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New back-end optimization pass: dead code elimination.

(Removes arithmetic and load instructions whose results are unused.)
(Cherry-picked from branch backend-optim.)


git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14686 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
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commit 9c1d005ebb21b9eff2804ac4d80450251ffe6b5a 1 parent 452390e
Xavier Leroy xavierleroy authored
79 .depend
View
@@ -1,4 +1,4 @@
-putils/ccomp.cmi :
+utils/ccomp.cmi :
utils/clflags.cmi :
utils/config.cmi :
utils/consistbl.cmi :
@@ -455,15 +455,15 @@ bytecomp/bytesections.cmx : utils/misc.cmx utils/config.cmx \
bytecomp/dll.cmo : utils/misc.cmi utils/config.cmi bytecomp/dll.cmi
bytecomp/dll.cmx : utils/misc.cmx utils/config.cmx bytecomp/dll.cmi
bytecomp/emitcode.cmo : bytecomp/translmod.cmi typing/primitive.cmi \
- bytecomp/opcodes.cmo utils/misc.cmi bytecomp/meta.cmi bytecomp/lambda.cmi \
- bytecomp/instruct.cmi typing/env.cmi utils/config.cmi \
- bytecomp/cmo_format.cmi utils/clflags.cmi typing/btype.cmi \
- parsing/asttypes.cmi bytecomp/emitcode.cmi
+ bytecomp/opcodes.cmo utils/misc.cmi bytecomp/meta.cmi \
+ parsing/location.cmi bytecomp/lambda.cmi bytecomp/instruct.cmi \
+ typing/env.cmi utils/config.cmi bytecomp/cmo_format.cmi utils/clflags.cmi \
+ typing/btype.cmi parsing/asttypes.cmi bytecomp/emitcode.cmi
bytecomp/emitcode.cmx : bytecomp/translmod.cmx typing/primitive.cmx \
- bytecomp/opcodes.cmx utils/misc.cmx bytecomp/meta.cmx bytecomp/lambda.cmx \
- bytecomp/instruct.cmx typing/env.cmx utils/config.cmx \
- bytecomp/cmo_format.cmi utils/clflags.cmx typing/btype.cmx \
- parsing/asttypes.cmi bytecomp/emitcode.cmi
+ bytecomp/opcodes.cmx utils/misc.cmx bytecomp/meta.cmx \
+ parsing/location.cmx bytecomp/lambda.cmx bytecomp/instruct.cmx \
+ typing/env.cmx utils/config.cmx bytecomp/cmo_format.cmi utils/clflags.cmx \
+ typing/btype.cmx parsing/asttypes.cmi bytecomp/emitcode.cmi
bytecomp/instruct.cmo : typing/types.cmi typing/subst.cmi \
parsing/location.cmi bytecomp/lambda.cmi typing/ident.cmi typing/env.cmi \
bytecomp/instruct.cmi
@@ -508,12 +508,12 @@ bytecomp/printlambda.cmx : typing/types.cmx typing/primitive.cmx \
parsing/asttypes.cmi bytecomp/printlambda.cmi
bytecomp/runtimedef.cmo : bytecomp/runtimedef.cmi
bytecomp/runtimedef.cmx : bytecomp/runtimedef.cmi
-bytecomp/simplif.cmo : utils/tbl.cmi typing/stypes.cmi bytecomp/lambda.cmi \
- typing/ident.cmi utils/clflags.cmi parsing/asttypes.cmi typing/annot.cmi \
- bytecomp/simplif.cmi
-bytecomp/simplif.cmx : utils/tbl.cmx typing/stypes.cmx bytecomp/lambda.cmx \
- typing/ident.cmx utils/clflags.cmx parsing/asttypes.cmi typing/annot.cmi \
- bytecomp/simplif.cmi
+bytecomp/simplif.cmo : utils/tbl.cmi typing/stypes.cmi utils/misc.cmi \
