Silence warning about loss of precision.
[oota-llvm.git] / lib / Target / X86 / X86TargetAsmInfo.cpp
index 229473c89c1c961e85bf1cf6b87a7d39993fcb34..6bfc326f20dd4f49ef47d64fbc469c2e93ed9f8e 100644 (file)
@@ -2,8 +2,8 @@
 //
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by James M. Laskey and is distributed under the
-// University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 #include "X86TargetAsmInfo.h"
 #include "X86TargetMachine.h"
 #include "X86Subtarget.h"
-
+#include "llvm/DerivedTypes.h"
+#include "llvm/InlineAsm.h"
+#include "llvm/Instructions.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/Module.h"
+#include "llvm/ADT/StringExtras.h"
 using namespace llvm;
 
+static const char* x86_asm_table[] = {"{si}", "S",
+                                      "{di}", "D",
+                                      "{ax}", "a",
+                                      "{cx}", "c",
+                                      "{memory}", "memory",
+                                      "{flags}", "",
+                                      "{dirflag}", "",
+                                      "{fpsr}", "",
+                                      "{cc}", "cc",
+                                      0,0};
+
 X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
   const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
   
   // FIXME - Should be simplified.
-   
+
+  AsmTransCBE = x86_asm_table;
+  
   switch (Subtarget->TargetType) {
   case X86Subtarget::isDarwin:
     AlignmentIsInBytes = false;
@@ -30,6 +48,8 @@ X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
       Data64bitsDirective = 0;       // we can't emit a 64-bit unit
     ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
     PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
+    BSSSection = 0;                       // no BSS section.
+    ZeroFillDirective = "\t.zerofill\t";  // Uses .zerofill
     ConstantPoolSection = "\t.const\n";
     JumpTableDataSection = "\t.const\n";
     CStringSection = "\t.cstring";
@@ -37,21 +57,43 @@ X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
     EightByteConstantSection = "\t.literal8\n";
     if (Subtarget->is64Bit())
       SixteenByteConstantSection = "\t.literal16\n";
+    ReadOnlySection = "\t.const\n";
     LCOMMDirective = "\t.lcomm\t";
     COMMDirectiveTakesAlignment = false;
     HasDotTypeDotSizeDirective = false;
-    StaticCtorsSection = ".mod_init_func";
-    StaticDtorsSection = ".mod_term_func";
+    if (TM.getRelocationModel() == Reloc::Static) {
+      StaticCtorsSection = ".constructor";
+      StaticDtorsSection = ".destructor";
+    } else {
+      StaticCtorsSection = ".mod_init_func";
+      StaticDtorsSection = ".mod_term_func";
+    }
+    PersonalityPrefix = "L";
+    PersonalitySuffix = "$non_lazy_ptr";
+    NeedsIndirectEncoding = true;
     InlineAsmStart = "# InlineAsm Start";
     InlineAsmEnd = "# InlineAsm End";
     SetDirective = "\t.set";
+    PCSymbol = ".";
     UsedDirective = "\t.no_dead_strip\t";
+    WeakDefDirective = "\t.weak_definition\t";
+    WeakRefDirective = "\t.weak_reference\t";
+    HiddenDirective = "\t.private_extern\t";
     
+    // In non-PIC modes, emit a special label before jump tables so that the
+    // linker can perform more accurate dead code stripping.
+    if (TM.getRelocationModel() != Reloc::PIC_) {
+      // Emit a local label that is preserved until the linker runs.
+      JumpTableSpecialLabelPrefix = "l";
+    }
+
+    SupportsDebugInformation = true;
     NeedsSet = true;
     DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug";
     DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";
     DwarfLineSection = ".section __DWARF,__debug_line,regular,debug";
     DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug";
+    GlobalEHDirective = "\t.globl\t";
     DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug";
     DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug";
     DwarfStrSection = ".section __DWARF,__debug_str,regular,debug";
@@ -59,18 +101,33 @@ X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
     DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug";
     DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug";
     DwarfMacInfoSection = ".section __DWARF,__debug_macinfo,regular,debug";
+
+    // Exceptions handling
+    if (!Subtarget->is64Bit())
+      SupportsExceptionHandling = true;
+    AbsoluteEHSectionOffsets = false;
+    DwarfEHFrameSection =
+    ".section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support";
+    DwarfExceptionSection = ".section __DATA,__gcc_except_tab";
     break;
 
   case X86Subtarget::isELF:
+    ReadOnlySection = "\t.section\t.rodata";
+    FourByteConstantSection = "\t.section\t.rodata.cst4,\"aM\",@progbits,4";
+    EightByteConstantSection = "\t.section\t.rodata.cst8,\"aM\",@progbits,8";
+    SixteenByteConstantSection = "\t.section\t.rodata.cst16,\"aM\",@progbits,16";
+    CStringSection = "\t.section\t.rodata.str1.1,\"aMS\",@progbits,1";
+    PrivateGlobalPrefix = ".L";
+    WeakRefDirective = "\t.weak\t";
+    SetDirective = "\t.set\t";
+    PCSymbol = ".";
+
     // Set up DWARF directives
     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
-    // bool HasLEB128; // Defaults to false.
-    // hasDotLoc - True if target asm supports .loc directives.
-    // bool HasDotLoc; // Defaults to false.
-    // HasDotFile - True if target asm supports .file directives.
-    // bool HasDotFile; // Defaults to false.
-    PrivateGlobalPrefix = ".";  // Prefix for private global symbols
-    DwarfRequiresFrameSection = false;
+
+    // Debug Information
+    AbsoluteDebugSectionOffsets = true;
+    SupportsDebugInformation = true;
     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"\",@progbits";
     DwarfInfoSection =    "\t.section\t.debug_info,\"\",@progbits";
     DwarfLineSection =    "\t.section\t.debug_line,\"\",@progbits";
@@ -82,19 +139,34 @@ X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
     DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits";
     DwarfRangesSection =  "\t.section\t.debug_ranges,\"\",@progbits";
     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits";
+
+    // Exceptions handling
+    if (!Subtarget->is64Bit())
+      SupportsExceptionHandling = true;
+    AbsoluteEHSectionOffsets = false;
+    DwarfEHFrameSection = "\t.section\t.eh_frame,\"aw\",@progbits";
+    DwarfExceptionSection = "\t.section\t.gcc_except_table,\"a\",@progbits";
     break;
 
