Author: Nikita Popov Date: 2025-04-29T15:22:30-07:00 New Revision: 1cf8c7797d2b2447a0eadd1443498bc9be38042e
URL: https://github.com/llvm/llvm-project/commit/1cf8c7797d2b2447a0eadd1443498bc9be38042e DIFF: https://github.com/llvm/llvm-project/commit/1cf8c7797d2b2447a0eadd1443498bc9be38042e.diff LOG: [GlobalOpt] Do not promote malloc if there are atomic loads/stores (#137158) When converting a malloc stored to a global into a global, we will introduce an i1 flag to track whether the global has been initialized. In case of atomic loads/stores, this will result in verifier failures, because atomic ops on i1 are illegal. Even if we changed this to i8, I don't think it is a good idea to change atomic types in that way. Instead, bail out of the transform is we encounter any atomic loads/stores of the global. Fixes https://github.com/llvm/llvm-project/issues/137152. (cherry picked from commit 57530c23a53b5e003d389437637f61c5b9814e22) Added: llvm/test/Transforms/GlobalOpt/malloc-promote-atomic.ll Modified: llvm/lib/Transforms/IPO/GlobalOpt.cpp Removed: ################################################################################ diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp index 9586fc97a39f7..236a531317678 100644 --- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp +++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp @@ -719,10 +719,14 @@ static bool allUsesOfLoadedValueWillTrapIfNull(const GlobalVariable *GV) { const Value *P = Worklist.pop_back_val(); for (const auto *U : P->users()) { if (auto *LI = dyn_cast<LoadInst>(U)) { + if (!LI->isSimple()) + return false; SmallPtrSet<const PHINode *, 8> PHIs; if (!AllUsesOfValueWillTrapIfNull(LI, PHIs)) return false; } else if (auto *SI = dyn_cast<StoreInst>(U)) { + if (!SI->isSimple()) + return false; // Ignore stores to the global. if (SI->getPointerOperand() != P) return false; diff --git a/llvm/test/Transforms/GlobalOpt/malloc-promote-atomic.ll b/llvm/test/Transforms/GlobalOpt/malloc-promote-atomic.ll new file mode 100644 index 0000000000000..0ecdf095efdd8 --- /dev/null +++ b/llvm/test/Transforms/GlobalOpt/malloc-promote-atomic.ll @@ -0,0 +1,28 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5 +; RUN: opt -passes=globalopt -S < %s | FileCheck %s + +@g = internal global ptr null, align 8 + +define void @init() { +; CHECK-LABEL: define void @init() local_unnamed_addr { +; CHECK-NEXT: [[ALLOC:%.*]] = call ptr @malloc(i64 48) +; CHECK-NEXT: store atomic ptr [[ALLOC]], ptr @g seq_cst, align 8 +; CHECK-NEXT: ret void +; + %alloc = call ptr @malloc(i64 48) + store atomic ptr %alloc, ptr @g seq_cst, align 8 + ret void +} + +define i1 @check() { +; CHECK-LABEL: define i1 @check() local_unnamed_addr { +; CHECK-NEXT: [[VAL:%.*]] = load atomic ptr, ptr @g seq_cst, align 8 +; CHECK-NEXT: [[CMP:%.*]] = icmp eq ptr [[VAL]], null +; CHECK-NEXT: ret i1 [[CMP]] +; + %val = load atomic ptr, ptr @g seq_cst, align 8 + %cmp = icmp eq ptr %val, null + ret i1 %cmp +} + +declare ptr @malloc(i64) allockind("alloc,uninitialized") allocsize(0) _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
