From d03d47c6e4ce9324d6d59ae36cb8db78b013be54 Mon Sep 17 00:00:00 2001 From: Bernhard Schommer Date: Fri, 26 Jun 2015 21:53:38 +0200 Subject: Merge branch 'asmexpand' of github.com:AbsInt/CompCert --- arm/Asmexpand.ml | 332 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 329 insertions(+), 3 deletions(-) (limited to 'arm/Asmexpand.ml') diff --git a/arm/Asmexpand.ml b/arm/Asmexpand.ml index 4baaac3d..95f35f37 100644 --- a/arm/Asmexpand.ml +++ b/arm/Asmexpand.ml @@ -11,8 +11,334 @@ (* *********************************************************************) (* Expanding built-ins and some pseudo-instructions by rewriting - of the ARM assembly code. Currently not done, this expansion - is performed on the fly in PrintAsm. *) + of the ARM assembly code. Currently not everything done, this + expansion is performed on the fly in PrintAsm. *) -let expand_program p = p +open Asm +open Asmexpandaux +open Asmgen +open AST +open Camlcoq +open Integers +(* Useful constants and helper functions *) + +let _0 = Integers.Int.zero +let _1 = Integers.Int.one +let _2 = coqint_of_camlint 2l +let _4 = coqint_of_camlint 4l +let _8 = coqint_of_camlint 8l +let _16 = coqint_of_camlint 16l + +(* Emit instruction sequences that set or offset a register by a constant. *) +(* No S suffix because they are applied to SP most of the time. *) + +let expand_movimm dst n = + match Asmgen.decompose_int n with + | [] -> assert false + | hd::tl-> + emit (Pmov (dst,SOimm hd)); + List.iter + (fun n -> emit (Porr (dst,dst, SOimm n))) tl + +let expand_subimm dst src n = + match Asmgen.decompose_int n with + | [] -> assert false + | hd::tl -> + emit (Psub(dst,src,SOimm hd)); + List.iter (fun n -> emit (Psub (dst,dst,SOimm n))) tl + +let expand_addimm dst src n = + match Asmgen.decompose_int n with + | [] -> assert false + | hd::tl -> + emit (Padd (dst,src,SOimm hd)); + List.iter (fun n -> emit (Padd (dst,dst,SOimm n))) tl + +let expand_int64_arith conflict rl fn = + if conflict then + begin + fn IR14; + emit (Pmov (rl,SOreg IR14)) + end else + fn rl + + +(* Built-ins. They come in two flavors: + - annotation statements: take their arguments in registers or stack + locations; generate no code; + - inlined by the compiler: take their arguments in arbitrary + registers. +*) + +(* Handling of annotations *) + +let expand_annot_val txt targ args res = + emit (Pannot (EF_annot(txt,[targ]), List.map (fun r -> AA_base r) args)); + match args, res with + | [IR src], [IR dst] -> + if dst <> src then emit (Pmov (dst,SOreg src)) + | [FR src], [FR dst] -> + if dst <> src then emit (Pfcpyd (dst,src)) + | _, _ -> assert false + + +(* Handling of memcpy *) + +(* The ARM has strict alignment constraints for 2 and 4 byte accesses. + 8-byte accesses must be 4-aligned. *) + +let expand_builtin_memcpy_small sz al src dst = + let rec copy ofs sz = + if sz >= 8 && al >= 4 && !Clflags.option_ffpu then begin + emit (Pfldd (FR7,src,ofs)); + emit (Pfstd (FR7,dst,ofs)); + copy (Int.add ofs _8) (sz - 8) + end else if sz >= 4 && al >= 4 then begin + emit (Pldr (IR14,src,SOimm ofs)); + emit (Pstr (IR14,dst,SOimm ofs)); + copy (Int.add ofs _4) (sz - 4) + end else if sz >= 2 && al >= 2 then begin + emit (Pldrh (IR14,src,SOimm ofs)); + emit (Pstrh (IR14,dst,SOimm ofs)); + copy (Int.add ofs _2) (sz - 2) + end else if sz >= 1 then begin + emit (Pldrb (IR14,src,SOimm ofs)); + emit (Pstrb (IR14,dst,SOimm ofs)); + copy (Int.add ofs _1) (sz - 1) + end else + () in + copy _0 sz + +let expand_builtin_memcpy_big sz al src dst = + assert (sz >= al); + assert (sz mod al = 0); + assert (src = IR2); + assert (dst = IR3); + let (load, store, chunksize) = + if