[llvm] r335918 - [COFF] Fix constant sharing regression for MinGW

[Martin Storsjo via llvm-commits]

Author: mstorsjo
Date: Thu Jun 28 13:28:29 2018
New Revision: 335918

URL: http://llvm.org/viewvc/llvm-project?rev=335918&view=rev
Log:
[COFF] Fix constant sharing regression for MinGW

This fixes a regression since SVN r334523, where the object files
built targeting MinGW were rejected by GNU binutils tools. Prior to
that commit, we only put constants in comdat for MSVC configurations.

Differential Revision: https://reviews.llvm.org/D48567

Modified:
    llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
    llvm/trunk/test/CodeGen/X86/win_cst_pool.ll

Modified: llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp?rev=335918&r1=335917&r2=335918&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp (original)
+++ llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp Thu Jun 28 13:28:29 2018
@@ -1350,7 +1350,10 @@ static std::string scalarConstantToHexSt
 MCSection *TargetLoweringObjectFileCOFF::getSectionForConstant(
     const DataLayout &DL, SectionKind Kind, const Constant *C,
     unsigned &Align) const {
-  if (Kind.isMergeableConst() && C) {
+  if (Kind.isMergeableConst() && C &&
+      getContext().getAsmInfo()->hasCOFFAssociativeComdats()) {
+    // GNU binutils doesn't support the kind of symbol with a null
+    // storage class that this generates.
     const unsigned Characteristics = COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                                      COFF::IMAGE_SCN_MEM_READ |
                                      COFF::IMAGE_SCN_LNK_COMDAT;

Modified: llvm/trunk/test/CodeGen/X86/win_cst_pool.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win_cst_pool.ll?rev=335918&r1=335917&r2=335918&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/win_cst_pool.ll (original)
+++ llvm/trunk/test/CodeGen/X86/win_cst_pool.ll Thu Jun 28 13:28:29 2018
@@ -1,4 +1,5 @@
 ; RUN: llc < %s -mtriple=x86_64-win32 -mattr=sse2 -mattr=avx | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-win32-gnu -mattr=sse2 -mattr=avx | FileCheck -check-prefix=MINGW %s
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-pc-windows-msvc"
 
@@ -14,6 +15,14 @@ define double @double() {
 ; CHECK:               movsd   __real at 0000000000800000(%rip), %xmm0
 ; CHECK-NEXT:          ret
 
+; MINGW:              .section        .rdata,"dr"
+; MINGW-NEXT:         .p2align  3
+; MINGW-NEXT: [[LABEL:\.LC.*]]:
+; MINGW-NEXT:         .quad   8388608
+; MINGW:      double:
+; MINGW:               movsd   [[LABEL]](%rip), %xmm0
+; MINGW-NEXT:          ret
+
 define <4 x i32> @vec1() {
   ret <4 x i32> <i32 3, i32 2, i32 1, i32 0>
 }