// reaching an op, but some ops can take
					// multiple pointers (e.g. NeqPtr, Phi etc.).
					// This is rare, so just propagate the first
					// value to keep things simple.
					used.Add(n)
					changed = true
				}
			}
		}
		if node == nil {
			return
		}
		if addr[v] == nil {
			// The address of an auto reaches this op.
			addr[v] = node
			changed = true
			return
		}

		}
	}
}

// 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:
//

// Copyright 2016 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.

// This file contains rules to decompose builtin compound types
// (complex,string,slice,interface) into their constituent
// types.  These rules work together with the decomposeBuiltIn
// pass which handles phis of these types.

(Store {t} _ _ mem) && t.Size() == 0 => mem

// complex ops

// 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

import "cmd/compile/internal/base"

// tighten moves Values closer to the Blocks in which they are used.
// This can reduce the amount of register spilling required,
// if it doesn't also create more live values.
// A Value can be moved to any block that

		c.removePhiArg(v, j)
		// Note: this is trickier than it looks. Replacing
		// a Phi with a Copy can in general cause problems because
		// Phi and Copy don't have exactly the same semantics.
		// Phi arguments always come from a predecessor block,
		// whereas copies don't. This matters in loops like:
		// 1: x = (Phi y)
		//    y = (Add x 1)
		//    goto 1
		// If we replace Phi->Copy, we get
		// 1: x = (Copy y)

// Copyright 2016 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

// phiopt eliminates boolean Phis based on the previous if.
//
// Main use case is to transform:
//
//	x := false
//	if b {
//	  x = true
//	}
//
// into x = b.
//
// In SSA code this appears as
//
//	b0
//	  If b -> b1 b2
//	b1

	work = append(work, bp{block: f.Entry})

	// map from value ID to known non-nil version of that value ID
	// (in the current dominator path being walked). This slice is updated by
	// walkStates to maintain the known non-nil values.
	// If there is extrinsic information about non-nil-ness, this map
	// points a value to itself. If a value is known non-nil because we
	// already did a nil check on it, it points to the nil check operation.

			If("bool2", "extra", "exit")),
		Bloc("extra",
			// prevent fuse from eliminating this block
			Valu("store", OpStore, types.TypeMem, 0, ptrType, "ptr1", "nilptr", "mem"),
			Goto("exit")),
		Bloc("exit",
			Valu("phi", OpPhi, types.TypeMem, 0, nil, "mem", "store"),
			Exit("phi")))

	CheckFunc(fun.f)
	// we need the opt here to rewrite the user nilcheck
	opt(fun.f)
	nilcheckelim(fun.f)

// Copyright 2016 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.

// This file contains rules to decompose [u]int64 types on 32-bit
// architectures. These rules work together with the decomposeBuiltIn
// pass which handles phis of these typ.

(Int64Hi (Int64Make hi _)) => hi
(Int64Lo (Int64Make _ lo)) => lo

				// of flag values.
				score[v.ID] = ScoreReadFlags
			case v.isFlagOp():
				// Schedule flag register generation as late as possible.
				// This makes sure that we only have one live flags
				// value at a time.
				// Note that this case is after the case above, so values
				// which both read and generate flags are given ScoreReadFlags.
				score[v.ID] = ScoreFlags
			default: