mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-22 18:54:02 +01:00
Simplify recursive launder.invariant.group and strip
Summary:
This patch is crucial for proving equality laundered/stripped
pointers. eg:
bool foo(A *a) {
return a == std::launder(a);
}
Clang with -fstrict-vtable-pointers will emit something like:
define dso_local zeroext i1 @_Z3fooP1A(%struct.A* %a) {
entry:
%c = bitcast %struct.A* %a to i8*
%call = tail call i8* @llvm.launder.invariant.group.p0i8(i8* %c)
%0 = bitcast %struct.A* %a to i8*
%1 = tail call i8* @llvm.strip.invariant.group.p0i8(i8* %0)
%2 = tail call i8* @llvm.strip.invariant.group.p0i8(i8* %call)
%cmp = icmp eq i8* %1, %2
ret i1 %cmp
}
and because %2 can be replaced with @llvm.strip.invariant.group(%0)
and that %2 and %1 will produce the same value (because strip is readnone)
we can replace compare with true.
Reviewers: rsmith, hfinkel, majnemer, amharc, kuhar
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D47423
llvm-svn: 336963
This commit is contained in:
Piotr Padlewski
parent
bcf4db053e
commit
c64e878f84
@ -1266,6 +1266,40 @@ static Instruction *simplifyMaskedGather(IntrinsicInst &II, InstCombiner &IC) {
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
/// This function transforms launder.invariant.group and strip.invariant.group
|
||||
/// like:
|
||||
/// launder(launder(%x)) -> launder(%x) (the result is not the argument)
|
||||
/// launder(strip(%x)) -> launder(%x)
|
||||
/// strip(strip(%x)) -> strip(%x) (the result is not the argument)
|
||||
/// strip(launder(%x)) -> strip(%x)
|
||||
/// This is legal because it preserves the most recent information about
|
||||
/// the presence or absence of invariant.group.
|
||||
static Instruction *simplifyInvariantGroupIntrinsic(IntrinsicInst &II,
|
||||
InstCombiner &IC) {
|
||||
auto *Arg = II.getArgOperand(0);
|
||||
auto *StrippedArg = Arg->stripPointerCasts();
|
||||
auto *StrippedInvariantGroupsArg = Arg->stripPointerCastsAndInvariantGroups();
|
||||
if (StrippedArg == StrippedInvariantGroupsArg)
|
||||
return nullptr; // No launders/strips to remove.
|
||||
|
||||
Value *Result = nullptr;
|
||||
|
||||
if (II.getIntrinsicID() == Intrinsic::launder_invariant_group)
|
||||
Result = IC.Builder.CreateLaunderInvariantGroup(StrippedInvariantGroupsArg);
|
||||
else if (II.getIntrinsicID() == Intrinsic::strip_invariant_group)
|
||||
Result = IC.Builder.CreateStripInvariantGroup(StrippedInvariantGroupsArg);
|
||||
else
|
||||
llvm_unreachable(
|
||||
"simplifyInvariantGroupIntrinsic only handles launder and strip");
|
||||
if (Result->getType()->getPointerAddressSpace() !=
|
||||
II.getType()->getPointerAddressSpace())
|
||||
Result = IC.Builder.CreateAddrSpaceCast(Result, II.getType());
|
||||
if (Result->getType() != II.getType())
|
||||
Result = IC.Builder.CreateBitCast(Result, II.getType());
|
||||
|
||||
return cast<Instruction>(Result);
|
||||
}
|
||||
|
||||
static Instruction *simplifyMaskedScatter(IntrinsicInst &II, InstCombiner &IC) {
|
||||
// If the mask is all zeros, a scatter does nothing.
