Prazek updated this revision to Diff 148313.
Prazek marked 2 inline comments as done.
Prazek added a comment.
Slitted commit into defining and using intrinsic
Repository:
rL LLVM
https://reviews.llvm.org/D47103
Files:
llvm/docs/LangRef.rst
llvm/include/llvm/IR/IRBuilder.h
llvm/include/llvm/IR/Intrinsics.td
llvm/lib/Analysis/BasicAliasAnalysis.cpp
llvm/lib/Analysis/ConstantFolding.cpp
llvm/lib/Analysis/ValueTracking.cpp
llvm/lib/CodeGen/CodeGenPrepare.cpp
llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/lib/IR/Value.cpp
llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
llvm/test/Analysis/ValueTracking/invariant.group.ll
llvm/test/CodeGen/Generic/intrinsics.ll
llvm/test/Other/invariant.group.ll
llvm/test/Other/launder.invariant.group.ll
llvm/test/Transforms/CodeGenPrepare/invariant.group.ll
llvm/test/Transforms/DeadStoreElimination/launder.invariant.group.ll
llvm/test/Transforms/FunctionAttrs/nocapture.ll
llvm/test/Transforms/GVN/invariant.group.ll
llvm/test/Transforms/GlobalOpt/invariant.group.barrier.ll
llvm/test/Transforms/GlobalOpt/invariant.group.ll
llvm/test/Transforms/InstCombine/invariant.group.ll
llvm/test/Transforms/NewGVN/invariant.group.ll
Index: llvm/test/Transforms/NewGVN/invariant.group.ll
===================================================================
--- llvm/test/Transforms/NewGVN/invariant.group.ll
+++ llvm/test/Transforms/NewGVN/invariant.group.ll
@@ -52,6 +52,19 @@
ret i8 %b
}
+; CHECK-LABEL: define i1 @proveEqualityForStrip(
+define i1 @proveEqualityForStrip(i8* %a) {
+; FIXME: The first call could be also removed by GVN. Right now
+; DCE removes it. The second call is CSE'd with the first one.
+; CHECK: %b1 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
+ %b1 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
+; CHECK-NOT: llvm.strip.invariant.group
+ %b2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
+ %r = icmp eq i8* %b1, %b2
+; CHECK: ret i1 true
+ ret i1 %r
+}
+
; CHECK-LABEL: define i8 @unoptimizable1() {
define i8 @unoptimizable1() {
entry:
Index: llvm/test/Transforms/InstCombine/invariant.group.ll
===================================================================
--- llvm/test/Transforms/InstCombine/invariant.group.ll
+++ llvm/test/Transforms/InstCombine/invariant.group.ll
@@ -1,5 +1,6 @@
; RUN: opt -instcombine -S < %s | FileCheck %s
+
; CHECK-LABEL: define i8* @simplifyNullLaunder()
define i8* @simplifyNullLaunder() {
; CHECK-NEXT: ret i8* null
@@ -29,6 +30,39 @@
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
+ %b2 = call i8* @llvm.strip.invariant.group.p0i8(i8* null)
+ ret i8* %b2
+}
+
+; CHECK-LABEL: define i8 addrspace(42)* @dontsimplifyNullStripForDifferentAddrspace()
+define i8 addrspace(42)* @dontsimplifyNullStripForDifferentAddrspace() {
+; CHECK: %b2 = call i8 addrspace(42)* @llvm.strip.invariant.group.p42i8(i8 addrspace(42)* null)
+; CHECK: ret i8 addrspace(42)* %b2
