Hi all,

sorry to have sent the same question around. I am quite desperately looking for a solution to this problem and I figured the mailing list is the best bet.

In my code, I generate the following function:

```
define i32 @gl.qi([500 x i32] %x, i32 %i) {
entry:
%x. = alloca [500 x i32]
%i. = alloca i32
%0 = alloca [500 x i32]
store [500 x i32] %x, [500 x i32]* %x.
store i32 %i, i32* %i.
%x.1 = load [500 x i32], [500 x i32]* %x.
%i.2 = load i32, i32* %i.
store [500 x i32] %x.1, [500 x i32]* %0
%1 = icmp slt i32 %i.2, 500
br i1 %1, label %in-bound, label %out-of-bound
out-of-bound: ; preds = %entry
call void @gen.panic(i8* getelementptr inbounds ([22 x i8], [22 x i8]* @pool.str.2, i32 0, i32 0))
unreachable
in-bound: ; preds = %entry
%2 = getelementptr inbounds [500 x i32], [500 x i32]* %0, i32 0, i32 %i.2
%idx = load i32, i32* %2
ret i32 %idx
}
```

the high level functionality is to use `%i`

to index `%x`

, and if `%i`

is out of bound, a panic function is called instead.

consider the store line:

```
store [500 x i32] %x, [500 x i32]* %x.
```

once I pass this function to `opt -O1 -S --verify --verify-each`

, it generates code like this:

```
define i32 @gl.qi([500 x i32] %x, i32 %i) local_unnamed_addr {
entry:
%0 = alloca [500 x i32], align 4
%x.fca.0.extract = extractvalue [500 x i32] %x, 0
%x.fca.1.extract = extractvalue [500 x i32] %x, 1
%x.fca.2.extract = extractvalue [500 x i32] %x, 2
%x.fca.3.extract = extractvalue [500 x i32] %x, 3
%x.fca.4.extract = extractvalue [500 x i32] %x, 4
%x.fca.5.extract = extractvalue [500 x i32] %x, 5
```

until 500. I put the number to 50000 and it won’t stop.

This is puzzling. I am not sure why must a `store`

command be expanded to a sequence of `etractvalue`

s then `store`

s? Is there a way to turn off this particular optimization without turning off the whole optimization?

Or am I looking at the wrong way to do this simple task?