Assembly code for iteration over StringPiece; with base::internal::find changed to take arguments by value

stringpiecefindtest-fixed.s

# Source:
# void StringPieceFindTestVal(const std::vector<base::StringPiece>& vector) {
#   for (base::StringPiece piece : vector)
#     printf("%zu\n", piece.find('x'));
# }
#
# void StringPieceFindTestRef(const std::vector<base::StringPiece>& vector) {
#   for (const base::StringPiece& piece : vector)
#     printf("%zu\n", piece.find('x'));
# }
# (both functions generate same code)
#
# With base::internal::find changed to take arguments by value.
# Compiler: clang++ Linux 64-bit

# BB#0:                                 # %entry
	pushq	%rbp
	movq	%rsp, %rbp
	pushq	%r15
	pushq	%r14
	pushq	%rbx
	pushq	%rax
	movq	(%rdi), %rbx
	movq	8(%rdi), %r15
	cmpq	%r15, %rbx
	je	.LBB25_3
# BB#1:
	leaq	.L.str.17(%rip), %r14
	.p2align	4, 0x90
.LBB25_2:                               # %for.body
	movq	(%rbx), %rdi
	movq	8(%rbx), %rsi
	movl	$120, %edx
	xorl	%ecx, %ecx
	callq	_ZN4base8internal4findENS_16BasicStringPieceISsEEcm@PLT
	movq	%rax, %rcx
	xorl	%eax, %eax
	movq	%r14, %rdi
	movq	%rcx, %rsi
	callq	printf@PLT
	addq	$16, %rbx
	cmpq	%r15, %rbx
	jne	.LBB25_2
.LBB25_3:                               # %for.cond.cleanup
	addq	$8, %rsp
	popq	%rbx
	popq	%r14
	popq	%r15
	popq	%rbp
	retq