From f396732d9bddd27b9496dda6f51d492d81ef3ed7 Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Tue, 24 Jun 2014 06:53:45 +0000 Subject: [PATCH] GlobalOpt: Don't optimize dllimport for initializers Referencing a dllimport variable requires actually instructions, not just a relocation. This fixes PR19955. Differential Revision: http://reviews.llvm.org/D4249 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211571 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/IPO/GlobalOpt.cpp | 13 +++++----- .../GlobalOpt/constantfold-initializers.ll | 28 ++++++++++++++++++++-- 2 files changed, 33 insertions(+), 8 deletions(-) diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp index ae80c437643..75c1878f3fd 100644 --- a/lib/Transforms/IPO/GlobalOpt.cpp +++ b/lib/Transforms/IPO/GlobalOpt.cpp @@ -1980,10 +1980,12 @@ isSimpleEnoughValueToCommit(Constant *C, static bool isSimpleEnoughValueToCommitHelper(Constant *C, SmallPtrSet &SimpleConstants, const DataLayout *DL) { - // Simple integer, undef, constant aggregate zero, global addresses, etc are - // all supported. - if (C->getNumOperands() == 0 || isa(C) || - isa(C)) + // Simple global addresses are supported, do not allow dllimport globals. + if (auto *GV = dyn_cast(C)) + return !GV->hasDLLImportStorageClass(); + + // Simple integer, undef, constant aggregate zero, etc are all supported. + if (C->getNumOperands() == 0 || isa(C)) return true; // Aggregate values are safe if all their elements are. @@ -2054,8 +2056,7 @@ static bool isSimpleEnoughPointerToCommit(Constant *C) { return false; if (GlobalVariable *GV = dyn_cast(C)) - // Do not allow weak/*_odr/linkonce/dllimport/dllexport linkage or - // external globals. + // Do not allow weak/*_odr/linkonce linkage or external globals. return GV->hasUniqueInitializer(); if (ConstantExpr *CE = dyn_cast(C)) { diff --git a/test/Transforms/GlobalOpt/constantfold-initializers.ll b/test/Transforms/GlobalOpt/constantfold-initializers.ll index ce6e2c46d62..53e8465b5e6 100644 --- a/test/Transforms/GlobalOpt/constantfold-initializers.ll +++ b/test/Transforms/GlobalOpt/constantfold-initializers.ll @@ -50,7 +50,31 @@ entry: ret void } +; PR19955 + +@dllimportptr = global i32* null, align 4 +; CHECK: @dllimportptr = global i32* null, align 4 +@dllimportvar = external dllimport global i32 +define internal void @test3() { +entry: + store i32* @dllimportvar, i32** @dllimportptr, align 4 + ret void +} + +@dllexportptr = global i32* null, align 4 +; CHECK: @dllexportptr = global i32* @dllexportvar, align 4 +@dllexportvar = dllexport global i32 0, align 4 +; CHECK: @dllexportvar = dllexport global i32 20, align 4 +define internal void @test4() { +entry: + store i32 20, i32* @dllexportvar, align 4 + store i32* @dllexportvar, i32** @dllexportptr, align 4 + ret void +} + @llvm.global_ctors = appending constant - [2 x { i32, void ()* }] + [4 x { i32, void ()* }] [{ i32, void ()* } { i32 65535, void ()* @test1 }, - { i32, void ()* } { i32 65535, void ()* @test2 }] + { i32, void ()* } { i32 65535, void ()* @test2 }, + { i32, void ()* } { i32 65535, void ()* @test3 }, + { i32, void ()* } { i32 65535, void ()* @test4 }] -- 2.11.0