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Re: [RFH] - Less than optimal code compiling 252.eon -O2 for x86



On Jun 24, 2005, at 6:07 PM, Fariborz Jahanian wrote:


A source file mrSurfaceList.cc of 252.eon produces less efficient code initializing instance objects to 0 at -O2 than at -O1. Behavior is random and it does not happen on all x86 platforms and making the test smaller makes the problem go away. But here is what I found out is the cause.


This cannot be simplified by fold_rtx, resulting in less efficient code.

I wonder why combine can do the simplification though which is why still produce good code for the simple testcase: void f1(double *d,float *f2) { *f2 = 0.0; *d = 0.0; }

Thanks,
Andrew Pinski


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