al >= 4 then (Pldr (IR12,src,SOimm _4), Pstr (IR12,dst,SOimm _4) , 4) + else if al = 2 then (Pldrh (IR12,src,SOimm _2), Pstrh (IR12,dst,SOimm _2), 2) + else (Pldrb (IR12,src,SOimm _1), Pstrb (IR12,dst,SOimm _1), 1) in + expand_movimm IR14 (coqint_of_camlint (Int32.of_int (sz / chunksize))); + let lbl = new_label () in + emit (Plabel lbl); + emit load; + emit (Psubs (IR14,IR14,SOimm _1)); + emit store; + emit (Pbne lbl) + +let expand_builtin_memcpy sz al args = + let (dst, src) = + match args with [IR d; IR s] -> (d, s) | _ -> assert false in + if sz <= 32 + then expand_builtin_memcpy_small sz al src dst + else expand_builtin_memcpy_big sz al src dst + +(* Handling of volatile reads and writes *) + +let expand_builtin_vload_common chunk args res = + match chunk, args, res with + | Mint8unsigned, [IR addr], [IR res] -> + emit (Pldrb (res, addr,SOimm _0)) + | Mint8signed, [IR addr], [IR res] -> + emit (Pldrsb (res, addr,SOimm _0)) + | Mint16unsigned, [IR addr], [IR res] -> + emit (Pldrh (res, addr, SOimm _0)) + | Mint16signed, [IR addr], [IR res] -> + emit (Pldrsh (res, addr, SOimm _0)) + | Mint32, [IR addr], [IR res] -> + emit (Pldr (res,addr, SOimm _0)) + | Mint64, [IR addr], [IR res1; IR res2] -> + if addr <> res2 then begin + emit (Pldr (res2, addr, SOimm _0)); + emit (Pldr (res1, addr, SOimm _4)) + end else begin + emit (Pldr (res1,addr, SOimm _4)); + emit (Pldr (res2,addr, SOimm _0)) + end + | Mfloat32, [IR addr], [FR res] -> + emit (Pflds (res, addr, _0)) + | Mfloat64, [IR addr], [FR res] -> + emit (Pfldd (res,addr, _0)) + | _ -> + assert false + +let expand_builtin_vload chunk args res = + expand_builtin_vload_common chunk args res + +let expand_builtin_vload_global chunk id ofs args res = + emit (Ploadsymbol (IR14,id,ofs)); + expand_builtin_vload_common chunk args res + +let expand_builtin_vstore_common chunk args = + match chunk, args with + | (Mint8signed | Mint8unsigned), [IR addr; IR src] -> + emit (Pstrb (src,addr, SOimm _0)) + | (Mint16signed | Mint16unsigned), [IR addr; IR src] -> + emit (Pstrh (src,addr, SOimm _0)) + | Mint32, [IR addr; IR src] -> + emit (Pstr (src,addr, SOimm _0)) + | Mint64, [IR addr; IR src1; IR src2] -> + emit (Pstr (src2,addr,SOimm _0)); + emit (Pstr (src1,addr,SOimm _0)) + | Mfloat32, [IR addr; FR src] -> + emit (Pfstd (src,addr,_0)) + | Mfloat64, [IR addr; FR src] -> + emit (Pfsts (src,addr,_0)); + | _ -> + assert false + +let expand_builtin_vstore chunk args = + expand_builtin_vstore_common chunk args + +let expand_builtin_vstore_global chunk id ofs args = + emit (Ploadsymbol (IR14,id,ofs)); + expand_builtin_vstore_common chunk args + +(* Handling of varargs *) + +let align n a = (n + a - 1) land (-a) + +let rec next_arg_location ir ofs = function + | [] -> + Int32.of_int (ir * 4 + ofs) + | (Tint | Tsingle | Tany32) :: l -> + if ir < 4 + then next_arg_location (ir + 1) ofs l + else next_arg_location ir (ofs + 4) l + | (Tfloat | Tlong | Tany64) :: l -> + if ir < 3 + then next_arg_location (align ir 2 + 2) ofs l + else next_arg_location ir (align ofs 8 + 8) l + +let expand_builtin_va_start r = + if not !current_function.fn_sig.sig_cc.cc_vararg then + invalid_arg "Fatal error: va_start used in non-vararg function"; + let ofs = + Int32.add + (next_arg_location 0 0 !current_function.fn_sig.sig_args) + !PrintAsmaux.current_function_stacksize in + expand_addimm IR14 IR13 (coqint_of_camlint ofs); + emit (Pstr (IR14,r,SOimm _0)) + + +(* Handling of compiler-inlined builtins *) +let expand_builtin_inline name args res = + match name, args, res with + (* Integer arithmetic *) + | ("__builtin_bswap" | "__builtin_bswap32"), [IR