   case X86Subtarget::isCygwin:
+  case X86Subtarget::isMingw:
     GlobalPrefix = "_";
+    LCOMMDirective = "\t.lcomm\t";
     COMMDirectiveTakesAlignment = false;
     HasDotTypeDotSizeDirective = false;
     StaticCtorsSection = "\t.section .ctors,\"aw\"";
     StaticDtorsSection = "\t.section .dtors,\"aw\"";
+    HiddenDirective = NULL;
+    PrivateGlobalPrefix = "L";  // Prefix for private global symbols
+    WeakRefDirective = "\t.weak\t";
+    SetDirective = "\t.set\t";
 
     // Set up DWARF directives
     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
-    PrivateGlobalPrefix = "L";  // Prefix for private global symbols
-    DwarfRequiresFrameSection = false;
+    AbsoluteDebugSectionOffsets = true;
+    AbsoluteEHSectionOffsets = false;
+    SupportsDebugInformation = true;
+    DwarfSectionOffsetDirective = "\t.secrel32\t";
     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"dr\"";
     DwarfInfoSection =    "\t.section\t.debug_info,\"dr\"";
     DwarfLineSection =    "\t.section\t.debug_line,\"dr\"";
@@ -107,12 +179,12 @@ X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
     DwarfRangesSection =  "\t.section\t.debug_ranges,\"dr\"";
     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"dr\"";
     break;
-    
-    break;
+
   case X86Subtarget::isWindows:
     GlobalPrefix = "_";
     HasDotTypeDotSizeDirective = false;
     break;
+
   default: break;
   }
   
@@ -134,10 +206,92 @@ X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
     
     TextSection = "_text";
     DataSection = "_data";
+    JumpTableDataSection = NULL;
     SwitchToSectionDirective = "";
     TextSectionStartSuffix = "\tsegment 'CODE'";
     DataSectionStartSuffix = "\tsegment 'DATA'";
     SectionEndDirectiveSuffix = "\tends\n";
   }
+
+  AssemblerDialect = Subtarget->getAsmFlavor();
 }
 
+bool X86TargetAsmInfo::LowerToBSwap(CallInst *CI) const {
+  // FIXME: this should verify that we are targetting a 486 or better.  If not,
+  // we will turn this bswap into something that will be lowered to logical ops
+  // instead of emitting the bswap asm.  For now, we don't support 486 or lower
+  // so don't worry about this.
+  
+  // Verify this is a simple bswap.
+  if (CI->getNumOperands() != 2 ||
+      CI->getType() != CI->getOperand(1)->getType() ||
+      !CI->getType()->isInteger())
+    return false;
+  
+  const IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
+  if (!Ty || Ty->getBitWidth() % 16 != 0)
+    return false;
+  
+  // Okay, we can do this xform, do so now.
+  const Type *Tys[] = { Ty };
+  Module *M = CI->getParent()->getParent()->getParent();
+  Constant *Int = Intrinsic::getDeclaration(M, Intrinsic::bswap, Tys, 1);
+  
+  Value *Op = CI->getOperand(1);
+  Op = new CallInst(Int, Op, CI->getName(), CI);
+  
+  CI->replaceAllUsesWith(Op);
+  CI->eraseFromParent();
+  return true;
+}
+
+
+bool X86TargetAsmInfo::ExpandInlineAsm(CallInst *CI) const {
+  InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
+  std::vector<InlineAsm::ConstraintInfo> Constraints = IA->ParseConstraints();
+  
+  std::string AsmStr = IA->getAsmString();
+  
+  // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
+  std::vector<std::string> AsmPieces;
+  SplitString(AsmStr, AsmPieces, "\n");  // ; as separator?
+  
+  switch (AsmPieces.size()) {
+  default: return false;    
+  case 1:
+    AsmStr = AsmPieces[0];
+    AsmPieces.clear();
+    SplitString(AsmStr, AsmPieces, " \t");  // Split with whitespace.
+    
+    // bswap $0
+    if (AsmPieces.size() == 2 && 
+        AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") {
+      // No need to check constraints, nothing other than the equivalent of
+      // "=r,0" would be valid here.
+      return LowerToBSwap(CI);
+    }
+    break;
+  case 3:
+    if (CI->getType() == Type::Int64Ty && Constraints.size() >= 2 &&
+        Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
+        Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
+      // bswap %eax / bswap %edx / xchgl %eax, %edx  -> llvm.bswap.i64
+      std::vector<std::string> Words;
+      SplitString(AsmPieces[0], Words, " \t");
+      if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") {
+        Words.clear();
+        SplitString(AsmPieces[1], Words, " \t");
+        if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") {
+          Words.clear();
+          SplitString(AsmPieces[2], Words, " \t,");
+          if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" &&
+              Words[2] == "%edx") {
+            return LowerToBSwap(CI);
+          }
+        }
+      }
+    }
+    break;
+  }
+  return false;
+}