llvm-6502/test/Analysis/BasicAA/store-promote.ll
Eli Friedman 0e382192c1 PR9634: Don't unconditionally tell the AliasSetTracker that the PreheaderLoad
is equivalent to any other relevant value; it isn't true in general.
If it is equivalent, the LoopPromoter will tell the AST the equivalence.
Also, delete the PreheaderLoad if it is unused.

Chris, since you were the last one to make major changes here, can you check
that this is sane?



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129049 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-07 01:35:06 +00:00

55 lines
1.9 KiB
LLVM

; 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
}