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      1 ; A store or load cannot alias a global if the accessed amount is larger then
      2 ; the global.
      3 
      4 ; RUN: opt < %s -basicaa -gvn -S | FileCheck %s
      5 target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
      6 
      7 @B = global i16 8
      8 
      9 ; CHECK: @test1
     10 define i16 @test1(i32* %P) {
     11         %X = load i16* @B
     12         store i32 7, i32* %P
     13         %Y = load i16* @B
     14         %Z = sub i16 %Y, %X
     15         ret i16 %Z
     16 ; CHECK: ret i16 0
     17 }
     18 
     19 ; Cannot know anything about the size of this global.
     20 ; rdar://8813415
     21 @window = external global [0 x i8]
     22 
     23 ; CHECK: @test2
     24 define i8 @test2(i32 %tmp79, i32 %w.2, i32 %indvar89) nounwind {
     25   %tmp92 = add i32 %tmp79, %indvar89
     26   %arrayidx412 = getelementptr [0 x i8]* @window, i32 0, i32 %tmp92
     27   %tmp93 = add i32 %w.2, %indvar89
     28   %arrayidx416 = getelementptr [0 x i8]* @window, i32 0, i32 %tmp93
     29 
     30   %A = load i8* %arrayidx412, align 1
     31   store i8 4, i8* %arrayidx416, align 1
     32 
     33   %B = load i8* %arrayidx412, align 1
     34   %C = sub i8 %A, %B
     35   ret i8 %C
     36 
     37 ; CHECK: %B = load i8
     38 ; CHECK: ret i8 %C
     39 }
     40 
     41