[dev.ssa] cmd/internal/gc: convert standard IR into SSA.
Hook into the current compiler to convert the existing
IR (after walk) into SSA. Any function ending in "_ssa"
will take this path. The resulting assembly is printed
and then discarded.
Use gc.Type directly in ssa instead of a wrapper for go types.
It makes the IR->SSA rewrite a lot simpler.
Only a few opcodes are implemented in this change. It is
enough to compile simple examples like
func f(p *int) int { return *p }
func g(a []int, i int) int { return a[i] }
Change-Id: I5e18841b752a83ca0519aa1b2d36ef02ce1de6f9
Reviewed-on: https://go-review.googlesource.com/8971
Reviewed-by: Alan Donovan <adonovan@google.com>
diff --git a/src/cmd/internal/ssa/rulegen/generic.rules b/src/cmd/internal/ssa/rulegen/generic.rules
index 1fc1620c..d174499 100644
--- a/src/cmd/internal/ssa/rulegen/generic.rules
+++ b/src/cmd/internal/ssa/rulegen/generic.rules
@@ -6,12 +6,14 @@
(Add <t> (Const [c]) (Const [d])) && is64BitInt(t) && isSigned(t) -> (Const [{c.(int64)+d.(int64)}])
(Add <t> (Const [c]) (Const [d])) && is64BitInt(t) && !isSigned(t) -> (Const [{c.(uint64)+d.(uint64)}])
-// load/store to stack
-(Load (FPAddr [offset]) mem) -> (LoadFP [offset] mem)
-(Store (FPAddr [offset]) val mem) -> (StoreFP [offset] val mem)
-
-(Load (SPAddr [offset]) mem) -> (LoadSP [offset] mem)
-(Store (SPAddr [offset]) val mem) -> (StoreSP [offset] val mem)
+// tear apart slices
+// TODO: anything that generates a slice needs to go in here.
+(SlicePtr (Load ptr mem)) -> (Load ptr mem)
+(SliceLen (Load ptr mem)) -> (Load (Add <ptr.Type> ptr (Const <v.Block.Func.Config.UIntPtr> [int64(v.Block.Func.Config.ptrSize)])) mem)
+(SliceCap (Load ptr mem)) -> (Load (Add <ptr.Type> ptr (Const <v.Block.Func.Config.UIntPtr> [int64(v.Block.Func.Config.ptrSize*2)])) mem)
// expand array indexing
// others? Depends on what is already done by frontend
+
+// Note: bounds check has already been done
+(SliceIndex s i mem) -> (Load (Add <s.Type.Elem().PtrTo()> (SlicePtr <s.Type.Elem().PtrTo()> s) (Mul <v.Block.Func.Config.UIntPtr> i (Const <v.Block.Func.Config.UIntPtr> [s.Type.Elem().Size()]))) mem)
