llvm-6502/test/Analysis/BasicAA/global-size.ll
Chris Lattner 895ace08e0 fix rdar://8813415 - a miscompilation of 164.gzip that loop-idiom
exposed.  It turns out to be a latent bug in basicaa, scary.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122772 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-03 21:03:33 +00:00

41 lines
1.1 KiB
LLVM

; A store or load cannot alias a global if the accessed amount is larger then
; the global.
; RUN: opt < %s -basicaa -gvn -S | FileCheck %s
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"
@B = global i16 8
; CHECK: @test1
define i16 @test1(i32* %P) {
%X = load i16* @B
store i32 7, i32* %P
%Y = load i16* @B
%Z = sub i16 %Y, %X
ret i16 %Z
; CHECK: ret i16 0
}
; Cannot know anything about the size of this global.
; rdar://8813415
@window = external global [0 x i8]
; CHECK: @test2
define i8 @test2(i32 %tmp79, i32 %w.2, i32 %indvar89) nounwind {
%tmp92 = add i32 %tmp79, %indvar89
%arrayidx412 = getelementptr [0 x i8]* @window, i32 0, i32 %tmp92
%tmp93 = add i32 %w.2, %indvar89
%arrayidx416 = getelementptr [0 x i8]* @window, i32 0, i32 %tmp93
%A = load i8* %arrayidx412, align 1
store i8 4, i8* %arrayidx416, align 1
%B = load i8* %arrayidx412, align 1
%C = sub i8 %A, %B
ret i8 %C
; CHECK: %B = load i8
; CHECK: ret i8 %C
}