ocaml/asmcomp/i386/emit.mlp

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(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 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. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Emission of Intel 386 assembly code *)
open Misc
open Cmm
open Arch
open Proc
open Reg
open Mach
open Linearize
open Emitaux
(* Tradeoff between code size and code speed *)
let fastcode_flag = ref true
let stack_offset = ref 0
(* Layout of the stack frame *)
let frame_size () = (* includes return address *)
!stack_offset + 4 * num_stack_slots.(0) + 8 * num_stack_slots.(1) + 4
let slot_offset loc cl =
match loc with
Incoming n -> frame_size() + n
| Local n ->
if cl = 0
then !stack_offset + n * 4
else !stack_offset + num_stack_slots.(0) * 4 + n * 8
| Outgoing n -> n
(* Prefixing of symbols with "_" *)
let symbol_prefix =
match Config.system with
"linux_elf" -> ""
| "bsd_elf" -> ""
| "solaris" -> ""
| "beos" -> ""
| _ -> "_"
let emit_symbol s =
emit_string symbol_prefix; Emitaux.emit_symbol '$' s
(* Output a label *)
let label_prefix =
match Config.system with
"linux_elf" -> ".L"
| "bsd_elf" -> ".L"
| "solaris" -> ".L"
| "beos" -> ".L"
| _ -> "L"
let emit_label lbl =
emit_string label_prefix; emit_int lbl
(* Some data directives have different names under Solaris *)
let word_dir =
match Config.system with
"solaris" -> ".value"
| _ -> ".word"
let skip_dir =
match Config.system with
"solaris" -> ".zero"
| _ -> ".space"
let use_ascii_dir =
match Config.system with
"solaris" -> false
| _ -> true
(* Output a .align directive.
The numerical argument to .align is log2 of alignment size, except
under ELF, where it is the alignment size... *)
let emit_align =
match Config.system with
"linux_elf" | "bsd_elf" | "solaris" | "beos" | "cygwin" ->
(fun n -> ` .align {emit_int n}\n`)
| _ ->
(fun n -> ` .align {emit_int(Misc.log2 n)}\n`)
let emit_Llabel fallthrough lbl =
if not fallthrough && !fastcode_flag then
emit_align 16 ;
emit_label lbl
(* Output a pseudo-register *)
let emit_reg = function
{ loc = Reg r } ->
emit_string (register_name r)
| { loc = Stack s } as r ->
let ofs = slot_offset s (register_class r) in
`{emit_int ofs}(%esp)`
| { loc = Unknown } ->
fatal_error "Emit_i386.emit_reg"
(* Output a reference to the lower 8 bits or lower 16 bits of a register *)
let reg_low_byte_name = [| "%al"; "%bl"; "%cl"; "%dl" |]
let reg_low_half_name = [| "%ax"; "%bx"; "%cx"; "%dx"; "%si"; "%di"; "%bp" |]
let emit_reg8 r =
match r.loc with
Reg r when r < 4 -> emit_string (reg_low_byte_name.(r))
| _ -> fatal_error "Emit_i386.emit_reg8"
let emit_reg16 r =
match r.loc with
Reg r when r < 7 -> emit_string (reg_low_half_name.(r))
| _ -> fatal_error "Emit_i386.emit_reg16"
(* Output an addressing mode *)
let emit_addressing addr r n =
match addr with