|
||||
auto *ConstMask = dyn_cast<Constant>(II.getArgOperand(3));
|
||||
@ -1940,7 +1974,11 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
|
||||
return simplifyMaskedGather(*II, *this);
|
||||
case Intrinsic::masked_scatter:
|
||||
return simplifyMaskedScatter(*II, *this);
|
||||
|
||||
case Intrinsic::launder_invariant_group:
|
||||
case Intrinsic::strip_invariant_group:
|
||||
if (auto *SkippedBarrier = simplifyInvariantGroupIntrinsic(*II, *this))
|
||||
return replaceInstUsesWith(*II, SkippedBarrier);
|
||||
break;
|
||||
case Intrinsic::powi:
|
||||
if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
|
||||
// 0 and 1 are handled in instsimplify
|
||||
|
||||
@ -2,9 +2,8 @@
|
||||
|
||||
; CHECK-LABEL: define void @checkNonnullLaunder()
|
||||
define void @checkNonnullLaunder() {
|
||||
; CHECK: %p = call i8* @llvm.launder.invariant.group.p0i8(i8* nonnull %0)
|
||||
; CHECK: %p2 = call i8* @llvm.launder.invariant.group.p0i8(i8* nonnull %p)
|
||||
; CHECK: call void @use(i8* nonnull %p2)
|
||||
; CHECK: %[[p:.*]] = call i8* @llvm.launder.invariant.group.p0i8(i8* nonnull %0)
|
||||
; CHECK: call void @use(i8* nonnull %[[p]])
|
||||
entry:
|
||||
%0 = alloca i8, align 8
|
||||
|
||||
@ -17,9 +16,8 @@ entry:
|
||||
|
||||
; CHECK-LABEL: define void @checkNonnullStrip()
|
||||
define void @checkNonnullStrip() {
|
||||
; CHECK: %p = call i8* @llvm.strip.invariant.group.p0i8(i8* nonnull %0)
|
||||
; CHECK: %p2 = call i8* @llvm.strip.invariant.group.p0i8(i8* nonnull %p)
|
||||
; CHECK: call void @use(i8* nonnull %p2)
|
||||
; CHECK: %[[p:.*]] = call i8* @llvm.strip.invariant.group.p0i8(i8* nonnull %0)
|
||||
; CHECK: call void @use(i8* nonnull %[[p]])
|
||||
entry:
|
||||
%0 = alloca i8, align 8
|
||||
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
; RUN: opt -instcombine -S < %s | FileCheck %s
|
||||
; RUN: opt -instcombine -early-cse -S < %s | FileCheck %s
|
||||
|
||||
|
||||
; CHECK-LABEL: define i8* @simplifyNullLaunder()
|
||||
@ -37,10 +37,6 @@ define i8 addrspace(42)* @simplifyUndefLaunder2() {
|
||||
ret i8 addrspace(42)* %b2
|
||||
}
|
||||
|
||||
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
|
||||
declare i8 addrspace(42)* @llvm.launder.invariant.group.p42i8(i8 addrspace(42)*)
|
||||
|
||||
|
||||
; CHECK-LABEL: define i8* @simplifyNullStrip()
|
||||
define i8* @simplifyNullStrip() {
|
||||
; CHECK-NEXT: ret i8* null
|
||||
@ -77,7 +73,78 @@ define i8 addrspace(42)* @simplifyUndefStrip2() {
|
||||
ret i8 addrspace(42)* %b2
|
||||
}
|
||||
|
||||
; CHECK-LABEL: define i8* @simplifyLaunderOfLaunder(
|
||||
define i8* @simplifyLaunderOfLaunder(i8* %a) {
|
||||
; CHECK: call i8* @llvm.launder.invariant.group.p0i8(i8* %a)
|
||||
; CHECK-NOT: llvm.launder.invariant.group
|
||||
%a2 = call i8* @llvm.launder.invariant.group.p0i8(i8* %a)
|
||||
%a3 = call i8* @llvm.launder.invariant.group.p0i8(i8* %a2)
|
||||
ret i8* %a3
|
||||
}
|
||||
|
||||
; CHECK-LABEL: define i8* @simplifyStripOfLaunder(
|
||||
define i8* @simplifyStripOfLaunder(i8* %a) {
|
||||
; CHECK-NOT: llvm.launder.invariant.group
|
||||
; CHECK: call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
|
||||
