From 9855b3f0a2869d456f0ee34a94a1231eb6d44c4a Mon Sep 17 00:00:00 2001 From: Andrew MacLeod Date: Wed, 16 Aug 2023 13:23:06 -0400 Subject: [PATCH 1/4] Don't process phi groups with one phi. The phi analyzer should not create a phi group containing a single phi. * gimple-range-phi.cc (phi_analyzer::operator[]): Return NULL if no group was created. (phi_analyzer::process_phi): Do not create groups of one phi node. --- gcc/gimple-range-phi.cc | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/gcc/gimple-range-phi.cc b/gcc/gimple-range-phi.cc index ffb4691d06b..a94b90a4660 100644 --- a/gcc/gimple-range-phi.cc +++ b/gcc/gimple-range-phi.cc @@ -344,9 +344,10 @@ phi_analyzer::operator[] (tree name) process_phi (as_a (SSA_NAME_DEF_STMT (name))); if (bitmap_bit_p (m_simple, v)) return NULL; - // If m_simple bit isn't set, then process_phi allocated the table - // and should have a group. - gcc_checking_assert (v < m_tab.length ()); + // If m_simple bit isn't set, and process_phi didn't allocated the table + // no group was created, so return NULL. + if (v >= m_tab.length ()) + return NULL; } return m_tab[v]; } @@ -363,6 +364,7 @@ phi_analyzer::process_phi (gphi *phi) unsigned x; m_work.truncate (0); m_work.safe_push (gimple_phi_result (phi)); + unsigned phi_count = 1; bitmap_clear (m_current); // We can only have 2 externals: an initial value and a modifier. @@ -407,6 +409,7 @@ phi_analyzer::process_phi (gphi *phi) gimple *arg_stmt = SSA_NAME_DEF_STMT (arg); if (arg_stmt && is_a (arg_stmt)) { + phi_count++; m_work.safe_push (arg); continue; } @@ -430,9 +433,12 @@ phi_analyzer::process_phi (gphi *phi) } } - // If there are no names in the group, we're done. - if (bitmap_empty_p (m_current)) + // If there are less than 2 names, just return. This PHI may be included + // by another PHI, making it simple or a group of one will prevent a larger + // group from being formed. + if (phi_count < 2) return; + gcc_checking_assert (!bitmap_empty_p (m_current)); phi_group *g = NULL; if (cycle_p) -- 2.41.0