Initial import of l5c

[snipe.git] / codegen / peephole.sml

diff --git a/codegen/peephole.sml b/codegen/peephole.sml
deleted file mode 100644 (file)
index 7bf55a1..0000000
--- a/codegen/peephole.sml
+++ /dev/null
@@ -1,46 +0,0 @@
-(* L3 compiler
- * peephole optimizer
- * optimizes away redundant insns such as:
-     mov a, b
-     mov a, b
-
-     mov a, b
-     mov b, a
-
-     mov a, a
-     
-     neg a
-     neg a
- * Author: Chris Lu <czl@andrew.cmu.edu>
- *)
-
-signature PEEPHOLE =
-sig
-  val peephole : x86.insn list -> x86.insn list
-end
-
-structure Peephole :> PEEPHOLE =
-struct
-  structure X = x86
-
-  (* val peephole : x86.insn list -> x86.insn list *)
-
-  fun peephole ((insn1 as X.MOV(a1,b1))::(insn2 as X.MOV(a2,b2))::l) =
-        if(x86.opereq(a1, b1) orelse (x86.opereq(a1, a2) andalso x86.opereq(b1, b2))) then
-          peephole (insn2::l)
-        else if(x86.opereq(a2, b2) orelse (x86.opereq(a1, b2) andalso x86.opereq(b1, a2))) then
-          peephole (insn1::l)
-        else
-          insn1::(peephole (insn2::l))
-    | peephole (X.MOV (X.REG r, X.CONST 0w0)::l) = (X.XOR (X.REG r, X.REG r))::(peephole l)
-    | peephole ((insn as X.MOV(a,b))::l) = if x86.opereq(a, b) then peephole l else insn::(peephole l)
-    | peephole ((insn1 as X.NEG(a))::(insn2 as X.NEG(b))::l) = if x86.opereq(a, b) then peephole l else insn1::(peephole (insn2::l))
-    | peephole (X.ADD (_, X.CONST 0w0)::l) = peephole l
-    | peephole (X.SUB (_, X.CONST 0w0)::l) = peephole l
-    | peephole (X.CMP (X.REG r, X.CONST 0w0)::l) = (X.TEST (X.REG r, X.REG r))::(peephole l)
-    | peephole ((X.JMP a)::(X.JMP b)::l) = peephole ((X.JMP a)::l) (* What the cock? Yes, we actually generate this. *)
-    | peephole ((X.JMP l1)::(X.LABEL l2)::l) = if (Label.compare (l1,l2) = EQUAL) then (X.LABEL l2)::(peephole l) else (X.JMP l1)::(X.LABEL l2)::(peephole l)
-    | peephole (a::l) = a::(peephole l)
-    | peephole nil = nil
-
-end