+ bytecomp/lambda.cmi typing/ident.cmi utils/clflags.cmi \
+ parsing/asttypes.cmi typing/annot.cmi bytecomp/simplif.cmi
+bytecomp/simplif.cmx : utils/tbl.cmx typing/stypes.cmx utils/misc.cmx \
+ bytecomp/lambda.cmx typing/ident.cmx utils/clflags.cmx \
+ parsing/asttypes.cmi typing/annot.cmi bytecomp/simplif.cmi
bytecomp/switch.cmo : bytecomp/switch.cmi
bytecomp/switch.cmx : bytecomp/switch.cmi
bytecomp/symtable.cmo : utils/tbl.cmi bytecomp/runtimedef.cmi \
@@ -592,6 +592,7 @@ asmcomp/coloring.cmi :
asmcomp/comballoc.cmi : asmcomp/mach.cmi
asmcomp/compilenv.cmi : typing/ident.cmi asmcomp/cmx_format.cmi \
asmcomp/clambda.cmi
+asmcomp/deadcode.cmi : asmcomp/mach.cmi
asmcomp/debuginfo.cmi : parsing/location.cmi bytecomp/lambda.cmi
asmcomp/emit.cmi : asmcomp/linearize.cmi asmcomp/cmm.cmi
asmcomp/emitaux.cmi : asmcomp/debuginfo.cmi
@@ -625,20 +626,20 @@ asmcomp/asmgen.cmo : bytecomp/translmod.cmi asmcomp/split.cmi \
asmcomp/printlinear.cmi asmcomp/printcmm.cmi asmcomp/printclambda.cmi \
typing/primitive.cmi utils/misc.cmi asmcomp/mach.cmi parsing/location.cmi \
asmcomp/liveness.cmi asmcomp/linearize.cmi asmcomp/interf.cmi \
- asmcomp/emitaux.cmi asmcomp/emit.cmi utils/config.cmi \
- asmcomp/compilenv.cmi asmcomp/comballoc.cmi asmcomp/coloring.cmi \
- asmcomp/cmmgen.cmi asmcomp/cmm.cmi asmcomp/closure.cmi utils/clflags.cmi \
- asmcomp/asmgen.cmi
+ asmcomp/emitaux.cmi asmcomp/emit.cmi asmcomp/deadcode.cmi \
+ utils/config.cmi asmcomp/compilenv.cmi asmcomp/comballoc.cmi \
+ asmcomp/coloring.cmi asmcomp/cmmgen.cmi asmcomp/cmm.cmi \
+ asmcomp/closure.cmi utils/clflags.cmi asmcomp/asmgen.cmi
asmcomp/asmgen.cmx : bytecomp/translmod.cmx asmcomp/split.cmx \
asmcomp/spill.cmx asmcomp/selection.cmx asmcomp/scheduling.cmx \
asmcomp/reload.cmx asmcomp/reg.cmx asmcomp/proc.cmx asmcomp/printmach.cmx \
asmcomp/printlinear.cmx asmcomp/printcmm.cmx asmcomp/printclambda.cmx \
typing/primitive.cmx utils/misc.cmx asmcomp/mach.cmx parsing/location.cmx \
asmcomp/liveness.cmx asmcomp/linearize.cmx asmcomp/interf.cmx \
- asmcomp/emitaux.cmx asmcomp/emit.cmx utils/config.cmx \
- asmcomp/compilenv.cmx asmcomp/comballoc.cmx asmcomp/coloring.cmx \
- asmcomp/cmmgen.cmx asmcomp/cmm.cmx asmcomp/closure.cmx utils/clflags.cmx \
- asmcomp/asmgen.cmi
+ asmcomp/emitaux.cmx asmcomp/emit.cmx asmcomp/deadcode.cmx \
+ utils/config.cmx asmcomp/compilenv.cmx asmcomp/comballoc.cmx \
+ asmcomp/coloring.cmx asmcomp/cmmgen.cmx asmcomp/cmm.cmx \
+ asmcomp/closure.cmx utils/clflags.cmx asmcomp/asmgen.cmi
asmcomp/asmlibrarian.cmo : utils/misc.cmi parsing/location.cmi \
utils/config.cmi asmcomp/compilenv.cmi asmcomp/cmx_format.cmi \
utils/clflags.cmi asmcomp/clambda.cmi utils/ccomp.cmi asmcomp/asmlink.cmi \
@@ -719,6 +720,10 @@ asmcomp/compilenv.cmo : utils/misc.cmi parsing/location.cmi typing/ident.cmi \
