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[IPSCCP] Drop argmemonly after replacing pointer argument. 

This patch updates IPSCCP to drop argmemonly and
inaccessiblemem_or_argmemonly if it replaces a pointer argument.

Fixes PR46717.

Reviewers: efriedma, davide, nikic, jdoerfert

Reviewed By: efriedma, jdoerfert

Differential Revision: https://reviews.llvm.org/D84432
This commit is contained in:
Florian Hahn 2020-07-25 11:52:14 +01:00
parent 4363ea6105
commit 3c1476d26c
2 changed files with 32 additions and 15 deletions
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30
llvm/lib/Transforms/Scalar/SCCP.cpp
View File

@ -1911,15 +1911,35 @@ bool llvm::runIPSCCP(
SmallVector<BasicBlock *, 512> BlocksToErase;
if (Solver.isBlockExecutable(&F.front()))
for (Function::arg_iterator AI = F.arg_begin(), E = F.arg_end(); AI != E;
++AI) {
if (!AI->use_empty() && tryToReplaceWithConstant(Solver, &*AI)) {
if (Solver.isBlockExecutable(&F.front())) {
bool ReplacedPointerArg = false;
for (Argument &Arg : F.args()) {
if (!Arg.use_empty() && tryToReplaceWithConstant(Solver, &Arg)) {
ReplacedPointerArg |= Arg.getType()->isPointerTy();
++IPNumArgsElimed;
continue;
}
}
// If we replaced an argument, the argmemonly and
// inaccessiblemem_or_argmemonly attributes do not hold any longer. Remove
// them from both the function and callsites.
if (ReplacedPointerArg) {
SmallVector<Attribute::AttrKind, 2> AttributesToRemove = {
Attribute::ArgMemOnly, Attribute::InaccessibleMemOrArgMemOnly};
for (auto Attr : AttributesToRemove)
F.removeFnAttr(Attr);
for (User *U : F.users()) {
auto *CB = dyn_cast<CallBase>(U);
if (!CB || CB->getCalledFunction() != &F)
continue;
for (auto Attr : AttributesToRemove)
CB->removeAttribute(AttributeList::FunctionIndex, Attr);
}
}
}
SmallPtrSet<Value *, 32> InsertedValues;
for (BasicBlock &BB : F) {
if (!Solver.isBlockExecutable(&BB)) {

17
llvm/test/Transforms/SCCP/ipscp-drop-argmemonly.ll
View File

@ -11,7 +11,7 @@
; Here the pointer argument %arg will be replaced by a constant. We need to
; drop argmemonly.
define internal void @ptrarg.1(i32* %arg, i32 %val) argmemonly nounwind {
; CHECK: Function Attrs: argmemonly nounwind
; CHECK: Function Attrs: nounwind
; CHECK-LABEL: @ptrarg.1(
; CHECK-NEXT: store i32 10, i32* @g, align 4
; CHECK-NEXT: ret void
@ -59,7 +59,7 @@ define void @caller.2(i32* %ptr) {
; Here the pointer argument %arg will be replaced by a constant. We need to
; drop inaccessiblemem_or_argmemonly.
define internal void @ptrarg.3(i32* %arg, i32 %val) inaccessiblemem_or_argmemonly nounwind {
; CHECK: Function Attrs: inaccessiblemem_or_argmemonly nounwind
; CHECK: Function Attrs: nounwind
; CHECK-LABEL: @ptrarg.3(
; CHECK-NEXT: store i32 10, i32* @g, align 4
; CHECK-NEXT: ret void
@ -107,7 +107,7 @@ define void @caller.4(i32* %ptr) {
; Here the pointer argument %arg will be replaced by a constant. We need to
; drop inaccessiblemem_or_argmemonly.
define internal void @ptrarg.5(i32* %arg, i32 %val) argmemonly inaccessiblemem_or_argmemonly nounwind {
; CHECK: Function Attrs: argmemonly inaccessiblemem_or_argmemonly nounwind
; CHECK: Function Attrs: nounwind
; CHECK-LABEL: @ptrarg.5(
; CHECK-NEXT: store i32 10, i32* @g, align 4
; CHECK-NEXT: ret void
@ -143,9 +143,9 @@ define internal void @ptrarg.6.cs.attributes(i32* %arg, i32 %val) {
define i32 @caller.6.cs.attributes(i32 %n) {
; CHECK-LABEL: @caller.6.cs.attributes(
; CHECK-NEXT: store i32 1, i32* @g, align 4
; CHECK-NEXT: tail call void @ptrarg.5(i32* @g, i32 10) [[ARGMEMONLY_INACCESSIBLEMEM_OR_ARGMEMONLY_NOUNWIND:#[0-9]+]]
; CHECK-NEXT: tail call void @ptrarg.5(i32* @g, i32 10) [[INACCESSIBLEMEM_OR_ARGMEMONLY_NOUNWIND:#[0-9]+]]
; CHECK-NEXT: tail call void @ptrarg.5(i32* @g, i32 10) [[ARGMEMONLY_NOUNWIND:#[0-9]+]]
; CHECK-NEXT: tail call void @ptrarg.5(i32* @g, i32 10) [[NOUNWIND:#[0-9]+]]
; CHECK-NEXT: tail call void @ptrarg.5(i32* @g, i32 10) [[NOUNWIND:#[0-9]+]]
; CHECK-NEXT: tail call void @ptrarg.5(i32* @g, i32 10) [[NOUNWIND:#[0-9]+]]
; CHECK-NEXT: tail call void @ptrarg.5(i32* @g, i32 10) [[NOUNWIND:#[0-9]+]]
; CHECK-NEXT: [[G_VAL:%.*]] = load i32, i32* @g, align 4
; CHECK-NEXT: ret i32 [[G_VAL]]
@ -159,7 +159,4 @@ define i32 @caller.6.cs.attributes(i32 %n) {
ret i32 %g.val
}
; CHECK-DAG: [[ARGMEMONLY_INACCESSIBLEMEM_OR_ARGMEMONLY_NOUNWIND]] = { argmemonly inaccessiblemem_or_argmemonly nounwind }
; CHECK-DAG: [[INACCESSIBLEMEM_OR_ARGMEMONLY_NOUNWIND]] = { inaccessiblemem_or_argmemonly nounwind }
; CHECK-DAG: [[ARGMEMONLY_NOUNWIND]] = { argmemonly nounwind }
; CHECK-DAG: [[NOUNWIND]] = { nounwind }
; CHECK: [[NOUNWIND]] = { nounwind }