Ibased(s, d) ->
`{emit_symbol s}`;
if d <> 0 then ` + {emit_int d}`
| Iindexed d ->
if d <> 0 then emit_int d;
`({emit_reg r.(n)})`
| Iindexed2 d ->
if d <> 0 then emit_int d;
`({emit_reg r.(n)}, {emit_reg r.(n+1)})`
| Iscaled(scale, d) ->
if d <> 0 then emit_int d;
`(, {emit_reg r.(n)}, {emit_int scale})`
| Iindexed2scaled(scale, d) ->
if d <> 0 then emit_int d;
`({emit_reg r.(n)}, {emit_reg r.(n+1)}, {emit_int scale})`
(* Record live pointers at call points *)
type frame_descr =
{ fd_lbl: int; (* Return address *)
fd_frame_size: int; (* Size of stack frame *)
fd_live_offset: int list } (* Offsets/regs of live addresses *)
let frame_descriptors = ref([] : frame_descr list)
let record_frame_label live =
let lbl = new_label() in
let live_offset = ref [] in
Reg.Set.iter
(function
{typ = Addr; loc = Reg r} ->
live_offset := ((r lsl 1) + 1) :: !live_offset
| {typ = Addr; loc = Stack s} as reg ->
live_offset := slot_offset s (register_class reg) :: !live_offset
| _ -> ())
live;
frame_descriptors :=
{ fd_lbl = lbl;
fd_frame_size = frame_size();
fd_live_offset = !live_offset } :: !frame_descriptors;
lbl
let record_frame live =
let lbl = record_frame_label live in `{emit_label lbl}:\n`
let emit_frame fd =
` .long {emit_label fd.fd_lbl}\n`;
` {emit_string word_dir} {emit_int fd.fd_frame_size}\n`;
` {emit_string word_dir} {emit_int (List.length fd.fd_live_offset)}\n`;
List.iter
(fun n ->
` {emit_string word_dir} {emit_int n}\n`)
fd.fd_live_offset;
emit_align 4
(* Record calls to the GC -- we've moved them out of the way *)
type gc_call =
{ gc_lbl: label; (* Entry label *)
gc_return_lbl: label; (* Where to branch after GC *)
gc_frame: label } (* Label of frame descriptor *)
let call_gc_sites = ref ([] : gc_call list)
let emit_call_gc gc =
`{emit_label gc.gc_lbl}: call {emit_symbol "caml_call_gc"}\n`;
`{emit_label gc.gc_frame}: jmp {emit_label gc.gc_return_lbl}\n`
(* Names for instructions *)
let instr_for_intop = function
Iadd -> "addl"
| Isub -> "subl"
| Imul -> "imull"
| Iand -> "andl"
| Ior -> "orl"
| Ixor -> "xorl"
| Ilsl -> "sall"
| Ilsr -> "shrl"
| Iasr -> "sarl"
| _ -> fatal_error "Emit_i386: instr_for_intop"
let instr_for_floatop = function
Inegf -> "fchs"
| Iabsf -> "fabs"
| Iaddf -> "faddl"
| Isubf -> "fsubl"
| Imulf -> "fmull"
| Idivf -> "fdivl"
| Ispecific Isubfrev -> "fsubrl"
| Ispecific Idivfrev -> "fdivrl"
| _ -> fatal_error "Emit_i386: instr_for_floatop"
let instr_for_floatop_reversed = function
Iaddf -> "faddl"
| Isubf -> "fsubrl"
| Imulf -> "fmull"
| Idivf -> "fdivrl"
| Ispecific Isubfrev -> "fsubl"
| Ispecific Idivfrev -> "fdivl"
| _ -> fatal_error "Emit_i386: instr_for_floatop_reversed"
let instr_for_floatop_pop = function
Iaddf -> "faddp"
| Isubf -> "fsubp"
| Imulf -> "fmulp"
| Idivf -> "fdivp"
| Ispecific Isubfrev -> "fsubrp"
