[dev.ssa] cmd/compile/internal/ssa: implement ODOT
Implement ODOT. Similar to ArrayIndex, StructSelect selects a field
out of a larger Value.
We may need more ways to rewrite StructSelect, but StructSelect/Load
is the typical way it is used.
Change-Id: Ida7b8aab3298f4754eaf9fee733974cf8736e45d
Reviewed-on: https://go-review.googlesource.com/12265
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/cmd/compile/internal/ssa/rewritegeneric.go b/src/cmd/compile/internal/ssa/rewritegeneric.go
index 78cb2c8..ca523ee 100644
--- a/src/cmd/compile/internal/ssa/rewritegeneric.go
+++ b/src/cmd/compile/internal/ssa/rewritegeneric.go
@@ -383,6 +383,32 @@
}
goto end061edc5d85c73ad909089af2556d9380
end061edc5d85c73ad909089af2556d9380:
+ ;
+ case OpStructSelect:
+ // match: (StructSelect [idx] (Load ptr mem))
+ // cond:
+ // result: (Load (OffPtr <v.Type.PtrTo()> [idx] ptr) mem)
+ {
+ idx := v.AuxInt
+ if v.Args[0].Op != OpLoad {
+ goto end16fdb45e1dd08feb36e3cc3fb5ed8935
+ }
+ ptr := v.Args[0].Args[0]
+ mem := v.Args[0].Args[1]
+ v.Op = OpLoad
+ v.AuxInt = 0
+ v.Aux = nil
+ v.resetArgs()
+ v0 := v.Block.NewValue0(v.Line, OpOffPtr, TypeInvalid)
+ v0.Type = v.Type.PtrTo()
+ v0.AuxInt = idx
+ v0.AddArg(ptr)
+ v.AddArg(v0)
+ v.AddArg(mem)
+ return true
+ }
+ goto end16fdb45e1dd08feb36e3cc3fb5ed8935
+ end16fdb45e1dd08feb36e3cc3fb5ed8935:
}
return false
}
