From 514f3a122d659dc45f272a1a519387680e221ffd Mon Sep 17 00:00:00 2001
From: Martin Storsjo <martin@martin.st>
Date: Tue, 20 Aug 2019 18:58:05 +0000
Subject: [PATCH] [TargetMachine] Don't try to create COFFSTUB references on
 windows on non-COFF

This avoids spurious relocation types for windows/elf targets.

Differential Revision: https://reviews.llvm.org/D66401

llvm-svn: 369426
---
 llvm/lib/Target/TargetMachine.cpp     | 8 +++++---
 llvm/lib/Target/X86/X86Subtarget.cpp  | 3 +++
 llvm/test/CodeGen/X86/mingw-refptr.ll | 7 +++++++
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/TargetMachine.cpp b/llvm/lib/Target/TargetMachine.cpp
index 9ee71c4..4c98e14 100644
--- a/llvm/lib/Target/TargetMachine.cpp
+++ b/llvm/lib/Target/TargetMachine.cpp
@@ -128,8 +128,8 @@ bool TargetMachine::shouldAssumeDSOLocal(const Module &M,
   // don't assume the variables to be DSO local unless we actually know
   // that for sure. This only has to be done for variables; for functions
   // the linker can insert thunks for calling functions from another DLL.
-  if (TT.isWindowsGNUEnvironment() && GV && GV->isDeclarationForLinker() &&
-      isa<GlobalVariable>(GV))
+  if (TT.isWindowsGNUEnvironment() && TT.isOSBinFormatCOFF() && GV &&
+      GV->isDeclarationForLinker() && isa<GlobalVariable>(GV))
     return false;
 
   // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
@@ -142,7 +142,9 @@ bool TargetMachine::shouldAssumeDSOLocal(const Module &M,
   // Make an exception for windows OS in the triple: Some firmware builds use
   // *-win32-macho triples. This (accidentally?) produced windows relocations
   // without GOT tables in older clang versions; Keep this behaviour.
-  if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
+  // Some JIT users use *-win32-elf triples; these shouldn't use GOT tables
+  // either.
+  if (TT.isOSBinFormatCOFF() || TT.isOSWindows())
     return true;
 
   // Most PIC code sequences that assume that a symbol is local cannot
diff --git a/llvm/lib/Target/X86/X86Subtarget.cpp b/llvm/lib/Target/X86/X86Subtarget.cpp
index d6d23ab..c826fdf 100644
--- a/llvm/lib/Target/X86/X86Subtarget.cpp
+++ b/llvm/lib/Target/X86/X86Subtarget.cpp
@@ -146,6 +146,9 @@ unsigned char X86Subtarget::classifyGlobalReference(const GlobalValue *GV,
       return X86II::MO_DLLIMPORT;
     return X86II::MO_COFFSTUB;
   }
+  // Some JIT users use *-win32-elf triples; these shouldn't use GOT tables.
+  if (isOSWindows())
+    return X86II::MO_NO_FLAG;
 
   if (is64Bit()) {
     // ELF supports a large, truly PIC code model with non-PC relative GOT
diff --git a/llvm/test/CodeGen/X86/mingw-refptr.ll b/llvm/test/CodeGen/X86/mingw-refptr.ll
index 158462d..8d5712b 100644
--- a/llvm/test/CodeGen/X86/mingw-refptr.ll
+++ b/llvm/test/CodeGen/X86/mingw-refptr.ll
@@ -1,5 +1,6 @@
 ; RUN: llc < %s -mtriple=x86_64-w64-mingw32 | FileCheck %s -check-prefix=CHECK-X64
 ; RUN: llc < %s -mtriple=i686-w64-mingw32 | FileCheck %s -check-prefix=CHECK-X86
+; RUN: llc < %s -mtriple=i686-w64-mingw32-none-elf | FileCheck %s -check-prefix=CHECK-X86-ELF
 
 @var = external local_unnamed_addr global i32, align 4
 @dsolocalvar = external dso_local local_unnamed_addr global i32, align 4
@@ -16,6 +17,9 @@ define dso_local i32 @getVar() {
 ; CHECK-X86:    movl .refptr._var, %eax
 ; CHECK-X86:    movl (%eax), %eax
 ; CHECK-X86:    retl
+; CHECK-X86-ELF-LABEL: getVar:
+; CHECK-X86-ELF:    movl var, %eax
+; CHECK-X86-ELF:    retl
 entry:
   %0 = load i32, i32* @var, align 4
   ret i32 %0
@@ -66,6 +70,9 @@ define dso_local i32 @getExtVar() {
 ; CHECK-X86:    movl __imp__extvar, %eax
 ; CHECK-X86:    movl (%eax), %eax
 ; CHECK-X86:    retl
+; CHECK-X86-ELF-LABEL: getExtVar:
+; CHECK-X86-ELF:    movl extvar, %eax
+; CHECK-X86-ELF:    retl
 entry:
   %0 = load i32, i32* @extvar, align 4
   ret i32 %0
-- 
2.7.4