js: times.now generates 1193 LOC (4.5K in debug mode)

[timotheecour]

js: times.now generates 1193 LOC in -d:danger (4.5K LOC in debug mdoe)

Example

import times
echo now()

Current Output

nim r -b:js $options main
wc -l main.js

• debug mode: 4521
• -d:release: 1480
• -d:danger: 1193

Expected Output

small codegen

Additional Information

1.5.1 devel b42e7c0

related issues (js code bloat)

• EDIT: this was actually the subject of https://forum.nim-lang.org/t/7282#46173
• JS codegen can produce extreme switch statements with case a of range nim-lang/Nim#8821
• this thread https://forum.nim-lang.org/t/7282 discusses code bloat in js
• tables:

when true:
  import tables
  let x = initTable[string, int]()
  echo x

-d:danger: 549 LOC

[ringabout]

After changing to if else, times.now generates more lines :)

1272 => 1293

After minifying, it reduces 1kb or less

24kb => 23kb

Edited:
Not finished, jsgen should traverse the case statement first finding the number of the range, then decide whether to generate case or if else.

[timotheecour]

After changing to if else, times.now generates more lines :)

what do you mean by that? some details would clarify

also, make sure you measure for -d:danger

contiguous case branches like this:

    case 26:
    case 27:
    case 28:
    case 29:
    case 30:
    case 31:

should be replaced by range checks, eg:
if x >= 26 and x <= 31: ...

[ringabout]

I doubt times.now can generate much smaller code. It is compact enough. Please use minify(half of the original size) or closure compiler to get smaller code.

I just change the case statement to if else

if ((Temporary1 == 7)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\a"));;
    }
    else {
    if ((Temporary1 == 8)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\b"));;
    }
    else {
    if ((Temporary1 == 9)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\t"));;
    }
    else {
    if ((Temporary1 == 10)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\n"));;
    }
    else {
    if ((Temporary1 == 11)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\v"));;
    }
    else {
    if ((Temporary1 == 12)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\f"));;
    }
    else {
    if ((Temporary1 == 13)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\r"));;
    }
    else {
    if ((Temporary1 == 27)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\e"));;
    }
    else {
    if ((Temporary1 == 92)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\\\"));;
    }
    else {
    if ((Temporary1 == 39)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\\'"));;
    }
    else {
    if ((Temporary1 == 34)) {
    s_33557848[s_33557848_Idx].push.apply(s_33557848[s_33557848_Idx], makeNimstrLit("\\\""));;
    }
    else {
    if (((Temporary1 >= 32) & (Temporary1 <= 33)) | ((Temporary1 >= 35) & (Temporary1 <= 38)) | ((Temporary1 >= 40) & (Temporary1 <= 91)) | ((Temporary1 >= 93) & (Temporary1 <= 126))) {
    addChar(s_33557848[s_33557848_Idx], c_33557849);;
    }

Before

    switch (c_33557845) {
    case 7:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\a"));;
      break;
    case 8:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\b"));;
      break;
    case 9:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\t"));;
      break;
    case 10:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\n"));;
      break;
    case 11:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\v"));;
      break;
    case 12:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\f"));;
      break;
    case 13:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\r"));;
      break;
    case 27:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\e"));;
      break;
    case 92:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\\\"));;
      break;
    case 39:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\\'"));;
      break;
    case 34:
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\\""));;
      break;
    case 32:
    case 33:
    case 35:
    case 36:
    case 37:
    case 38:
    case 40:
    case 41:
    case 42:
    case 43:
    case 44:
    case 45:
    case 46:
    case 47:
    case 48:
    case 49:
    case 50:
    case 51:
    case 52:
    case 53:
    case 54:
    case 55:
    case 56:
    case 57:
    case 58:
    case 59:
    case 60:
    case 61:
    case 62:
    case 63:
    case 64:
    case 65:
    case 66:
    case 67:
    case 68:
    case 69:
    case 70:
    case 71:
    case 72:
    case 73:
    case 74:
    case 75:
    case 76:
    case 77:
    case 78:
    case 79:
    case 80:
    case 81:
    case 82:
    case 83:
    case 84:
    case 85:
    case 86:
    case 87:
    case 88:
    case 89:
    case 90:
    case 91:
    case 93:
    case 94:
    case 95:
    case 96:
    case 97:
    case 98:
    case 99:
    case 100:
    case 101:
    case 102:
    case 103:
    case 104:
    case 105:
    case 106:
    case 107:
    case 108:
    case 109:
    case 110:
    case 111:
    case 112:
    case 113:
    case 114:
    case 115:
    case 116:
    case 117:
    case 118:
    case 119:
    case 120:
    case 121:
    case 122:
    case 123:
    case 124:
    case 125:
    case 126:
      addChar(s_33557844[s_33557844_Idx], c_33557845);;
      break;
    default: 
      s_33557844[s_33557844_Idx].push.apply(s_33557844[s_33557844_Idx], makeNimstrLit("\\x"));;
      var n_33557855 = c_33557845;
      addChar(s_33557844[s_33557844_Idx], makeNimstrLit("0123456789ABCDEF")[((n_33557855 & 240) >> 4)]);;
      addChar(s_33557844[s_33557844_Idx], makeNimstrLit("0123456789ABCDEF")[(n_33557855 & 15)]);;
      break;

I may optimize it later.