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|
; RUN: opt < %s -aa-pipeline=basic-aa,globals-aa -passes='require<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(ptr %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, ptr @g1
; CHECK-NOT: load i32
; CHECK: ret i32 42
entry:
store i32 42, ptr @g1
store i32 7, ptr %param
%v = load i32, ptr @g1
ret i32 %v
}
@g1_tls = internal thread_local global i32 0
define i32 @test1_tls(ptr %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: define i32 @test1_tls(
; CHECK-SAME: ptr [[PARAM:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[P:%.*]] = call ptr @llvm.threadlocal.address.p0(ptr @g1_tls)
; CHECK-NEXT: store i32 42, ptr [[P]], align 4
; CHECK-NEXT: store i32 7, ptr [[PARAM]], align 4
; CHECK-NEXT: ret i32 42
;
entry:
%p = call ptr @llvm.threadlocal.address(ptr @g1_tls)
store i32 42, ptr %p
store i32 7, ptr %param
%p2 = call ptr @llvm.threadlocal.address(ptr @g1_tls)
%v = load i32, ptr %p2
ret i32 %v
}
define ptr @test1_tls_noopt(ptr %coro, ptr %param) presplitcoroutine {
; CHECK-LABEL: define ptr @test1_tls_noopt(
; CHECK-SAME: ptr [[CORO:%.*]], ptr [[PARAM:%.*]]) #[[ATTR0:[0-9]+]] {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[P:%.*]] = call ptr @llvm.threadlocal.address.p0(ptr @g1_tls)
; CHECK-NEXT: store i32 42, ptr [[P]], align 4
; CHECK-NEXT: [[TMP0:%.*]] = call i8 @llvm.coro.suspend(token none, i1 false)
; CHECK-NEXT: switch i8 [[TMP0]], label [[SUSPEND:%.*]] [
; CHECK-NEXT: i8 0, label [[RESUME:%.*]]
; CHECK-NEXT: i8 1, label [[SUSPEND]]
; CHECK-NEXT: ]
; CHECK: resume:
; CHECK-NEXT: [[P2:%.*]] = call ptr @llvm.threadlocal.address.p0(ptr @g1_tls)
; CHECK-NEXT: [[V:%.*]] = load i32, ptr [[P2]], align 4
; CHECK-NEXT: store i32 [[V]], ptr [[PARAM]], align 4
; CHECK-NEXT: ret ptr [[CORO]]
; CHECK: suspend:
; CHECK-NEXT: [[TMP1:%.*]] = call i1 @llvm.coro.end(ptr [[CORO]], i1 false, token none)
; CHECK-NEXT: ret ptr [[CORO]]
;
entry:
%p = call ptr @llvm.threadlocal.address(ptr @g1_tls)
store i32 42, ptr %p
%0 = call i8 @llvm.coro.suspend(token none, i1 false)
switch i8 %0, label %suspend [i8 0, label %resume
i8 1, label %suspend]
resume:
%p2 = call ptr @llvm.threadlocal.address(ptr @g1_tls)
%v = load i32, ptr %p2
store i32 %v, ptr %param, align 4
ret ptr %coro
suspend:
call i1 @llvm.coro.end(ptr %coro, i1 0)
ret ptr %coro
}
declare ptr @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, ptr @g1
; CHECK-NOT: load i32
; CHECK: ret i32 42
entry:
%ptr = call ptr @f() readnone
store i32 42, ptr @g1
store i32 7, ptr %ptr
%v = load i32, ptr @g1
ret i32 %v
}
@g2 = external global ptr
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, ptr @g1
; CHECK: store i32 7, ptr
; CHECK-NOT: load i32
; CHECK: ret i32 42
entry:
store i32 42, ptr @g1
%ptr1 = load ptr, ptr @g2
store i32 7, ptr %ptr1
%v = load i32, ptr @g1
ret i32 %v
}
@g3 = internal global i32 1
@g4 = internal global [10 x ptr] zeroinitializer
define i32 @test4(ptr %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, ptr @g1
; CHECK: store i32 7, ptr
; CHECK: ret i32 42
entry:
%call = call ptr @f()
store i32 42, ptr @g1
%ptr1 = load ptr, ptr @g2
%ptr2 = select i1 %c1, ptr %ptr1, ptr %param
%ptr3 = select i1 %c3, ptr %ptr2, ptr @g3
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %inc, %loop ]
%ptr = phi ptr [ %ptr3, %entry ], [ %ptr5, %loop ]
store i32 7, ptr %ptr
%ptr4 = load ptr, ptr getelementptr ([10 x ptr], ptr @g4, i32 0, i32 1)
%ptr5 = select i1 %c2, ptr %ptr4, ptr %call
%inc = add i32 %iv, 1
%test = icmp slt i32 %inc, %n
br i1 %test, label %loop, label %exit
exit:
%v = load i32, ptr @g1
ret i32 %v
}
define i32 @test5(ptr %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 ptr
; CHECK: store i32 42, ptr @g1
; CHECK-NOT: load i32
; CHECK: ret i32 42
entry:
%p = load ptr, ptr %param
store i32 42, ptr @g1
store i32 7, ptr %p
%v = load i32, ptr @g1
ret i32 %v
}
|
