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; 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
}
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