[Bug c/47892] New: Fails to vectorize comparison code
jeremysalwen at gmail dot com
gcc-bugzilla@gcc.gnu.org
Fri Feb 25 10:22:00 GMT 2011
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47892
Summary: Fails to vectorize comparison code
Product: gcc
Version: 4.5.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: jeremysalwen@gmail.com
I have the following function
#define PIO6 0.523598776
#define SA5 2.74201854577e-06
#define SA4 -1.98410347969e-04
#define SA3 8.33333320429e-03
#define SA2 -1.66666666666e-01
static void bestseries9(float * __restrict__ arr,int len) {
for(int i=0; i<len; i++) {
float or=arr[i];
float orig=or / 3*(or>PIO6);
float sqr=orig*orig;
arr[i]=orig*(1+sqr*(SA2+sqr*(SA3+sqr*(SA4+SA5*sqr))));
arr[i]=arr[i]*(1+(or>PIO6)*(2-4*arr[i]*arr[i]));
}
}
which should be vectorized, but it is not. If I turn on verbose vectorization,
it says that there is a conditional in the loop, and so it won't vectorize it.
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