[cfe-dev] Over-aligned vst1.64 and vld1.64 for arm-linux-androideabi

[Friedman, Eli via cfe-dev]

On 2/14/2018 1:05 PM, Greg McGary wrote:
>
> On Wed, Feb 14, 2018 at 12:44 PM, Friedman, Eli 
> <efriedma at codeaurora.org <mailto:efriedma at codeaurora.org>> wrote:
>
>
>     There are three forms of vld1.64 which load two registers
>     (encoding comments generated using "llvm-mc --arch=arm
>     -mattr=+neon -show-encoding"):
>
>             vld1.64 {d16, d17}, [r2]!       @ encoding:
>     [0xcd,0x0a,0x62,0xf4]
>             vld1.64 {d16, d17}, [r2:64]!    @ encoding:
>     [0xdd,0x0a,0x62,0xf4]
>             vld1.64 {d16, d17}, [r2:128]!   @ encoding:
>     [0xed,0x0a,0x62,0xf4]
>
>     The first requires no alignment, the second requires 64-bit
>     alignment, the third requires 128-bit alignment.
>
>
> I see the first form (no alignment) from "clang -S ..."
> When I compile to object via "clang -c ...", subsequent disassembly 
> shows the third form (128-bit alignment).
> What's up with that?

I can't reproduce that; compiling and disassembling your testcase with 
clang and arm-linux-androideabi-objdump from NDK version r15c, I get the 
expected disassembly without the alignment specifier.

-Eli

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20180214/785643cc/attachment.html>