Reducing runtime coherency checking using global data flow analysis is provided. A determination is made as to whether a call is for at least one of a DMA get operation or a DMA put operation in response to the call being issued during execution of a compiled and optimized code. A determination is made as to whether a software cache write operation has been issued since a last flush operation in response to the call being the DMA get operation. A DMA get runtime coherency check is then performed in response to the software cache write operation being issued since the fast flush operation.