Re: OpenJDK 8 & GCC 5

Aurelien Jarno <[email protected]> Sun, 20 Dec 2015 17:05:50 +0100
Newsgroups	gmane.linux.debian.ports.mips
Message-ID	<[email protected]>
On 2015-12-15 19:52, James Cowgill wrote:
> Hi,
> 
> On Tue, 2015-12-15 at 12:42 +0100, Aurelien Jarno wrote:
> > OpenJDK 8 doesn't compile with GCC 5 on mips, presumably due to the
> > switch to the FPXX ABI [1]:
> > 
> > > /bin/bash ../../../../libtool   --mode=compile mipsel-linux-gnu-gcc-5 -DHAVE_CONFIG_H -I. -I../../../../../jamvm/src/os/linux/mips -I../../../../src  -I../../../../src -D_FORTIFY_SOURCE=2 -I../../../../src -g -fstack-protector-strong -Wformat -Werror=format-security -O3 -MT callNative.lo -MD -MP -MF .deps/callNative.Tpo -c -o callNative.lo ../../../../../jamvm/src/os/linux/mips/callNative.S
> > > libtool: compile:  mipsel-linux-gnu-gcc-5 -DHAVE_CONFIG_H -I. -I../../../../../jamvm/src/os/linux/mips -I../../../../src -I../../../../src -D_FORTIFY_SOURCE=2 -I../../../../src -g -fstack-protector-strong -Wformat -Werror=format-security -O3 -MT callNative.lo -MD -MP -MF .deps/callNative.Tpo -c ../../../../../jamvm/src/os/linux/mips/callNative.S  -fPIC -DPIC -o .libs/callNative.o
> > > ../../../../../jamvm/src/os/linux/mips/callNative.S: Assembler messages:
> > > ../../../../../jamvm/src/os/linux/mips/callNative.S:161: Error: float register should be even, was 1
> > > Makefile:298: recipe for target 'callNative.lo' failed
> > 
> > It is now built again with GCC 4.9, but we will eventually need to build
> > it with GCC 5. Therefore if someone has time to look at it, it would be
> > nice to provide patch.
> 
> I've attached a completely and utterly untested patch which might
> work...
> 

Thanks for the patch. The only concern with this patch is that it
increases the alignment requirement of a double from 32-bit from 64-bit.
OTOH, it's what the ABI requires.

> diff -u -ur a/src/os/linux/mips/callNative.S b/src/os/linux/mips/callNative.S
> --- a/src/os/linux/mips/callNative.S	2012-05-17 22:01:47.000000000 +0100
> +++ b/src/os/linux/mips/callNative.S	2015-12-15 19:46:03.679022719 +0000
> @@ -157,8 +157,7 @@
>  
>  ret_double:
>  #ifdef __mips_hard_float
> -	swc1 $f0,0($8)
> -	swc1 $f1,4($8)
> +	sdc1 $f0,0($8)
>  	addu $8,8
>  	j return
>  #endif

I have tried to build openjdk-8 with this patch on mipsel. It builds
fine and I haven't seen any regression in the testsuite.

Matthias, could you please add this patch in the next openjdk-8 upload
and switch again to GCC 5? Note that mipsel is currently still trying to
use GCC 5 due to a typo in the debian/rules file.

Thanks,
Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
[email protected]                 http://www.aurel32.net
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