Klaus Post <******@****.***> 1457448890 +0100

// license that can be found in the LICENSE file.

// Non-Go-constant but constant values aren't ok for shifts.

package p

import "unsafe"

func f() {
	_ = complex(1<<uintptr(unsafe.Pointer(nil)), 0) // ERROR "invalid operation: shifted operand 1 \(type float64\) must be integer|non-integer type for left operand of shift"

// Example from #52031.
//
// The following shifts should not produce errors on Go < 1.13, as their
// untyped constant operands are representable by type uint.
const (
	_ resultFlags = (1 << iota) / 2

	reportEqual
	reportUnequal
	reportByIgnore
	reportByMethod
	reportByFunc
	reportByCycle
)

// Invalid cases.
var x int = 1
var _ = (8 << x /* ERRORx `signed shift count .* requires go1.13 or later` */)

Klaus Post <******@****.***> 1457448890 +0100

		// the compiler to generate better code for the shift operation.
		shift := uint(bits.TrailingZeros(uint(base))) & 7
		b := uint64(base)
		m := uint(base) - 1 // == 1<<shift - 1
		for u >= b {
			i--
			a[i] = digits[uint(u)&m]
			u >>= shift
		}
		// u < base
		i--
		a[i] = digits[uint(u)]
	} else {
		// general case
		b := uint64(base)
		for u >= b {
			i--

Klaus Post <******@****.***> 1457448890 +0100

	sign = uint32(b >> 63)
	exp = int32(b>>52) & mask
	mantissa = b & fracMask

	if exp == 0 {
		// Normalize value if subnormal.
		shift := uint(bits.LeadingZeros64(mantissa) - 11)
		mantissa <<= shift
		exp = 1 - int32(shift)
	} else {
		// Add implicit 1 bit
		mantissa |= 1 << 52
	}
	return
}

// FMA returns x * y + z, computed with only one rounding.

			Valu("c", OpConst64, c.config.Types.UInt64, amount, nil),
			Valu("shift", op, typ, 0, nil, "load", "c"),
			Valu("store", OpStore, types.TypeMem, 0, c.config.Types.UInt64, "resptr", "shift", "mem"),
			Exit("store")))
	Compile(fun.f)
	return fun
}

func TestShiftToExtensionAMD64(t *testing.T) {
	c := testConfig(t)
	// Test that eligible pairs of constant shifts are converted to extensions.
	// For example:

Klaus Post <******@****.***> 1457448890 +0100

Klaus Post <******@****.***> 1457448890 +0100