[dev.ssa] cmd/compile/internal/ssa: implement ITAB
Implement ITAB, selecting the itable field of an interface.
Soften the lowering check to allow lowerings that leave
generic but dead ops behind. (The ITAB lowering does this.)
Change-Id: Icc84961dd4060d143602f001311aa1d8be0d7fc0
Reviewed-on: https://go-review.googlesource.com/13144
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
diff --git a/src/cmd/compile/internal/ssa/gen/genericOps.go b/src/cmd/compile/internal/ssa/gen/genericOps.go
index 7536415..657973e 100644
--- a/src/cmd/compile/internal/ssa/gen/genericOps.go
+++ b/src/cmd/compile/internal/ssa/gen/genericOps.go
@@ -244,6 +244,9 @@
{name: "StringPtr"}, // ptr(arg0)
{name: "StringLen"}, // len(arg0)
+ // Interfaces
+ {name: "ITab"}, // arg0=interface, returns itable field
+
// Spill&restore ops for the register allocator. These are
// semantically identical to OpCopy; they do not take/return
// stores like regular memory ops do. We can get away without memory
