RFR(S): 8166742 : SIGFPE in C2 Loop IV elimination

[Vladimir Kozlov]

Slightly different (cast after /) and jlong type:

   jlong ratio_conl = (jlong) (stride_con2 / stride_con);

   if ((ratio_conl * stride_con) == (jlong)stride_con2) { // Check for exact

Vladimir

On 9/26/16 5:01 PM, Chuck Rasbold wrote:
> Just to confirm, are you suggesting that the ratio be first computed as a 64 bit quantity, effectively along the lines of...
>
>    long ratio_conl = ((long) stride_con2) / stride_con;
>
>    if ((ratio_conl * stride_con) == stride_con2 &&
>        ratio_conl < 0x8000000 ) { // Check for exact
>      int ratio_con = (int) ratio_conl;
>
>
> On Mon, Sep 26, 2016 at 3:45 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com <mailto:vladimir.kozlov at oracle.com>> wrote:
>
>     Hi Chuck
>
>     Can you do 'long' arithmetic in existing condition to catch integer overflow instead?
>
>     if ((ratio_con * stride_con) == stride_con2) { // Check for exact
>
>     thanks,
>     Vladimir
>
>
>
>     On 9/26/16 3:18 PM, Chuck Rasbold wrote:
>
>         A small fix for an edge case crash in C2...
>
>         Bug: https://bugs.openjdk.java.net/browse/JDK-8166742 <https://bugs.openjdk.java.net/browse/JDK-8166742>
>         Webrev: http://cr.openjdk.java.net/~rasbold/8166742/webrev.00/ <http://cr.openjdk.java.net/~rasbold/8166742/webrev.00/>
>
>         Requesting a sponsor and reviews.  Thanks.
>
>         -- Chuck
>
>