Back when I added intrinsics to mspgcc I got confirmation that CCS and IAR both implicitly added the required NOP after a DINT instruction generated with _disable_interrupts(). (The MSP430 instruction set explains that this is necessary to eliminate the possibility of interrupting a subsequent pipelined instruction.)
The implementation of _disable_interrupts() in in430.h from TI's GCC_RH_20140508.zip does not include this required instruction, making it inconsistent with all other MSP430 toolchains. (Fortunately, msp430-elf does generate a warning in this situation.)
Interestingly, the implementation of _enable_interrupts() unconditionally adds a NOP after EINT, even though that workaround is arguably required only on certain devices with a specific erratum, and this behavior is AFAIK also inconsistent with other toolchains.
msp430-elf should behave as close to CCS and IAR as possible so developers don't have to work around toolchain-specific inconsistencies in how these operations are implemented.
Please fix this for the next header release.
Please also add a monotonically increasing version number to in430.h or iomacros.h so applications can work around bugs like this.