2 files changed, 34 insertions, 0 deletions
diff --git a/src/glsl/loop_analysis.cpp b/src/glsl/loop_analysis.cpp
index 9bba6a97c48..6a0e4da5100 100644
--- a/src/glsl/loop_analysis.cpp
+++ b/src/glsl/loop_analysis.cpp
@@ -110,6 +110,8 @@ public:
    virtual ir_visitor_status visit(ir_loop_jump *);
    virtual ir_visitor_status visit(ir_dereference_variable *);
 
+   virtual ir_visitor_status visit_enter(ir_call *);
+
    virtual ir_visitor_status visit_enter(ir_loop *);
    virtual ir_visitor_status visit_leave(ir_loop *);
    virtual ir_visitor_status visit_enter(ir_assignment *);
@@ -153,6 +155,21 @@ loop_analysis::visit(ir_loop_jump *ir)
 
 
 ir_visitor_status
+loop_analysis::visit_enter(ir_call *ir)
+{
+   /* If we're not somewhere inside a loop, there's nothing to do. */
+   if (this->state.is_empty())
+      return visit_continue;
+
+   loop_variable_state *const ls =
+      (loop_variable_state *) this->state.get_head();
+
+   ls->contains_calls = true;
+   return visit_continue_with_parent;
+}
+
+
+ir_visitor_status
 loop_analysis::visit(ir_dereference_variable *ir)
 {
    /* If we're not somewhere inside a loop, there's nothing to do.
@@ -209,6 +226,17 @@ loop_analysis::visit_leave(ir_loop *ir)
    loop_variable_state *const ls =
       (loop_variable_state *) this->state.pop_head();
 
+   /* Function calls may contain side effects.  These could alter any of our
+    * variables in ways that cannot be known, and may even terminate shader
+    * execution (say, calling discard in the fragment shader).  So we can't
+    * rely on any of our analysis about assignments to variables.
+    *
+    * We could perform some conservative analysis (prove there's no statically
+    * possible assignment, etc.) but it isn't worth it for now; function
+    * inlining will allow us to unroll loops anyway.
+    */
+   if (ls->contains_calls)
+      return visit_continue;
 
    foreach_list(node, &ir->body_instructions) {
       /* Skip over declarations at the start of a loop.
diff --git a/src/glsl/loop_analysis.h b/src/glsl/loop_analysis.h
index 229730836a8..8bed1db0210 100644
--- a/src/glsl/loop_analysis.h
+++ b/src/glsl/loop_analysis.h
@@ -122,10 +122,16 @@ public:
     */
    unsigned num_loop_jumps;
 
+   /**
+    * Whether this loop contains any function calls.
+    */
+   bool contains_calls;
+
    loop_variable_state()
    {
       this->max_iterations = -1;
       this->num_loop_jumps = 0;
+      this->contains_calls = false;
       this->var_hash = hash_table_ctor(0, hash_table_pointer_hash,
 				       hash_table_pointer_compare);
    }