void Zero(void *p[], int size) {
  int i, *q;
  for (i = 0; i < size; i++) {
    printf("p[%d] is %d.\n", i, p[i]);
    q = (int *)p[i];
    printf("q is %d.\n", q);
  }
}


x86 assembly (clang, -O0):
<Zero>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
cmp    -0xc(%rbp),%eax
jge    117f <Zero+0x6f>
mov    -0x10(%rbp),%esi
mov    -0x8(%rbp),%rax
movslq -0x10(%rbp),%rcx
mov    (%rax,%rcx,8),%rdx
lea    0xeb8(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x8(%rbp),%rax
movslq -0x10(%rbp),%rcx
mov    (%rax,%rcx,8),%rax
mov    %rax,-0x18(%rbp)
mov    -0x18(%rbp),%rsi
lea    0xea4(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    1126 <Zero+0x16>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<Zero>:
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
test   %esi,%esi
jle    1167 <Zero+0x57>
mov    %rdi,%r12
mov    %esi,%r13d
lea    0xed6(%rip),%r14
lea    0xedd(%rip),%r15
xor    %ebx,%ebx
cs nopw 0x0(%rax,%rax,1)
nopl   (%rax)
mov    (%r12,%rbx,8),%rdx
mov    %r14,%rdi
mov    %ebx,%esi
xor    %eax,%eax
call   1030 <printf@plt>
mov    (%r12,%rbx,8),%rsi
mov    %r15,%rdi
xor    %eax,%eax
call   1030 <printf@plt>
add    $0x1,%rbx
cmp    %rbx,%r13
jne    1140 <Zero+0x30>
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [14 x i8] c"p[%d] is %d.\0A\00"
@.str.1 = [10 x i8] c"q is %d.\0A\00"
define void @Zero(i8** %0, i32 %1) {
%3 = alloca i8**
%4 = alloca i32
%5 = alloca i32
%6 = alloca i32*
store i8** %0, i8*** %3
store i32 %1, i32* %4
store i32 0, i32* %5
br label %7
7: ; preds = %27, %2
%8 = load i32, i32* %5
%9 = load i32, i32* %4
%10 = icmp slt i32 %8, %9
br i1 %10, label %11, label %30
11: ; preds = %7
%12 = load i32, i32* %5
%13 = load i8**, i8*** %3
%14 = load i32, i32* %5
%15 = sext i32 %14 to i64
%16 = getelementptr inbounds i8*, i8** %13, i64 %15
%17 = load i8*, i8** %16
%18 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str, i64 0, i64 0), i32 %12, i8* %17)
%19 = load i8**, i8*** %3
%20 = load i32, i32* %5
%21 = sext i32 %20 to i64
%22 = getelementptr inbounds i8*, i8** %19, i64 %21
%23 = load i8*, i8** %22
%24 = bitcast i8* %23 to i32*
store i32* %24, i32** %6
%25 = load i32*, i32** %6
%26 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.1, i64 0, i64 0), i32* %25)
br label %27
27: ; preds = %11
%28 = load i32, i32* %5
%29 = add nsw i32 %28, 1
store i32 %29, i32* %5
br label %7
30: ; preds = %7
ret void
}

LLVM IR (-O2):
@.str = [14 x i8] c"p[%d] is %d.\0A\00"
@.str.1 = [10 x i8] c"q is %d.\0A\00"
define void @Zero(i8** nocapture %0, i32 %1) {
%3 = icmp sgt i32 %1, 0
br i1 %3, label %4, label %17
4: ; preds = %2
%5 = zext i32 %1 to i64
br label %6
6: ; preds = %4, %6
%7 = phi i64 [ 0, %4 ], [ %15, %6 ]
%8 = getelementptr inbounds i8*, i8** %0, i64 %7
%9 = load i8*, i8** %8
%10 = trunc i64 %7 to i32
%11 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([14 x i8], [14 x i8]* @.str, i64 0, i64 0), i32 %10, i8* %9)
%12 = bitcast i8** %8 to i32**
%13 = load i32*, i32** %12
%14 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([10 x i8], [10 x i8]* @.str.1, i64 0, i64 0), i32* %13)
%15 = add nuw nsw i64 %7, 1
%16 = icmp eq i64 %15, %5
br i1 %16, label %17, label %6
17: ; preds = %6, %2
ret void
}