line  =
      ws? s:stmt eol { yy->v = s; }
    | eol { yy->v.kind = ASM_BLANK; }
    | . { yy->v.kind = ASM_SYNTAX_ERROR; }

ws = 
    [ \t]+
  | "/*" (! "*/" . )* "*/" # XXX multiline comments break our line numbers.

eol = ws? "\n"

stmt =
    '.' d:directive {$$ = d;}
  | i:instr { $$ = i; }
  | l:label {  $$ = l; } 

directive =
   "glob" 'o'? 'l' ws i:ident
   { $$.globl = (Globl){.kind = ASM_DIR_GLOBL, .name = i.charptr }; }
  | "ascii" <'z'?> ws s:string
    { s.kind = *yytext ? ASM_DIR_ASCII : ASM_DIR_ASCIIZ ; $$ = s; }
  | "data" 
    { $$.kind = ASM_DIR_DATA; }
  | "text"
    { $$.kind = ASM_DIR_TEXT; }
  | "balign" ws n:number 
    { $$.balign = (Balign){.kind = ASM_DIR_BALIGN, .align = n.i64 }; }
  | "byte" ws v:value
    { $$.dirbyte = (Byte){.kind = ASM_DIR_BYTE, .value = v.value }; }
  | "int" ws v:value
    { $$.dirint = (Int){.kind = ASM_DIR_INT,  .value = v.value }; }
  | "quad" ws v:value
    { $$.dirquad = (Quad){.kind = ASM_DIR_QUAD, .value = v.value }; }
  | fd:fill-directive
    { $$ = fd; }
  | sd:section-directive
    { $$ = sd; }

fill-directive = 
  "fill" ws r:number ws? "," ws? s:number ws? "," ws? v:number
  { $$.fill = (Fill){ .kind=ASM_DIR_FILL, .repeat = r.i64, .size = s.i64, .value = v.i64 }; }

section-directive =
  "section" ws? n:section-name (
      ws? ',' ws? f:section-flags ws? ',' ws? t:section-type
      {$$.section = (DirSection){.kind=ASM_DIR_SECTION, .name=n.charptr, .flags=f.charptr, .type=t.i64}; }
    | ws? ',' ws? f:section-flags
      {$$.section = (DirSection){.kind=ASM_DIR_SECTION, .name=n.charptr, .flags=f.charptr, .type=SHT_PROGBITS}; }
    | 
      {$$.section = (DirSection){.kind=ASM_DIR_SECTION, .name=n.charptr, .flags="", .type=SHT_PROGBITS}; }
  )

section-name = <[.a-zA-Z0-9\-]+> { $$.charptr = xstrdup(yytext); }
section-flags = '"' <[awx]*> '"' { $$.charptr = xstrdup(yytext); }
section-type =
    "@nobits" { $$.i64 = SHT_NOBITS; }
  | "@progbits" { $$.i64 = SHT_PROGBITS; }

label = 
  i:ident ':'
  { $$.label = (Label){.kind = ASM_LABEL, .name = i.charptr}; }

