[dev.ssa] cmd/compile: implement static data generation
The existing backend recognizes special
assignment statements as being implementable
with static data rather than code.
Unfortunately, it assumes that it is in the middle
of codegen; it emits data and modifies the AST.
This does not play well with SSA's two-phase
bootstrapping approach, in which we attempt to
compile code but fall back to the existing backend
if something goes wrong.
To work around this:
* Add the ability to inquire about static data
without side-effects.
* Save the static data required for a function.
* Emit that static data during SSA codegen.
Change-Id: I2e8a506c866ea3e27dffb597095833c87f62d87e
Reviewed-on: https://go-review.googlesource.com/12790
Reviewed-by: Keith Randall <khr@golang.org>
diff --git a/src/cmd/compile/internal/gc/gen.go b/src/cmd/compile/internal/gc/gen.go
index 6390818..4ff4f7a 100644
--- a/src/cmd/compile/internal/gc/gen.go
+++ b/src/cmd/compile/internal/gc/gen.go
@@ -853,7 +853,7 @@
cgen_dcl(n.Left)
case OAS:
- if gen_as_init(n) {
+ if gen_as_init(n, false) {
break
}
Cgen_as(n.Left, n.Right)
