In article <5a860ea3.0411171118.3d9b5a3c@[EMAIL PROTECTED]
>,
luz_info@[EMAIL PROTECTED]
(Lukas Zeller) wrote:
>Hello,
>
>the original post is nearly 2 years ago, but it seems that the problem
>described then still exists at least up to CW Win 8.3:
>
>When the Optimization Level is > 1, long longs are sometimes not
>passed on the stack but in a register pair. In this case the value
>passed is destroyed (32 bits of the 64 bit contain garbage). This is
>really happening in the code, and is not a debugger inspection issue.
>I verified this by compiling the entire project without touching a
>single source line once for each optimizer level. At 0 and 1, it works
>as ist should; at Levels 2-4, long longs get corrupted.
>
>In addition, there seems to be a debugger bug that displays 64bit
>values stored in a register pair with longwords swapped.
>The debugger problem is a "oops"; I know that debugging optimized code
>is not reliable (however sometimes inevitable like here, when trying
>to track down why the optimized code behaves differently... The
>compiler bug combined with the debugger bug caused this to be very
>very time consuming, it cost me a full day :-(
>
>The actual compiler bug however is catastrophic, especially because
>there are apparently many cases of passing long longs where everything
>works ok, and only under special circumstances it is not. Simply
>moving a routine's implementation from one (large) source file to
>another (smaller) one has made the difference in my case.
>
>Reading trough the CW Win 9 release notes, I found:
>
>* Fixed bug spilling long longs. If only the upper half was spilled,
> only four bytes would be allocated (but addressed at an offset of
> 4), leading to stack corruption. (WB1-49664) (26 September 2003)
>
>This sounds at least related, but does not exactly match what I see
>happening.
>
>As this potentially could have desastrous effects (but for mere luck
>apparently did not in the past two years I was using CW 8), I am very
>worried using the optimizer at all until I know what's really
>happening, and if the WB1-49664 release note entry below means that it
>is now fixed.
>
>Thanks for any information about this in advance!
Download the eval version from our web site. Try it and see. It is
fully operational for 15 days and then reverts to an evaluation version
after that.
Ron
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Ron Liechty - MWRon@[EMAIL PROTECTED]
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