preliminary peephole optimization of if statements

1 files changed, 5 insertions, 3 deletions

diff --git a/ir.h b/ir.h
index ff75163..c7fa118 100644
--- a/ir.h
+++ b/ir.h
@@ -12,7 +12,8 @@ typedef enum {
 	T_TOP, /* may or may not be a constant */
 	T_CONST, /* known compile-time constant */
 	T_BOT, /* known not a constant */
-	T_CTRL /* bottom of control flow */
+	T_CTRL, /* control flow bottom */
+	T_XCTRL, /* control flow top (dead) */
 } TypeLevel;
 
 typedef enum {
@@ -75,7 +76,7 @@ typedef struct Node {
 			int walked;
 			NodeType type;
 			LexSpan src_pos;
-			NodeInputs in;
+			NodeInputs in; /* note: index 0 used for control flow */
 			NodeOutputs out;
 			Value val;
 		};
@@ -133,7 +134,7 @@ void node_add_in(Proc *p, Node *a, Node *b);
 
 void node_remove(Proc *p, Node *src, Node *dest);
 Node *node_new_empty(Proc *p, NodeType t);
-Node *node_newv(Proc *p, NodeType t, ...);
+Node *node_newv(Proc *p, NodeType t, Node *ctrl, ...);
 Node *node_dedup_lit(Proc *p, Value v);
 Value node_compute(Node *n, Lexer *l);
 Node *node_peephole(Node *n, Proc *p, Lexer *l);
@@ -153,5 +154,6 @@ NameBinding *scope_find(Scope *scope, Str name);
 NameBinding *scope_bind(Scope *scope, Str name, Node *value, LexSpan pos, Proc *proc);
 NameBinding *scope_update(Scope *scope, Str name, Node *to, Proc *proc);
 void scope_collect(Scope *scope, Proc *proc, ScopeNameList *nl, Arena *arena);
+void scope_uncollect(Scope *scope, Proc *proc, ScopeNameList *nl);
 
 #endif