// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package bytealg

import (
	"internal/cpu"
	"unsafe"
)

// Offsets into internal/cpu records for use in assembly.
const (
	offsetX86HasSSE42  = unsafe.Offsetof(cpu.X86.HasSSE42)
	offsetX86HasAVX2   = unsafe.Offsetof(cpu.X86.HasAVX2)
	offsetX86HasPOPCNT = unsafe.Offsetof(cpu.X86.HasPOPCNT)

// that are known to the runtime.
//
// The first local is a bool called retValid with a whole pointer-word reserved
// for it on the stack. The purpose of this word is so that the runtime knows
// whether the stack-allocated return space contains valid values for stack
// scanning.
//
// The second local is an abi.RegArgs value whose offset is also known to the

	}
	for i, m := range methods {
		m.Offset = int64(i) * int64(PtrSize)
	}

	t.SetAllMethods(methods)
}

// calcStructOffset computes the offsets of a sequence of fields,
// starting at the given offset. It returns the resulting offset and
// maximum field alignment.
func calcStructOffset(t *Type, fields []*Field, offset int64) int64 {
	for _, f := range fields {
		CalcSize(f.Type)

	//                         size_t len, unsigned int flags);
	//
	// Note that in the call to unix.CopyFileRange below, we use nil
	// values for off_in and off_out. For the system call, this means
	// "use and update the file offsets". That is why we must acquire
	// locks for both file descriptors (and why this whole machinery is
	// in the internal/poll package to begin with).
	if err := dst.writeLock(); err != nil {
		return 0, err
	}

	_ = *bigstructp // ERROR "nil check"
	_ = *empty1p    // ERROR "nil check"
}

func fx10k() *[10000]int

var b bool

func f3(x *[10000]int) {
	// Using a huge type and huge offsets so the compiler
	// does not expect the memory hardware to fault.
	_ = x[9999] // ERROR "nil check"

	for {
		if x[9999] != 0 { // ERROR "nil check"
			break
		}
	}

	x = fx10k()

// Returns the type of the size tensor used to track a data structure's element
// count. It is a tensor<1xi32>, and we use R1 instead of a scalar because it is
// easier to concat it with other offsets.
TensorType GetSizeType(OpBuilder builder);

// Reshapes a scalar value to match the size type tensor<i32>.
Value ReshapeScalarToSizeType(OpBuilder builder, Value scalar, Location loc);

	MOVL	$SYS_thr_new, AX
	INT	$0x80
	JAE	2(PC)
	NEGL	AX
	MOVL	AX, ret+8(FP)
	RET

// Called by OS using C ABI.
TEXT runtime·thr_start(SB),NOSPLIT,$0
	NOP	SP	// tell vet SP changed - stop checking offsets
	MOVL	4(SP), AX // m
	MOVL	m_g0(AX), BX
	LEAL	m_tls(AX), BP
	MOVL	m_id(AX), DI
	ADDL	$7, DI
	PUSHAL
	PUSHL	$32
	PUSHL	BP
	PUSHL	DI
	CALL	runtime·setldt(SB)
	POPL	AX
	POPL	AX
	POPL	AX
	POPAL

		return len(x.Args) == 1 &&
			hasBasicType(info, x.Fun, types.Uintptr) &&
			hasBasicType(info, x.Args[0], types.UnsafePointer)

	case *ast.BinaryExpr:
		// "It is valid both to add and to subtract offsets from a
		// pointer in this way. It is also valid to use &^ to round
		// pointers, usually for alignment."
		switch x.Op {
		case token.ADD, token.SUB, token.AND_NOT:
			// TODO(mdempsky): Match compiler

		//     be.baseline = 1 << e.sym
		//     be.basebits = e.sym
		// That would give us an offset value that corresponds to
		// the one described in the RFC. However, for offsets > 3
		// we have to subtract 3. And for offset values 1, 2, 3
		// we use a repeated offset.
		//
		// The baseline is always a power of 2, and is never 0,
		// so for those low values we will see one entry that is

				//	{-1, 0, -1}  LowerCase (Upper, Title are previous)
				// The characters at even offsets from the beginning of the
				// sequence are upper case; the ones at odd offsets are lower.
				// The correct mapping can be done by clearing or setting the low
				// bit in the sequence offset.
				// The constants UpperCase and TitleCase are even while LowerCase
				// is odd so we take the low bit from _case.