libgo: update to Go 1.8 release candidate 1

    
    Compiler changes:
      * Change map assignment to use mapassign and assign value directly.
      * Change string iteration to use decoderune, faster for ASCII strings.
      * Change makeslice to take int, and use makeslice64 for larger values.
      * Add new noverflow field to hmap struct used for maps.
    
    Unresolved problems, to be fixed later:
      * Commented out test in go/types/sizes_test.go that doesn't compile.
      * Commented out reflect.TestStructOf test for padding after zero-sized field.
    
    Reviewed-on: https://go-review.googlesource.com/35231

gotools/:
	Updates for Go 1.8rc1.
	* Makefile.am (go_cmd_go_files): Add bug.go.
	(s-zdefaultcc): Write defaultPkgConfig.
	* Makefile.in: Rebuild.

From-SVN: r244456

1 files changed, 26 insertions, 30 deletions

diff --git a/libgo/go/runtime/runtime2.go b/libgo/go/runtime/runtime2.go
index 7dc2743..195d65b 100644
--- a/libgo/go/runtime/runtime2.go
+++ b/libgo/go/runtime/runtime2.go
@@ -209,6 +209,14 @@ func (gp *guintptr) cas(old, new guintptr) bool {
 	return atomic.Casuintptr((*uintptr)(unsafe.Pointer(gp)), uintptr(old), uintptr(new))
 }
 
+// setGNoWB performs *gp = new without a write barrier.
+// For times when it's impractical to use a guintptr.
+//go:nosplit
+//go:nowritebarrier
+func setGNoWB(gp **g, new *g) {
+	(*guintptr)(unsafe.Pointer(gp)).set(new)
+}
+
 type puintptr uintptr
 
 //go:nosplit
@@ -225,6 +233,14 @@ func (mp muintptr) ptr() *m { return (*m)(unsafe.Pointer(mp)) }
 //go:nosplit
 func (mp *muintptr) set(m *m) { *mp = muintptr(unsafe.Pointer(m)) }
 
+// setMNoWB performs *mp = new without a write barrier.
+// For times when it's impractical to use an muintptr.
+//go:nosplit
+//go:nowritebarrier
+func setMNoWB(mp **m, new *m) {
+	(*muintptr)(unsafe.Pointer(mp)).set(new)
+}
+
 // sudog represents a g in a wait list, such as for sending/receiving
 // on a channel.
 //
@@ -249,6 +265,7 @@ type sudog struct {
 	// The following fields are never accessed concurrently.
 	// waitlink is only accessed by g.
 
+	acquiretime int64
 	releasetime int64
 	ticket      uint32
 	waitlink    *sudog // g.waiting list
@@ -538,7 +555,7 @@ type p struct {
 
 	runSafePointFn uint32 // if 1, run sched.safePointFn at next safe point
 
-	pad [64]byte
+	pad [sys.CacheLineSize]byte
 }
 
 const (
@@ -626,29 +643,6 @@ const (
 	_SigUnblock              // unblocked in minit
 )
 
-/*
-gccgo does not use this.
-
-// Layout of in-memory per-function information prepared by linker
-// See https://golang.org/s/go12symtab.
-// Keep in sync with linker
-// and with package debug/gosym and with symtab.go in package runtime.
-type _func struct {
-	entry   uintptr // start pc
-	nameoff int32   // function name
-
-	args int32 // in/out args size
-	_    int32 // previously legacy frame size; kept for layout compatibility
-
-	pcsp      int32
-	pcfile    int32
-	pcln      int32
-	npcdata   int32
-	nfuncdata int32
-}
-
-*/
-
 // Lock-free stack node.
 // // Also known to export_test.go.
 type lfnode struct {
@@ -766,15 +760,17 @@ var (
 	newprocs   int32
 
 	// Information about what cpu features are available.
-	// Set on startup.
+	// Set on startup in asm_{x86,amd64}.s.
 	cpuid_ecx   uint32
 	support_aes bool
 
-//	cpuid_edx         uint32
-//	cpuid_ebx7        uint32
-//	lfenceBeforeRdtsc bool
-//	support_avx       bool
-//	support_avx2      bool
+	// cpuid_edx         uint32
+	// cpuid_ebx7        uint32
+	// lfenceBeforeRdtsc bool
+	// support_avx       bool
+	// support_avx2      bool
+	// support_bmi1      bool
+	// support_bmi2      bool
 
 //	goarm                uint8 // set by cmd/link on arm systems
 //	framepointer_enabled bool  // set by cmd/link