Thank you for your excellent articles on GCC/LLVM on ARM. I'm an Android developer, and have noticed severe performance degradation on the Cortex-A15 (Qualcomm Snapdragon Pro S4 "Krait" line) SoC in conjunction with GCC (both 4.6 and 4.7). I'm not sure if it is due to GCC, the Qualcomm Snapdragon S4 Pro "Krait" SoC or something in the Android NDK itself.
On my mostly integer based code, I've been seeing performance on the Krait that is inline with the first generation Snapdragon hardware! I don't have the resources to run a comprehensive performance analysis, but perhaps you do. It would be very interesting to see if such performance regressions exist on the Linux side (i'd be surprised if they didn't) with the "Krait" hardware. If you get a chance, could you please run some benchmarks on the new Qualcomm Krait and compare it against another Cortex-A15 (Exynos) SoC as well as the Cortex-A9?