On Thu, Apr 3, 2014 at 2:27 PM, Charles Baylis <charles.bay...@linaro.org> wrote: > Hi > > This bug causes the compiler to create a Thumb-2 TBB instruction with > a jump table containing an out of range value in a .byte field: > > whatever.s:148: Error: value of 256 too large for field of 1 bytes at 100 > > This occurs because the jump table is followed with a ".align 1" due > to ASM_OUTPUT_CASE_END, but the 'shorten' phase does not account for > the space taken by this align directive.
My first reaction is to wonder why this is this not a bug in the "shorten" phase. > > This patch addresses the issue by removing ASM_OUTPUT_CASE_END from > arm.h, and ensuring that the alignment after an ADDR_DIFF_VEC is > instead inserted by aligning the label following the barrier which > follows it. This is achieved by defining LABEL_ALIGN_AFTER_BARRIER > appropriately. On first glance this feels like a blunt hammer, what's the code size bloat with putting out such an alignment after each barrier that the compiler emits rather than tracking this in ASM_OUTPUT_CASE_END. I'll try and have a look at this again tomorrow morning. regards Ramana > > Bootstrapped/checked on arm-unknown-linux-gnueabihf. > > OK for trunk, and backporting to 4.8? > > > > 2014-04-02 Charles Baylis <charles.bay...@linaro.org> > > PR target/60609 > * config/arm/arm.h (ASM_OUTPUT_CASE_END) Remove. > (LABEL_ALIGN_AFTER_BARRIER) Align barriers which occur after > ADDR_DIFF_VEC. > > > 2014-04-02 Charles Baylis <charles.bay...@linaro.org> > > PR target/60609 > * g++.dg/torture/pr60609.C: New test.