instr = 
  # XXX Order the rules by frequency to get better lookup time.
    "nop"      { $$.kind = ASM_NOP; }
  | "leave"    { $$.kind = ASM_LEAVE; }
  | "ret"      { $$.kind = ASM_RET; }
  | "cltd"     { $$.kind = ASM_CLTD; }
  | "cqto"     { $$.kind = ASM_CQTO; }
  | i:push     { $$ = i; }
  | i:pop      { $$ = i; }
  | i:call     { $$ = i; }
  | i:jmp      { $$ = i; }
  | i:add      { $$ = i; }
  | i:and      { $$ = i; }
  | i:cvtss2sd { $$ = i; }
  | i:cvtsd2ss { $$ = i; }
  | i:cmp      { $$ = i; }
  | i:div      { $$ = i; }
  | i:idiv     { $$ = i; }
  | i:lea      { $$ = i; }
  | i:mulsd    { $$ = i; }
  | i:mulss    { $$ = i; }
  | i:mul      { $$ = i; }
  | i:imul     { $$ = i; }
  | i:neg      { $$ = i; }
  | i:movsd    { $$ = i; }
  | i:movss    { $$ = i; }
  | i:movsx    { $$ = i; }
  | i:movzx    { $$ = i; }
  | i:mov      { $$ = i; }
  | i:or       { $$ = i; }
  | i:set      { $$ = i; }
  | i:sub      { $$ = i; }
  | i:sal      { $$ = i; }
  | i:sar      { $$ = i; }
  | i:shl      { $$ = i; }
  | i:shr      { $$ = i; }
  | i:test     { $$ = i; }
  | i:ucomisd  { $$ = i; }
  | i:ucomiss  { $$ = i; }
  | i:test     { $$ = i; }
  | i:xchg     { $$ = i; }
  | i:xorpd    { $$ = i; }
  | i:xorps    { $$ = i; }
  | i:xor      { $$ = i; }

push = 
  "push" (
      'q'? ws  s:r64 { $$ = INSTR1(0, s); }
    | 'q'  ws  s:m   { $$ = INSTR1(1, s); }
  ) { $$.instr.kind = ASM_PUSH; }

pop = 
  "pop" (
      'q'? ws d:r64 { $$ = INSTR1(0, d); }
    | 'q'  ws d:m   { $$ = INSTR1(1, d); }
  ) { $$.instr.kind = ASM_POP; }

call = 
  "call" 'q'? ws t:ident 
  { $$.call = (Call){ .kind = ASM_CALL, .target=t.charptr } ; }

jmp = 'j' v:jmp-variant ws t:ident
    { $$.jmp = (Jmp) {.kind = ASM_JMP, .variant=v.i64, .target=t.charptr}; }

jmp-variant =
      "mp"  { $$.i64 = 0; }
    | cc:condition-code { $$.i64 = cc.i64 + 1;}

condition-code = 
      "z"   { $$.i64 = 0; }
    | "s"   { $$.i64 = 1; }
    | "po"  { $$.i64 = 2; }
    | "pe"  { $$.i64 = 3; }
    | "p"   { $$.i64 = 4; }
    | "o"   { $$.i64 = 5; }
    | "nz"  { $$.i64 = 6; }
    | "ns"  { $$.i64 = 7; }
    | "np"  { $$.i64 = 8; }
    | "no"  { $$.i64 = 9; }
    | "nle" { $$.i64 = 10; }
    | "nl"  { $$.i64 = 11; }
    | "nge" { $$.i64 = 12; }
    | "ng"  { $$.i64 = 13; }
    | "ne"  { $$.i64 = 14; }
    | "nc"  { $$.i64 = 15; }
    | "nbe" { $$.i64 = 16; }
    | "nb"  { $$.i64 = 17; }
    | "nae" { $$.i64 = 18; }
    | "na"  { $$.i64 = 19; }
    | "le"  { $$.i64 = 20; }
    | "l"   { $$.i64 = 21; }
    | "ge"  { $$.i64 = 22; }
    | "g"   { $$.i64 = 23; }
    | "e"   { $$.i64 = 24; }
    | "c"   { $$.i64 = 25; }
    | "be"  { $$.i64 = 26; }
    | "b"   { $$.i64 = 27; }
    | "ae"  { $$.i64 = 28; }
    | "a"   { $$.i64 = 29; }

lea = 
  "lea" (
      'w'? ws s:m ws? ',' ws? d:r16 { $$ = INSTR2(0, s, d); }
    | 'l'? ws s:m ws? ',' ws? d:r32 { $$ = INSTR2(1, s, d); }
    | 'q'? ws s:m ws? ',' ws? d:r64 { $$ = INSTR2(2, s, d); }
  ) { $$.instr.kind = ASM_LEA; }

div = "div" (
    args:m-opargs { $$ = args; }
  | args:r-opargs { args.instr.variant += 4 ; $$ = args; }
)  { $$.instr.kind = ASM_DIV; }

idiv = "idiv" (
    args:m-opargs { $$ = args; }
  | args:r-opargs { args.instr.variant += 4 ; $$ = args; }
)  { $$.instr.kind = ASM_IDIV; }

