From eab20602b1a11b9f989a8d73460e3ccfb7c173e9 Mon Sep 17 00:00:00 2001
From: Dale Weiler <weilercdale@gmail.com>
Date: Thu, 24 Nov 2016 14:44:28 +0000
Subject: [PATCH] more intelligent handling of unused vector fields
---
ir.cpp | 29 ++++++++++++++++++++++++++---
1 file changed, 26 insertions(+), 3 deletions(-)
diff --git a/ir.cpp b/ir.cpp
index 51aab91..d6a5493 100644
--- a/ir.cpp
+++ b/ir.cpp
@@ -633,9 +633,32 @@ bool ir_function_finalize(ir_function *self)
for (auto& lp : self->m_locals) {
ir_value *v = lp.get();
- if (v->m_reads.empty() && v->m_writes.size()
- && irwarning(v->m_context, WARN_UNUSED_VARIABLE,
- "unused variable: `%s`", v->m_name.c_str())) return false;
+ if (v->m_reads.empty() && v->m_writes.size()) {
+ // if it's a vector check to ensure all it's members are unused before
+ // claiming it's unused, otherwise skip the vector entierly
+ if (v->m_vtype == TYPE_VECTOR)
+ {
+ size_t mask = (1 << 0) | (1 << 1) | (1 << 2), bits = 0;
+ for (size_t i = 0; i < 3; i++)
+ if (!v->m_members[i] || (v->m_members[i]->m_reads.empty()
+ && v->m_members[i]->m_writes.size()))
+ bits |= (1 << i);
+ // all components are unused so just report the vector
+ if (bits == mask && irwarning(v->m_context, WARN_UNUSED_VARIABLE,
+ "unused variable: `%s`", v->m_name.c_str()))
+ return false;
+ else if (bits != mask)
+ // individual components are unused so mention them
+ for (size_t i = 0; i < 3; i++)
+ if ((bits & (1 << i))
+ && irwarning(v->m_context, WARN_UNUSED_VARIABLE,
+ "unused variable: `%s.%c`", v->m_name.c_str(), "xyz"[i]))
+ return false;
+ }
+ // just a standard variable
+ else if (irwarning(v->m_context, WARN_UNUSED_VARIABLE,
+ "unused variable: `%s`", v->m_name.c_str())) return false;
+ }
}
if (OPTS_OPTIMIZATION(OPTIM_PEEPHOLE)) {
--
2.39.5