Opened 12 years ago

Closed 12 years ago

Last modified 12 years ago

#19366 closed defect (invalid)

Apple GCC pathologically slow

Reported by: dave@… Owned by: macports-tickets@…
Priority: Normal Milestone:
Component: ports Version: 1.7.1
Keywords: Cc: MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)


  • Install openssh with macports
  • time an scp some large-ish directory from a remote host
  • launch a linux VM on the same hardware
  • time the same scp
  • compare

My results: openssh on the Mac is roughly half the speed of openssh on Linux. Now:

  • install gcc43 and gcc_select with macports
  • gcc_select mp-gcc43
  • port upgrade -f openssh
  • run the timing test again

My results: timing approximately identical to Linux.

My conclusions: When MacPorts is installed, it should force-install and use a stock gcc. Failing that, all the installation guides should be updated to note that you might want to do that before installing anything else.

Change History (6)

comment:1 Changed 12 years ago by dave@…

Sorry, title should've been "Apple GCC generates slow code"

comment:2 Changed 12 years ago by MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)

Cc: mcalhoun@… added

Cc Me!

comment:3 Changed 12 years ago by MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)

If they are working correctly, ports do not start using a different compiler just because gcc_select has been changed.
If you use the debug option (port -df upgrade openssh) you should be able to see which compiler is being used.
Did you do something special to force the the gcc_select compiler to be used?
If not, then I am not sure the results say anything about the Apple GCC.

comment:4 Changed 12 years ago by dave@…

Gah! You're right! No, it's not choosing the gcc_select compiler. I'm once again at a total loss to explain the discrepancy I've seen.

comment:5 Changed 12 years ago by MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)

Resolution: invalid
Status: newclosed

This is puzzling.
Since this might not be a MacPorts problem, I will close this ticket for now.

If it turns out it is a MacPorts problem, we can reopen.

comment:6 Changed 12 years ago by (none)

Milestone: Port Bugs

Milestone Port Bugs deleted

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