# TODO XXX Combine the xmm variants into single instructions??

cvtss2sd = "cvtss2sd" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m     ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
)  { $$.instr.kind = ASM_CVTSS2SD; }

cvtsd2ss = "cvtsd2ss" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m     ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
)  { $$.instr.kind = ASM_CVTSD2SS; }

mulsd = "mulsd" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m     ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
)  { $$.instr.kind = ASM_MULSD; }

mulss = "mulss" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m     ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
)  { $$.instr.kind = ASM_MULSS; }

movss = "movss" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m   ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
  | ws s:xmm ws? ',' ws? d:m   { $$ = INSTR2(2, s, d); }
)  { $$.instr.kind = ASM_MOVSS; }

movsd = "movsd" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m   ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
  | ws s:xmm ws? ',' ws? d:m   { $$ = INSTR2(2, s, d); }
)  { $$.instr.kind = ASM_MOVSD; }

ucomiss = "ucomiss" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m     ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
)  { $$.instr.kind = ASM_UCOMISS; }

ucomisd = "ucomisd" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m     ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
)  { $$.instr.kind = ASM_UCOMISD; }

xorpd = "xorpd" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m   ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
)  { $$.instr.kind = ASM_XORPD; }

xorps = "xorps" (
    ws s:xmm ws? ',' ws? d:xmm { $$ = INSTR2(0, s, d); }
  | ws s:m   ws? ',' ws? d:xmm { $$ = INSTR2(1, s, d); }
)  { $$.instr.kind = ASM_XORPS; }

mul = "mul" (
    args:m-opargs { $$ = args; }
  | args:r-opargs { args.instr.variant += 4 ; $$ = args; }
)  { $$.instr.kind = ASM_MUL; }

neg = "neg" (
    args:m-opargs { $$ = args; }
  | args:r-opargs { args.instr.variant += 4 ; $$ = args; }
)  { $$.instr.kind = ASM_NEG; }

imul = "imul" (
    (
        'w'? ws s:m     ws? ',' ws? d:r16 { $$ = INSTR2(8, s, d); }
      | 'l'? ws s:m     ws? ',' ws? d:r32 { $$ = INSTR2(9, s, d); }
      | 'q'? ws s:m     ws? ',' ws? d:r64 { $$ = INSTR2(10, s, d); }
      | 'w'? ws s:r16   ws? ',' ws? d:r16 { $$ = INSTR2(11, s, d); }
      | 'l'? ws s:r32   ws? ',' ws? d:r32 { $$ = INSTR2(12, s, d); }
      | 'q'? ws s:r64   ws? ',' ws? d:r64 { $$ = INSTR2(13, s, d); }
      | 'w'? ws i:imm16 ws? ',' ws? s:m   ws? ',' ws? d:r16 { $$ = INSTR3(14, s, d, i); }
      | 'l'? ws i:imm32 ws? ',' ws? s:m   ws? ',' ws? d:r32 { $$ = INSTR3(15, s, d, i); }
      | 'q'? ws i:imm32 ws? ',' ws? s:m   ws? ',' ws? d:r64 { $$ = INSTR3(16, s, d, i); }
      | 'w'? ws i:imm16 ws? ',' ws? s:r16 ws? ',' ws? d:r16 { $$ = INSTR3(17, s, d, i); }
      | 'l'? ws i:imm32 ws? ',' ws? s:r32 ws? ',' ws? d:r32 { $$ = INSTR3(18, s, d, i); }
      | 'q'? ws i:imm32 ws? ',' ws? s:r64 ws? ',' ws? d:r64 { $$ = INSTR3(19, s, d, i); }
    )
    # Must come last due to peg ordering.
    | args:m-opargs { $$ = args; }
    | args:r-opargs { args.instr.variant += 4 ; $$ = args; } 
)  { $$.instr.kind = ASM_IMUL; }

