1 files changed, 0 insertions, 75 deletions
diff --git a/src/cmd/compile/internal/ssa/phielim.go b/src/cmd/compile/internal/ssa/phielim.go
deleted file mode 100644
index 4fc942375f..0000000000
--- a/src/cmd/compile/internal/ssa/phielim.go
+++ /dev/null
@@ -1,75 +0,0 @@
-// 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
-
-// phielim eliminates redundant phi values from f.
-// A phi is redundant if its arguments are all equal. For
-// purposes of counting, ignore the phi itself. Both of
-// these phis are redundant:
-//
-//	v = phi(x,x,x)
-//	v = phi(x,v,x,v)
-//
-// We repeat this process to also catch situations like:
-//
-//	v = phi(x, phi(x, x), phi(x, v))
-//
-// TODO: Can we also simplify cases like:
-//
-//	v = phi(v, w, x)
-//	w = phi(v, w, x)
-//
-// and would that be useful?
-func phielim(f *Func) {
-	for {
-		change := false
-		for _, b := range f.Blocks {
-			for _, v := range b.Values {
-				copyelimValue(v)
-				change = phielimValue(v) || change
-			}
-		}
-		if !change {
-			break
-		}
-	}
-}
-
-// phielimValue tries to convert the phi v to a copy.
-func phielimValue(v *Value) bool {
-	if v.Op != OpPhi {
-		return false
-	}
-
-	// If there are two distinct args of v which
-	// are not v itself, then the phi must remain.
-	// Otherwise, we can replace it with a copy.
-	var w *Value
-	for _, x := range v.Args {
-		if x == v {
-			continue
-		}
-		if x == w {
-			continue
-		}
-		if w != nil {
-			return false
-		}
-		w = x
-	}
-
-	if w == nil {
-		// v references only itself. It must be in
-		// a dead code loop. Don't bother modifying it.
-		return false
-	}
-	v.Op = OpCopy
-	v.SetArgs1(w)
-	f := v.Block.Func
-	if f.pass.debug > 0 {
-		f.Warnl(v.Pos, "eliminated phi")
-	}
-	return true
-}