[dev.ssa] cmd/compile/internal/ssa: Handle variables correctly
Use *Node of type ONAME instead of string as the key for variable maps.
This will prevent aliasing between two identically named but
differently scoped variables.
Introduce an Aux value that encodes the offset of a variable
from a base pointer (either global base pointer or stack pointer).
Allow LEAQ and derivatives (MOVQ, etc.) to also have such an Aux field.
Allocate space for AUTO variables in stackalloc.
Change-Id: Ibdccdaea4bbc63a1f4882959ac374f2b467e3acd
Reviewed-on: https://go-review.googlesource.com/11238
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
diff --git a/src/cmd/compile/internal/ssa/value.go b/src/cmd/compile/internal/ssa/value.go
index 9c7f148..e6e23d5 100644
--- a/src/cmd/compile/internal/ssa/value.go
+++ b/src/cmd/compile/internal/ssa/value.go
@@ -114,3 +114,40 @@
func (v *Value) Logf(msg string, args ...interface{}) { v.Block.Logf(msg, args...) }
func (v *Value) Fatalf(msg string, args ...interface{}) { v.Block.Fatalf(msg, args...) }
func (v *Value) Unimplementedf(msg string, args ...interface{}) { v.Block.Unimplementedf(msg, args...) }
+
+// ExternSymbol is an aux value that encodes a variable's
+// constant offset from the static base pointer.
+type ExternSymbol struct {
+ Typ Type // Go type
+ Sym fmt.Stringer // A *gc.Sym referring to a global variable
+ // Note: the offset for an external symbol is not
+ // calculated until link time.
+}
+
+// ArgSymbol is an aux value that encodes an argument or result
+// variable's constant offset from FP (FP = SP + framesize).
+type ArgSymbol struct {
+ Typ Type // Go type
+ Offset int64 // Distance above frame pointer
+ Sym fmt.Stringer // A *gc.Sym referring to the argument/result variable.
+}
+
+// AutoSymbol is an aux value that encodes a local variable's
+// constant offset from SP.
+type AutoSymbol struct {
+ Typ Type // Go type
+ Offset int64 // Distance above stack pointer. Set by stackalloc in SSA.
+ Sym fmt.Stringer // A *gc.Sym referring to a local (auto) variable.
+}
+
+func (s *ExternSymbol) String() string {
+ return s.Sym.String()
+}
+
+func (s *ArgSymbol) String() string {
+ return s.Sym.String()
+}
+
+func (s *AutoSymbol) String() string {
+ return s.Sym.String()
+}
