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|
; RUN: opt < %s -passes=gvn -S | FileCheck %s
%struct.A = type { ptr }
@_ZTV1A = available_externally unnamed_addr constant [4 x ptr] [ptr null, ptr @_ZTI1A, ptr @_ZN1A3fooEv, ptr @_ZN1A3barEv], align 8
@_ZTI1A = external constant ptr
; Checks if indirect calls can be replaced with direct
; assuming that %vtable == @_ZTV1A (with alignment).
; Checking const propagation across other BBs
; CHECK-LABEL: define void @_Z1gb(
define void @_Z1gb(i1 zeroext %p) {
entry:
%call = tail call noalias ptr @_Znwm(i64 8) #4
tail call void @_ZN1AC1Ev(ptr %call) #1
%vtable = load ptr, ptr %call, align 8
%cmp.vtables = icmp eq ptr %vtable, getelementptr inbounds ([4 x ptr], ptr @_ZTV1A, i64 0, i64 2)
tail call void @llvm.assume(i1 %cmp.vtables)
br i1 %p, label %if.then, label %if.else
if.then: ; preds = %entry
%0 = load ptr, ptr %vtable, align 8
; CHECK: call i32 @_ZN1A3fooEv(
%call2 = tail call i32 %0(ptr %call) #1
br label %if.end
if.else: ; preds = %entry
%vfn47 = getelementptr inbounds ptr, ptr %vtable, i64 1
; CHECK: call i32 @_ZN1A3barEv(
%1 = load ptr, ptr %vfn47, align 8
%call5 = tail call i32 %1(ptr %call) #1
br label %if.end
if.end: ; preds = %if.else, %if.then
ret void
}
; Check integration with invariant.group handling
; CHECK-LABEL: define void @invariantGroupHandling(i1 zeroext %p) {
define void @invariantGroupHandling(i1 zeroext %p) {
entry:
%call = tail call noalias ptr @_Znwm(i64 8) #4
tail call void @_ZN1AC1Ev(ptr %call) #1
%vtable = load ptr, ptr %call, align 8, !invariant.group !0
%cmp.vtables = icmp eq ptr %vtable, getelementptr inbounds ([4 x ptr], ptr @_ZTV1A, i64 0, i64 2)
tail call void @llvm.assume(i1 %cmp.vtables)
br i1 %p, label %if.then, label %if.else
if.then: ; preds = %entry
%0 = load ptr, ptr %vtable, align 8
; CHECK: call i32 @_ZN1A3fooEv(
%call2 = tail call i32 %0(ptr %call) #1
%vtable1 = load ptr, ptr %call, align 8, !invariant.group !0
%call1 = load ptr, ptr %vtable1, align 8
; CHECK: call i32 @_ZN1A3fooEv(
%callx = tail call i32 %call1(ptr %call) #1
%vtable2 = load ptr, ptr %call, align 8, !invariant.group !0
%call4 = load ptr, ptr %vtable2, align 8
; CHECK: call i32 @_ZN1A3fooEv(
%cally = tail call i32 %call4(ptr %call) #1
%vtable3 = load ptr, ptr %call, align 8, !invariant.group !0
%vfun = load ptr, ptr %vtable3, align 8
; CHECK: call i32 @_ZN1A3fooEv(
%unknown = tail call i32 %vfun(ptr %call) #1
br label %if.end
if.else: ; preds = %entry
%vfn47 = getelementptr inbounds ptr, ptr %vtable, i64 1
; CHECK: call i32 @_ZN1A3barEv(
%1 = load ptr, ptr %vfn47, align 8
%call5 = tail call i32 %1(ptr %call) #1
br label %if.end
if.end: ; preds = %if.else, %if.then
ret void
}
; Checking const propagation in the same BB
; CHECK-LABEL: define i32 @main()
define i32 @main() {
entry:
%call = tail call noalias ptr @_Znwm(i64 8)
tail call void @_ZN1AC1Ev(ptr %call)
%vtable = load ptr, ptr %call, align 8
%cmp.vtables = icmp eq ptr %vtable, getelementptr inbounds ([4 x ptr], ptr @_ZTV1A, i64 0, i64 2)
tail call void @llvm.assume(i1 %cmp.vtables)
; CHECK: call i32 @_ZN1A3fooEv(
%0 = load ptr, ptr %vtable, align 8
%call2 = tail call i32 %0(ptr %call)
ret i32 0
}
; This tests checks const propatation with fcmp instruction.
