Author: Eli Friedman Date: 2020-10-30T18:51:54-07:00 New Revision: 38399ced95bca0aede9baaecd75936952758b1b6
URL: https://github.com/llvm/llvm-project/commit/38399ced95bca0aede9baaecd75936952758b1b6 DIFF: https://github.com/llvm/llvm-project/commit/38399ced95bca0aede9baaecd75936952758b1b6.diff LOG: [ConstantFold] Make areGlobalsPotentiallyEqual less aggressive. In particular, we shouldn't make assumptions about globals which are unnamed_addr: we can fold them together with other globals. Also while I'm here, use isInterposable() instead of trying to explicitly name all the different kinds of weak linkage. Fixes https://bugs.llvm.org/show_bug.cgi?id=47090 Differential Revision: https://reviews.llvm.org/D87123 (cherry picked from commit d751f86189a7f7ef2a6fe06974a5da3349b02f20) Added: Modified: llvm/lib/IR/ConstantFold.cpp llvm/test/Assembler/ConstantExprNoFold.ll llvm/test/Transforms/InstCombine/2010-03-03-ExtElim.ll Removed: ################################################################################ diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp index f3c3e9ad9f69..c20d0955f3d8 100644 --- a/llvm/lib/IR/ConstantFold.cpp +++ b/llvm/lib/IR/ConstantFold.cpp @@ -1589,7 +1589,7 @@ static FCmpInst::Predicate evaluateFCmpRelation(Constant *V1, Constant *V2) { static ICmpInst::Predicate areGlobalsPotentiallyEqual(const GlobalValue *GV1, const GlobalValue *GV2) { auto isGlobalUnsafeForEquality = [](const GlobalValue *GV) { - if (GV->hasExternalWeakLinkage() || GV->hasWeakAnyLinkage()) + if (GV->isInterposable() || GV->hasGlobalUnnamedAddr()) return true; if (const auto *GVar = dyn_cast<GlobalVariable>(GV)) { Type *Ty = GVar->getValueType(); diff --git a/llvm/test/Assembler/ConstantExprNoFold.ll b/llvm/test/Assembler/ConstantExprNoFold.ll index 42e558eb3865..d91855925c89 100644 --- a/llvm/test/Assembler/ConstantExprNoFold.ll +++ b/llvm/test/Assembler/ConstantExprNoFold.ll @@ -42,6 +42,12 @@ target datalayout = "p:32:32" @empty.2 = external global [0 x i8], align 1 @empty.cmp = global i1 icmp eq ([0 x i8]* @empty.1, [0 x i8]* @empty.2) +; Two unnamed_addr globals can share an address +; CHECK: @unnamed.cmp = global i1 icmp eq ([5 x i8]* @unnamed.1, [5 x i8]* @unnamed.2) +@unnamed.1 = unnamed_addr constant [5 x i8] c"asdf\00" +@unnamed.2 = unnamed_addr constant [5 x i8] c"asdf\00" +@unnamed.cmp = global i1 icmp eq ([5 x i8]* @unnamed.1, [5 x i8]* @unnamed.2) + @addrspace3 = internal addrspace(3) global i32 undef ; CHECK: @no.fold.addrspace.icmp.eq.gv.null = global i1 icmp eq (i32 addrspace(3)* @addrspace3, i32 addrspace(3)* null) diff --git a/llvm/test/Transforms/InstCombine/2010-03-03-ExtElim.ll b/llvm/test/Transforms/InstCombine/2010-03-03-ExtElim.ll index ad0fe5a21783..da9d0469e5e2 100644 --- a/llvm/test/Transforms/InstCombine/2010-03-03-ExtElim.ll +++ b/llvm/test/Transforms/InstCombine/2010-03-03-ExtElim.ll @@ -16,8 +16,8 @@ define i1 @PR6486() nounwind { ; CHECK: ret i1 true } -@d = common global i32 0, align 4 -@a = common global [1 x i32] zeroinitializer, align 4 +@d = global i32 0, align 4 +@a = global [1 x i32] zeroinitializer, align 4 define i1 @PR16462_1() nounwind { ; CHECK-LABEL: @PR16462_1( _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
