PVS_SRC_REG_TYPE:
PVS_SRC_REG_TEMPORARY     = 0
PVS_SRC_REG_INPUT         = 1
PVS_SRC_REG_CONSTANT      = 2
PVS_SRC_REG_ALT_TEMPORARY = 3
PVS_SRC_SWIZZLE_SEL:
PVS_SRC_SELECT_X       = 0
PVS_SRC_SELECT_Y       = 1
PVS_SRC_SELECT_Z       = 2
PVS_SRC_SELECT_W       = 3
PVS_SRC_SELECT_FORCE_0 = 4
PVS_SRC_SELECT_FORCE_1 = 5
PVS_SRC_ADDR_MODE:
Absolute addressing = 0
Relative addressing using A0 register = 1
Relative addressing using I0 register = 2
