From 8be20f3b0bded7f9b690b27cbee58b283dbe827b Mon Sep 17 00:00:00 2001 From: Andrew MacLeod Date: Thu, 12 Oct 2023 17:06:36 -0400 Subject: [PATCH] Do not add partial equivalences with no uses. PR tree-optimization/111622 * value-relation.cc (equiv_oracle::add_partial_equiv): Do not register a partial equivalence if an operand has no uses. --- gcc/value-relation.cc | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/gcc/value-relation.cc b/gcc/value-relation.cc index 0326fe7cde6..c0f513a0eb1 100644 --- a/gcc/value-relation.cc +++ b/gcc/value-relation.cc @@ -392,6 +392,9 @@ equiv_oracle::add_partial_equiv (relation_kind r, tree op1, tree op2) // In either case, if PE2 has an entry, we simply do nothing. if (pe2.members) return; + // If there are no uses of op2, do not register. + if (has_zero_uses (op2)) + return; // PE1 is the LHS and already has members, so everything in the set // should be a slice of PE2 rather than PE1. pe2.code = pe_min (r, pe1.code); @@ -409,6 +412,9 @@ equiv_oracle::add_partial_equiv (relation_kind r, tree op1, tree op2) } if (pe2.members) { + // If there are no uses of op1, do not register. + if (has_zero_uses (op1)) + return; pe1.ssa_base = pe2.ssa_base; // If pe2 is a 16 bit value, but only an 8 bit copy, we can't be any // more than an 8 bit equivalence here, so choose MIN value. @@ -418,6 +424,9 @@ equiv_oracle::add_partial_equiv (relation_kind r, tree op1, tree op2) } else { + // If there are no uses of either operand, do not register. + if (has_zero_uses (op1) || has_zero_uses (op2)) + return; // Neither name has an entry, simply create op1 as slice of op2. pe2.code = bits_to_pe (TYPE_PRECISION (TREE_TYPE (op2))); if (pe2.code == VREL_VARYING)