https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68123
Bug ID: 68123 Summary: GCC vector extension behaves funny with large vector size Product: gcc Version: 4.8.3 Status: UNCONFIRMED Severity: minor Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: dxin at usc dot edu Target Milestone: --- Created attachment 36599 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36599&action=edit test source file It would complete unroll the loop and produces a huge assembly. With -O3 the produced assembly is smaller, but compilation takes a lot longer than no -O3. I attached test source file. With CFLAGS=-std=gnu11 -O3 -mcpu=cortex-a9 -mfloat-abi=hard -mfpu=neon -fPIE -Wall -S -fverbose-asm it compiles to a 57K line assembly and takes about 2min to compile, on a XEON 1245v3 machine. Tested on "GCC: (crosstool-NG linaro-1.13.1-4.8-2013.11 - Linaro GCC 2013.10) 4.8.3 20131111 (prerelease)"