| Ispecific Idivfrev -> "fdivrp"
| _ -> fatal_error "Emit_i386: instr_for_floatop_pop"
let instr_for_floatarithmem double = function
Ifloatadd -> if double then "faddl" else "fadds"
| Ifloatsub -> if double then "fsubl" else "fsubs"
| Ifloatsubrev -> if double then "fsubrl" else "fsubrs"
| Ifloatmul -> if double then "fmull" else "fmuls"
| Ifloatdiv -> if double then "fdivl" else "fdivs"
| Ifloatdivrev -> if double then "fdivrl" else "fdivrs"
let name_for_cond_branch = function
Isigned Ceq -> "e" | Isigned Cne -> "ne"
| Isigned Cle -> "le" | Isigned Cgt -> "g"
| Isigned Clt -> "l" | Isigned Cge -> "ge"
| Iunsigned Ceq -> "e" | Iunsigned Cne -> "ne"
| Iunsigned Cle -> "be" | Iunsigned Cgt -> "a"
| Iunsigned Clt -> "b" | Iunsigned Cge -> "ae"
(* Output an = 0 or <> 0 test. *)
let output_test_zero arg =
match arg.loc with
Reg r -> ` testl {emit_reg arg}, {emit_reg arg}\n`
| _ -> ` cmpl $0, {emit_reg arg}\n`
(* Deallocate the stack frame before a return or tail call *)
let output_epilogue () =
let n = frame_size() - 4 in
if n > 0 then ` addl ${emit_int n}, %esp\n`
(* Output the assembly code for an instruction *)
(* Name of current function *)
let function_name = ref ""
(* Entry point for tail recursive calls *)
let tailrec_entry_point = ref 0
(* Label of trap for out-of-range accesses *)
let range_check_trap = ref 0
let float_constants = ref ([] : (int * string) list)
let tos = phys_reg 100
let emit_instr fallthrough i =
match i.desc with
Lend -> ()
| Lop(Imove | Ispill | Ireload) ->
let src = i.arg.(0) and dst = i.res.(0) in
if src.loc <> dst.loc then begin
if src.typ = Float then
if src = tos then
` fstpl {emit_reg dst}\n`
else begin
` fldl {emit_reg src}\n`;
` fstpl {emit_reg dst}\n`
end
else
` movl {emit_reg src}, {emit_reg dst}\n`
end
| Lop(Iconst_int n) ->
if n = Nativeint.zero then begin
match i.res.(0).loc with
Reg n -> ` xorl {emit_reg i.res.(0)}, {emit_reg i.res.(0)}\n`
| _ -> ` movl $0, {emit_reg i.res.(0)}\n`
end else
` movl ${emit_nativeint n}, {emit_reg i.res.(0)}\n`
| Lop(Iconst_float s) ->
let f = float_of_string s in
if f = 0.0 then
` fldz\n`
else if f = 1.0 then
` fld1\n`
else begin
let lbl = new_label() in
float_constants := (lbl, s) :: !float_constants;
` fldl {emit_label lbl}\n`
end
| Lop(Iconst_symbol s) ->
` movl ${emit_symbol s}, {emit_reg i.res.(0)}\n`
| Lop(Icall_ind) ->
` call *{emit_reg i.arg.(0)}\n`;
record_frame i.live
| Lop(Icall_imm s) ->
` call {emit_symbol s}\n`;
record_frame i.live
| Lop(Itailcall_ind) ->
output_epilogue();
` jmp *{emit_reg i.arg.(0)}\n`
| Lop(Itailcall_imm s) ->
if s = !function_name then
` jmp {emit_label !tailrec_entry_point}\n`
else begin
output_epilogue();
` jmp {emit_symbol s}\n`
end
| Lop(Iextcall(s, alloc)) ->
if alloc then begin
` movl ${emit_symbol s}, %eax\n`;
` call {emit_symbol "caml_c_call"}\n`;