+ %b2 = call i8 addrspace(42)* @llvm.strip.invariant.group.p42i8(i8 addrspace(42)* null)
+ ret i8 addrspace(42)* %b2
+}
+
+; CHECK-LABEL: define i8* @simplifyUndefStrip()
+define i8* @simplifyUndefStrip() {
+; CHECK-NEXT: ret i8* undef
+ %b2 = call i8* @llvm.strip.invariant.group.p0i8(i8* undef)
+ ret i8* %b2
+}
+
+; CHECK-LABEL: define i8 addrspace(42)* @simplifyUndefStrip2()
+define i8 addrspace(42)* @simplifyUndefStrip2() {
+; CHECK-NEXT: ret i8 addrspace(42)* undef
+ %b2 = call i8 addrspace(42)* @llvm.strip.invariant.group.p42i8(i8 addrspace(42)* undef)
+ ret i8 addrspace(42)* %b2
+}
+
+declare i8* @llvm.strip.invariant.group.p0i8(i8*)
+declare i8 addrspace(42)* @llvm.strip.invariant.group.p42i8(i8 addrspace(42)*)
+
Index: llvm/test/Transforms/GlobalOpt/invariant.group.ll
===================================================================
--- llvm/test/Transforms/GlobalOpt/invariant.group.ll
+++ llvm/test/Transforms/GlobalOpt/invariant.group.ll
@@ -27,46 +27,46 @@
define void @_optimizable() {
enter:
%valptr = alloca i32
-
+
%val = call i32 @TheAnswerToLifeTheUniverseAndEverything()
store i32 %val, i32* @tmp
store i32 %val, i32* %valptr
-
+
%0 = bitcast i32* %valptr to i8*
%barr = call i8* @llvm.launder.invariant.group(i8* %0)
%1 = bitcast i8* %barr to i32*
-
+
%val2 = load i32, i32* %1
store i32 %val2, i32* @tmp2
ret void
}
; We can't step through launder.invariant.group here, because that would change
; this load in @usage_of_globals()
-; val = load i32, i32* %ptrVal, !invariant.group !0
-; into
+; val = load i32, i32* %ptrVal, !invariant.group !0
+; into
; %val = load i32, i32* @tmp3, !invariant.group !0
-; and then we could assume that %val and %val2 to be the same, which coud be
+; and then we could assume that %val and %val2 to be the same, which coud be
; false, because @changeTmp3ValAndCallBarrierInside() may change the value
; of @tmp3.
define void @_not_optimizable() {
enter:
store i32 13, i32* @tmp3, !invariant.group !0
-
+
%0 = bitcast i32* @tmp3 to i8*
%barr = call i8* @llvm.launder.invariant.group(i8* %0)
%1 = bitcast i8* %barr to i32*
-
+
store i32* %1, i32** @ptrToTmp3
store i32 42, i32* %1, !invariant.group !0
-
+
ret void
}
define void @usage_of_globals() {
entry:
%ptrVal = load i32*, i32** @ptrToTmp3
%val = load i32, i32* %ptrVal, !invariant.group !0
-
+
call void @changeTmp3ValAndCallBarrierInside()
%val2 = load i32, i32* @tmp3, !invariant.group !0
ret void;
Index: llvm/test/Transforms/GVN/invariant.group.ll
===================================================================
--- llvm/test/Transforms/GVN/invariant.group.ll
+++ llvm/test/Transforms/GVN/invariant.group.ll
@@ -51,6 +51,18 @@
ret i8 %b
}
+; CHECK-LABEL: define i1 @proveEqualityForStrip(
+define i1 @proveEqualityForStrip(i8* %a) {
+; FIXME: The first call could be also removed by GVN. Right now
+; DCE removes it. The second call is CSE'd with the first one.