; CHECK-LABEL: define float @_Z1gf(float %p)
define float @_Z1gf(float %p) {
entry:
%p.addr = alloca float, align 4
%f = alloca float, align 4
store float %p, ptr %p.addr, align 4
store float 3.000000e+00, ptr %f, align 4
%0 = load float, ptr %p.addr, align 4
%1 = load float, ptr %f, align 4
%cmp = fcmp oeq float %1, %0 ; note const on lhs
call void @llvm.assume(i1 %cmp)
; CHECK: ret float 3.000000e+00
ret float %0
}
; CHECK-LABEL: define float @_Z1hf(float %p)
define float @_Z1hf(float %p) {
entry:
%p.addr = alloca float, align 4
store float %p, ptr %p.addr, align 4
%0 = load float, ptr %p.addr, align 4
%cmp = fcmp nnan ueq float %0, 3.000000e+00
call void @llvm.assume(i1 %cmp)
; CHECK: ret float 3.000000e+00
ret float %0
}
; CHECK-LABEL: define float @_Z1if(float %p)
define float @_Z1if(float %p) {
entry:
%p.addr = alloca float, align 4
store float %p, ptr %p.addr, align 4
%0 = load float, ptr %p.addr, align 4
%cmp = fcmp ueq float %0, 3.000000e+00 ; no nnan flag - can't propagate
call void @llvm.assume(i1 %cmp)
; CHECK-NOT: ret float 3.000000e+00
ret float %0
}
; This test checks if constant propagation works for multiple node edges
; CHECK-LABEL: define i32 @_Z1ii(i32 %p)
define i32 @_Z1ii(i32 %p) {
entry:
%cmp = icmp eq i32 %p, 42
call void @llvm.assume(i1 %cmp)
; CHECK: br i1 true, label %bb2, label %bb2
br i1 %cmp, label %bb2, label %bb2
bb2:
call void @llvm.assume(i1 true)
; CHECK: br i1 true, label %bb2, label %bb2
br i1 %cmp, label %bb2, label %bb2
; CHECK: ret i32 42
ret i32 %p
}
; CHECK-LABEL: define i32 @_Z1ij(i32 %p)
define i32 @_Z1ij(i32 %p) {
entry:
%cmp = icmp eq i32 %p, 42
call void @llvm.assume(i1 %cmp)
; CHECK: br i1 true, label %bb2, label %bb2
br i1 %cmp, label %bb2, label %bb2
bb2:
; CHECK-NOT: %cmp2 =
%cmp2 = icmp eq i32 %p, 42
; CHECK-NOT: call void @llvm.assume(
call void @llvm.assume(i1 %cmp2)
; CHECK: br i1 true, label %bb2, label %bb2
br i1 %cmp, label %bb2, label %bb2
; CHECK: ret i32 42
ret i32 %p
}
; CHECK-LABEL: define i32 @_Z1ik(i32 %p)
define i32 @_Z1ik(i32 %p) {
entry:
%cmp = icmp eq i32 %p, 42
call void @llvm.assume(i1 %cmp)
; CHECK: br i1 true, label %bb2, label %bb3
br i1 %cmp, label %bb2, label %bb3
bb2:
; CHECK-NOT: %cmp3 =
%cmp3 = icmp eq i32 %p, 43
; CHECK: store i8 poison, ptr null
call void @llvm.assume(i1 %cmp3)
ret i32 15
bb3:
ret i32 17
}
; This test checks if GVN can do the constant propagation correctly
; when there are multiple uses of the same assume value in the
; basic block that has a loop back-edge pointing to itself.
;
; CHECK-LABEL: define i32 @_Z1il(i32 %val, i1 %k)
define i32 @_Z1il(i32 %val, i1 %k) {
br label %next
next:
; CHECK: tail call void @llvm.assume(i1 %k)
; CHECK-NEXT: %cmp = icmp eq i32 %val, 50
tail call void @llvm.assume(i1 %k)
tail call void @llvm.assume(i1 %k)
%cmp = icmp eq i32 %val, 50
br i1 %cmp, label %next, label %meh
meh:
ret i32 0
}
; This test checks if GVN can prevent the constant propagation correctly
; in the successor blocks that are not dominated by the basic block
; with the assume instruction.
;
; CHECK-LABEL: define i1 @_z1im(i32 %val, i1 %k, i1 %j)
define i1 @_z1im(i32 %val, i1 %k, i1 %j) {
br i1 %j, label %next, label %meh
next:
; CHECK: tail call void @llvm.assume(i1 %k)
; CHECK-NEXT: br label %meh
tail call void @llvm.assume(i1 %k)
tail call void @llvm.assume(i1 %k)
br label %meh
meh:
; CHECK: ret i1 %k
ret i1 %k
}
declare noalias ptr @_Znwm(i64)
declare void @_ZN1AC1Ev(ptr)
declare void @llvm.assume(i1)
declare i32 @_ZN1A3fooEv(ptr)
declare i32 @_ZN1A3barEv(ptr)
!0 = !{!"struct A"}
|
