forked from OSchip/llvm-project
159 lines
4.6 KiB
LLVM
159 lines
4.6 KiB
LLVM
; RUN: opt -S -early-cse < %s | FileCheck %s
|
|
; RUN: opt -S -basicaa -early-cse-memssa < %s | FileCheck %s
|
|
|
|
declare void @clobber_and_use(i32)
|
|
|
|
define void @f_0(i32* %ptr) {
|
|
; CHECK-LABEL: @f_0(
|
|
; CHECK: %val0 = load i32, i32* %ptr, !invariant.load !0
|
|
; CHECK: call void @clobber_and_use(i32 %val0)
|
|
; CHECK: call void @clobber_and_use(i32 %val0)
|
|
; CHECK: call void @clobber_and_use(i32 %val0)
|
|
; CHECK: ret void
|
|
|
|
%val0 = load i32, i32* %ptr, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %val0)
|
|
%val1 = load i32, i32* %ptr, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %val1)
|
|
%val2 = load i32, i32* %ptr, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %val2)
|
|
ret void
|
|
}
|
|
|
|
define void @f_1(i32* %ptr) {
|
|
; We can forward invariant loads to non-invariant loads.
|
|
|
|
; CHECK-LABEL: @f_1(
|
|
; CHECK: %val0 = load i32, i32* %ptr, !invariant.load !0
|
|
; CHECK: call void @clobber_and_use(i32 %val0)
|
|
; CHECK: call void @clobber_and_use(i32 %val0)
|
|
|
|
%val0 = load i32, i32* %ptr, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %val0)
|
|
%val1 = load i32, i32* %ptr
|
|
call void @clobber_and_use(i32 %val1)
|
|
ret void
|
|
}
|
|
|
|
define void @f_2(i32* %ptr) {
|
|
; We can forward a non-invariant load into an invariant load.
|
|
|
|
; CHECK-LABEL: @f_2(
|
|
; CHECK: %val0 = load i32, i32* %ptr
|
|
; CHECK: call void @clobber_and_use(i32 %val0)
|
|
; CHECK: call void @clobber_and_use(i32 %val0)
|
|
|
|
%val0 = load i32, i32* %ptr
|
|
call void @clobber_and_use(i32 %val0)
|
|
%val1 = load i32, i32* %ptr, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %val1)
|
|
ret void
|
|
}
|
|
|
|
define void @f_3(i1 %cond, i32* %ptr) {
|
|
; CHECK-LABEL: @f_3(
|
|
%val0 = load i32, i32* %ptr, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %val0)
|
|
br i1 %cond, label %left, label %right
|
|
|
|
; CHECK: %val0 = load i32, i32* %ptr, !invariant.load !0
|
|
; CHECK: left:
|
|
; CHECK-NEXT: call void @clobber_and_use(i32 %val0)
|
|
|
|
left:
|
|
%val1 = load i32, i32* %ptr
|
|
call void @clobber_and_use(i32 %val1)
|
|
ret void
|
|
|
|
right:
|
|
ret void
|
|
}
|
|
|
|
define void @f_4(i1 %cond, i32* %ptr) {
|
|
; Negative test -- can't forward %val0 to %va1 because that'll break
|
|
; def-dominates-use.
|
|
|
|
; CHECK-LABEL: @f_4(
|
|
br i1 %cond, label %left, label %merge
|
|
|
|
left:
|
|
; CHECK: left:
|
|
; CHECK-NEXT: %val0 = load i32, i32* %ptr, !invariant.load !
|
|
; CHECK-NEXT: call void @clobber_and_use(i32 %val0)
|
|
|
|
%val0 = load i32, i32* %ptr, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %val0)
|
|
br label %merge
|
|
|
|
merge:
|
|
; CHECK: merge:
|
|
; CHECK-NEXT: %val1 = load i32, i32* %ptr
|
|
; CHECK-NEXT: call void @clobber_and_use(i32 %val1)
|
|
|
|
%val1 = load i32, i32* %ptr
|
|
call void @clobber_and_use(i32 %val1)
|
|
ret void
|
|
}
|
|
|
|
; By assumption, the call can't change contents of p
|
|
; LangRef is a bit unclear about whether the store is reachable, so
|
|
; for the moment we chose to be conservative and just assume it's valid
|
|
; to restore the same unchanging value.
|
|
define void @test_dse1(i32* %p) {
|
|
; CHECK-LABEL: @test_dse1
|
|
; CHECK-NOT: store
|
|
%v1 = load i32, i32* %p, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %v1)
|
|
store i32 %v1, i32* %p
|
|
ret void
|
|
}
|
|
|
|
; By assumption, v1 must equal v2 (TODO)
|
|
define void @test_false_negative_dse2(i32* %p, i32 %v2) {
|
|
; CHECK-LABEL: @test_false_negative_dse2
|
|
; CHECK: store
|
|
%v1 = load i32, i32* %p, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %v1)
|
|
store i32 %v2, i32* %p
|
|
ret void
|
|
}
|
|
|
|
; If we remove the load, we still start an invariant scope since
|
|
; it lets us remove later loads not explicitly marked invariant
|
|
define void @test_scope_start_without_load(i32* %p) {
|
|
; CHECK-LABEL: @test_scope_start_without_load
|
|
; CHECK: %v1 = load i32, i32* %p
|
|
; CHECK: %add = add i32 %v1, %v1
|
|
; CHECK: call void @clobber_and_use(i32 %add)
|
|
; CHECK: call void @clobber_and_use(i32 %v1)
|
|
; CHECK: ret void
|
|
%v1 = load i32, i32* %p
|
|
%v2 = load i32, i32* %p, !invariant.load !{}
|
|
%add = add i32 %v1, %v2
|
|
call void @clobber_and_use(i32 %add)
|
|
%v3 = load i32, i32* %p
|
|
call void @clobber_and_use(i32 %v3)
|
|
ret void
|
|
}
|
|
|
|
; If we already have an invariant scope, don't want to start a new one
|
|
; with a potentially greater generation. This hides the earlier invariant
|
|
; load
|
|
define void @test_scope_restart(i32* %p) {
|
|
; CHECK-LABEL: @test_scope_restart
|
|
; CHECK: %v1 = load i32, i32* %p
|
|
; CHECK: call void @clobber_and_use(i32 %v1)
|
|
; CHECK: %add = add i32 %v1, %v1
|
|
; CHECK: call void @clobber_and_use(i32 %add)
|
|
; CHECK: call void @clobber_and_use(i32 %v1)
|
|
; CHECK: ret void
|
|
%v1 = load i32, i32* %p, !invariant.load !{}
|
|
call void @clobber_and_use(i32 %v1)
|
|
%v2 = load i32, i32* %p, !invariant.load !{}
|
|
%add = add i32 %v1, %v2
|
|
call void @clobber_and_use(i32 %add)
|
|
%v3 = load i32, i32* %p
|
|
call void @clobber_and_use(i32 %v3)
|
|
ret void
|
|
}
|