m-opargs = 
    'b' ws a:m { $$ = INSTR1(0, a); }
  | 'w' ws a:m { $$ = INSTR1(1, a); }
  | 'l' ws a:m { $$ = INSTR1(2, a); }
  | 'q' ws a:m { $$ = INSTR1(3, a); }

r-opargs = 
    'b'? ws a:r8  { $$ = INSTR1(0, a); }
  | 'w'? ws a:r16 { $$ = INSTR1(1, a); }
  | 'l'? ws a:r32 { $$ = INSTR1(2, a); }
  | 'q'? ws a:r64 { $$ = INSTR1(3, a); }

imm-r-opargs =  
    'b'? ws s:imm8  ws? ',' ws? d:r8  { $$ = INSTR2(0, s, d); }
  | 'w'? ws s:imm16 ws? ',' ws? d:r16 { $$ = INSTR2(1, s, d); }
  | 'l'? ws s:imm32 ws? ',' ws? d:r32 { $$ = INSTR2(2, s, d); }
  | 'q'? ws s:imm32 ws? ',' ws? d:r64 { $$ = INSTR2(3, s, d); }

imm-m-opargs =  
    'b'  ws s:imm8  ws? ',' ws? d:m { $$ = INSTR2(0, s, d); }
  | 'w'  ws s:imm16 ws? ',' ws? d:m { $$ = INSTR2(1, s, d); }
  | 'l'  ws s:imm32 ws? ',' ws? d:m { $$ = INSTR2(2, s, d); }
  | 'q'  ws s:imm32 ws? ',' ws? d:m { $$ = INSTR2(3, s, d); }

r-r-opargs =  
    'b'? ws s:r8  ws? ',' ws? d:r8  { $$ = INSTR2(0, s, d); }
  | 'w'? ws s:r16 ws? ',' ws? d:r16 { $$ = INSTR2(1, s, d); }
  | 'l'? ws s:r32 ws? ',' ws? d:r32 { $$ = INSTR2(2, s, d); }
  | 'q'? ws s:r64 ws? ',' ws? d:r64 { $$ = INSTR2(3, s, d); }

r-m-opargs =  
    'b'? ws s:r8  ws? ',' ws? d:m { $$ = INSTR2(0, s, d); }
  | 'w'? ws s:r16 ws? ',' ws? d:m { $$ = INSTR2(1, s, d); }
  | 'l'? ws s:r32 ws? ',' ws? d:m { $$ = INSTR2(2, s, d); }
  | 'q'? ws s:r64 ws? ',' ws? d:m { $$ = INSTR2(3, s, d); }

m-r-opargs =  
    'b'? ws s:m ws? ',' ws? d:r8  { $$ = INSTR2(0, s, d); }
  | 'w'? ws s:m ws? ',' ws? d:r16 { $$ = INSTR2(1, s, d); }
  | 'l'? ws s:m ws? ',' ws? d:r32 { $$ = INSTR2(2, s, d); }
  | 'q'? ws s:m ws? ',' ws? d:r64 { $$ = INSTR2(3, s, d); }

imm-rm-opargs = 
    args:imm-m-opargs { $$ = args; } 
  | args:imm-r-opargs { args.instr.variant += 4 ; $$ = args; } 

r-rm-opargs = 
    args:m-r-opargs { $$ = args; }
  | args:r-m-opargs { args.instr.variant += 4; $$ = args; }
  | args:r-r-opargs { args.instr.variant += 8; $$ = args; }