asmcomp/compilenv.cmx : utils/misc.cmx parsing/location.cmx typing/ident.cmx \
typing/env.cmx utils/config.cmx asmcomp/cmx_format.cmi \
asmcomp/clambda.cmx asmcomp/compilenv.cmi
+asmcomp/deadcode.cmo : asmcomp/reg.cmi asmcomp/proc.cmi asmcomp/mach.cmi \
+ asmcomp/deadcode.cmi
+asmcomp/deadcode.cmx : asmcomp/reg.cmx asmcomp/proc.cmx asmcomp/mach.cmx \
+ asmcomp/deadcode.cmi
asmcomp/debuginfo.cmo : parsing/location.cmi bytecomp/lambda.cmi \
asmcomp/debuginfo.cmi
asmcomp/debuginfo.cmx : parsing/location.cmx bytecomp/lambda.cmx \
@@ -983,18 +988,22 @@ toplevel/opttopmain.cmx : utils/warnings.cmx asmcomp/printmach.cmx \
driver/compenv.cmx utils/clflags.cmx toplevel/opttopmain.cmi
toplevel/opttopstart.cmo : toplevel/opttopmain.cmi
toplevel/opttopstart.cmx : toplevel/opttopmain.cmx
-toplevel/topdirs.cmo : utils/warnings.cmi typing/types.cmi \
- toplevel/trace.cmi toplevel/toploop.cmi bytecomp/symtable.cmi \
- typing/printtyp.cmi typing/path.cmi bytecomp/opcodes.cmo utils/misc.cmi \
- bytecomp/meta.cmi parsing/longident.cmi typing/ident.cmi typing/env.cmi \
- bytecomp/dll.cmi typing/ctype.cmi utils/consistbl.cmi utils/config.cmi \
- bytecomp/cmo_format.cmi utils/clflags.cmi toplevel/topdirs.cmi
-toplevel/topdirs.cmx : utils/warnings.cmx typing/types.cmx \
- toplevel/trace.cmx toplevel/toploop.cmx bytecomp/symtable.cmx \
- typing/printtyp.cmx typing/path.cmx bytecomp/opcodes.cmx utils/misc.cmx \
- bytecomp/meta.cmx parsing/longident.cmx typing/ident.cmx typing/env.cmx \
- bytecomp/dll.cmx typing/ctype.cmx utils/consistbl.cmx utils/config.cmx \
- bytecomp/cmo_format.cmi utils/clflags.cmx toplevel/topdirs.cmi
+toplevel/topdirs.cmo : utils/warnings.cmi typing/typetexp.cmi \
+ typing/types.cmi toplevel/trace.cmi toplevel/toploop.cmi \
+ bytecomp/symtable.cmi typing/printtyp.cmi typing/path.cmi \
+ parsing/parsetree.cmi bytecomp/opcodes.cmo utils/misc.cmi \
+ bytecomp/meta.cmi parsing/longident.cmi parsing/location.cmi \
+ typing/ident.cmi typing/env.cmi bytecomp/dll.cmi typing/ctype.cmi \
+ utils/consistbl.cmi utils/config.cmi bytecomp/cmo_format.cmi \
+ utils/clflags.cmi toplevel/topdirs.cmi
+toplevel/topdirs.cmx : utils/warnings.cmx typing/typetexp.cmx \
+ typing/types.cmx toplevel/trace.cmx toplevel/toploop.cmx \
+ bytecomp/symtable.cmx typing/printtyp.cmx typing/path.cmx \
+ parsing/parsetree.cmi bytecomp/opcodes.cmx utils/misc.cmx \
+ bytecomp/meta.cmx parsing/longident.cmx parsing/location.cmx \
+ typing/ident.cmx typing/env.cmx bytecomp/dll.cmx typing/ctype.cmx \
+ utils/consistbl.cmx utils/config.cmx bytecomp/cmo_format.cmi \
+ utils/clflags.cmx toplevel/topdirs.cmi
toplevel/toploop.cmo : utils/warnings.cmi typing/types.cmi \
typing/typemod.cmi typing/typedtree.cmi typing/typecore.cmi \
