Apple's A9 SoC will be manufactured by Samsung
Year after year, Apple continues to impress with constantly improving performance of their ARM-based SoCs. Their in-house designs focusing on performance per clock rather than increasing amount of cores pay off, forcing other ARM chipmakers to play catch-up every year. However, Apple doesn't actually own any chip manufacturing facilties and therefore must contract companies that do. For a few generations, the majority of Apple's chips was produced by Samsung, but with A8 and A8X the Californian company has attempted to move away from depending on its archrival and instead partnered up with TSMC. Samsung was still involved with the production but was responsible only for about 40% of the chips.
It was assumed that Apple will continue to migrate away from Samsung's fabs with its next SoCs, but the South Korean chipmaker was the first to introduce and roll out the advanced 14nm FinFET manufacturing process. Thanks to it, the Exynos 7420 Octa chip which powers Samsung's smartphones Galaxy S6 and S6 Edge turned out to be a real powerhouse, beating its main rival Qualcomm Snapdragon 810 in many benchmarks. Meanwhile, TSMC's current most advanced process is still 16nm FinFET.
With this in mind, it's not surprising that Apple has apparently decided to return to Samsung as its main SoC supplier - at least according to Bloomberg's anonymous industry insiders. Contrary to the previous rumors, which claimed Samsung to have lost the majority (70%) of the A9 contract to TSMC, Apple will utilize Samsung's new process exclusively. Samsung's S1-Line foundry in Giheung, South Korea will be used for manufacturing and Samsung's partner Global Foundries (who has licensed the process) will handle surplus orders at one or more of its facilities in South Korea or the US.
Representatives of Apple, Samsung, TSMC and Global Foundries have all declined to comment on the matter. However, that doesn't necessarily confirm (or deny) the information - refusal to comment on business arrangements regardless of their actual status is common. Apple's new iPhones (which could be called 6S or 7 and will allegedly come in three sizes) are only expected in the fall, and there's still plenty of time for the rumor mill to reverse its direction again later (possibly multiple times) until the final deal is confirmed publicly.