From 0182a25607fa353274c27ec57ca497c00f1d1b76 Mon Sep 17 00:00:00 2001 From: Andrew MacLeod Date: Mon, 6 Nov 2023 11:33:32 -0500 Subject: [PATCH] Choose better initial values for ranger. Instead of defaulting to VARYING, fold the stmt using just global ranges. PR tree-optimization/105834 gcc/ * gimple-range-cache.cc (ranger_cache::get_global_range): Call fold_range with global query to choose an initial value. gcc/testsuite/ * gcc.dg/pr105834.c --- gcc/gimple-range-cache.cc | 17 ++++++++++++++++- gcc/testsuite/gcc.dg/pr105834.c | 17 +++++++++++++++++ 2 files changed, 33 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/pr105834.c diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc index e4e75943632..b09df6c81bf 100644 --- a/gcc/gimple-range-cache.cc +++ b/gcc/gimple-range-cache.cc @@ -846,7 +846,22 @@ ranger_cache::get_global_range (vrange &r, tree name, bool ¤t_p) || m_temporal->current_p (name, m_gori.depend1 (name), m_gori.depend2 (name)); else - m_globals.set_global_range (name, r); + { + // If no global value has been set and value is VARYING, fold the stmt + // using just global ranges to get a better initial value. + // After inlining we tend to decide some things are constant, so + // do not do this evaluation after inlining. + if (r.varying_p () && !cfun->after_inlining) + { + gimple *s = SSA_NAME_DEF_STMT (name); + if (gimple_get_lhs (s) == name) + { + if (!fold_range (r, s, get_global_range_query ())) + gimple_range_global (r, name); + } + } + m_globals.set_global_range (name, r); + } // If the existing value was not current, mark it as always current. if (!current_p) diff --git a/gcc/testsuite/gcc.dg/pr105834.c b/gcc/testsuite/gcc.dg/pr105834.c new file mode 100644 index 00000000000..d0eda03ef8b --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr105834.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ + +static int a, b; + +void foo(); + +int main() { + for (int c = 0; c < 2; c = c + (unsigned)3) + if (a) + for (;;) + if (c > 0) + b = 0; + if (b) + foo(); +} +/* { dg-final { scan-tree-dump-not "foo" "optimized" } } */ -- 2.41.0