bytecomp/translmod.cmi bytecomp/symtable.cmi bytecomp/simplif.cmi \
2  Changes
View
@@ -39,6 +39,8 @@ Compilers:
int32/int64/nativeint arithmetic. Constant propagation for floats
can be turned off with option -no-float-const-prop, for codes that
change FP rounding modes at run-time.
+- New back-end optimization pass: dead code elimination.
+ (Removes arithmetic and load instructions whose results are unused.)
- PR#6269 Optimization of string matching (patch by Benoit Vaugon
and Luc Maranget)
- Experimental native code generator for AArch64 (ARM 64 bits)
1  Makefile
View
@@ -88,6 +88,7 @@ ASMCOMP=asmcomp/arch.cmo asmcomp/debuginfo.cmo \
asmcomp/spill.cmo asmcomp/split.cmo \
asmcomp/interf.cmo asmcomp/coloring.cmo \
asmcomp/reloadgen.cmo asmcomp/reload.cmo \
+ asmcomp/deadcode.cmo \
asmcomp/printlinear.cmo asmcomp/linearize.cmo \
asmcomp/schedgen.cmo asmcomp/scheduling.cmo \
asmcomp/emitaux.cmo asmcomp/emit.cmo asmcomp/asmgen.cmo \
11 asmcomp/amd64/proc.ml
View
@@ -294,6 +294,17 @@ let max_register_pressure = function
if fp then [| 12; 15 |] else [| 13; 15 |]
| _ -> if fp then [| 12; 16 |] else [| 13; 16 |]
+(* Pure operations (without any side effect besides updating their result
+ registers). *)
+
+let op_is_pure = function
+ | Icall_ind | Icall_imm _ | Itailcall_ind | Itailcall_imm _
+ | Iextcall _ | Istackoffset _ | Istore _ | Ialloc _
+ | Iintop(Icheckbound) | Iintop_imm(Icheckbound, _) -> false
+ | Ispecific(Ilea _) -> true
+ | Ispecific _ -> false
+ | _ -> true
+
(* Layout of the stack frame *)
let num_stack_slots = [| 0; 0 |]
9 asmcomp/arm/proc.ml
View
@@ -225,6 +225,15 @@ let max_register_pressure = function
| Iload(Single, _) | Istore(Single, _) -> [| 9; 15; 31 |]
| _ -> [| 9; 16; 32 |]
+(* Pure operations (without any side effect besides updating their result
+ registers). *)
+
+let op_is_pure = function
+ | Icall_ind | Icall_imm _ | Itailcall_ind | Itailcall_imm _
+ | Iextcall _ | Istackoffset _ | Istore _ | Ialloc _
+ | Iintop(Icheckbound) | Iintop_imm(Icheckbound, _) -> false
+ | _ -> true
+
(* Layout of the stack *)
let num_stack_slots = [| 0; 0; 0 |]
1  asmcomp/asmgen.ml
View
@@ -65,6 +65,7 @@ let compile_fundecl (ppf : formatter) fd_cmm =
++ Comballoc.fundecl
++ pass_dump_if ppf dump_combine "After allocation combining"
++ liveness ppf
+ ++ Deadcode.fundecl
++ pass_dump_if ppf dump_live "Liveness analysis"
++ Spill.fundecl
++ liveness ppf
66 asmcomp/deadcode.ml
View
@@ -0,0 +1,66 @@
+(***********************************************************************)
+(* *)
+(* OCaml *)
+(* *)
+(* Xavier Leroy, projet Gallium, INRIA Rocquencourt *)
+(* *)
+(* Copyright 2012 Institut National de Recherche en Informatique et *)
+(* en Automatique. All rights reserved. This file is distributed *)
+(* under the terms of the Q Public License version 1.0. *)
+(* *)
