Back in 2012 (among other times) were plans for an LLVM back-end to the Intel Linux graphics driver for increasing performance and delivering a better experience. Up to now the Intel graphics driver developers have been relying upon their own shader compiler but as of last year they were still investigating LLVM for its eventual adoption -- just as is done now by the Nouveau and Radeon open-source GPU drivers. In that article last year I mentioned Intel developers said LLVM integration was "more of a nightmare than anticipated" but at that point it was still happening.
Now it seems any Intel LLVM GPU driver integration on the Linux front is dead. After yesterday's article about the Mesa flatland GLSL IR proposal and the discussion that happened, Ian Romanick of Intel wrote, "We're absolutely not interested in anything involving LLVM. We've tried, several times, to make it work, and it has always ended with a table-flip-rage-quit."