+; CHECK: %b1 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
+ %b1 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
+; CHECK-NOT: llvm.strip.invariant.group
+ %b2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
+ %r = icmp eq i8* %b1, %b2
+; CHECK: ret i1 true
+ ret i1 %r
+}
; CHECK-LABEL: define i8 @unoptimizable1() {
define i8 @unoptimizable1() {
entry:
@@ -437,10 +449,10 @@
declare void @fooBit(i1*, i1)
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
+declare i8* @llvm.strip.invariant.group.p0i8(i8*)
+
-; Function Attrs: nounwind
-declare void @llvm.assume(i1 %cmp.vtables) #0
+declare void @llvm.assume(i1 %cmp.vtables)
-attributes #0 = { nounwind }
!0 = !{}
\ No newline at end of file
Index: llvm/test/Transforms/FunctionAttrs/nocapture.ll
===================================================================
--- llvm/test/Transforms/FunctionAttrs/nocapture.ll
+++ llvm/test/Transforms/FunctionAttrs/nocapture.ll
@@ -237,4 +237,21 @@
ret void
}
+; CHECK: @nocaptureStrip(i8* nocapture %p)
+define void @nocaptureStrip(i8* %p) {
+entry:
+ %b = call i8* @llvm.strip.invariant.group.p0i8(i8* %p)
+ store i8 42, i8* %b
+ ret void
+}
+
+@g3 = global i8* null
+; CHECK: define void @captureStrip(i8* %p)
+define void @captureStrip(i8* %p) {
+ %b = call i8* @llvm.strip.invariant.group.p0i8(i8* %p)
+ store i8* %b, i8** @g3
+ ret void
+}
+
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
+declare i8* @llvm.strip.invariant.group.p0i8(i8*)
Index: llvm/test/Transforms/DeadStoreElimination/launder.invariant.group.ll
===================================================================
--- llvm/test/Transforms/DeadStoreElimination/launder.invariant.group.ll
+++ llvm/test/Transforms/DeadStoreElimination/launder.invariant.group.ll
@@ -27,4 +27,39 @@
ret void
}
+; CHECK-LABEL: void @skip3Barriers(i8* %ptr)
+define void @skip3Barriers(i8* %ptr) {
+; CHECK-NOT: store i8 42
+ store i8 42, i8* %ptr
+; CHECK: %ptr2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %ptr)
+ %ptr2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %ptr)
+; CHECK-NOT: store i8 43
+ store i8 43, i8* %ptr2
+ %ptr3 = call i8* @llvm.strip.invariant.group.p0i8(i8* %ptr2)
+ %ptr4 = call i8* @llvm.strip.invariant.group.p0i8(i8* %ptr3)
+
+; CHECK: store i8 44
+ store i8 44, i8* %ptr4
+ ret void
+}
+
+; CHECK-LABEL: void @skip4Barriers(i8* %ptr)
+define void @skip4Barriers(i8* %ptr) {
+; CHECK-NOT: store i8 42
+ store i8 42, i8* %ptr
+; CHECK: %ptr2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %ptr)
+ %ptr2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %ptr)
+; CHECK-NOT: store i8 43
+ store i8 43, i8* %ptr2
+ %ptr3 = call i8* @llvm.launder.invariant.group.p0i8(i8* %ptr2)
+ %ptr4 = call i8* @llvm.strip.invariant.group.p0i8(i8* %ptr3)
+ %ptr5 = call i8* @llvm.launder.invariant.group.p0i8(i8* %ptr3)
+
+; CHECK: store i8 44
+ store i8 44, i8* %ptr5
+ ret void
+}
+
+
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
+declare i8* @llvm.strip.invariant.group.p0i8(i8*)
\ No newline at end of file
Index: llvm/test/Transforms/CodeGenPrepare/invariant.group.ll
===================================================================
--- llvm/test/Transforms/CodeGenPrepare/invariant.group.ll
+++ llvm/test/Transforms/CodeGenPrepare/invariant.group.ll
@@ -7,8 +7,8 @@
enter:
; CHECK-NOT: !invariant.group
; CHECK-NOT: @llvm.launder.invariant.group.p0i8(
- ; CHECK: %val = load i8, i8* @tmp, !tbaa
- %val = load i8, i8* @tmp, !invariant.group !0, !tbaa !{!1, !1, i64 0}
+ ; CHECK: %val = load i8, i8* @tmp{{$}}
+ %val = load i8, i8* @tmp, !invariant.group !0
%ptr = call i8* @llvm.launder.invariant.group.p0i8(i8* @tmp)
; CHECK: store i8 42, i8* @tmp{{$}}
@@ -18,7 +18,23 @@
}
; CHECK-LABEL: }
-declare i8* @llvm.launder.invariant.group.p0i8(i8*)
+; CHECK-LABEL: define void @foo2() {
+define void @foo2() {