+(***********************************************************************)
+
+(* $Id: linearize.ml 11156 2011-07-27 14:17:02Z doligez $ *)
+
+(* Dead code elimination: remove pure instructions whose results are
+ not used. *)
+
+open Mach
+
+(* [deadcode i] returns a pair of an optimized instruction [i']
+ and a set of registers live "before" instruction [i]. *)
+
+let rec deadcode i =
+ match i.desc with
+ | Iend | Ireturn | Iop(Itailcall_ind) | Iop(Itailcall_imm _) | Iraise _ ->
+ (i, Reg.add_set_array i.live i.arg)
+ | Iop op ->
+ let (s, before) = deadcode i.next in
+ if Proc.op_is_pure op
+ && Reg.disjoint_set_array before i.res then begin
+ assert (Array.length i.res > 0); (* sanity check *)
+ (s, before)
+ end else begin
+ ({i with next = s}, Reg.add_set_array i.live i.arg)
+ end
+ | Iifthenelse(test, ifso, ifnot) ->
+ let (ifso', _) = deadcode ifso in
+ let (ifnot', _) = deadcode ifnot in
+ let (s, _) = deadcode i.next in
+ ({i with desc = Iifthenelse(test, ifso', ifnot'); next = s},
+ Reg.add_set_array i.live i.arg)
+ | Iswitch(index, cases) ->
+ let cases' = Array.map (fun c -> fst (deadcode c)) cases in
+ let (s, _) = deadcode i.next in
+ ({i with desc = Iswitch(index, cases'); next = s},
+ Reg.add_set_array i.live i.arg)
+ | Iloop(body) ->
+ let (body', _) = deadcode body in
+ let (s, _) = deadcode i.next in
+ ({i with desc = Iloop body'; next = s}, i.live)
+ | Icatch(nfail, body, handler) ->
+ let (body', _) = deadcode body in
+ let (handler', _) = deadcode handler in
+ let (s, _) = deadcode i.next in
+ ({i with desc = Icatch(nfail, body', handler'); next = s}, i.live)
+ | Iexit nfail ->
+ (i, i.live)
+ | Itrywith(body, handler) ->
+ let (body', _) = deadcode body in
+ let (handler', _) = deadcode handler in
+ let (s, _) = deadcode i.next in
+ ({i with desc = Itrywith(body', handler'); next = s}, i.live)
+
+let fundecl f =
+ let (new_body, _) = deadcode f.fun_body in
+ {f with fun_body = new_body}
18 asmcomp/deadcode.mli
View
@@ -0,0 +1,18 @@
+(***********************************************************************)
+(* *)
+(* OCaml *)
+(* *)
+(* Xavier Leroy, projet Gallium, INRIA Rocquencourt *)
+(* *)
+(* Copyright 2012 Institut National de Recherche en Informatique et *)
+(* en Automatique. All rights reserved. This file is distributed *)
+(* under the terms of the Q Public License version 1.0. *)
+(* *)
+(***********************************************************************)
+
+(* $Id: linearize.ml 11156 2011-07-27 14:17:02Z doligez $ *)
+
+(* Dead code elimination: remove pure instructions whose results are
+ not used. *)
+
+val fundecl: Mach.fundecl -> Mach.fundecl
14 asmcomp/i386/proc.ml
View
@@ -182,6 +182,20 @@ let max_register_pressure = function
Iintoffloat -> [| 6; max_int |]
| _ -> [|7; max_int |]