%a2 = call i8* @llvm.launder.invariant.group.p0i8(i8* %a)
|
||||
%a3 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a2)
|
||||
ret i8* %a3
|
||||
}
|
||||
|
||||
; CHECK-LABEL: define i1 @simplifyForCompare(
|
||||
define i1 @simplifyForCompare(i8* %a) {
|
||||
%a2 = call i8* @llvm.launder.invariant.group.p0i8(i8* %a)
|
||||
|
||||
%a3 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a2)
|
||||
%b2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
|
||||
%c = icmp eq i8* %a3, %b2
|
||||
; CHECK: ret i1 true
|
||||
ret i1 %c
|
||||
}
|
||||
|
||||
; CHECK-LABEL: define i16* @skipWithDifferentTypes(
|
||||
define i16* @skipWithDifferentTypes(i8* %a) {
|
||||
%a2 = call i8* @llvm.launder.invariant.group.p0i8(i8* %a)
|
||||
%c1 = bitcast i8* %a2 to i16*
|
||||
|
||||
; CHECK: %[[b:.*]] = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
|
||||
%a3 = call i16* @llvm.strip.invariant.group.p0i16(i16* %c1)
|
||||
; CHECK-NEXT: %[[r:.*]] = bitcast i8* %[[b]] to i16*
|
||||
; CHECK-NEXT: ret i16* %[[r]]
|
||||
ret i16* %a3
|
||||
}
|
||||
|
||||
; CHECK-LABEL: define i16 addrspace(42)* @skipWithDifferentTypesAddrspace(
|
||||
define i16 addrspace(42)* @skipWithDifferentTypesAddrspace(i8 addrspace(42)* %a) {
|
||||
%a2 = call i8 addrspace(42)* @llvm.launder.invariant.group.p42i8(i8 addrspace(42)* %a)
|
||||
%c1 = bitcast i8 addrspace(42)* %a2 to i16 addrspace(42)*
|
||||
|
||||
; CHECK: %[[b:.*]] = call i8 addrspace(42)* @llvm.strip.invariant.group.p42i8(i8 addrspace(42)* %a)
|
||||
%a3 = call i16 addrspace(42)* @llvm.strip.invariant.group.p42i16(i16 addrspace(42)* %c1)
|
||||
; CHECK-NEXT: %[[r:.*]] = bitcast i8 addrspace(42)* %[[b]] to i16 addrspace(42)*
|
||||
; CHECK-NEXT: ret i16 addrspace(42)* %[[r]]
|
||||
ret i16 addrspace(42)* %a3
|
||||
}
|
||||
|
||||
; CHECK-LABEL: define i16 addrspace(42)* @skipWithDifferentTypesDifferentAddrspace(
|
||||
define i16 addrspace(42)* @skipWithDifferentTypesDifferentAddrspace(i8* %a) {
|
||||
%cast = addrspacecast i8* %a to i8 addrspace(42)*
|
||||
%a2 = call i8 addrspace(42)* @llvm.launder.invariant.group.p42i8(i8 addrspace(42)* %cast)
|
||||
%c1 = bitcast i8 addrspace(42)* %a2 to i16 addrspace(42)*
|
||||
|
||||
; CHECK: %[[b:.*]] = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
|
||||
%a3 = call i16 addrspace(42)* @llvm.strip.invariant.group.p42i16(i16 addrspace(42)* %c1)
|
||||
; CHECK-NEXT: %[[r:.*]] = bitcast i8* %[[b]] to i16*
|
||||
; CHECK-NEXT: %[[r2:.*]] = addrspacecast i16* %[[r]] to i16 addrspace(42)*
|
||||
; CHECK-NEXT: ret i16 addrspace(42)* %[[r2]]
|
||||
ret i16 addrspace(42)* %a3
|
||||
}
|
||||
|
||||
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
|
||||
declare i8 addrspace(42)* @llvm.launder.invariant.group.p42i8(i8 addrspace(42)*)
|
||||
declare i8* @llvm.strip.invariant.group.p0i8(i8*)
|
||||
declare i8 addrspace(42)* @llvm.strip.invariant.group.p42i8(i8 addrspace(42)*)
|
||||
declare i16* @llvm.strip.invariant.group.p0i16(i16* %c1)
|
||||
declare i16 addrspace(42)* @llvm.strip.invariant.group.p42i16(i16 addrspace(42)* %c1)
|
||||
|
||||
attributes #0 = { "null-pointer-is-valid"="true" }
|
||||
|
||||
Loading…
Reference in New Issue
Block a user