1 files changed, 52 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/lower.go b/src/cmd/compile/internal/ssa/lower.go
new file mode 100644
index 0000000..e4aac47
--- /dev/null
+++ b/src/cmd/compile/internal/ssa/lower.go
@@ -0,0 +1,52 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssa
+
+// convert to machine-dependent ops.
+func lower(f *Func) {
+	// repeat rewrites until we find no more rewrites
+	applyRewrite(f, f.Config.lowerBlock, f.Config.lowerValue, removeDeadValues)
+}
+
+// lateLower applies those rules that need to be run after the general lower rules.
+func lateLower(f *Func) {
+	// repeat rewrites until we find no more rewrites
+	if f.Config.lateLowerValue != nil {
+		applyRewrite(f, f.Config.lateLowerBlock, f.Config.lateLowerValue, removeDeadValues)
+	}
+}
+
+// checkLower checks for unlowered opcodes and fails if we find one.
+func checkLower(f *Func) {
+	// Needs to be a separate phase because it must run after both
+	// lowering and a subsequent dead code elimination (because lowering
+	// rules may leave dead generic ops behind).
+	for _, b := range f.Blocks {
+		for _, v := range b.Values {
+			if !opcodeTable[v.Op].generic {
+				continue // lowered
+			}
+			switch v.Op {
+			case OpSP, OpSPanchored, OpSB, OpInitMem, OpArg, OpArgIntReg, OpArgFloatReg, OpPhi, OpVarDef, OpVarLive, OpKeepAlive, OpSelect0, OpSelect1, OpSelectN, OpConvert, OpInlMark, OpWBend:
+				continue // ok not to lower
+			case OpMakeResult:
+				if b.Controls[0] == v {
+					continue
+				}
+			case OpGetG:
+				if f.Config.hasGReg {
+					// has hardware g register, regalloc takes care of it
+					continue // ok not to lower
+				}
+			}
+			s := "not lowered: " + v.String() + ", " + v.Op.String() + " " + v.Type.SimpleString()
+
+			for _, a := range v.Args {
+				s += " " + a.Type.SimpleString()
+			}
+			f.Fatalf("%s", s)
+		}
+	}
+}