mov = "mov" (
    args:imm-rm-opargs { $$ = args; }
  | args:r-rm-opargs { args.instr.variant += 8; $$ = args; }
) { $$.instr.kind = ASM_MOV; }

movsx = "movs" (
       args:mov-extend-opargs { $$ = args; }
     | 'lq' ws s:m ws? ',' ws? d:r64 { $$ = INSTR2(10, s, d); }
     | 'lq' ws s:r32 ws? ',' ws? d:r64 { $$ = INSTR2(11, s, d); }
) { $$.instr.kind = ASM_MOVSX; }

movzx = "movz" args:mov-extend-opargs { $$ = args; $$.instr.kind = ASM_MOVZX; }

mov-extend-opargs =
    'bw' ws s:m  ws?  ',' ws? d:r16 { $$ = INSTR2(0, s, d); }
  | 'bl' ws s:m  ws?  ',' ws? d:r32 { $$ = INSTR2(1, s, d); }
  | 'bq' ws s:m  ws?  ',' ws? d:r64 { $$ = INSTR2(2, s, d); }
  | 'wl' ws s:m  ws?  ',' ws? d:r32 { $$ = INSTR2(3, s, d); }
  | 'wq' ws s:m  ws?  ',' ws? d:r64 { $$ = INSTR2(4, s, d); }
  | 'bw' ws s:r8 ws?  ',' ws? d:r16 { $$ = INSTR2(5, s, d); }
  | 'bl' ws s:r8 ws?  ',' ws? d:r32 { $$ = INSTR2(6, s, d); }
  | 'bq' ws s:r8 ws?  ',' ws? d:r64 { $$ = INSTR2(7, s, d); }
  | 'wl' ws s:r16 ws? ',' ws? d:r32 { $$ = INSTR2(8, s, d); }
  | 'wq' ws s:r16 ws? ',' ws? d:r64 { $$ = INSTR2(9, s, d); }

xchg = 
  'xchg' (
      'w'? ws s:ax  ws? ',' ws? d:r16 { $$ = INSTR2(0, s, d); }
    | 'w'? ws s:r16 ws? ',' ws? d:ax  { $$ = INSTR2(1, s, d); }
    | 'l'? ws s:eax ws? ',' ws? d:r32 { $$ = INSTR2(2, s, d); }
    | 'l'? ws s:r32 ws? ',' ws? d:eax { $$ = INSTR2(3, s, d); }
    | 'q'? ws s:rax ws? ',' ws? d:r64 { $$ = INSTR2(4, s, d); }
    | 'q'? ws s:r64 ws? ',' ws? d:rax { $$ = INSTR2(5, s, d); }
    | args:r-rm-opargs { args.instr.variant += 6; $$ = args; }
  ) { $$.instr.kind = ASM_XCHG; }

add = "cmp" a:basic-op-args { a.instr.kind = ASM_CMP; $$ = a; }
cmp = "add" a:basic-op-args { a.instr.kind = ASM_ADD; $$ = a; }
and = "and" a:basic-op-args { a.instr.kind = ASM_AND; $$ = a; }
or  = "or"  a:basic-op-args { a.instr.kind = ASM_OR;  $$ = a; }
sub = "sub" a:basic-op-args { a.instr.kind = ASM_SUB; $$ = a; }
xor = "xor" a:basic-op-args { a.instr.kind = ASM_XOR; $$ = a; }

basic-op-args =
    'b'? ws s:imm8  ws? ',' ws? d:al  { $$ = INSTR2(0, s, d); }
  | 'w'? ws s:imm16 ws? ',' ws? d:ax  { $$ = INSTR2(1, s, d); }
  | 'l'? ws s:imm32 ws? ',' ws? d:eax { $$ = INSTR2(2, s, d); }
  | 'q'? ws s:imm32 ws? ',' ws? d:rax { $$ = INSTR2(3, s, d); }
  | args:imm-rm-opargs { args.instr.variant += 4; $$ = args; }
  | args:r-rm-opargs { args.instr.variant += 12; $$ = args; }