record_frame i.live
end else begin
` call {emit_symbol s}\n`
end
| Lop(Istackoffset n) ->
if n < 0
then ` addl ${emit_int(-n)}, %esp\n`
else ` subl ${emit_int(n)}, %esp\n`;
stack_offset := !stack_offset + n
| Lop(Iload(chunk, addr)) ->
let dest = i.res.(0) in
begin match chunk with
| Byte_unsigned ->
` movzbl {emit_addressing addr i.arg 0}, {emit_reg dest}\n`
| Byte_signed ->
` movsbl {emit_addressing addr i.arg 0}, {emit_reg dest}\n`
| Sixteen_unsigned ->
` movzwl {emit_addressing addr i.arg 0}, {emit_reg dest}\n`
| Sixteen_signed ->
` movswl {emit_addressing addr i.arg 0}, {emit_reg dest}\n`
| Single ->
` flds {emit_addressing addr i.arg 0}\n`
| Double | Double_u ->
` fldl {emit_addressing addr i.arg 0}\n`
| _ (* Word | Thirtytwo_signed | Thirtytwo_unsigned *) ->
` movl {emit_addressing addr i.arg 0}, {emit_reg dest}\n`
end
| Lop(Istore(chunk, addr)) ->
begin match chunk with
| Word | Thirtytwo_signed | Thirtytwo_unsigned ->
` movl {emit_reg i.arg.(0)}, {emit_addressing addr i.arg 1}\n`
| Byte_unsigned | Byte_signed ->
` movb {emit_reg8 i.arg.(0)}, {emit_addressing addr i.arg 1}\n`
| Sixteen_unsigned | Sixteen_signed ->
` movw {emit_reg16 i.arg.(0)}, {emit_addressing addr i.arg 1}\n`
| Single ->
if i.arg.(0) = tos then
` fstps {emit_addressing addr i.arg 1}\n`
else begin
` fldl {emit_reg i.arg.(0)}\n`;
` fstps {emit_addressing addr i.arg 1}\n`
end
| Double | Double_u ->
if i.arg.(0) = tos then
` fstpl {emit_addressing addr i.arg 1}\n`
else begin
` fldl {emit_reg i.arg.(0)}\n`;
` fstpl {emit_addressing addr i.arg 1}\n`
end
end
| Lop(Ialloc n) ->
if !fastcode_flag then begin
let lbl_redo = new_label() in
`{emit_label lbl_redo}: movl {emit_symbol "young_ptr"}, %eax\n`;
` subl ${emit_int n}, %eax\n`;
` movl %eax, {emit_symbol "young_ptr"}\n`;
` cmpl {emit_symbol "young_limit"}, %eax\n`;
let lbl_call_gc = new_label() in
let lbl_frame = record_frame_label i.live in
` jb {emit_label lbl_call_gc}\n`;
` leal 4(%eax), {emit_reg i.res.(0)}\n`;
call_gc_sites :=
{ gc_lbl = lbl_call_gc;
gc_return_lbl = lbl_redo;
gc_frame = lbl_frame } :: !call_gc_sites
end else begin
begin match n with
8 -> ` call {emit_symbol "caml_alloc1"}\n`
| 12 -> ` call {emit_symbol "caml_alloc2"}\n`
| 16 -> ` call {emit_symbol "caml_alloc3"}\n`
| _ -> ` movl ${emit_int n}, %eax\n`;
` call {emit_symbol "caml_alloc"}\n`
end;
`{record_frame i.live} leal 4(%eax), {emit_reg i.res.(0)}\n`
end
| Lop(Iintop(Icomp cmp)) ->
` cmpl {emit_reg i.arg.(1)}, {emit_reg i.arg.(0)}\n`;
let b = name_for_cond_branch cmp in
` set{emit_string b} %al\n`;
` movzbl %al, {emit_reg i.res.(0)}\n`
| Lop(Iintop_imm(Icomp cmp, n)) ->
` cmpl ${emit_int n}, {emit_reg i.arg.(0)}\n`;
let b = name_for_cond_branch cmp in
` set{emit_string b} %al\n`;
` movzbl %al, {emit_reg i.res.(0)}\n`
| Lop(Iintop Icheckbound) ->