+(* Pure operations (without any side effect besides updating their result
+ registers). Note that floating-point operations are not pure
+ because they update the float stack. *)
+
+let op_is_pure = function
+ | Icall_ind | Icall_imm _ | Itailcall_ind | Itailcall_imm _
+ | Iextcall _ | Istackoffset _ | Istore _ | Ialloc _
+ | Iintop(Icheckbound) | Iintop_imm(Icheckbound, _) -> false
+ | Iconst_float _ | Inegf | Iabsf | Iaddf | Isubf | Imulf | Idivf
+ | Iintoffloat | Ifloatofint | Iload((Single | Double | Double_u), _) -> false
+ | Ispecific(Ilea _) -> true
+ | Ispecific _ -> false
+ | _ -> true
+
(* Layout of the stack frame *)
let num_stack_slots = [| 0; 0 |]
45 asmcomp/liveness.ml
View
@@ -16,13 +16,13 @@
open Mach
let live_at_exit = ref []
+
let find_live_at_exit k =
try
List.assoc k !live_at_exit
with
- | Not_found -> Misc.fatal_error "Spill.find_live_at_exit"
+ | Not_found -> Misc.fatal_error "Liveness.find_live_at_exit"
-let live_at_break = ref Reg.Set.empty
let live_at_raise = ref Reg.Set.empty
let rec live i finally =
@@ -37,8 +37,30 @@ let rec live i finally =
i.live <- finally;
finally
| Ireturn | Iop(Itailcall_ind) | Iop(Itailcall_imm _) ->
- (* i.live remains empty since no regs are live across *)
+ i.live <- Reg.Set.empty; (* no regs are live across *)
Reg.set_of_array i.arg
+ | Iop op ->
+ let after = live i.next finally in
+ if Proc.op_is_pure op && Reg.disjoint_set_array after i.res then begin
+ (* This operation is dead code. Ignore its arguments. *)
+ i.live <- after;
+ after
+ end else begin
+ let across_after = Reg.diff_set_array after i.res in
+ let across =
+ match op with
+ | Icall_ind | Icall_imm _ | Iextcall _
+ | Iintop Icheckbound | Iintop_imm(Icheckbound, _) ->
+ (* The function call may raise an exception, branching to the
+ nearest enclosing try ... with. Similarly for bounds checks.
+ Hence, everything that must be live at the beginning of
+ the exception handler must also be live across this instr. *)
+ Reg.Set.union across_after !live_at_raise
+ | _ ->
+ across_after in
+ i.live <- across;
+ Reg.add_set_array across i.arg
+ end
| Iifthenelse(test, ifso, ifnot) ->
let at_join = live i.next finally in
let at_fork = Reg.Set.union (live ifso at_join) (live ifnot at_join) in
@@ -90,23 +112,8 @@ let rec live i finally =
i.live <- before_body;
before_body
| Iraise _ ->
- (* i.live remains empty since no regs are live across *)
+ i.live <- !live_at_raise;
Reg.add_set_array !live_at_raise i.arg
- | _ ->
- let across_after = Reg.diff_set_array (live i.next finally) i.res in
- let across =
- match i.desc with
- Iop Icall_ind | Iop(Icall_imm _) | Iop(Iextcall _)
- | Iop(Iintop Icheckbound) | Iop(Iintop_imm(Icheckbound, _)) ->
- (* The function call may raise an exception, branching to the
- nearest enclosing try ... with. Similarly for bounds checks.
