function failing to run in Jit

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1

Is there any reason this generated code won't run in the Jit?
I've pretty much got everything else working for my front end
which all runs fin in the Jit but I can't get global arrays to work.

; ModuleID = 'test'
target datalayout =
"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
target triple = "i686-pc-linux-gnu"

@MyArray = external global [1000 x i32]

define i32 @foo(i32 %a, i32 %b) {
Entry:
  %mul = mul i32 %b, %a
  %ptr = getelementptr inbounds [1000 x i32]* @MyArray, i32 0, i32 %a
  store i32 %mul, i32* %ptr, align 4
  ret i32 %a
}

Comparing it to the web compiled c equivalent I can't see any relevant
difference.

; ModuleID = '/tmp/webcompile/_925_0.bc'
target datalayout =
"e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-linux-gnu"

@array = common global [1000 x i32] zeroinitializer, align 32 ; <[1000 x
i32]*> [#uses=1]

define i32 @foo(i32 %a, i32 %b) nounwind {
entry:
  %0 = mul nsw i32 %b, %a ; <i32> [#uses=1]
  %1 = sext i32 %a to i64 ; <i64> [#uses=1]
  %2 = getelementptr inbounds [1000 x i32]* @array, i64 0, i64 %1 ;
<i32*> [#uses=1]
  store i32 %0, i32* %2, align 4
  ret i32 %a
}

2

Try using i64 indices with GEP

3

That doesn't work either.

%1 = sext i32 %a to i64
%2 = getelementptr inbounds [1000 x i32]* @array, i64 0, i64 %1 ;

4

Hi Andrew,

@MyArray = external global [1000 x i32]

since MyArray is declared as being defined somewhere else (extern) you need to
link with something that actually defines @MyArray.

@array = common global [1000 x i32] zeroinitializer, align 32 ;<[1000 x
i32]*> [#uses=1]

Here MyArray is being defined, with an initial value that is all zero. Thus
there is no need to link with something that provides a definition.

Ciao, Duncan.