if !range_check_trap = 0 then range_check_trap := new_label();
` cmpl {emit_reg i.arg.(1)}, {emit_reg i.arg.(0)}\n`;
` jbe {emit_label !range_check_trap}\n`
| Lop(Iintop_imm(Icheckbound, n)) ->
if !range_check_trap = 0 then range_check_trap := new_label();
` cmpl ${emit_int n}, {emit_reg i.arg.(0)}\n`;
` jbe {emit_label !range_check_trap}\n`
| Lop(Iintop(Idiv | Imod)) ->
` cltd\n`;
` idivl {emit_reg i.arg.(1)}\n`
| Lop(Iintop(Ilsl | Ilsr | Iasr as op)) ->
(* We have i.arg.(0) = i.res.(0) and i.arg.(1) = %ecx *)
` {emit_string(instr_for_intop op)} %cl, {emit_reg i.res.(0)}\n`
| Lop(Iintop op) ->
(* We have i.arg.(0) = i.res.(0) *)
` {emit_string(instr_for_intop op)} {emit_reg i.arg.(1)}, {emit_reg i.res.(0)}\n`
| Lop(Iintop_imm(Iadd, 1) | Iintop_imm(Isub, -1)) ->
` incl {emit_reg i.res.(0)}\n`
| Lop(Iintop_imm(Iadd, -1) | Iintop_imm(Isub, 1)) ->
` decl {emit_reg i.res.(0)}\n`
| Lop(Iintop_imm(Iadd, n)) when i.arg.(0).loc <> i.res.(0).loc ->
` leal {emit_int n}({emit_reg i.arg.(0)}), {emit_reg i.res.(0)}\n`
| Lop(Iintop_imm(Idiv, n)) ->
let l = Misc.log2 n in
let lbl = new_label() in
output_test_zero i.arg.(0);
` jge {emit_label lbl}\n`;
` addl ${emit_int(n-1)}, {emit_reg i.arg.(0)}\n`;
`{emit_label lbl}: sarl ${emit_int l}, {emit_reg i.arg.(0)}\n`
| Lop(Iintop_imm(Imod, n)) ->
let l = Misc.log2 n in
let lbl = new_label() in
` movl {emit_reg i.arg.(0)}, %eax\n`;
` testl %eax, %eax\n`;
` jge {emit_label lbl}\n`;
` addl ${emit_int(n-1)}, %eax\n`;
`{emit_label lbl}: andl ${emit_int(-n)}, %eax\n`;
` subl %eax, {emit_reg i.arg.(0)}\n`
| Lop(Iintop_imm(op, n)) ->
(* We have i.arg.(0) = i.res.(0) *)
` {emit_string(instr_for_intop op)} ${emit_int n}, {emit_reg i.res.(0)}\n`
| Lop(Inegf | Iabsf as floatop) ->
if i.arg.(0) <> tos then
` fldl {emit_reg i.arg.(0)}\n`;
` {emit_string(instr_for_floatop floatop)}\n`
| Lop(Iaddf | Isubf | Imulf | Idivf | Ispecific(Isubfrev | Idivfrev)
as floatop) ->
if i.arg.(0) = tos && i.arg.(1) = tos then
(* both operands on top of FP stack *)
` {emit_string(instr_for_floatop_pop floatop)} %st, %st(1)\n`
else if i.arg.(0) = tos then
(* first operand on stack *)
` {emit_string(instr_for_floatop floatop)} {emit_reg i.arg.(1)}\n`
else if i.arg.(1) = tos then
(* second operand on stack *)
` {emit_string(instr_for_floatop_reversed floatop)} {emit_reg i.arg.(0)}\n`
else begin
(* both operands in memory *)
` fldl {emit_reg i.arg.(0)}\n`;
` {emit_string(instr_for_floatop floatop)} {emit_reg i.arg.(1)}\n`
end
| Lop(Ifloatofint) ->
begin match i.arg.(0).loc with
Stack s ->
` fildl {emit_reg i.arg.(0)}\n`
| _ ->
` pushl {emit_reg i.arg.(0)}\n`;
` fildl (%esp)\n`;
` addl $4, %esp\n`
end
| Lop(Iintoffloat) ->
if i.arg.(0) <> tos then
` fldl {emit_reg i.arg.(0)}\n`;
stack_offset := !stack_offset - 8;
` subl $8, %esp\n`;
` fnstcw 4(%esp)\n`;
` movl 4(%esp), %eax\n`;
