117 lines
3.3 KiB
LLVM
117 lines
3.3 KiB
LLVM
|
; RUN: opt < %s -globals-aa -gvn -S | FileCheck %s
|
||
|
|
;
|
||
|
|
; This tests the safe no-alias conclusions of GMR -- when there is
|
||
|
|
; a non-escaping global as one indentified underlying object and some pointer
|
||
|
|
; that would inherently have escaped any other function as the other underlying
|
||
|
|
; pointer of an alias query.
|
||
|
|
|
||
|
|
@g1 = internal global i32 0
|
||
|
|
|
||
|
|
define i32 @test1(i32* %param) {
|
||
|
|
; Ensure that we can fold a store to a load of a global across a store to
|
||
|
|
; a parameter when the global is non-escaping.
|
||
|
|
;
|
||
|
|
; CHECK-LABEL: @test1(
|
||
|
|
; CHECK: store i32 42, i32* @g1
|
||
|
|
; CHECK-NOT: load i32
|
||
|
|
; CHECK: ret i32 42
|
||
|
|
entry:
|
||
|
|
store i32 42, i32* @g1
|
||
|
|
store i32 7, i32* %param
|
||
|
|
%v = load i32, i32* @g1
|
||
|
|
ret i32 %v
|
||
|
|
}
|
||
|
|
|
||
|
|
declare i32* @f()
|
||
|
|
|
||
|
|
define i32 @test2() {
|
||
|
|
; Ensure that we can fold a store to a load of a global across a store to
|
||
|
|
; the pointer returned by a function call. Since the global could not escape,
|
||
|
|
; this function cannot be returning its address.
|
||
|
|
;
|
||
|
|
; CHECK-LABEL: @test2(
|
||
|
|
; CHECK: store i32 42, i32* @g1
|
||
|
|
; CHECK-NOT: load i32
|
||
|
|
; CHECK: ret i32 42
|
||
|
|
entry:
|
||
|
|
%ptr = call i32* @f() readnone
|
||
|
|
store i32 42, i32* @g1
|
||
|
|
store i32 7, i32* %ptr
|
||
|
|
%v = load i32, i32* @g1
|
||
|
|
ret i32 %v
|
||
|
|
}
|
||
|
|
|
||
|
|
@g2 = external global i32*
|
||
|
|
|
||
|
|
define i32 @test3() {
|
||
|
|
; Ensure that we can fold a store to a load of a global across a store to
|
||
|
|
; the pointer loaded from that global. Because the global does not escape, it
|
||
|
|
; cannot alias a pointer loaded out of a global.
|
||
|
|
;
|
||
|
|
; CHECK-LABEL: @test3(
|
||
|
|
; CHECK: store i32 42, i32* @g1
|
||
|
|
; CHECK: store i32 7, i32*
|
||
|
|
; CHECK-NOT: load i32
|
||
|
|
; CHECK: ret i32 42
|
||
|
|
entry:
|
||
|
|
store i32 42, i32* @g1
|
||
|
|
%ptr1 = load i32*, i32** @g2
|
||
|
|
store i32 7, i32* %ptr1
|
||
|
|
%v = load i32, i32* @g1
|
||
|
|
ret i32 %v
|
||
|
|
}
|
||
|
|
|
||
|
|
@g3 = internal global i32 1
|
||
|
|
@g4 = internal global [10 x i32*] zeroinitializer
|
||
|
|
|
||
|
|
define i32 @test4(i32* %param, i32 %n, i1 %c1, i1 %c2, i1 %c3) {
|
||
|
|
; Ensure that we can fold a store to a load of a global across a store to
|
||
|
|
; the pointer loaded from that global even when the load is behind PHIs and
|
||
|
|
; selects, and there is a mixture of a load and another global or argument.
|
||
|
|
; Note that we can't eliminate the load here because it is used in a PHI and
|
||
|
|
; GVN doesn't try to do real DCE. The store is still forwarded by GVN though.
|
||
|
|
;
|
||
|
|
; CHECK-LABEL: @test4(
|
||
|
|
; CHECK: store i32 42, i32* @g1
|
||
|
|
; CHECK: store i32 7, i32*
|
||
|
|
; CHECK: ret i32 42
|
||
|
|
entry:
|
||
|
|
%call = call i32* @f()
|
||
|
|
store i32 42, i32* @g1
|
||
|
|
%ptr1 = load i32*, i32** @g2
|
||
|
|
%ptr2 = select i1 %c1, i32* %ptr1, i32* %param
|
||
|
|
%ptr3 = select i1 %c3, i32* %ptr2, i32* @g3
|
||
|
|
br label %loop
|
||
|
|
|
||
|
|
loop:
|
||
|
|
%iv = phi i32 [ 0, %entry ], [ %inc, %loop ]
|
||
|
|
%ptr = phi i32* [ %ptr3, %entry ], [ %ptr5, %loop ]
|
||
|
|
store i32 7, i32* %ptr
|
||
|
|
%ptr4 = load i32*, i32** getelementptr ([10 x i32*], [10 x i32*]* @g4, i32 0, i32 1)
|
||
|
|
%ptr5 = select i1 %c2, i32* %ptr4, i32* %call
|
||
|
|
%inc = add i32 %iv, 1
|
||
|
|
%test = icmp slt i32 %inc, %n
|
||
|
|
br i1 %test, label %loop, label %exit
|
||
|
|
|
||
|
|
exit:
|
||
|
|
%v = load i32, i32* @g1
|
||
|
|
ret i32 %v
|
||
|
|
}
|
||
|
|
|
||
|
|
define i32 @test5(i32** %param) {
|
||
|
|
; Ensure that we can fold a store to a load of a global across a store to
|
||
|
|
; a parameter that has been dereferenced when the global is non-escaping.
|
||
|
|
;
|
||
|
|
; CHECK-LABEL: @test5(
|
||
|
|
; CHECK: %p = load i32*
|
||
|
|
; CHECK: store i32 42, i32* @g1
|
||
|
|
; CHECK-NOT: load i32
|
||
|
|
; CHECK: ret i32 42
|
||
|
|
entry:
|
||
|
|
%p = load i32*, i32** %param
|
||
|
|
store i32 42, i32* @g1
|
||
|
|
store i32 7, i32* %p
|
||
|
|
%v = load i32, i32* @g1
|
||
|
|
ret i32 %v
|
||
|
|
}
|