Use move semantics if possible to construct ConstantRanges.

[oota-llvm.git] / lib / MC / MCWin64EH.cpp

diff --git a/lib/MC/MCWin64EH.cpp b/lib/MC/MCWin64EH.cpp
index b8b07d3a180875f6bfd101c0bf576fedb353ffc2..c5b637c92443cffb18e3060cf9afd66e8fd4455e 100644 (file)
--- a/lib/MC/MCWin64EH.cpp
+++ b/lib/MC/MCWin64EH.cpp
@@ -64,7 +64,7 @@ static void EmitAbsDifference(MCStreamer &streamer, MCSymbol *lhs,
 
 static void EmitUnwindCode(MCStreamer &streamer, MCSymbol *begin,
                            MCWin64EHInstruction &inst) {
-  uint8_t b2;
+  uint8_t b1, b2;
   uint16_t w;
   b2 = (inst.getOperation() & 0x0F);
   switch (inst.getOperation()) {
@@ -93,7 +93,8 @@ static void EmitUnwindCode(MCStreamer &streamer, MCSymbol *begin,
     streamer.EmitIntValue(b2, 1);
     break;
   case Win64EH::UOP_SetFPReg:
-    EmitAbsDifference(streamer, inst.getLabel(), begin);
+    b1 = inst.getOffset() & 0xF0;
+    streamer.EmitIntValue(b1, 1);
     streamer.EmitIntValue(b2, 1);
     break;
   case Win64EH::UOP_SaveNonVol:
@@ -128,29 +129,14 @@ static void EmitUnwindCode(MCStreamer &streamer, MCSymbol *begin,
   }
 }
 
-static void EmitSymbolRefWithOfs(MCStreamer &streamer,
-                                 const MCSymbol *Base,
-                                 const MCSymbol *Other) {
-  MCContext &Context = streamer.getContext();
-  const MCSymbolRefExpr *BaseRef = MCSymbolRefExpr::Create(Base, Context);
-  const MCSymbolRefExpr *OtherRef = MCSymbolRefExpr::Create(Other, Context);
-  const MCExpr *Ofs = MCBinaryExpr::CreateSub(OtherRef, BaseRef, Context);
-  const MCSymbolRefExpr *BaseRefRel = MCSymbolRefExpr::Create(Base,
-                                              MCSymbolRefExpr::VK_COFF_IMGREL32,
-                                              Context);
-  streamer.EmitValue(MCBinaryExpr::CreateAdd(BaseRefRel, Ofs, Context), 4);
-}
-
 static void EmitRuntimeFunction(MCStreamer &streamer,
                                 const MCWin64EHUnwindInfo *info) {
   MCContext &context = streamer.getContext();
 
   streamer.EmitValueToAlignment(4);
-  EmitSymbolRefWithOfs(streamer, info->Function, info->Begin);
-  EmitSymbolRefWithOfs(streamer, info->Function, info->End);
-  streamer.EmitValue(MCSymbolRefExpr::Create(info->Symbol,
-                                             MCSymbolRefExpr::VK_COFF_IMGREL32,
-                                             context), 4);
+  streamer.EmitValue(MCSymbolRefExpr::Create(info->Begin, context), 4);
+  streamer.EmitValue(MCSymbolRefExpr::Create(info->End, context), 4);
+  streamer.EmitValue(MCSymbolRefExpr::Create(info->Symbol, context), 4);
 }
 
 static void EmitUnwindInfo(MCStreamer &streamer, MCWin64EHUnwindInfo *info) {
@@ -159,11 +145,11 @@ static void EmitUnwindInfo(MCStreamer &streamer, MCWin64EHUnwindInfo *info) {
 
   MCContext &context = streamer.getContext();
   streamer.EmitValueToAlignment(4);
+  // Upper 3 bits are the version number (currently 1).
+  uint8_t flags = 0x01;
   info->Symbol = context.CreateTempSymbol();
   streamer.EmitLabel(info->Symbol);
 
-  // Upper 3 bits are the version number (currently 1).
-  uint8_t flags = 0x01;
   if (info->ChainedParent)
     flags |= Win64EH::UNW_ChainInfo << 3;
   else {
@@ -199,26 +185,20 @@ static void EmitUnwindInfo(MCStreamer &streamer, MCWin64EHUnwindInfo *info) {
     EmitUnwindCode(streamer, info->Begin, inst);
   }
 
-  // For alignment purposes, the instruction array will always have an even
-  // number of entries, with the final entry potentially unused (in which case
-  // the array will be one longer than indicated by the count of unwind codes
-  // field).
-  if (numCodes & 1) {
-    streamer.EmitIntValue(0, 2);
-  }
-
   if (flags & (Win64EH::UNW_ChainInfo << 3))
     EmitRuntimeFunction(streamer, info->ChainedParent);
   else if (flags &
            ((Win64EH::UNW_TerminateHandler|Win64EH::UNW_ExceptionHandler) << 3))
-    streamer.EmitValue(MCSymbolRefExpr::Create(info->ExceptionHandler,
-                                              MCSymbolRefExpr::VK_COFF_IMGREL32,
-                                              context), 4);
-  else if (numCodes == 0) {
+    streamer.EmitValue(MCSymbolRefExpr::Create(info->ExceptionHandler, context),
+                       4);
+  else if (numCodes < 2) {
     // The minimum size of an UNWIND_INFO struct is 8 bytes. If we're not
     // a chained unwind info, if there is no handler, and if there are fewer
     // than 2 slots used in the unwind code array, we have to pad to 8 bytes.
-    streamer.EmitIntValue(0, 4);
+    if (numCodes == 1)
+      streamer.EmitIntValue(0, 2);
+    else
+      streamer.EmitIntValue(0, 4);
   }
 }