Bug 18736 – SQUIRRELFISH: switch statements with no default have incorrect codegen

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Cameron Zwarich (cpst)]

If no conditions match, we should skip all the case
clauses, but instead we fall through to the first.

function f2(i) {
    switch (i) {
    case 0:
    case 1:
        return 1;
    case 2:
        return 2;
    }
    // with no default, control will fall through                               
    return 3;
}


[   0] load             tr0, 0(@k0)             
[   3] stricteq         tr0, tr0, lr1
[   7] jtrue            tr0, 21(->30)
[  10] load             tr0, 1(@k1)             
[  13] stricteq         tr0, tr0, lr1
[  17] jtrue            tr0, 11(->30)
[  20] load             tr0, 2(@k2)             
[  23] stricteq         tr0, tr0, lr1
[  27] jtrue            tr0, 6(->35)
[  30] load             tr0, 1(@k1)             
[  33] ret              tr0
[  35] load             tr0, 2(@k2)             
[  38] ret              tr0
[  40] load             tr0, 3(@k3)             
[  43] ret              tr0

This affects the JavaScriptCore regression test js1_2/statements/switch2.js.

[Oliver Hunt]

Committed r32547