- Hence, everything that must be live at the beginning of
- the exception handler must also be live across this instr. *)
- Reg.Set.union across_after !live_at_raise
- | _ ->
- across_after in
- i.live <- across;
- Reg.add_set_array across i.arg
let fundecl ppf f =
let initially_live = live f.fun_body Reg.Set.empty in
11 asmcomp/power/proc.ml
View
@@ -224,6 +224,17 @@ let max_register_pressure = function
Iextcall(_, _) -> [| 15; 18 |]
| _ -> [| 23; 30 |]
+(* Pure operations (without any side effect besides updating their result
+ registers). *)
+
+let op_is_pure = function
+ | Icall_ind | Icall_imm _ | Itailcall_ind | Itailcall_imm _
+ | Iextcall _ | Istackoffset _ | Istore _ | Ialloc _
+ | Iintop(Icheckbound) | Iintop_imm(Icheckbound, _) -> false
+ | Ispecific(Imultaddf | Imultsubf) -> true
+ | Ispecific _ -> false
+ | _ -> true
+
(* Layout of the stack *)
let num_stack_slots = [| 0; 0 |]
3  asmcomp/proc.mli
View
@@ -40,6 +40,9 @@ val max_register_pressure: Mach.operation -> int array
val destroyed_at_oper: Mach.instruction_desc -> Reg.t array
val destroyed_at_raise: Reg.t array
+(* Pure operations *)
+val op_is_pure: Mach.operation -> bool
+
(* Info for laying out the stack frame *)
val num_stack_slots: int array
val contains_calls: bool ref
10 asmcomp/reg.ml
View
@@ -178,6 +178,16 @@ let inter_set_array s v =
else inter_all(i+1)
in inter_all 0
+let disjoint_set_array s v =
+ match Array.length v with
+ 0 -> true
+ | 1 -> not (Set.mem v.(0) s)
+ | n -> let rec disjoint_all i =
+ if i >= n then true
+ else if Set.mem v.(i) s then false
+ else disjoint_all (i+1)
+ in disjoint_all 0
+
let set_of_array v =
match Array.length v with
0 -> Set.empty
1  asmcomp/reg.mli
View
@@ -58,6 +58,7 @@ module Map: Map.S with type key = t
val add_set_array: Set.t -> t array -> Set.t
val diff_set_array: Set.t -> t array -> Set.t
val inter_set_array: Set.t -> t array -> Set.t
+val disjoint_set_array: Set.t -> t array -> bool
val set_of_array: t array -> Set.t
val reset: unit -> unit
9 asmcomp/sparc/proc.ml
View
@@ -196,6 +196,15 @@ let max_register_pressure = function
Iextcall(_, _) -> [| 11; 0 |]
| _ -> [| 19; 15 |]
+(* Pure operations (without any side effect besides updating their result
+ registers). *)
+
+let op_is_pure = function
+ | Icall_ind | Icall_imm _ | Itailcall_ind | Itailcall_imm _
+ | Iextcall _ | Istackoffset _ | Istore _ | Ialloc _
+ | Iintop(Icheckbound) | Iintop_imm(Icheckbound, _) -> false
+ | _ -> true
+
(* Layout of the stack *)
let num_stack_slots = [| 0; 0 |]
7 asmcomp/spill.ml
View
@@ -233,7 +233,12 @@ let rec reload i before =
(i, Reg.Set.empty)
| Itrywith(body, handler) ->
let (new_body, after_body) = reload body before in
- let (new_handler, after_handler) = reload handler handler.live in
+ (* All registers live at the beginning of the handler are destroyed,
+ except the exception bucket *)
+ let before_handler =
+ Reg.Set.remove Proc.loc_exn_bucket
+ (Reg.add_set_array handler.live handler.arg) in
+ let (new_handler, after_handler) = reload handler before_handler in
let (new_next, finally) =
reload i.next (Reg.Set.union after_body after_handler) in
(instr_cons (Itrywith(new_body, new_handler)) i.arg i.res new_next,
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