llvm-6502/test/Analysis/BasicAA/store-promote.ll

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; Test that LICM uses basicaa to do alias analysis, which is capable of
; disambiguating some obvious cases. If LICM is able to disambiguate the
; two pointers, then the load should be hoisted, and the store sunk.
; RUN: opt < %s -basicaa -licm -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"
@A = global i32 7 ; <i32*> [#uses=3]
@B = global i32 8 ; <i32*> [#uses=2]
@C = global [2 x i32] [ i32 4, i32 8 ] ; <[2 x i32]*> [#uses=2]
define i32 @test1(i1 %c) {
%Atmp = load i32* @A ; <i32> [#uses=2]
br label %Loop
Loop: ; preds = %Loop, %0
%ToRemove = load i32* @A ; <i32> [#uses=1]
store i32 %Atmp, i32* @B
br i1 %c, label %Out, label %Loop
Out: ; preds = %Loop
%X = sub i32 %ToRemove, %Atmp ; <i32> [#uses=1]
ret i32 %X
; The Loop block should be empty after the load/store are promoted.
; CHECK: @test1
; CHECK: load i32* @A
; CHECK: Loop:
; CHECK-NEXT: br i1 %c, label %Out, label %Loop
; CHECK: Out:
; CHECK: store i32 %Atmp, i32* @B
}
define i32 @test2(i1 %c) {
br label %Loop
Loop: ; preds = %Loop, %0
%AVal = load i32* @A ; <i32> [#uses=2]
%C0 = getelementptr [2 x i32]* @C, i64 0, i64 0 ; <i32*> [#uses=1]
store i32 %AVal, i32* %C0
%BVal = load i32* @B ; <i32> [#uses=2]
%C1 = getelementptr [2 x i32]* @C, i64 0, i64 1 ; <i32*> [#uses=1]
store i32 %BVal, i32* %C1
br i1 %c, label %Out, label %Loop
Out: ; preds = %Loop
%X = sub i32 %AVal, %BVal ; <i32> [#uses=1]
ret i32 %X
; The Loop block should be empty after the load/store are promoted.
; CHECK: @test2
; CHECK: Loop:
; CHECK-NEXT: br i1 %c, label %Out, label %Loop
}