-O3 - optimization level 3 turned on -qarch=ppc - sets architecture to PowerPC -Q=500 - Inlining on(inlines all functions with less executable statements than 500 -qpdf1/pdf2 - profile directed feedback optimization -qarch=pwrx - sets architecture to Power2 -qhsflt - prevents rounding of single-precision expressions and replacing floati ng-point division by multiplication by the reciprocal of the divisor -lmass - link mathematical acceleration subsystem library -qtune=pwr2 - instruction selection, scheduling, and other implementation dependent performance enhancements to Power2 -Q - turns on inlining -qdatalocal - assume all data items are local -qhot - performs high order loop transformations -qstrict - ensures that optimzations of -O3 do not alter the semantics of the program -qnosave - sets default storage class of local variables to automatic -qrndsngl - rounds the result of each single-precision operation to single- precision, rather than waiting until the full expression is evaluated -qintlog - allows for mixing integer and logical data entities in expressions and statements -qipa - turns on interprocedural analysis -qdpc - increase the precision of real constants, for maximum accuracy when assigning real constants to DOUBLE PRECISION variables. -Pk -Wp - turns on the Kap pre-processor -ag=a - pads common blocks and memory local to the subroutine to avoid cache line collisions. -r=2 - sets roundoff level to 2 -ur2=xxx - sets a maximum weight (estimate of work) for each unrolled iteration. (Work is estimated by counting operands and operators in a loop.) -Pv -Wp - turns on the Vast Pre-processor -me - informs the preprocessor to enable alignment, inter-array padding and array redimensioning. -ea2478 - (-ea allows alassociative trnsformations.) (-e2 specifies that no data dependencies exist in loop containing pointer-based variables.) (-e4 generates calls to optimized BLAS library routines.) (-e7 automatically expands called routines inline.) (-e8 searches input file first for expandable routines.)