Revert of binary-operator-reducer: reduce mul+div(shift) (patchset #11 id:200001 of https://codereview.chromium.org/1350223006/ )
Reason for revert:
This is also unsound for the reasons outlined in
https://codereview.chromium.org/1473073004/
Will help Fedor to implement a solution based on simplified operators.
Original issue's description:
> binary-operator-reducer: reduce mul+div(shift)
>
> Reduction Input:
>
> ChangeInt32ToFloat64=> TruncateFloat64ToInt32
> Float64Mul=>
> ChangeInt32ToFloat64=> Float64Div=>TruncateFloat64ToInt32
>
> Output:
>
> => TruncateInt64ToInt32
> Int64Mul
> => Int64Shr => TruncateInt64ToInt32
>
> Test code:
>
> function mul(a, b) {
> var l = a & 0x3ffffff;
> var h = b & 0x3ffffff;
> var m = l * h;
>
> var rl = m & 0x3ffffff;
> var rh = (m / 0x4000000) | 0;
>
> return rl | rh;
> }
>
> mul(1, 2);
> var a0 = mul(0x3ffffff, 0x3ffffff);
> mul(0x0, 0x0);
> %OptimizeFunctionOnNextCall(mul);
> var a1 = mul(0x3ffffff, 0x3ffffff);
>
> print(a0 + ' == ' + a1);
>
> BUG=
> R=mstarzinger@chromium.org
>
> Committed: https://crrev.com/461e5b49d022335a7fc4e9d172397a4bd48b93d4
> Cr-Commit-Position: refs/heads/master@{#31899}
TBR=mstarzinger@chromium.org,danno@chromium.org,titzer@chromium.org,fedor@indutny.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review URL: https://codereview.chromium.org/1478923002
Cr-Commit-Position: refs/heads/master@{#32313}
5d18e93bd6