a1], [IR res] -> + emit (Prev (IR res,IR a1)) + | "__builtin_bswap16", [IR a1], [IR res] -> + emit (Prev16 (IR res,IR a1)) + | "__builtin_clz", [IR a1], [IR res] -> + emit (Pclz (IR res, IR a1)) + (* Float arithmetic *) + | "__builtin_fabs", [FR a1], [FR res] -> + emit (Pfabsd (res,a1)) + | "__builtin_fsqrt", [FR a1], [FR res] -> + emit (Pfsqrt (res,a1)) + (* 64-bit integer arithmetic *) + | "__builtin_negl", [IR ah;IR al], [IR rh; IR rl] -> + emit (Prsbs (rl,al,SOimm _0)); + if !Clflags.option_mthumb then begin + emit (Pmvn (rh,SOreg ah)); + emit (Padc (rh,rh,SOimm _0)) + end else + begin + emit (Prsc (rh,ah,SOimm _0)) + end + | "__builtin_addl", [IR ah; IR al; IR bh; IR bl], [IR rh; IR rl] -> + expand_int64_arith (rl = ah || rl = bh) rl + (fun rl -> + emit (Padds (rl,al,SOreg bl)); + emit (Padc (rh,ah,SOreg bh))) + | "__builtin_subl", [IR ah; IR al; IR bh; IR bl], [IR rh; IR rl] -> + expand_int64_arith (rl = ah || rl = bh) rl + (fun rl -> + emit (Psubs (rl,al,SOreg bl)); + emit (Psbc (rh,ah,SOreg bh))) + | "__builtin_mull", [IR a; IR b], [IR rh; IR rl] -> + emit (Pumull (rl,rh,a,b)) + (* Memory accesses *) + | "__builtin_read16_reversed", [IR a1], [IR res] -> + emit (Pldrh (res,a1,SOimm _0)); + emit (Prev16 (IR res,IR res)); + | "__builtin_read32_reversed", [IR a1], [IR res] -> + emit (Pldr (res,a1,SOimm _0)); + emit (Prev (IR res,IR res)); + | "__builtin_write16_reverse", [IR a1; IR a2], _ -> + emit (Prev16 (IR IR14, IR a2)); + emit (Pstrh (IR14, a1, SOimm _0)) + | "__builtin_write32_reverse", [IR a1; IR a2], _ -> + emit (Prev (IR IR14, IR a2)); + emit (Pstr (IR14, a1, SOimm _0)) + (* Synchronization *) + | "__builtin_membar",[], _ -> + () + | "__builtin_dmb", [], _ -> + emit Pdmb + | "__builtin_dsb", [], _ -> + emit Pdsb + | "__builtin_isb", [], _ -> + emit Pisb + (* Vararg stuff *) + | "__builtin_va_start", [IR a], _ -> + expand_builtin_va_start a + (* Catch-all *) + | _ -> + invalid_arg ("unrecognized builtin " ^ name) + +let expand_instruction instr = + match instr with + | Pallocframe (sz, ofs) -> + emit (Pmov (IR12,SOreg IR13)); + if (!current_function).fn_sig.sig_cc.cc_vararg then begin + emit (Ppush [IR0;IR1;IR2;IR3]); + emit (Pcfi_adjust _16); + end; + expand_subimm IR13 IR13 sz; + emit (Pcfi_adjust sz); + emit (Pstr (IR12,IR13,SOimm ofs)) + | Pfreeframe (sz, ofs) -> + let sz = + if (!current_function).fn_sig.sig_cc.cc_vararg + then coqint_of_camlint (Int32.add 16l (camlint_of_coqint sz)) + else sz in + if Asmgen.is_immed_arith sz + then emit (Padd (IR13,IR13,SOimm sz)) + else emit (Pldr (IR13,IR13,SOimm sz)) + | Pbuiltin (ef,args,res) -> + begin match ef with + | EF_builtin (name,sg) -> + expand_builtin_inline (extern_atom name) args res + | EF_vload chunk -> + expand_builtin_vload chunk args res + | EF_vstore chunk -> + expand_builtin_vstore chunk args + | EF_vload_global(chunk, id, ofs) -> + expand_builtin_vload_global chunk id ofs args res + | EF_vstore_global(chunk, id, ofs) -> + expand_builtin_vstore_global chunk id ofs args + | EF_annot_val (txt,targ) -> + expand_annot_val txt targ args res + | EF_memcpy(sz, al) -> + expand_builtin_memcpy (Int32.to_int (camlint_of_coqint sz)) + (Int32.to_int (camlint_of_coqint al)) args + | EF_inline_asm(txt, sg, clob) -> + emit instr + | _ -> assert false + end + | _ -> + emit instr + +let expand_function fn = + set_current_function fn; + List.iter expand_instruction fn.fn_code; + get_current_function () + +let expand_fundef = function + | Internal f -> Internal (expand_function f) + | External ef -> External ef + +let expand_program (p: Asm.program) : Asm.program = + AST.transform_program expand_fundef p -- cgit