r249559 - in /trunk: gcc/go/gofrontend/MERGE li...

[ian at gcc dot gnu dot org]

Author: ian
Date: Thu Jun 22 14:33:13 2017
New Revision: 249559

URL: https://gcc.gnu.org/viewcvs?rev=249559&root=gcc&view=rev
Log:
    runtime: avoid write barriers when calling deferred function
    
    Calling a deferred function currently requires changing from a uintptr
    to the function code to a Go function value. That is done by setting
    the value of a func local variable using unsafe.Pointer. The local
    variable will always be on the stack. Adjust the code that sets the
    local variable to avoid generating a write barrier.
    
    A write barrier is never needed here. Also, for deferreturn, we must
    avoid write barriers entirely when called from a cgo function; that
    requires more than just this, but this is a start.
    
    The test for this is runtime tests that use the go tool; these are not
    currently run, but they will be in the future.
    
    Reviewed-on: https://go-review.googlesource.com/46455

Modified:
    trunk/gcc/go/gofrontend/MERGE
    trunk/libgo/go/runtime/panic.go