ARM64: add and recognize specific operation for sign extension

ocaml · Sep 22, 2020 · 3b7f1f8 · 3b7f1f8
1 parent 946b606
commit 3b7f1f8
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Showing 3 changed files with 16 additions and 1 deletion.
diff --git a/asmcomp/arm64/arch.ml b/asmcomp/arm64/arch.ml
@@ -61,6 +61,7 @@ type specific_operation =
   | Isqrtf        (* floating-point square root *)
   | Ibswap of int (* endianness conversion *)
   | Imove32       (* 32-bit integer move *)
+  | Isignext of int (* sign extension *)
 
 and arith_operation =
     Ishiftadd
@@ -70,7 +71,7 @@ let spacetime_node_hole_pointer_is_live_before = function
   | Ifar_alloc _ | Ifar_intop_checkbound _ | Ifar_intop_imm_checkbound _
   | Ishiftarith _ | Ishiftcheckbound _ | Ifar_shiftcheckbound _ -> false
   | Imuladd | Imulsub | Inegmulf | Imuladdf | Inegmuladdf | Imulsubf
-  | Inegmulsubf | Isqrtf | Ibswap _ | Imove32 -> false
+  | Inegmulsubf | Isqrtf | Ibswap _ | Imove32 | Isignext _ -> false
 
 (* Sizes, endianness *)
 
@@ -178,6 +179,9 @@ let print_specific_operation printreg op ppf arg =
   | Imove32 ->
       fprintf ppf "move32 %a"
         printreg arg.(0)
+  | Isignext n ->
+      fprintf ppf "signext%d %a"
+        n printreg arg.(0)
 
 (* Recognition of logical immediate arguments *)
 

diff --git a/asmcomp/arm64/emit.mlp b/asmcomp/arm64/emit.mlp
@@ -530,6 +530,7 @@ module BR = Branch_relaxation.Make (struct
     | Lop (Ispecific (Ibswap 16)) -> 2
     | Lop (Ispecific (Ibswap _)) -> 1
     | Lop (Ispecific Imove32) -> 1
+    | Lop (Ispecific (Isignext _)) -> 1
     | Lop (Iname_for_debugger _) -> 0
     | Lreloadretaddr -> 0
     | Lreturn -> epilogue_size ()
@@ -876,6 +877,8 @@ let emit_instr i =
         | _ ->
             assert false
         end
+    | Lop(Ispecific(Isignext size)) ->
+        `	sbfm	{emit_reg i.res.(0)}, {emit_reg i.arg.(0)}, #0, #{emit_int (size - 1)}\n`
     | Lop (Iname_for_debugger _) -> ()
     | Lreloadretaddr ->
         ()

diff --git a/asmcomp/arm64/selection.ml b/asmcomp/arm64/selection.ml
@@ -160,6 +160,14 @@ method! select_operation op args dbg =
       | _ ->
           super#select_operation op args dbg
       end
+  (* Recognize sign extension *)
+  | Casr ->
+      begin match args with
+        [Cop(Clsl, [k; Cconst_int (n, _)], _); Cconst_int (n', _)]
+        when n' = n && 0 < n && n < 64 ->
+          (Ispecific (Isignext (64 - n)), [k])
+        | _ -> super#select_operation op args dbg
+      end
   (* Recognize floating-point negate and multiply *)
   | Cnegf ->
       begin match args with