set = "set" cc:condition-code (
    'b'? ws a:m  { $$ = INSTR1(0, a); $$.instr.variant = cc.i64; }
  | 'b'? ws a:r8 { $$ = INSTR1(0, a); $$.instr.variant = 31 + cc.i64; }
) { $$.instr.kind = ASM_SET }

sal = 
  "sal" args:shift-args {$$ = args; $$.instr.kind = ASM_SAL}
sar = 
  "sar" args:shift-args {$$ = args; $$.instr.kind = ASM_SAR}
shl = 
  "shl" args:shift-args {$$ = args; $$.instr.kind = ASM_SHL}
shr = 
  "shr" args:shift-args {$$ = args; $$.instr.kind = ASM_SHR}

shift-args =
    # There are some more specific variants we could add.
    'w'  ws c:cl ws? ',' ws? d:m { $$ = INSTR2(0, c, d); }
  | 'l'  ws c:cl ws? ',' ws? d:m { $$ = INSTR2(1, c, d); }
  | 'q'  ws c:cl ws? ',' ws? d:m { $$ = INSTR2(2, c, d); }
  | 'w'? ws c:cl ws? ',' ws? d:r16 { $$ = INSTR2(3, c, d); }
  | 'l'? ws c:cl ws? ',' ws? d:r32 { $$ = INSTR2(4, c, d); }
  | 'q'? ws c:cl ws? ',' ws? d:r64 { $$ = INSTR2(5, c, d); }
  | 'w'  ws i:imm8 ws? ',' ws? d:m { $$ = INSTR2(6, i, d); }
  | 'l'  ws i:imm8 ws? ',' ws? d:m { $$ = INSTR2(7, i, d); }
  | 'q'  ws i:imm8 ws? ',' ws? d:m { $$ = INSTR2(8, i, d); }
  | 'w'? ws i:imm8 ws? ',' ws? d:r16 { $$ = INSTR2(9, i, d); }
  | 'l'? ws i:imm8 ws? ',' ws? d:r32 { $$ = INSTR2(10, i, d); }
  | 'q'? ws i:imm8 ws? ',' ws? d:r64 { $$ = INSTR2(11, i, d); }

test = "test" (
    'b'? ws s:imm8  ws? ',' ws? d:al  { $$ = INSTR2(0, s, d); }
  | 'w'? ws s:imm16 ws? ',' ws? d:ax  { $$ = INSTR2(1, s, d); }
  | 'l'? ws s:imm32 ws? ',' ws? d:eax { $$ = INSTR2(2, s, d); }
  | 'q'? ws s:imm32 ws? ',' ws? d:rax { $$ = INSTR2(3, s, d); }
  |  args:imm-rm-opargs { args.instr.variant += 4;  $$ = args; }
  |  args:r-m-opargs    { args.instr.variant += 12; $$ = args; }
  |  args:r-r-opargs    { args.instr.variant += 16; $$ = args; }
) { $$.instr.kind = ASM_TEST; }

r64-or-rip = (
    r:r64 
  | r:rip
) { $$ = r; }

scale-index-base = 
     '(' ws? b:r64 ws? ',' ws? i:r64 ws? ',' ws? s:number ws? ')'
     {  $$.memarg = (Memarg){.kind=ASM_MEMARG, .scale = s.i64, .index=i.kind, .base = b.kind, .disp = (Value){ .c = 0, .l = NULL }  }; }
   | '(' ws? b:r64 ws? ',' ws? i:r64 ')'
     {  $$.memarg = (Memarg){.kind=ASM_MEMARG, .scale = 1, .index=i.kind, .base = b.kind, .disp = (Value){ .c = 0, .l = NULL }  }; }
   | '(' ws? b:r64-or-rip ws? ')'
     {  $$.memarg = (Memarg){.kind=ASM_MEMARG, .scale = 0, .index=ASM_NO_REG, .base = b.kind, .disp = (Value){ .c = 0, .l = NULL }  }; }

