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[MemDep] Also remove load instructions from NonLocalDesCache. 

Currently load instructions are added to the cache for invariant pointer
group dependencies, but only pointer values are removed currently. That
leads to dangling AssertingVHs in the test case below, where we delete a
load from an invariant pointer group. We should also remove the entries
from the cache.

Fixes PR46054.

Reviewers: efriedma, hfinkel, asbirlea

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D81726
This commit is contained in:
Florian Hahn 2020-06-17 09:24:56 +01:00
parent 8bc8d2d678
commit e4b58ea8c1
2 changed files with 96 additions and 5 deletions
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20
llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
View File

@ -1518,15 +1518,25 @@ void MemoryDependenceResults::removeInstruction(Instruction *RemInst) {
LocalDeps.erase(LocalDepEntry);
}
// If we have any cached pointer dependencies on this instruction, remove
// them. If the instruction has non-pointer type, then it can't be a pointer
// base.
// If we have any cached dependencies on this instruction, remove
// them.
// Remove it from both the load info and the store info. The instruction
// can't be in either of these maps if it is non-pointer.
// If the instruction is a pointer, remove it from both the load info and the
// store info.
if (RemInst->getType()->isPointerTy()) {
RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, false));
RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, true));
} else {
// Otherwise, if the instructions is in the map directly, it must be a load.
// Remove it.
auto toRemoveIt = NonLocalDefsCache.find(RemInst);
if (toRemoveIt != NonLocalDefsCache.end()) {
assert(isa<LoadInst>(RemInst) &&
"only load instructions should be added directly");
const Instruction *DepV = toRemoveIt->second.getResult().getInst();
ReverseNonLocalDefsCache.find(DepV)->second.erase(RemInst);
NonLocalDefsCache.erase(toRemoveIt);
}
}
// Loop over all of the things that depend on the instruction we're removing.

81
llvm/test/Transforms/GVN/pr46054-md-nonlocaldefcache-cleanup.ll Normal file
View File

@ -0,0 +1,81 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -gvn -S %s | FileCheck %s
; Test for PR46054. Make sure we correctly invalidate MemoryDependenceAnalysis,
; after removing a nonlocaldef.
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
define void @test_double(double* %data) {
; CHECK-LABEL: @test_double(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[LUC:%.*]] = tail call noalias nonnull i64* @data()
; CHECK-NEXT: store i64 1, i64* [[LUC]], align 8, !invariant.group !0
; CHECK-NEXT: call void @fn(i64 1)
; CHECK-NEXT: br i1 true, label [[A:%.*]], label [[ENTRY_B_CRIT_EDGE:%.*]]
; CHECK: entry.B_crit_edge:
; CHECK-NEXT: br label [[B:%.*]]
; CHECK: A:
; CHECK-NEXT: br label [[B]]
; CHECK: B:
; CHECK-NEXT: call void @fn(i64 1)
; CHECK-NEXT: ret void
;
entry:
%luc = tail call noalias nonnull i64* @data()
store i64 1, i64* %luc, !invariant.group !0
%QQ = load i64, i64* %luc, !invariant.group !0
call void @fn(i64 %QQ)
br i1 true, label %A, label %B
A: ; preds = %loop
br label %B
B: ; preds = %A, %loop
%QQ.1 = load i64, i64* %luc, !invariant.group !0
call void @fn(i64 %QQ.1)
ret void
}
declare void @fn(i64)
declare noalias i64* @data()
define void @test_double_ptr(double** %data) {
; CHECK-LABEL: @test_double_ptr(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[LUC:%.*]] = tail call noalias nonnull i64** @data.ptr()
; CHECK-NEXT: store i64* null, i64** [[LUC]], align 8, !invariant.group !0
; CHECK-NEXT: call void @fn.ptr(i64* null)
; CHECK-NEXT: br i1 true, label [[A:%.*]], label [[ENTRY_B_CRIT_EDGE:%.*]]
; CHECK: entry.B_crit_edge:
; CHECK-NEXT: br label [[B:%.*]]
; CHECK: A:
; CHECK-NEXT: br label [[B]]
; CHECK: B:
; CHECK-NEXT: call void @fn.ptr(i64* null)
; CHECK-NEXT: ret void
;
entry:
%luc = tail call noalias nonnull i64** @data.ptr()
store i64* null, i64** %luc, !invariant.group !0
%QQ = load i64*, i64** %luc, !invariant.group !0
call void @fn.ptr(i64* %QQ)
br i1 true, label %A, label %B
A: ; preds = %loop
br label %B
B: ; preds = %A, %loop
%QQ.1 = load i64*, i64** %luc, !invariant.group !0
call void @fn.ptr(i64* %QQ.1)
ret void
}
declare void @fn.ptr(i64 *)
declare noalias i64** @data.ptr()
!0 = distinct !{}