core/x86/instr.c
/* Returns true iff instr has been marked as targeting the prefix of its
 * target fragment.
 *
 * Some code manipulations need to store a target address in a
 * register and then jump there, but need the register to be restored
 * as well.  DR provides a single-instruction prefix that is
 * placed on all fragments (basic blocks as well as traces) that
 * restores ecx.  It is on traces for internal DR use.  To have
 * it added to basic blocks as well, call
 * dr_add_prefixes_to_basic_blocks() during initialization.
 */
Returns true iff instr has been marked as targeting the prefix of its
target fragment.

Some code manipulations need to store a target address in a
register and then jump there, but need the register to be restored
as well.  DR provides a single-instruction prefix that is
placed on all fragments (basic blocks as well as traces) that
restores ecx.  It is on traces for internal DR use.  To have
it added to basic blocks as well, call
dr_add_prefixes_to_basic_blocks() during initialization.
Returns true iff instr has been marked as targeting the prefix of its target fragment . Some code manipulations need to store a target address in a register and then jump there but need the register to be restored as well . DR provides a single - instruction prefix that is placed on all fragments ( basic blocks as well as traces ) that restores ecx . It is on traces for internal DR use . To have it added to basic blocks as well call dr_add_prefixes_to_basic_blocks () during initialization .
bool
instr_branch_targets_prefix(instr_t *instr)
{
    return ((instr->flags & INSTR_BRANCH_TARGETS_PREFIX) != 0);
}
bool instr_branch_targets_prefix ( instr_t * instr ) { return ( ( instr -> flags & INSTR_BRANCH_TARGETS_PREFIX ) != 0 ) ; }
Returns true iff instr has been marked as targeting the prefix of its
 target fragment.
Returns true iff instr has been marked as targeting the prefix of its target fragment .