| Message ID | 20230328131110.7780-1-amonakov@ispras.ru |
|---|---|
| State | New |
| Headers | show |
| Series | haifa-sched: fix autopref_rank_for_schedule comparator [PR109187] | expand |
On Tue, Mar 28, 2023 at 3:11 PM Alexander Monakov via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > Do not attempt to use a plain subtraction for generating a three-way > comparison result in autopref_rank_for_schedule qsort comparator, as > offsets are not restricted and subtraction may overflow. Open-code > a safe three-way comparison instead. OK. > gcc/ChangeLog: > > PR rtl-optimization/109187 > * haifa-sched.cc (autopref_rank_for_schedule): Avoid use of overflowing > subtraction in three-way comparison. > > gcc/testsuite/ChangeLog: > > PR rtl-optimization/109187 > * gcc.dg/pr109187.c: New test. > --- > > I think I can commit this as obvious if no comment in a day, but explicit ack > is always appreciated. > > Alexander > > gcc/haifa-sched.cc | 2 +- > gcc/testsuite/gcc.dg/pr109187.c | 8 ++++++++ > 2 files changed, 9 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/gcc.dg/pr109187.c > > diff --git a/gcc/haifa-sched.cc b/gcc/haifa-sched.cc > index 4efaa9445..e11cc5c35 100644 > --- a/gcc/haifa-sched.cc > +++ b/gcc/haifa-sched.cc > @@ -5686,7 +5686,7 @@ autopref_rank_for_schedule (const rtx_insn *insn1, const rtx_insn *insn2) > > if (!irrel1 && !irrel2) > /* Sort memory references from lowest offset to the largest. */ > - r = data1->offset - data2->offset; > + r = (data1->offset > data2->offset) - (data1->offset < data2->offset); > else if (write) > /* Schedule "irrelevant" insns before memory stores to resolve > as many producer dependencies of stores as possible. */ > diff --git a/gcc/testsuite/gcc.dg/pr109187.c b/gcc/testsuite/gcc.dg/pr109187.c > new file mode 100644 > index 000000000..1ef14a73d > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/pr109187.c > @@ -0,0 +1,8 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 --param sched-autopref-queue-depth=1" } */ > + > +void f(int *a) > +{ > + for (;;) > + asm("" :: "r"(a[-0x10000000]), "r"(a[0x10000000]), "r"(a[0]) : "memory"); > +} > -- > 2.39.1 >
diff --git a/gcc/haifa-sched.cc b/gcc/haifa-sched.cc index 4efaa9445..e11cc5c35 100644 --- a/gcc/haifa-sched.cc +++ b/gcc/haifa-sched.cc @@ -5686,7 +5686,7 @@ autopref_rank_for_schedule (const rtx_insn *insn1, const rtx_insn *insn2) if (!irrel1 && !irrel2) /* Sort memory references from lowest offset to the largest. */ - r = data1->offset - data2->offset; + r = (data1->offset > data2->offset) - (data1->offset < data2->offset); else if (write) /* Schedule "irrelevant" insns before memory stores to resolve as many producer dependencies of stores as possible. */ diff --git a/gcc/testsuite/gcc.dg/pr109187.c b/gcc/testsuite/gcc.dg/pr109187.c new file mode 100644 index 000000000..1ef14a73d --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr109187.c @@ -0,0 +1,8 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 --param sched-autopref-queue-depth=1" } */ + +void f(int *a) +{ + for (;;) + asm("" :: "r"(a[-0x10000000]), "r"(a[0x10000000]), "r"(a[0]) : "memory"); +}