// TESTx: compare (arg0 & arg1) to 0
		{name: "TESTQ", argLength: 2, reg: gp2flags, commutative: true, asm: "TESTQ", typ: "Flags"},
		{name: "TESTL", argLength: 2, reg: gp2flags, commutative: true, asm: "TESTL", typ: "Flags"},
		{name: "TESTW", argLength: 2, reg: gp2flags, commutative: true, asm: "TESTW", typ: "Flags"},
		{name: "TESTB", argLength: 2, reg: gp2flags, commutative: true, asm: "TESTB", typ: "Flags"},

		// TESTxconst: compare (arg0 & auxint) to 0

	{name: "And8", argLength: 2, commutative: true}, // arg0 & arg1
	{name: "And16", argLength: 2, commutative: true},
	{name: "And32", argLength: 2, commutative: true},
	{name: "And64", argLength: 2, commutative: true},

	{name: "Or8", argLength: 2, commutative: true}, // arg0 | arg1
	{name: "Or16", argLength: 2, commutative: true},
	{name: "Or32", argLength: 2, commutative: true},
	{name: "Or64", argLength: 2, commutative: true},

		{name: "MUL", argLength: 2, reg: gp21, asm: "MUL", commutative: true, typ: "Int64"}, // arg0 * arg1
		{name: "MULW", argLength: 2, reg: gp21, asm: "MULW", commutative: true, typ: "Int32"},
		{name: "MULH", argLength: 2, reg: gp21, asm: "MULH", commutative: true, typ: "Int64"},
		{name: "MULHU", argLength: 2, reg: gp21, asm: "MULHU", commutative: true, typ: "UInt64"},

		{name: "HMULL", argLength: 2, reg: gp21hmul, commutative: true, asm: "IMULL", clobberFlags: true}, // (arg0 * arg1) >> width
		{name: "HMULLU", argLength: 2, reg: gp21hmul, commutative: true, asm: "MULL", clobberFlags: true}, // (arg0 * arg1) >> width

		{name: "MULLQU", argLength: 2, reg: gp21mul, commutative: true, asm: "MULL", clobberFlags: true}, // arg0 * arg1, high 32 in result[0], low 32 in result[1]

		{name: "MULT", argLength: 2, reg: gp2hilo, asm: "MUL", commutative: true, typ: "(Int32,Int32)"},                                                  // arg0 * arg1, signed, results hi,lo

		{name: "MOVHloadidx", argLength: 3, reg: gploadidx, commutative: true, asm: "MOVH", aux: "SymOff", typ: "Int16", symEffect: "Read"},     // load 2 bytes from arg0+arg1+auxint+aux. arg2=mem. Sign extend.

			t.Errorf("%v: unexpected result: %d", test, c)
		}
		if ok != test.ok {
			t.Errorf("%v: unexpected overflow: %t", test, ok)
		}
		// addition is commutative
		d, ok2 := int64Add(test.b, test.a)
		if c != d || ok != ok2 {
			t.Errorf("%v: not commutative: %d %t", test, d, ok2)
		}
	}
}

func TestDetectOverflowMultiply(t *testing.T) {
	for _, test := range []struct {
		a, b int64
		c    int64
		ok   bool

		{name: "MUL", argLength: 2, reg: gp21, asm: "MUL", commutative: true},     // arg0 * arg1
		{name: "HMUL", argLength: 2, reg: gp21, asm: "MULL", commutative: true},   // (arg0 * arg1) >> 32, signed
		{name: "HMULU", argLength: 2, reg: gp21, asm: "MULLU", commutative: true}, // (arg0 * arg1) >> 32, unsigned

		// udiv runtime call for soft division

		{name: "MULV", argLength: 2, reg: gp21, asm: "MULV", commutative: true, typ: "Int64"},      // arg0 * arg1
		{name: "MULHV", argLength: 2, reg: gp21, asm: "MULHV", commutative: true, typ: "Int64"},    // (arg0 * arg1) >> 64, signed
		{name: "MULHVU", argLength: 2, reg: gp21, asm: "MULHVU", commutative: true, typ: "UInt64"}, // (arg0 * arg1) >> 64, unsigned

		{name: "MULHD", argLength: 2, reg: gp21, asm: "MULHD", commutative: true},   // (arg0 * arg1) >> 64, signed
		{name: "MULHW", argLength: 2, reg: gp21, asm: "MULHW", commutative: true},   // (arg0 * arg1) >> 32, signed
		{name: "MULHDU", argLength: 2, reg: gp21, asm: "MULHDU", commutative: true}, // (arg0 * arg1) >> 64, unsigned
		{name: "MULHWU", argLength: 2, reg: gp21, asm: "MULHWU", commutative: true}, // (arg0 * arg1) >> 32, unsigned