Fix alignment of .comm and .lcomm on mingw32.

For some reason .lcomm uses byte alignment and .comm log2 alignment so we can't
use the same setting for both. Fix this by reintroducing the LCOMM enum.
I verified this against mingw's gcc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163420 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/MC/MCAsmInfo.h b/include/llvm/MC/MCAsmInfo.h
index 73709364fef3ab277167a2f63d84903d9500f4da..97aad71fd95514d1d20c0513d966f567c9f6ccfe 100644 (file)
--- a/include/llvm/MC/MCAsmInfo.h
+++ b/include/llvm/MC/MCAsmInfo.h
@@ -32,6 +32,10 @@ namespace llvm {
     enum ExceptionsType { None, DwarfCFI, SjLj, ARM, Win64 };
   }
 
+  namespace LCOMM {
+    enum LCOMMType { NoAlignment, ByteAlignment, Log2Alignment };
+  }
+
   /// MCAsmInfo - This class is intended to be used as a base class for asm
   /// properties and features specific to the target.
   class MCAsmInfo {
@@ -247,9 +251,9 @@ namespace llvm {
     /// alignment is to be specified in bytes instead of log2(n).
     bool COMMDirectiveAlignmentIsInBytes;    // Defaults to true;
 
-    /// LCOMMDirectiveSupportsAlignment - True if .lcomm supports an optional
-    /// alignment argument on this target.
-    bool LCOMMDirectiveSupportsAlignment;    // Defaults to false.
+    /// LCOMMDirectiveAlignment - Describes if the .lcomm directive for the
+    /// target supports an alignment argument and how it is interpreted.
+    LCOMM::LCOMMType LCOMMDirectiveAlignmentType; // Defaults to NoAlignment.
 
     /// HasDotTypeDotSizeDirective - True if the target has .type and .size
     /// directives, this is true for most ELF targets.
@@ -495,8 +499,8 @@ namespace llvm {
     bool getCOMMDirectiveAlignmentIsInBytes() const {
       return COMMDirectiveAlignmentIsInBytes;
     }
-    bool getLCOMMDirectiveSupportsAlignment() const {
-      return LCOMMDirectiveSupportsAlignment;
+    LCOMM::LCOMMType getLCOMMDirectiveAlignmentType() const {
+      return LCOMMDirectiveAlignmentType;
     }
     bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
     bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 2aae37696ba8d77aaf8bcdc8cb2ab81f8cc49f11..d6d45104098a4dcf7db9fdf779669fee97bf77cf 100644 (file)
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -312,7 +312,8 @@ void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
       return;
     }
 
-    if (Align == 1 || MAI->getLCOMMDirectiveSupportsAlignment()) {
+    if (Align == 1 ||
+        MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
       // .lcomm _foo, 42
       OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
       return;

diff --git a/lib/MC/MCAsmInfo.cpp b/lib/MC/MCAsmInfo.cpp
index 11e368c81a3ff8765978095e3a3e1f96dc29c6f1..7ea0f3b85a53b15dd7a79dce862ef24334dea6f0 100644 (file)
--- a/lib/MC/MCAsmInfo.cpp
+++ b/lib/MC/MCAsmInfo.cpp
@@ -69,7 +69,7 @@ MCAsmInfo::MCAsmInfo() {
   HasSetDirective = true;
   HasAggressiveSymbolFolding = true;
   COMMDirectiveAlignmentIsInBytes = true;
-  LCOMMDirectiveSupportsAlignment = false;
+  LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
   HasDotTypeDotSizeDirective = true;
   HasSingleParameterDotFile = true;
   HasNoDeadStrip = false;

diff --git a/lib/MC/MCAsmInfoCOFF.cpp b/lib/MC/MCAsmInfoCOFF.cpp
index 4b426f8a731a57721ea63d34e0a71c3c5a3935b6..fd79193073df369e0e9b2634700839cbf0c68310 100644 (file)
--- a/lib/MC/MCAsmInfoCOFF.cpp
+++ b/lib/MC/MCAsmInfoCOFF.cpp
@@ -19,8 +19,10 @@ void MCAsmInfoCOFF::anchor() { }
 
 MCAsmInfoCOFF::MCAsmInfoCOFF() {
   GlobalPrefix = "_";
-  COMMDirectiveAlignmentIsInBytes = true;
-  LCOMMDirectiveSupportsAlignment = true;
+  // MingW 4.5 and later support .comm with log2 alignment, but .lcomm uses byte
+  // alignment.
+  COMMDirectiveAlignmentIsInBytes = false;
+  LCOMMDirectiveAlignmentType = LCOMM::ByteAlignment;
   HasDotTypeDotSizeDirective = false;
   HasSingleParameterDotFile = false;
   PrivateGlobalPrefix = "L";  // Prefix for private global symbols

diff --git a/lib/MC/MCAsmInfoDarwin.cpp b/lib/MC/MCAsmInfoDarwin.cpp
index 99520d4bf9ac4539c1538e2dc3e687f7b338cca6..a0e3ebad5e2bd47266bb9f67ec4d67cdf279ecf6 100644 (file)
--- a/lib/MC/MCAsmInfoDarwin.cpp
+++ b/lib/MC/MCAsmInfoDarwin.cpp
@@ -32,7 +32,7 @@ MCAsmInfoDarwin::MCAsmInfoDarwin() {
 
