RFR: JDK-8269031: linux x86_64 check for binutils 2.25 or higher after 8265783

[Magnus Ihse Bursie]

On Tue, 22 Jun 2021 07:39:28 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> This change adds a check for binutils 2.25 or higher after 8265783. The change 8265783 introduced on linux x86_64 a minimum requirement for binutils : "Minimum required would be binutils 2.25 where AVX512 support was added for Skylake."  (see https://bugs.openjdk.java.net/browse/JDK-8265783 )
> I adjusted the existing check that already checked the binutils version by looking at the linker output (we do not look at the assembler version and it seems to me we do not really invoke the assembler directly, just indirectly via gcc).

Marked as reviewed by ihse (Reviewer).

The test should really be on as version, but I agree that it does not seem worth the hassle to add another version check, when in practice ld and as are bundled together as binutils.

However, I would appreciate a comment clarifying this. I added a suggestion, feel free to use it or modify it. Apart from this it looks good, so I'll approve it.

make/autoconf/toolchain.m4 line 225:

> 223: 
> 224:   # Linux x86_64 needs higher binutils after 8265783
> 225:   if test "x$OPENJDK_TARGET_CPU" = "xx86_64"; then

Suggestion:

  # (This really is a dependency on as version, but we mis-use ld as a check for a general binutils version)
  if test "x$OPENJDK_TARGET_CPU" = "xx86_64"; then

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PR: https://git.openjdk.java.net/jdk/pull/4548