Align the __LD,__compact_unwind section.
I know what would be cool! We should align the compact unwind section because
aligned data access is faster.
<rdar://problem/13723271>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180171 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index f91cb54..18982e9 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -1177,8 +1177,6 @@
if (!DwarfEHFrameOnly && Frame.Lsda)
Encoding |= 0x40000000;
- Streamer.SwitchSection(MOFI->getCompactUnwindSection());
-
// Range Start
unsigned FDEEncoding = MOFI->getFDEEncoding(UsingCFI);
unsigned Size = getSizeForEncoding(Streamer, FDEEncoding);
@@ -1421,7 +1419,6 @@
}
// Call Frame Instructions
-
EmitCFIInstructions(streamer, frame.Instructions, frame.Begin);
// Padding
@@ -1482,11 +1479,23 @@
ArrayRef<MCDwarfFrameInfo> FrameArray = Streamer.getFrameInfos();
// Emit the compact unwind info if available.
- if (IsEH && MOFI->getCompactUnwindSection())
- for (unsigned i = 0, n = Streamer.getNumFrameInfos(); i < n; ++i) {
- const MCDwarfFrameInfo &Frame = Streamer.getFrameInfo(i);
- Emitter.EmitCompactUnwind(Streamer, Frame);
+ if (IsEH && MOFI->getCompactUnwindSection()) {
+ unsigned NumFrameInfos = Streamer.getNumFrameInfos();
+ bool SectionEmitted = false;
+
+ if (NumFrameInfos) {
+ for (unsigned i = 0; i < NumFrameInfos; ++i) {
+ const MCDwarfFrameInfo &Frame = Streamer.getFrameInfo(i);
+ if (Frame.CompactUnwindEncoding == 0) continue;
+ if (!SectionEmitted) {
+ Streamer.SwitchSection(MOFI->getCompactUnwindSection());
+ Streamer.EmitValueToAlignment(Context.getAsmInfo().getPointerSize());
+ SectionEmitted = true;
+ }
+ Emitter.EmitCompactUnwind(Streamer, Frame);
+ }
}
+ }
const MCSection &Section = IsEH ? *MOFI->getEHFrameSection() :
*MOFI->getDwarfFrameSection();