From b76df593eb660d1e4c9f1384a75b404ee5bcd06f Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Tue, 29 Sep 2020 09:18:19 +0100 Subject: [PATCH] Revert "Recommit "[SCCP] Do not replace deref'able ptr with un-deref'able one."" Looks like there is still another remaining issue: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-msan/builds/22273/steps/build%20libcxx%2Fmsan/logs/stdio This reverts commit 86a20d9e34f5a9989da72097f23f3b0a44157e73. --- llvm/lib/Analysis/Loads.cpp | 4 ---- llvm/lib/Transforms/Scalar/SCCP.cpp | 11 --------- llvm/test/Transforms/SCCP/apint-bigint2.ll | 6 ++--- llvm/test/Transforms/SCCP/indirectbr.ll | 4 +--- ...eferenceable-ptr-with-undereferenceable.ll | 23 ++----------------- 5 files changed, 5 insertions(+), 43 deletions(-) diff --git a/llvm/lib/Analysis/Loads.cpp b/llvm/lib/Analysis/Loads.cpp index 5b9f46652382..d63f6b9b1964 100644 --- a/llvm/lib/Analysis/Loads.cpp +++ b/llvm/lib/Analysis/Loads.cpp @@ -510,10 +510,6 @@ bool llvm::canReplacePointersIfEqual(Value *A, Value *B, const DataLayout &DL, assert(Ty == B->getType() && Ty->isPointerTy() && "values must have matching pointer types"); - // Function pointers are not directly dereferenced using load/store - // instructions. Allow any replacements for now. - if (A->getType()->getPointerElementType()->isFunctionTy()) - return true; // NOTE: The checks in the function are incomplete and currently miss illegal // cases! The current implementation is a starting point and the // implementation should be made stricter over time. diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp index b73842ed6a12..33ab2907906e 100644 --- a/llvm/lib/Transforms/Scalar/SCCP.cpp +++ b/llvm/lib/Transforms/Scalar/SCCP.cpp @@ -31,7 +31,6 @@ #include "llvm/Analysis/DomTreeUpdater.h" #include "llvm/Analysis/GlobalsModRef.h" #include "llvm/Analysis/InstructionSimplify.h" -#include "llvm/Analysis/Loads.h" #include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/Analysis/ValueLattice.h" #include "llvm/Analysis/ValueLatticeUtils.h" @@ -178,8 +177,6 @@ class SCCPSolver : public InstVisitor { LLVMContext &Ctx; public: - const DataLayout &getDataLayout() const { return DL; } - void addAnalysis(Function &F, AnalysisResultsForFn A) { AnalysisResults.insert({&F, std::move(A)}); } @@ -1652,14 +1649,6 @@ static bool tryToReplaceWithConstant(SCCPSolver &Solver, Value *V) { return false; } - // Do not propagate equality of a un-dereferenceable pointer. - // FIXME: Currently this only treats pointers one past the last element - // for array types. Should probably be much stricter. - if (Const->getType()->isPointerTy() && - !canReplacePointersIfEqual(V, Const, Solver.getDataLayout(), - dyn_cast(V))) - return false; - LLVM_DEBUG(dbgs() << " Constant: " << *Const << " = " << *V << '\n'); // Replaces all of the uses of a variable with uses of the constant. diff --git a/llvm/test/Transforms/SCCP/apint-bigint2.ll b/llvm/test/Transforms/SCCP/apint-bigint2.ll index 7d1a9a68372c..8effa2181a4c 100644 --- a/llvm/test/Transforms/SCCP/apint-bigint2.ll +++ b/llvm/test/Transforms/SCCP/apint-bigint2.ll @@ -51,10 +51,8 @@ define i101 @large_aggregate_2() { } ; CHECK-LABEL: @index_too_large -; CHECK-NEXT: %ptr1 = getelementptr [6 x i101], [6 x i101]* @Y, i32 0, i32 -1 -; CHECK-NEXT: %ptr2 = getelementptr i101, i101* %ptr1, i101 9224497936761618431 -; CHECK-NEXT: store i101* %ptr2, i101** undef -; CHECK-NEXT: ret void +; CHECK-NEXT: store i101* getelementptr (i101, i101* getelementptr ([6 x i101], [6 x i101]* @Y, i32 0, i32 -1), i101 9224497936761618431), i101** undef +; CHECK-NEXT: ret void define void @index_too_large() { %ptr1 = getelementptr [6 x i101], [6 x i101]* @Y, i32 0, i32 -1 %ptr2 = getelementptr i101, i101* %ptr1, i101 9224497936761618431 diff --git a/llvm/test/Transforms/SCCP/indirectbr.ll b/llvm/test/Transforms/SCCP/indirectbr.ll index 1a9ae8a128f1..6889282e3874 100644 --- a/llvm/test/Transforms/SCCP/indirectbr.ll +++ b/llvm/test/Transforms/SCCP/indirectbr.ll @@ -31,9 +31,7 @@ BB1: define void @indbrtest2() { ; CHECK-LABEL: @indbrtest2( ; CHECK-NEXT: entry: -; CHECK-NEXT: [[B:%.*]] = inttoptr i64 ptrtoint (i8* blockaddress(@indbrtest2, [[BB1:%.*]]) to i64) to i8* -; CHECK-NEXT: [[C:%.*]] = bitcast i8* [[B]] to i8* -; CHECK-NEXT: br label [[BB1]] +; CHECK-NEXT: br label [[BB1:%.*]] ; CHECK: BB1: ; CHECK-NEXT: call void @BB1_f() ; CHECK-NEXT: ret void diff --git a/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll b/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll index 898da01b356f..5857ce2d30b7 100644 --- a/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll +++ b/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll @@ -11,7 +11,7 @@ define i32 @eq_undereferenceable(i32* %p) { ; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32* [[P:%.*]], getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1) ; CHECK-NEXT: br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] ; CHECK: if.then: -; CHECK-NEXT: store i32 2, i32* [[P]], align 4 +; CHECK-NEXT: store i32 2, i32* getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1), align 4 ; CHECK-NEXT: br label [[IF_END]] ; CHECK: if.end: ; CHECK-NEXT: [[TMP0:%.*]] = load i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4 @@ -65,7 +65,7 @@ define i1 @eq_undereferenceable_cmp_simp(i32* %p) { ; CHECK-NEXT: [[CMP_0:%.*]] = icmp eq i32* [[P:%.*]], getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1) ; CHECK-NEXT: br i1 [[CMP_0]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] ; CHECK: if.then: -; CHECK-NEXT: store i32 2, i32* [[P]], align 4 +; CHECK-NEXT: store i32 2, i32* getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1), align 4 ; CHECK-NEXT: ret i1 true ; CHECK: if.end: ; CHECK-NEXT: [[CMP_2:%.*]] = icmp eq i32* [[P]], getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1) @@ -84,22 +84,3 @@ if.end: ; preds = %if.then, %entry %cmp.2 = icmp eq i32* %p, getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1) ret i1 %cmp.2 } - - -; Test cases with function pointers. Currently any replacements are allowed -; for them. -@FnGlobal1 = internal global void (i8*)* undef, align 8 - -define void (i8*)* @test_global_undef_fn_ptr() { - %lv = load void (i8*)*, void (i8*)** @FnGlobal1, align 8 - ret void (i8*)* %lv -} - -declare void @foo(i8*) - -@FnGlobal2 = internal global void (i8*)* @foo, align 8 - -define void (i8*)* @test_global_undef_fn_ptr2() { - %lv = load void (i8*)*, void (i8*)** @FnGlobal2, align 8 - ret void (i8*)* %lv -}