1 ; RUN: opt -O3 -S < %s | FileCheck %s 2 target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128" 3 target triple = "aarch64" 4 5 @v = internal unnamed_addr global i32 0, align 4 6 @p = common global i32* null, align 8 7 8 9 ; This test checks that a number of loads and stores are eliminated, 10 ; that can only be eliminated based on GlobalsAA information. As such, 11 ; it tests that GlobalsAA information is retained until the passes 12 ; that perform this optimization, and it protects against accidentally 13 ; dropping the GlobalsAA information earlier in the pipeline, which 14 ; has happened a few times. 15 16 ; GlobalsAA invalidation might happen later in the FunctionPassManager 17 ; pipeline than the optimization eliminating unnecessary loads/stores. 18 ; Since GlobalsAA is a module-level analysis, any FunctionPass 19 ; invalidating the GlobalsAA information will affect FunctionPass 20 ; pipelines that execute later. For example, assume a FunctionPass1 | 21 ; FunctionPass2 pipeline and 2 functions to be processed: f1 and f2. 22 ; Assume furthermore that FunctionPass1 uses GlobalsAA info to do an 23 ; optimization, and FunctionPass2 invalidates GlobalsAA. Assume the 24 ; function passes run in the following order: FunctionPass1(f1), 25 ; FunctionPass2(f1), FunctionPass1(f2), FunctionPass2(f2). Then 26 ; FunctionPass1 will not be able to optimize f2, since GlobalsAA will 27 ; have been invalidated in FuntionPass2(f1). 28 29 ; To try and also test this scenario, there is an empty function 30 ; before and after the function we're checking so that one of them 31 ; will be processed by the whole set of FunctionPasses before @f. That 32 ; will ensure that if the invalidation happens, it happens before the 33 ; actual optimizations on @f start. 34 define void @bar() { 35 entry: 36 ret void 37 } 38 39 ; Function Attrs: norecurse nounwind 40 define void @f(i32 %n) { 41 entry: 42 %0 = load i32, i32* @v, align 4 43 %inc = add nsw i32 %0, 1 44 store i32 %inc, i32* @v, align 4 45 %1 = load i32*, i32** @p, align 8 46 store i32 %n, i32* %1, align 4 47 %2 = load i32, i32* @v, align 4 48 %inc1 = add nsw i32 %2, 1 49 store i32 %inc1, i32* @v, align 4 50 ret void 51 } 52 53 ; check variable v is loaded/stored only once after optimization, 54 ; which should be prove that globalsAA survives until the optimization 55 ; that can use it to optimize away the duplicate load/stores on 56 ; variable v. 57 ; CHECK: load i32, i32* @v, align 4 58 ; CHECK: store i32 {{.*}}, i32* @v, align 4 59 ; CHECK-NOT: load i32, i32* @v, align 4 60 ; CHECK-NOT: store i32 {{.*}}, i32* @v, align 4 61 62 ; Same as @bar above, in case the functions are processed in reverse order. 63 define void @bar2() { 64 entry: 65 ret void 66 } 67
