cmd/internal/gc: inline x := y.(*T) and x, ok := y.(*T)
These can be implemented with just a compare and a move instruction.
Do so, avoiding the overhead of a call into the runtime.
These assertions are a significant cost in Go code that uses interface{}
as a safe alternative to C's void* (or unsafe.Pointer), such as the
current version of the Go compiler.
*T here includes pointer to T but also any Go type represented as
a single pointer (chan, func, map). It does not include [1]*T or struct{*int}.
That requires more work in other parts of the compiler; there is a TODO.
Change-Id: I7ff681c20d2c3eb6ad11dd7b3a37b1f3dda23965
Reviewed-on: https://go-review.googlesource.com/7862
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/cmd/internal/gc/builtin/runtime.go b/src/cmd/internal/gc/builtin/runtime.go
index 0e1ebea..554d787 100644
--- a/src/cmd/internal/gc/builtin/runtime.go
+++ b/src/cmd/internal/gc/builtin/runtime.go
@@ -79,6 +79,7 @@
func assertI2I2(typ *byte, iface any, ret *any) bool
func assertI2T(typ *byte, iface any, ret *any)
func assertI2T2(typ *byte, iface any, ret *any) bool
+func panicdottype(have, want, iface *byte)
func ifaceeq(i1 any, i2 any) (ret bool)
func efaceeq(i1 any, i2 any) (ret bool)