   AlignmentIsInBytes = false;
   COMMDirectiveAlignmentIsInBytes = false;
-  LCOMMDirectiveSupportsAlignment = true;
+  LCOMMDirectiveAlignmentType = LCOMM::Log2Alignment;
   InlineAsmStart = " InlineAsm Start";
   InlineAsmEnd = " InlineAsm End";
 

diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 804e38ead087823ae94f0a2e678a8c9d40bc2f08..b0bc2900ecbd27d9b223dbc77785c648f81e6723 100644 (file)
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -519,13 +519,16 @@ void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                           unsigned ByteAlign) {
   OS << "\t.lcomm\t" << *Symbol << ',' << Size;
   if (ByteAlign > 1) {
-    assert(MAI.getLCOMMDirectiveSupportsAlignment() &&
-           "alignment not supported on .lcomm!");
-    if (MAI.getCOMMDirectiveAlignmentIsInBytes()) {
+    switch (MAI.getLCOMMDirectiveAlignmentType()) {
+    case LCOMM::NoAlignment:
+      llvm_unreachable("alignment not supported on .lcomm!");
+    case LCOMM::ByteAlignment:
       OS << ',' << ByteAlign;
-    } else {
+      break;
+    case LCOMM::Log2Alignment:
       assert(isPowerOf2_32(ByteAlign) && "alignment must be a power of 2");
       OS << ',' << Log2_32(ByteAlign);
+      break;
     }
   }
   EmitEOL();

diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 271fee02ada0f02e9af28cdf0df58ce9ec5f8c94..55ef01c79613dde3dcc06bd76f5a48c322cf7116 100644 (file)
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -2280,11 +2280,13 @@ bool AsmParser::ParseDirectiveComm(bool IsLocal) {
     if (ParseAbsoluteExpression(Pow2Alignment))
       return true;
 
-    if (IsLocal && !Lexer.getMAI().getLCOMMDirectiveSupportsAlignment())
+    LCOMM::LCOMMType LCOMM = Lexer.getMAI().getLCOMMDirectiveAlignmentType();
+    if (IsLocal && LCOMM == LCOMM::NoAlignment)
       return Error(Pow2AlignmentLoc, "alignment not supported on this target");
 
     // If this target takes alignments in bytes (not log) validate and convert.
-    if (Lexer.getMAI().getCOMMDirectiveAlignmentIsInBytes()) {
+    if ((!IsLocal && Lexer.getMAI().getCOMMDirectiveAlignmentIsInBytes()) ||
+        (IsLocal && LCOMM == LCOMM::ByteAlignment)) {
       if (!isPowerOf2_64(Pow2Alignment))
         return Error(Pow2AlignmentLoc, "alignment must be a power of 2");
       Pow2Alignment = Log2_64(Pow2Alignment);

diff --git a/lib/Target/Hexagon/MCTargetDesc/HexagonMCAsmInfo.cpp b/lib/Target/Hexagon/MCTargetDesc/HexagonMCAsmInfo.cpp
index ec6b721f127c72d869034de8af3c5bbd2e3bda39..86f75d1c2d7a66939c3a25428bc5c09276e35dee 100644 (file)
--- a/lib/Target/Hexagon/MCTargetDesc/HexagonMCAsmInfo.cpp
+++ b/lib/Target/Hexagon/MCTargetDesc/HexagonMCAsmInfo.cpp
@@ -24,7 +24,7 @@ HexagonMCAsmInfo::HexagonMCAsmInfo(const Target &T, StringRef TT) {
   HasLEB128 = true;
 
   PrivateGlobalPrefix = ".L";
-  LCOMMDirectiveSupportsAlignment = true;
+  LCOMMDirectiveAlignmentType = LCOMM::ByteAlignment;
   InlineAsmStart = "# InlineAsm Start";
   InlineAsmEnd = "# InlineAsm End";
   ZeroDirective = "\t.space\t";

diff --git a/test/MC/COFF/comm.ll b/test/MC/COFF/comm.ll
new file mode 100644 (file)
index 0000000..74da557
--- /dev/null
+++ b/test/MC/COFF/comm.ll
@@ -0,0 +1,13 @@
+; RUN: llc -mtriple i386-pc-mingw32 < %s | FileCheck %s
+
+@a = internal global i8 0, align 1
+@b = internal global double 0.000000e+00, align 8
+@c = common global i8 0, align 1
+@d = common global double 0.000000e+00, align 8
+
+; .lcomm uses byte alignment
+; CHECK: .lcomm        _a,1
+; CHECK: .lcomm        _b,8,8
+; .comm uses log2 alignment
+; CHECK: .comm _c,1,0
+; CHECK: .comm _d,8,3