+enter:
+ ; CHECK-NOT: !invariant.group
+ ; CHECK-NOT: @llvm.strip.invariant.group.p0i8(
+ ; CHECK: %val = load i8, i8* @tmp{{$}}
+ %val = load i8, i8* @tmp, !invariant.group !0
+ %ptr = call i8* @llvm.strip.invariant.group.p0i8(i8* @tmp)
+
+ ; CHECK: store i8 42, i8* @tmp{{$}}
+ store i8 42, i8* %ptr, !invariant.group !0
+ ret void
+}
+; CHECK-LABEL: }
+
+
+declare i8* @llvm.launder.invariant.group.p0i8(i8*)
+declare i8* @llvm.strip.invariant.group.p0i8(i8*)
!0 = !{}
-!1 = !{!"x", !0}
Index: llvm/test/Other/invariant.group.ll
===================================================================
--- llvm/test/Other/invariant.group.ll
+++ llvm/test/Other/invariant.group.ll
@@ -77,8 +77,14 @@
define void @dontProveEquality(i8* %a) {
%b = call i8* @llvm.launder.invariant.group.p0i8(i8* %a)
%r = icmp eq i8* %b, %a
-;CHECK: call void @useBool(i1 %r)
+; CHECK: call void @useBool(i1 %r)
call void @useBool(i1 %r)
+
+ %b2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
+ %r2 = icmp eq i8* %b2, %a
+; CHECK: call void @useBool(i1 %r2)
+ call void @useBool(i1 %r2)
+
ret void
}
@@ -90,5 +96,9 @@
; CHECK-NEXT: declare i8* @llvm.launder.invariant.group.p0i8(i8*)
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
-!0 = !{}
+; CHECK: Function Attrs: nounwind readnone speculatable{{$}}
+; CHECK-NEXT: declare i8* @llvm.strip.invariant.group.p0i8(i8*)
+declare i8* @llvm.strip.invariant.group.p0i8(i8*)
+
+!0 = !{}
\ No newline at end of file
Index: llvm/test/CodeGen/Generic/intrinsics.ll
===================================================================
--- llvm/test/CodeGen/Generic/intrinsics.ll
+++ llvm/test/CodeGen/Generic/intrinsics.ll
@@ -41,11 +41,19 @@
declare i8* @llvm.launder.invariant.group(i8*)
-define i8* @barrier(i8* %p) {
+define i8* @launder(i8* %p) {
%q = call i8* @llvm.launder.invariant.group(i8* %p)
ret i8* %q
}
+declare i8* @llvm.strip.invariant.group(i8*)
+
+define i8* @strip(i8* %p) {
+ %q = call i8* @llvm.strip.invariant.group(i8* %p)
+ ret i8* %q
+}
+
+
; sideeffect
declare void @llvm.sideeffect()
Index: llvm/test/Analysis/ValueTracking/invariant.group.ll
===================================================================
--- llvm/test/Analysis/ValueTracking/invariant.group.ll
+++ llvm/test/Analysis/ValueTracking/invariant.group.ll
@@ -1,7 +1,7 @@
; RUN: opt -S -instsimplify -instcombine < %s | FileCheck %s
-; CHECK-LABEL: define void @checkNonnull()
-define void @checkNonnull() {
+; 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)
@@ -15,5 +15,22 @@
ret void
}
+; 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)
+entry:
+ %0 = alloca i8, align 8
+
+ %p = call i8* @llvm.strip.invariant.group.p0i8(i8* %0)
+ %p2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %p)
+ call void @use(i8* %p2)
+
+ ret void
+}
+
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
+declare i8* @llvm.strip.invariant.group.p0i8(i8*)
+
declare void @use(i8*)
Index: llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
+++ llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
@@ -457,6 +457,7 @@
case Intrinsic::invariant_start:
case Intrinsic::invariant_end:
case Intrinsic::launder_invariant_group:
+ case Intrinsic::strip_invariant_group:
case Intrinsic::objectsize:
return true;
default:
@@ -883,6 +884,7 @@
case Intrinsic::invariant_start:
case Intrinsic::invariant_end:
case Intrinsic::launder_invariant_group:
+ case Intrinsic::strip_invariant_group:
Intr->eraseFromParent();
// FIXME: I think the invariant marker should still theoretically apply,
// but the intrinsics need to be changed to accept pointers with any
Index: llvm/lib/IR/Value.cpp
===================================================================
--- llvm/lib/IR/Value.cpp
+++ llvm/lib/IR/Value.cpp
@@ -550,7 +550,8 @@
// but it can't be marked with returned attribute, that's why it needs
// special case.
if (StripKind == PSK_ZeroIndicesAndAliasesAndInvariantGroups &&
- CS.getIntrinsicID() == Intrinsic::launder_invariant_group) {
+ (CS.getIntrinsicID() == Intrinsic::launder_invariant_group ||
+ CS.getIntrinsicID() == Intrinsic::strip_invariant_group)) {
V = CS.getArgOperand(0);
continue;
}
Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5758,6 +5758,7 @@
case Intrinsic::annotation:
case Intrinsic::ptr_annotation:
case Intrinsic::launder_invariant_group:
+ case Intrinsic::strip_invariant_group:
// Drop the intrinsic, but forward the value
setValue(&I, getValue(I.getOperand(0)));
return nullptr;
Index: llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -1446,6 +1446,7 @@
return true;
}
case Intrinsic::launder_invariant_group:
+ case Intrinsic::strip_invariant_group:
case Intrinsic::expect: {
unsigned ResultReg = getRegForValue(II->getArgOperand(0));
if (!ResultReg)
Index: llvm/lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -1694,6 +1694,7 @@
return true;
}
case Intrinsic::launder_invariant_group:
+ case Intrinsic::strip_invariant_group:
II->replaceAllUsesWith(II->getArgOperand(0));
II->eraseFromParent();
return true;
Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -3397,8 +3397,9 @@
}
bool llvm::isIntrinsicReturningPointerAliasingArgumentWithoutCapturing(
- ImmutableCallSite CS) {
- return CS.getIntrinsicID() == Intrinsic::launder_invariant_group;
+ ImmutableCallSite CS) {
+ return CS.getIntrinsicID() == Intrinsic::launder_invariant_group ||
+ CS.getIntrinsicID() == Intrinsic::strip_invariant_group;
}
/// \p PN defines a loop-variant pointer to an object. Check if the
@@ -3447,13 +3448,15 @@
return V;
} else {
if (auto CS = CallSite(V)) {
- // Note: getArgumentAliasingToReturnedPointer keeps it in sync with
- // CaptureTracking, which is needed for correctness. This is because
- // some intrinsics like launder.invariant.group returns pointers that
- // are aliasing it's argument, which is known to CaptureTracking.
- // If AliasAnalysis does not use the same information, it could assume
- // that pointer returned from launder does not alias it's argument
- // because launder could not return it if the pointer was not captured.
+ // CaptureTracking can know about special capturing properties of some
+ // intrinsics like launder.invariant.group, that can't be expressed with
+ // the attributes, but have properties like returning aliasing pointer.
+ // Because some analysis may assume that nocaptured pointer is not
+ // returned from some special intrinsic (because function would have to
+ // be marked with returns attribute), it is crucial to use this function
+ // because it should be in sync with CaptureTracking. Not using it may
+ // cause weird miscompilations where 2 aliasing pointers are assumed to
+ // noalias.
if (auto *RP = getArgumentAliasingToReturnedPointer(CS)) {
V = RP;
continue;
Index: llvm/lib/Analysis/ConstantFolding.cpp
===================================================================
--- llvm/lib/Analysis/ConstantFolding.cpp
+++ llvm/lib/Analysis/ConstantFolding.cpp
@@ -1393,6 +1393,7 @@
case Intrinsic::fmuladd:
case Intrinsic::copysign:
case Intrinsic::launder_invariant_group:
+ case Intrinsic::strip_invariant_group:
case Intrinsic::round:
case Intrinsic::masked_load:
case Intrinsic::sadd_with_overflow:
@@ -1596,14 +1597,16 @@
return Constant::getNullValue(Ty);
if (IntrinsicID == Intrinsic::bswap ||
IntrinsicID == Intrinsic::bitreverse ||
- IntrinsicID == Intrinsic::launder_invariant_group)
+ IntrinsicID == Intrinsic::launder_invariant_group ||
+ IntrinsicID == Intrinsic::strip_invariant_group)
return Operands[0];
}
if (isa<ConstantPointerNull>(Operands[0]) &&
Operands[0]->getType()->getPointerAddressSpace() == 0) {
- // launder(null) == null iff in addrspace 0
- if (IntrinsicID == Intrinsic::launder_invariant_group)
+ // launder(null) == null == strip(null) iff in addrspace 0
+ if (IntrinsicID == Intrinsic::launder_invariant_group ||
+ IntrinsicID == Intrinsic::strip_invariant_group)
return Operands[0];
return nullptr;
}
Index: llvm/lib/Analysis/BasicAliasAnalysis.cpp
===================================================================
--- llvm/lib/Analysis/BasicAliasAnalysis.cpp
+++ llvm/lib/Analysis/BasicAliasAnalysis.cpp
@@ -431,13 +431,15 @@
const GEPOperator *GEPOp = dyn_cast<GEPOperator>(Op);
if (!GEPOp) {
if (auto CS = ImmutableCallSite(V)) {
- // Note: getArgumentAliasingToReturnedPointer keeps it in sync with
- // CaptureTracking, which is needed for correctness. This is because
- // some intrinsics like launder.invariant.group returns pointers that
- // are aliasing it's argument, which is known to CaptureTracking.
- // If AliasAnalysis does not use the same information, it could assume
- // that pointer returned from launder does not alias it's argument
- // because launder could not return it if the pointer was not captured.
+ // CaptureTracking can know about special capturing properties of some
+ // intrinsics like launder.invariant.group, that can't be expressed with
+ // the attributes, but have properties like returning aliasing pointer.
+ // Because some analysis may assume that nocaptured pointer is not
+ // returned from some special intrinsic (because function would have to
+ // be marked with returns attribute), it is crucial to use this function
+ // because it should be in sync with CaptureTracking. Not using it may
+ // cause weird miscompilations where 2 aliasing pointers are assumed to
+ // noalias.
if (auto *RP = getArgumentAliasingToReturnedPointer(CS)) {
V = RP;
continue;
Index: llvm/include/llvm/IR/Intrinsics.td
===================================================================
--- llvm/include/llvm/IR/Intrinsics.td
+++ llvm/include/llvm/IR/Intrinsics.td
@@ -728,6 +728,11 @@
[LLVMMatchType<0>],
[IntrInaccessibleMemOnly, IntrSpeculatable]>;
+
+def int_strip_invariant_group : Intrinsic<[llvm_anyptr_ty],
+ [LLVMMatchType<0>],
+ [IntrSpeculatable, IntrNoMem]>;
+
//===------------------------ Stackmap Intrinsics -------------------------===//
//
def int_experimental_stackmap : Intrinsic<[],
Index: llvm/include/llvm/IR/IRBuilder.h
===================================================================
--- llvm/include/llvm/IR/IRBuilder.h
+++ llvm/include/llvm/IR/IRBuilder.h
@@ -1968,6 +1968,7 @@
Value *CreateLaunderInvariantGroup(Value *Ptr) {
assert(isa<PointerType>(Ptr->getType()) &&
"launder.invariant.group only applies to pointers.");
+ // FIXME: we could potentially avoid casts to/from i8*.
