https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61194
Bug ID: 61194 Summary: vectorization failed with "bit-precision arithmetic not supported" even if conversion to int is requested Product: gcc Version: 4.9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: vincenzo.innocente at cern dot ch z[i] = ( (x[i]>0) & (w[i]<0)) ? z[i] : y[i]; produces bit-precision arithmetic not supported. note: not vectorized: relevant stmt not supported: _6 = _5 > 0.0; while integer bitwise operators are vectorized at will z[i] = ( k[i] & j[i] ) ? z[i] : y[i]; I tried to force conversion to int in many ways (see below) such as z[i] = ( int(x[i]>0) & int(w[i]<0)) ? z[i] : y[i]; succeeding only with the quite expensive z[i] = (2==(int(x[i]>0) + int(w[i]<0))) ? z[i] : y[i]; is there a way to force gcc to use integer w/o using arithmetic operators? c++ -Ofast -Wall -fno-tree-slp-vectorize -ftree-loop-if-convert-stores -S cond.cc -msse4.2 -fopt-info-vec -fno-tree-slp-vectorize -fopenmp cat cond.cc float x[1024]; float y[1024]; float z[1024]; float w[1024]; int k[1024]; int j[1024]; void bar() { for (int i=0; i<1024; ++i) z[i] = ( (x[i]>0) & (w[i]<0)) ? z[i] : y[i]; } void barMP() { #pragma omp simd for (int i=0; i<1024; ++i) z[i] = ( int(x[i]>0) & int(w[i]<0)) ? z[i] : y[i]; } void barInt() { for (int i=0; i<1024; ++i) z[i] = ( int(x[i]>0) & int(w[i]<0)) ? z[i] : y[i]; } void barInt0() { for (int i=0; i<1024; ++i) z[i] = ( (0+int(x[i]>0)) & (0+int(w[i]<0)) ) ? z[i] : y[i]; } void barPlus() { for (int i=0; i<1024; ++i) z[i] = (2==(int(x[i]>0) + int(w[i]<0))) ? z[i] : y[i]; } void foo() { for (int i=0; i<1024; ++i) z[i] = ( k[i] & j[i] ) ? z[i] : y[i]; } void foo2() { for (int i=0; i<1024; ++i) { k[i] = x[i]>0; j[i] = w[i]<0; } } void bar2() { for (int i=0; i<1024; ++i) { k[i] = x[i]>0; j[i] = w[i]<0; z[i] = ( k[i] & j[i]) ? z[i] : y[i]; } }