v.Pos = v.Pos.WithNotStmt()
						}
						// This is a redundant explicit nil check.
						v.reset(OpConstBool)
						v.AuxInt = 1 // true
					}
				case OpNilCheck:
					ptr := v.Args[0]
					if nilCheck := nonNilValues[ptr.ID]; nilCheck != nil {
						// This is a redundant implicit nil check.
						// Logging in the style of the former compiler -- and omit line 1,
						// which is usually in generated code.

// otherwise v is ordered before s.
// Specifically, values are ordered like
//
//	store1
//	NilCheck that depends on store1
//	other values that depends on store1
//	store2
//	NilCheck that depends on store2
//	other values that depends on store2
//	...
//
// The order of non-store and non-NilCheck values are undefined
// (not necessarily dependency order). This should be cheaper

		if b == fun.blocks["secondCheck"] && isNilCheck(b) {
			t.Errorf("secondCheck was not eliminated")
		}
		if b == fun.blocks["differentCheck"] && isNilCheck(b) {
			foundDifferentCheck = true
		}
	}
	if !foundDifferentCheck {
		t.Errorf("removed differentCheck, but shouldn't have")
	}
}

// TestNilcheckInFalseBranch tests that nil checks in the false branch of a nilcheck
// block are *not* removed.

				}
			case OpNilCheck:
				// nil checks have pointer type before scheduling, and
				// void type after scheduling.
				if f.scheduled {
					if v.Uses != 0 {
						f.Fatalf("nilcheck must have 0 uses %s", v.Uses)
					}
					if !v.Type.IsVoid() {
						f.Fatalf("nilcheck must have void type %s", v.Type.String())
					}
				} else {

	// checkLower must run after lowering & subsequent dead code elim
	{"lower", "checkLower"},
	{"lowered deadcode", "checkLower"},
	{"late lower", "checkLower"},
	// late nilcheck needs instructions to be scheduled.
	{"schedule", "late nilcheck"},
	// flagalloc needs instructions to be scheduled.
	{"schedule", "flagalloc"},
	// regalloc needs flags to be allocated first.
	{"flagalloc", "regalloc"},

				fmt.Fprintln(w, "needIntTemp: true,")
			}
			if v.call {
				fmt.Fprintln(w, "call: true,")
			}
			if v.tailCall {
				fmt.Fprintln(w, "tailCall: true,")
			}
			if v.nilCheck {
				fmt.Fprintln(w, "nilCheck: true,")
			}
			if v.faultOnNilArg0 {
				fmt.Fprintln(w, "faultOnNilArg0: true,")

		{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gp}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil. arg1=mem

(TailCall ...) => (LoweredTailCall ...)

// Miscellaneous
(Convert ...) => (LoweredConvert ...)
(IsNonNil p) => (I64Eqz (I64Eqz p))
(IsInBounds ...) => (I64LtU ...)
(IsSliceInBounds ...) => (I64LeU ...)
(NilCheck ...) => (LoweredNilCheck ...)
(GetClosurePtr ...) => (LoweredGetClosurePtr ...)
(GetCallerPC ...) => (LoweredGetCallerPC ...)
(GetCallerSP ...) => (LoweredGetCallerSP ...)
(Addr {sym} base) => (LoweredAddr {sym} [0] base)

// if its use count drops to 0.
func (v *Value) removeable() bool {
	if v.Type.IsVoid() {
		// Void ops (inline marks), must stay.
		return false
	}
	if opcodeTable[v.Op].nilCheck {
		// Nil pointer checks must stay.
		return false
	}
	if v.Type.IsMemory() {
		// We don't need to preserve all memory ops, but we do need
		// to keep calls at least (because they might have

	needIntTemp       bool      // need a temporary free integer register
	call              bool      // is a function call
	tailCall          bool      // is a tail call
	nilCheck          bool      // this op is a nil check on arg0
	faultOnNilArg0    bool      // this op will fault if arg0 is nil (and aux encodes a small offset)