` movb $12, %ah\n`;
` movl %eax, (%esp)\n`;
` fldcw (%esp)\n`;
begin match i.res.(0).loc with
Stack s ->
` fistpl {emit_reg i.res.(0)}\n`
| _ ->
` fistpl (%esp)\n`;
` movl (%esp), {emit_reg i.res.(0)}\n`
end;
` fldcw 4(%esp)\n`;
` addl $8, %esp\n`;
stack_offset := !stack_offset + 8
| Lop(Ispecific(Ilea addr)) ->
` lea {emit_addressing addr i.arg 0}, {emit_reg i.res.(0)}\n`
| Lop(Ispecific(Istore_int(n, addr))) ->
` movl ${emit_nativeint n}, {emit_addressing addr i.arg 0}\n`
| Lop(Ispecific(Istore_symbol(s, addr))) ->
` movl ${emit_symbol s}, {emit_addressing addr i.arg 0}\n`
| Lop(Ispecific(Ioffset_loc(n, addr))) ->
` addl ${emit_int n}, {emit_addressing addr i.arg 0}\n`
| Lop(Ispecific(Ipush)) ->
(* Push arguments in reverse order *)
for n = Array.length i.arg - 1 downto 0 do
let r = i.arg.(n) in
match r with
{loc = Reg _; typ = Float} ->
` subl $8, %esp\n`;
` fstpl 0(%esp)\n`;
stack_offset := !stack_offset + 8
| {loc = Stack sl; typ = Float} ->
let ofs = slot_offset sl 1 in
` pushl {emit_int(ofs + 4)}(%esp)\n`;
` pushl {emit_int(ofs + 4)}(%esp)\n`;
stack_offset := !stack_offset + 8
| _ ->
` pushl {emit_reg r}\n`;
stack_offset := !stack_offset + 4
done
| Lop(Ispecific(Ipush_int n)) ->
` pushl ${emit_nativeint n}\n`;
stack_offset := !stack_offset + 4
| Lop(Ispecific(Ipush_symbol s)) ->
` pushl ${emit_symbol s}\n`;
stack_offset := !stack_offset + 4
| Lop(Ispecific(Ipush_load addr)) ->
` pushl {emit_addressing addr i.arg 0}\n`;
stack_offset := !stack_offset + 4
| Lop(Ispecific(Ipush_load_float addr)) ->
` pushl {emit_addressing (offset_addressing addr 4) i.arg 0}\n`;
` pushl {emit_addressing addr i.arg 0}\n`;
stack_offset := !stack_offset + 8
| Lop(Ispecific(Ifloatarithmem(double, op, addr))) ->
if i.arg.(0) <> tos then
` fldl {emit_reg i.arg.(0)}\n`;
` {emit_string(instr_for_floatarithmem double op)} {emit_addressing addr i.arg 1}\n`
| Lreloadretaddr ->
()
| Lreturn ->
output_epilogue();
` ret\n`
| Llabel lbl ->
`{emit_Llabel fallthrough lbl}:\n`
| Lbranch lbl ->
` jmp {emit_label lbl}\n`
| Lcondbranch(tst, lbl) ->
begin match tst with
Itruetest ->
output_test_zero i.arg.(0);
` jne {emit_label lbl}\n`
| Ifalsetest ->
output_test_zero i.arg.(0);
` je {emit_label lbl}\n`
| Iinttest cmp ->
` cmpl {emit_reg i.arg.(1)}, {emit_reg i.arg.(0)}\n`;
let b = name_for_cond_branch cmp in
` j{emit_string b} {emit_label lbl}\n`
| Iinttest_imm((Isigned Ceq | Isigned Cne |
Iunsigned Ceq | Iunsigned Cne) as cmp, 0) ->
output_test_zero i.arg.(0);
let b = name_for_cond_branch cmp in
` j{emit_string b} {emit_label lbl}\n`
| Iinttest_imm(cmp, n) ->
` cmpl ${emit_int n}, {emit_reg i.arg.(0)}\n`;
let b = name_for_cond_branch cmp in
` j{emit_string b} {emit_label lbl}\n`
| Ifloattest((Ceq | Cne as cmp), neg) ->
if i.arg.(1) <> tos then
` fldl {emit_reg i.arg.(1)}\n`;
if i.arg.(0) <> tos then
` fldl {emit_reg i.arg.(0)}\n`;
` fucompp\n`;
` fnstsw %ax\n`;
let neg1 = if cmp = Ceq then neg else not neg in
if neg1 then begin (* branch if different *)
` andb $68, %ah\n`;
` xorb $64, %ah\n`;
` jne {emit_label lbl}\n`
end else begin (* branch if equal *)
` andb $69, %ah\n`;
` cmpb $64, %ah\n`;
` je {emit_label lbl}\n`
end
| Ifloattest(cmp, neg) ->
let actual_cmp =
if i.arg.(0) = tos && i.arg.(1) = tos then begin
(* both args on top of FP stack *)
` fcompp\n`;
cmp
end else if i.arg.(0) = tos then begin
(* first arg on top of FP stack *)
` fcompl {emit_reg i.arg.(1)}\n`;
cmp
end else if i.arg.(1) = tos then begin
(* second arg on top of FP stack *)
` fcompl {emit_reg i.arg.(0)}\n`;
Cmm.swap_comparison cmp
end else begin
` fldl {emit_reg i.arg.(0)}\n`;
` fcompl {emit_reg i.arg.(1)}\n`;
cmp
end in
` fnstsw %ax\n`;
begin match actual_cmp with
Cle ->
` andb $69, %ah\n`;
` decb %ah\n`;
` cmpb $64, %ah\n`;
if neg
then ` jae `
else ` jb `
| Cge ->
` andb $5, %ah\n`;
if neg
then ` jne `
else ` je `
| Clt ->
` andb $69, %ah\n`;
` cmpb $1, %ah\n`;
if neg
then ` jne `
else ` je `
| Cgt ->
` andb $69, %ah\n`;
if neg
then ` jne `
else ` je `
| _ -> fatal_error "Emit_i386: floattest"
end;
`{emit_label lbl}\n`
| Ioddtest ->
` testl $1, {emit_reg i.arg.(0)}\n`;
` jne {emit_label lbl}\n`
| Ieventest ->
` testl $1, {emit_reg i.arg.(0)}\n`;
` je {emit_label lbl}\n`
end
| Lcondbranch3(lbl0, lbl1, lbl2) ->
` cmpl $1, {emit_reg i.arg.(0)}\n`;
begin match lbl0 with
None -> ()
| Some lbl -> ` jb {emit_label lbl}\n`
end;
begin match lbl1 with
None -> ()
| Some lbl -> ` je {emit_label lbl}\n`
end;
begin match lbl2 with
None -> ()
| Some lbl -> ` jg {emit_label lbl}\n`
end
| Lswitch jumptbl ->
let lbl = new_label() in
` jmp *{emit_label lbl}(, {emit_reg i.arg.(0)}, 4)\n`;
` .data\n`;
`{emit_label lbl}:`;
for i = 0 to Array.length jumptbl - 1 do
` .long {emit_label jumptbl.(i)}\n`
done;
` .text\n`
| Lsetuptrap lbl ->
` call {emit_label lbl}\n`
| Lpushtrap ->
` pushl {emit_symbol "caml_exception_pointer"}\n`;
` movl %esp, {emit_symbol "caml_exception_pointer"}\n`;
stack_offset := !stack_offset + 8
| Lpoptrap ->
` popl {emit_symbol "caml_exception_pointer"}\n`;
` addl $4, %esp\n`;
stack_offset := !stack_offset - 8
| Lraise ->
` movl {emit_symbol "caml_exception_pointer"}, %esp\n`;
` popl {emit_symbol "caml_exception_pointer"}\n`;
` ret\n`
let rec emit_all fallthrough i =
match i.desc with
| Lend -> ()
| _ ->
emit_instr fallthrough i;
emit_all
(Linearize.has_fallthrough i.desc)
i.next
(* Emission of the floating-point constants *)
let emit_float_constant (lbl, cst) =
` .data\n`;
`{emit_label lbl}: .double {emit_string cst}\n`
(* Emission of the profiling prelude *)
let emit_profile () =
match Config.system with
"linux_elf" ->
` pushl %eax\n`;
` movl %esp, %ebp\n`;
` pushl %ecx\n`;
