}
	for j := 1; j < len(q); j++ {
		q[j-1] = 1 // difference is only found on the last byte
		for i := range b {
			idx := Index(b[i:], q[:j])
			if idx != -1 {
				t.Fatalf("Index(b[%d:], q[:%d])=%d, want -1\n", i, j, idx)
			}
		}
		q[j-1] = 0
	}

	// Test differing alignments and sizes of q which always end on a page boundary.
	q[len(q)-1] = 1 // difference is only found on the last byte
	for j := 0; j < len(q); j++ {

func IsARMFloatCmp(op obj.As) bool {
	switch op {
	case arm.ACMPF, arm.ACMPD:
		return true
	}
	return false
}

// ARMMRCOffset implements the peculiar encoding of the MRC and MCR instructions.
// The difference between MRC and MCR is represented by a bit high in the word, not
// in the usual way by the opcode itself. Asm must use AMRC for both instructions, so
// we return the opcode for MRC so that asm doesn't need to import obj/arm.

	// position to discover whether there is a blank before the parenthesis.
	// We only get here if defining a macro inside a macro.
	// This imperfect implementation means we cannot tell the difference between
	//	#define A #define B(x) x
	// and
	//	#define A #define B (x) x
	// The first definition of B has an argument, the second doesn't. Because we let

			}
			b[k] = a[k]
		}
	}
}

func TestEndianBaseCompare(t *testing.T) {
	// This test compares byte slices that are almost identical, except one
	// difference that for some j, a[j]>b[j] and a[j+1]<b[j+1]. If the implementation
	// compares large chunks with wrong endianness, it gets wrong result.
	// no vector register is larger than 512 bytes for now
	const maxLength = 512

	// for each entry in names and then dereference the type we
	// learn for __cgo__i.
	var b bytes.Buffer
	b.WriteString(builtinProlog)
	b.WriteString(f.Preamble)
	b.WriteString("#line 1 \"cgo-dwarf-inference\"\n")
	for i, n := range names {
		fmt.Fprintf(&b, "__typeof__(%s) *__cgo__%d;\n", n.C, i)
		if n.Kind == "iconst" {
			fmt.Fprintf(&b, "enum { __cgo_enum__%d = %s };\n", i, n.C)
		}
	}

	if exitCode == 1 {
		t.Errorf("API database problems found")
	}
	if !compareAPI(bw, features, required, exception) {
		t.Errorf("API differences found")
	}
}

// export emits the exported package features.
func (w *Walker) export(pkg *apiPackage) {
	if verbose {
		log.Println(pkg)
	}
	pop := w.pushScope("pkg " + pkg.Path())