(MOVBUreg (ANDI [c] x)) && c < 0 => (ANDI [int64(uint8(c))] x)
(MOVHUreg (ANDI [c] x)) && c < 0 => (ANDI [int64(uint16(c))] x)
(MOVWUreg (ANDI [c] x)) && c < 0 => (AND (MOVDconst [int64(uint32(c))]) x)

// Avoid sign/zero extension for consts.
(MOVBreg  (MOVDconst [c])) => (MOVDconst [int64(int8(c))])
(MOVHreg  (MOVDconst [c])) => (MOVDconst [int64(int16(c))])
(MOVWreg  (MOVDconst [c])) => (MOVDconst [int64(int32(c))])

changes in data layout either in the Go type definitions or in the
layout rules used by the Go compiler.
</p>

<p>
Constants are of the form <code>const_<i>name</i></code>.
For example, given the Go declaration <code>const bufSize =
1024</code>, assembly code can refer to the value of this constant
as <code>const_bufSize</code>.
</p>

<p>
Field offsets are of the form <code><i>type</i>_<i>field</i></code>.

	}
	if want, got := uint32(268435455), invalidMul_ssa(1); want != got {
		t.Errorf("testLargeConst mul failed, wanted %d got %d", want, got)
	}
}

// testArithRshConst ensures that "const >> const" right shifts correctly perform
// sign extension on the lhs constant
func testArithRshConst(t *testing.T) {
	wantu := uint64(0x4000000000000000)
	if got := arithRshuConst_ssa(); got != wantu {