + + __BB(14): + _48 = p_2(D) != 0; + goto __BB7; + + __BB(5): + goto __BB7; + + __BB(7): + _59 = __PHI (__BB5: _Literal (_Bool) 1, __BB14: _48); + if (b_36(D) != 0) + goto __BB8; + else + goto __BB13; + + __BB(8): + _50 = _59 != _Literal (_Bool) 0; // Important being != 0 + _57 = _50 ? 1 : 0; // can be unused but need around for _50 being used + goto __BB9; + + __BB(9,loop_header(2)): + if (_59 != _Literal (_Bool) 0) + goto __BB13; + else + goto __BB9; + + __BB(13): + return; + + +} diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index 7ef0bd01d3c..8d74731a891 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -7964,7 +7964,8 @@ insert_predicates_for_cond (tree_code code, tree lhs, tree rhs, edge nf = false_e; if (code == EQ_EXPR) std::swap (nt, nf); - insert_predicates_for_cond (nc, nlhs, nrhs, nt, nf); + if (lhs != nlhs) + insert_predicates_for_cond (nc, nlhs, nrhs, nt, nf); } /* (a | b) == 0 -> on true edge assert: a == 0 & b == 0. */
Like r15-5063-g6e84a41622f56c, but this is for the `a != 0` case. After adding vn_valueize to the handle the `a ==/!= 0` case of insert_predicates_for_cond, it would go into an infinite loop as the Value number for a could be the same as what it is for the whole expression. This avoids that recursion so there is no infinite loop here. Note lim was introducing `bool_var2 = bool_var1 != 0` originally but with the gimple testcase in -2, there is no dependency on what passes before hand will do. Bootstrapped and tested on x86_64-linux-gnu. PR tree-optimization/117859 gcc/ChangeLog: * tree-ssa-sccvn.cc (insert_predicates_for_cond): If the valueization for the new lhs for `lhs != 0` is the same as the old ones, don't recurse. gcc/testsuite/ChangeLog: * gcc.dg/torture/pr117859-1.c: New test. * gcc.dg/torture/pr117859-2.c: New test. Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com> --- gcc/testsuite/gcc.dg/torture/pr117859-1.c | 23 ++++++++++ gcc/testsuite/gcc.dg/torture/pr117859-2.c | 51 +++++++++++++++++++++++ gcc/tree-ssa-sccvn.cc | 3 +- 3 files changed, 76 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr117859-1.c create mode 100644 gcc/testsuite/gcc.dg/torture/pr117859-2.c