> -----Original Message----- > From: Richard Earnshaw > Sent: Thursday, May 01, 2014 10:03 PM > To: Bin Cheng > Cc: gcc-patches@gcc.gnu.org > Subject: Re: [PATCH ARM]Handle REG addressing mode in > output_move_neon explicitly > > On 29/04/14 04:02, bin.cheng wrote: > > Hi, > > Function output_move_neon now generates vld1.64 for memory ref like > > "dx <- [r1:SI]", this is bogus because it requires at least 64-bit > > alignment for 32-bit aligned memory ref. It works now because GCC > > doesn't generate such insns in the first place, but things are going > > to change if memset/memcpy calls are inlined by using neon instructions. > > > > V[LD/ST]1.64 only need to be 64-bit aligned if strict alignment is enabled. We > normally assume that not to be the case. The exception to this is when an theoretically, this doesn't make the problem go away, right?
> explicit alignment check is used in the address expression (the :64 suffix), > which causes the address to be checked for strict alignment at all times. > > Do you have a testcase? I can't provide a test case without the memset inlining patch. Thanks, bin
