[OpenJDK 2D-Dev] RFR: 8246032: Implementation of JEP 347: Adopt C++14 Language Features in HotSpot

[Jim Laskey]

I know there was a discussion about this elsewhere but I would like to take the opportunity to correct this now

make//autoconf/flags-cflags.m4:241

  elif test "x$TOOLCHAIN_TYPE" = xclang; then
    if test "x$OPENJDK_TARGET_OS" = xmacosx; then
      # On MacOSX we optimize for size, something
      # we should do for all platforms?
      C_O_FLAG_HIGHEST_JVM="-Os"
      C_O_FLAG_HIGHEST="-Os"
      C_O_FLAG_HI="-Os"
      C_O_FLAG_NORM="-Os"
      C_O_FLAG_DEBUG_JVM=""
    else
      C_O_FLAG_HIGHEST_JVM="-O3"
      C_O_FLAG_HIGHEST="-O3"
      C_O_FLAG_HI="-O3"
      C_O_FLAG_NORM="-O2"
      C_O_FLAG_DEBUG_JVM="-O0"
    fi
    C_O_FLAG_SIZE="-Os"
    C_O_FLAG_DEBUG="-O0"
    C_O_FLAG_NONE="-O0"
  elif test "x$TOOLCHAIN_TYPE" = xxlc; then

should be changed to 

  elif test "x$TOOLCHAIN_TYPE" = xclang; then
    C_O_FLAG_HIGHEST_JVM="-O3"
    C_O_FLAG_HIGHEST="-O3"
    C_O_FLAG_HI="-O3"
    C_O_FLAG_NORM="-O2"
    C_O_FLAG_DEBUG_JVM="-O0"
    C_O_FLAG_SIZE="-Os"
    C_O_FLAG_DEBUG="-O0"
    C_O_FLAG_NONE="-O0"
  elif test "x$TOOLCHAIN_TYPE" = xxlc; then

MacOSX has been paying a historic and significant performance penalty for no valid reason.

Otherwise +1.

Cheers,

-- Jim



> On Jun 5, 2020, at 4:52 AM, Kim Barrett <kim.barrett at oracle.com> wrote:
> 
> [Changes are only to the build system, but since the changes have jdk-wide
> effect I’ve cc’d what I think are the relevant dev lists.]
> 
> This change is part of JEP 347; the intent is to target JDK 16.
> 
> Please review this change to the building of C++ code in the JDK to
> enable the use of C++14 language features.  This change does not make
> any code changes to use new features provided by C++11 or C++14.
> 
> This requires trimming the supported compiler versions, moving the
> minimum supported versions forward (significantly, in some cases).
> The new minimums are based on compiler documentation rather than
> testing.  It may be that more recent versions are actually required.
> 
> This change needs to be tested on platforms not supported by Oracle.
> The JEP test plan includes additional Oracle testing beyond what I’ve done.
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8246032
> 
> Webrev:
> https://cr.openjdk.java.net/~kbarrett/8246032/open.02/
> 
> Testing:
> mach5 tier1-5 on Oracle supported platforms.
> 
> Performance testing showed no significant changes in either direction.
> 
> Build-only (no tests) for linux-arm32, linux-s390x, linux-ppc64le
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.java.net/pipermail/2d-dev/attachments/20200605/bd0cda27/attachment.htm>