From 0f1cadd92008a2671cae9b8ef0890007dc923f39 Mon Sep 17 00:00:00 2001 From: John Brawn Date: Fri, 2 Jun 2017 10:24:14 +0000 Subject: [PATCH] [GlobalMerge] Don't merge globals that may be preempted When a global may be preempted it needs to be accessed directly, instead of indirectly through a MergedGlobals symbol, for the preemption to work. This fixes PR33136. Differential Revision: https://reviews.llvm.org/D33727 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304537 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/GlobalMerge.cpp | 4 ++++ test/CodeGen/ARM/global-merge-external.ll | 1 + 2 files changed, 5 insertions(+) diff --git a/lib/CodeGen/GlobalMerge.cpp b/lib/CodeGen/GlobalMerge.cpp index 23812a2a234..3603f9b7ed9 100644 --- a/lib/CodeGen/GlobalMerge.cpp +++ b/lib/CodeGen/GlobalMerge.cpp @@ -556,6 +556,10 @@ bool GlobalMerge::doInitialization(Module &M) { if (GV.isDeclaration() || GV.isThreadLocal() || GV.hasSection()) continue; + // It's not safe to merge globals that may be preempted + if (TM && !TM->shouldAssumeDSOLocal(M, &GV)) + continue; + if (!(MergeExternalGlobals && GV.hasExternalLinkage()) && !GV.hasInternalLinkage()) continue; diff --git a/test/CodeGen/ARM/global-merge-external.ll b/test/CodeGen/ARM/global-merge-external.ll index a9e0d199705..03c97761432 100644 --- a/test/CodeGen/ARM/global-merge-external.ll +++ b/test/CodeGen/ARM/global-merge-external.ll @@ -2,6 +2,7 @@ ; RUN: llc < %s -mtriple=arm-eabi -arm-global-merge -global-merge-on-external=true | FileCheck %s --check-prefix=CHECK-MERGE ; RUN: llc < %s -mtriple=arm-eabi -arm-global-merge -global-merge-on-external=false | FileCheck %s --check-prefix=CHECK-NO-MERGE ; RUN: llc < %s -mtriple=arm-macho -arm-global-merge | FileCheck %s --check-prefix=CHECK-NO-MERGE +; RUN: llc < %s -mtriple=arm-eabi -arm-global-merge -relocation-model=pic | FileCheck %s --check-prefix=CHECK-NO-MERGE @x = global i32 0, align 4 @y = global i32 0, align 4 -- 2.50.1