auto *PtrType = Ptr->getType();
auto *Int8PtrTy = getInt8PtrTy(PtrType->getPointerAddressSpace());
if (PtrType != Int8PtrTy)
@@ -1988,6 +1989,34 @@
return Fn;
}
+ /// \brief Create a strip.invariant.group intrinsic call. If Ptr type is
+ /// different from pointer to i8, it's casted to pointer to i8 in the same
+ /// address space before call and casted back to Ptr type after call.
+ Value *CreateStripInvariantGroup(Value *Ptr) {
+ assert(isa<PointerType>(Ptr->getType()) &&
+ "strip.invariant.group only applies to pointers.");
+
+ // FIXME: we could potentially avoid casts to/from i8*.
+ auto *PtrType = Ptr->getType();
+ auto *Int8PtrTy = getInt8PtrTy(PtrType->getPointerAddressSpace());
+ if (PtrType != Int8PtrTy)
+ Ptr = CreateBitCast(Ptr, Int8PtrTy);
+ Module *M = BB->getParent()->getParent();
+ Function *FnStripInvariantGroup = Intrinsic::getDeclaration(
+ M, Intrinsic::strip_invariant_group, {Int8PtrTy});
+
+ assert(FnStripInvariantGroup->getReturnType() == Int8PtrTy &&
+ FnStripInvariantGroup->getFunctionType()->getParamType(0) ==
+ Int8PtrTy &&
+ "StripInvariantGroup should take and return the same type");
+
+ CallInst *Fn = CreateCall(FnStripInvariantGroup, {Ptr});
+
+ if (PtrType != Int8PtrTy)
+ return CreateBitCast(Fn, PtrType);
+ return Fn;
+ }
+
/// Return a vector value that contains \arg V broadcasted to \p
/// NumElts elements.
Value *CreateVectorSplat(unsigned NumElts, Value *V, const Twine &Name = "") {
Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -12924,24 +12924,61 @@
"""""""""
The '``llvm.launder.invariant.group``' intrinsic can be used when an invariant
-established by invariant.group metadata no longer holds, to obtain a new pointer
-value that does not carry the invariant information. It is an experimental
+established by ``invariant.group`` metadata no longer holds, to obtain a new pointer
+value that does carries fresh invariant group information. It is an experimental
intrinsic, which means that its semantics might change in the future.
Arguments:
""""""""""
-The ``llvm.launder.invariant.group`` takes only one argument, which is
-the pointer to the memory for which the ``invariant.group`` no longer holds.
+The ``llvm.launder.invariant.group`` takes only one argument, which is a pointer
+to the memory.
Semantics:
""""""""""
Returns another pointer that aliases its argument but which is considered different
for the purposes of ``load``/``store`` ``invariant.group`` metadata.
It does not read any accessible memory and the execution can be speculated.
+'``llvm.strip.invariant.group``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+This is an overloaded intrinsic. The memory object can belong to any address
+space. The returned pointer must belong to the same address space as the
+argument.
+
+::
+
+ declare i8* @llvm.strip.invariant.group.p0i8(i8* <ptr>)
+
+Overview:
+"""""""""
+
+The '``llvm.strip.invariant.group``' intrinsic can be used when an invariant
+established by ``invariant.group`` metadata no longer holds, to obtain a new pointer
+value that does not carry the invariant information. It is an experimental
+intrinsic, which means that its semantics might change in the future.
+
+
+Arguments:
+""""""""""
+
+The ``llvm.strip.invariant.group`` takes only one argument, which is a pointer
+to the memory.
+
+Semantics:
+""""""""""
+
+Returns another pointer that aliases its argument but which has no associated
+``invariant.group`` metadata.
+It does not read any memory and can be speculated.
+
+
+
.. _constrainedfp:
Constrained Floating-Point Intrinsics
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