From 5500762bacffd7b45a0bfa8f89333e955734820f Mon Sep 17 00:00:00 2001 From: Andrew MacLeod Date: Mon, 16 Jan 2023 15:02:51 -0500 Subject: [PATCH 3/3] Correctly detect shifts out of range get_shift_range was incorrectly communicating that it couldn't calculate a range when the shift values was always out fo range. Fix this and alwasy return [0, 0] when the shift value is always out of range. PR tree-optimization/108306 gcc/ * range-op.cc (operator_lshift::fold_range): Return [0, 0] not varying for shifts that are always out of void range. (operator_rshift::fold_range): Return [0, 0] not varying for shifts that are always out of void range. gcc/testsuite/ * gcc.dg/pr108306.c: New. --- gcc/range-op.cc | 4 ++-- gcc/testsuite/gcc.dg/pr108306.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr108306.c diff --git a/gcc/range-op.cc b/gcc/range-op.cc index ec75e07bc8a..6e5754e9130 100644 --- a/gcc/range-op.cc +++ b/gcc/range-op.cc @@ -2166,7 +2166,7 @@ operator_lshift::fold_range (irange &r, tree type, if (op2.undefined_p ()) r.set_undefined (); else - r.set_varying (type); + r.set_zero (type); return true; } @@ -2440,7 +2440,7 @@ operator_rshift::fold_range (irange &r, tree type, if (op2.undefined_p ()) r.set_undefined (); else - r.set_varying (type); + r.set_zero (type); return true; } diff --git a/gcc/testsuite/gcc.dg/pr108306.c b/gcc/testsuite/gcc.dg/pr108306.c new file mode 100644 index 00000000000..1044c646de7 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr108306.c @@ -0,0 +1,29 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-strict-overflow -fsanitize=shift -Warray-bounds" } */ + +enum psi_task_count { + NR_IOWAIT, + NR_PSI_TASK_COUNTS = 4, +}; + +unsigned int tasks[NR_PSI_TASK_COUNTS]; + +static void psi_group_change(unsigned int set) +{ + unsigned int t; + unsigned int state_mask = 0; + + for (t = 0; set; set &= ~(1 << t), t++) + if (set & (1 << t)) + tasks[t]++; +} + +void psi_task_switch(int sleep) +{ + int set = 0; + + if (sleep) + set |= (1 << NR_IOWAIT); + + psi_group_change(set); +} -- 2.39.0