m = 
    sib:scale-index-base
    { $$ = sib; }
  | d:value ws? sib:scale-index-base
    { sib.memarg.disp = d.value; $$ = sib; }

imm8 = i:imm { i.imm.nbytes = 1; $$ = i; }
imm16 = i:imm { i.imm.nbytes = 2; $$ = i; }
imm32 = i:imm { i.imm.nbytes = 4; $$ = i; }

imm = 
    '$' ws? val:value
    { $$.imm = (Imm){ .kind = ASM_IMM, .v = val.value, .nbytes = 0}; }

al = "%al" { $$ = REG(ASM_AL); }
cl = "%cl" { $$ = REG(ASM_CL); }
ax = "%ax" { $$ = REG(ASM_AX); }
eax = "%eax" { $$ = REG(ASM_EAX); }
rax = "%rax" { $$ = REG(ASM_RAX); }
rip = "%rip" { $$ = REG(ASM_RIP); }

r8 =
    "%al" { $$ = REG(ASM_AL); }
  | "%cl" { $$ = REG(ASM_CL); }
  | "%dl" { $$ = REG(ASM_DL); }
  | "%bl" { $$ = REG(ASM_BL); }
  | "%spl" { $$ = REG(ASM_SPL); }
  | "%bpl" { $$ = REG(ASM_BPL); }
  | "%sil" { $$ = REG(ASM_SIL); }
  | "%dil" { $$ = REG(ASM_DIL); }
  | "%r8b"  { $$ = REG(ASM_R8B); }
  | "%r9b"  { $$ = REG(ASM_R9B); }
  | "%r10b" { $$ = REG(ASM_R10B); }
  | "%r11b" { $$ = REG(ASM_R11B); }
  | "%r12b" { $$ = REG(ASM_R12B); }
  | "%r13b" { $$ = REG(ASM_R13B); }
  | "%r14b" { $$ = REG(ASM_R14B); }
  | "%r15b" { $$ = REG(ASM_R15B); }

r16 = 
    "%ax" { $$ = REG(ASM_AX); }
  | "%cx" { $$ = REG(ASM_CX); }
  | "%dx" { $$ = REG(ASM_DX); }
  | "%bx" { $$ = REG(ASM_BX); }
  | "%sp" { $$ = REG(ASM_SP); }
  | "%bp" { $$ = REG(ASM_BP); }
  | "%si" { $$ = REG(ASM_SI); }
  | "%di" { $$ = REG(ASM_DI); }
  | "%r8w"  { $$ = REG(ASM_R8W); }
  | "%r9w"  { $$ = REG(ASM_R9W); }
  | "%r10w" { $$ = REG(ASM_R10W); }
  | "%r11w" { $$ = REG(ASM_R11W); }
  | "%r12w" { $$ = REG(ASM_R12W); }
  | "%r13w" { $$ = REG(ASM_R13W); }
  | "%r14w" { $$ = REG(ASM_R14W); }
  | "%r15w" { $$ = REG(ASM_R15W); }

r32 =
    "%eax" { $$ = REG(ASM_EAX); }
  | "%ecx" { $$ = REG(ASM_ECX); }
  | "%edx" { $$ = REG(ASM_EDX); }
  | "%ebx" { $$ = REG(ASM_EBX); }
  | "%esp" { $$ = REG(ASM_ESP); }
  | "%ebp" { $$ = REG(ASM_EBP); }
  | "%esi" { $$ = REG(ASM_ESI); }
  | "%edi" { $$ = REG(ASM_EDI); }
  | "%r8d"  { $$ = REG(ASM_R8D); }
  | "%r9d"  { $$ = REG(ASM_R9D); }
  | "%r10d" { $$ = REG(ASM_R10D); }
  | "%r11d" { $$ = REG(ASM_R11D); }
  | "%r12d" { $$ = REG(ASM_R12D); }
  | "%r13d" { $$ = REG(ASM_R13D); }
  | "%r14d" { $$ = REG(ASM_R14D); }
  | "%r15d" { $$ = REG(ASM_R15D); }