` pushl %edx\n`;
` call {emit_symbol "mcount"}\n`;
` popl %edx\n`;
` popl %ecx\n`;
` popl %eax\n`
| "bsd_elf" ->
` pushl %eax\n`;
` movl %esp, %ebp\n`;
` pushl %ecx\n`;
` pushl %edx\n`;
` call .mcount\n`;
` popl %edx\n`;
` popl %ecx\n`;
` popl %eax\n`
| _ -> () (*unsupported yet*)
(* Emission of a function declaration *)
let fundecl fundecl =
function_name := fundecl.fun_name;
fastcode_flag := fundecl.fun_fast;
tailrec_entry_point := new_label();
stack_offset := 0;
float_constants := [];
call_gc_sites := [];
range_check_trap := 0;
` .text\n`;
emit_align 16;
` .globl {emit_symbol fundecl.fun_name}\n`;
`{emit_symbol fundecl.fun_name}:\n`;
if !Clflags.gprofile then emit_profile();
let n = frame_size() - 4 in
if n > 0 then
` subl ${emit_int n}, %esp\n`;
`{emit_label !tailrec_entry_point}:\n`;
emit_all true fundecl.fun_body;
List.iter emit_call_gc !call_gc_sites;
if !range_check_trap > 0 then
`{emit_label !range_check_trap}: call {emit_symbol "caml_array_bound_error"}\n`;
(* Never returns, but useful to have retaddr on stack for debugging *)
List.iter emit_float_constant !float_constants
(* Emission of data *)
let emit_item = function
Cdefine_symbol s ->
` .globl {emit_symbol s}\n`;
`{emit_symbol s}:\n`
| Cdefine_label lbl ->
`{emit_label (100000 + lbl)}:\n`
| Cint8 n ->
` .byte {emit_int n}\n`
| Cint16 n ->
` {emit_string word_dir} {emit_int n}\n`
| Cint32 n ->
` .long {emit_nativeint n}\n`
| Cint n ->
` .long {emit_nativeint n}\n`
| Csingle f ->
` .float {emit_string f}\n`
| Cdouble f ->
` .double {emit_string f}\n`
| Csymbol_address s ->
` .long {emit_symbol s}\n`
| Clabel_address lbl ->
` .long {emit_label (100000 + lbl)}\n`
| Cstring s ->
if use_ascii_dir
then emit_string_directive " .ascii " s
else emit_bytes_directive " .byte " s
| Cskip n ->
if n > 0 then ` {emit_string skip_dir} {emit_int n}\n`
| Calign n ->
emit_align n
let data l =
` .data\n`;
List.iter emit_item l
(* Beginning / end of an assembly file *)
let begin_assembly() =
let lbl_begin = Compilenv.current_unit_name() ^ "_data_begin" in
` .data\n`;
` .globl {emit_symbol lbl_begin}\n`;
`{emit_symbol lbl_begin}:\n`;
let lbl_begin = Compilenv.current_unit_name() ^ "_code_begin" in
` .text\n`;
` .globl {emit_symbol lbl_begin}\n`;
`{emit_symbol lbl_begin}:\n`
let end_assembly() =
let lbl_end = Compilenv.current_unit_name() ^ "_code_end" in
` .text\n`;
` .globl {emit_symbol lbl_end}\n`;
`{emit_symbol lbl_end}:\n`;
` .data\n`;
let lbl_end = Compilenv.current_unit_name() ^ "_data_end" in
` .globl {emit_symbol lbl_end}\n`;
`{emit_symbol lbl_end}:\n`;
` .long 0\n`;
let lbl = Compilenv.current_unit_name() ^ "_frametable" in
` .globl {emit_symbol lbl}\n`;
`{emit_symbol lbl}:\n`;
` .long {emit_int (List.length !frame_descriptors)}\n`;
List.iter emit_frame !frame_descriptors;
frame_descriptors := []