r64 =
    "%rax" { $$ = REG(ASM_RAX); }
  | "%rcx" { $$ = REG(ASM_RCX); }
  | "%rdx" { $$ = REG(ASM_RDX); }
  | "%rbx" { $$ = REG(ASM_RBX); }
  | "%rsp" { $$ = REG(ASM_RSP); }
  | "%rbp" { $$ = REG(ASM_RBP); }
  | "%rsi" { $$ = REG(ASM_RSI); }
  | "%rdi" { $$ = REG(ASM_RDI); }
  | "%r8"  ![lwb] { $$ = REG(ASM_R8); }
  | "%r9"  ![lwb] { $$ = REG(ASM_R9); }
  | "%r10" ![lwb] { $$ = REG(ASM_R10); }
  | "%r11" ![lwb] { $$ = REG(ASM_R11); }
  | "%r12" ![lwb] { $$ = REG(ASM_R12); }
  | "%r13" ![lwb] { $$ = REG(ASM_R13); }
  | "%r14" ![lwb] { $$ = REG(ASM_R14); }
  | "%r15" ![lwb] { $$ = REG(ASM_R15); }

xmm = 
  # Reverse order due to peg ordering.
    "%xmm15" { $$ = REG(ASM_XMM15); }
  | "%xmm14" { $$ = REG(ASM_XMM14); }
  | "%xmm13" { $$ = REG(ASM_XMM13); }
  | "%xmm12" { $$ = REG(ASM_XMM12); }
  | "%xmm11" { $$ = REG(ASM_XMM11); }
  | "%xmm10" { $$ = REG(ASM_XMM10); }
  | "%xmm9"  { $$ = REG(ASM_XMM7); }
  | "%xmm8"  { $$ = REG(ASM_XMM7); }
  | "%xmm7"  { $$ = REG(ASM_XMM7); }
  | "%xmm6"  { $$ = REG(ASM_XMM6); }
  | "%xmm5"  { $$ = REG(ASM_XMM5); }
  | "%xmm4"  { $$ = REG(ASM_XMM4); }
  | "%xmm3"  { $$ = REG(ASM_XMM3); }
  | "%xmm2"  { $$ = REG(ASM_XMM2); }
  | "%xmm1"  { $$ = REG(ASM_XMM1); }
  | "%xmm0"  { $$ = REG(ASM_XMM0); }

# We disallow newlines in our strings, it is simpler for lineno tracking.
string = '"' <(string-escape | ( ! '\n' ! '\\' !'"' .))*> '"'
         { $$.string = decodestring(yytext); }

string-escape = '\\' (
    '\\'
  | '"'
  | [nrt]
  | 'x' [0-9A-Fa-f]+
  | [0-7][0-7][0-7]
)

value = 
    n:number { $$.value = (Value){ .l = NULL, .c = n.i64 }; }
  |
    i:ident ws? ( 
      '+' ws? n:number    { $$.value = (Value){ .c = n.i64 }; }
      | &'-' n:number { $$.value = (Value){ .c = n.i64 }; }
      | { $$.value = (Value){ .c = 0 }; }
    ) { $$.value.l = i.charptr; }

ident = 
  <[._a-zA-Z][._a-zA-Z0-9]*>
  { $$.charptr = xstrdup(yytext); } 

number =
    <'-'? ws? [0-9]+>
    { $$.i64 = strtoll(yytext, NULL, 10); }
  | <[0-9]+>
    { $$.i64 = (int64_t)strtoull(yytext, NULL, 10); }