Add the align_to_end option to .bundle_lock in the MC implementation of aligned

bundling. The document describing this feature and the implementation has also
been updated:

https://sites.google.com/a/chromium.org/dev/nativeclient/pnacl/aligned-bundling-support-in-llvm


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171797 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 4 deletions

diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index e3acc44a85..e9afff6bed 100644
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -379,8 +379,14 @@ void MCELFStreamer::EmitInstToData(const MCInst &Inst) {
     MCSectionData *SD = getCurrentSectionData();
     if (SD->isBundleLocked() && !SD->isBundleGroupBeforeFirstInst())
       DF = getOrCreateDataFragment();
-    else
+    else {
       DF = new MCDataFragment(SD);
+      if (SD->getBundleLockState() == MCSectionData::BundleLockedAlignToEnd) {
+        // If this is a new fragment created for a bundle-locked group, and the
+        // group was marked as "align_to_end", set a flag in the fragment.
+        DF->setAlignToBundleEnd(true);
+      }
+    }
 
     // We're now emitting an instruction in a bundle group, so this flag has
     // to be turned off.
@@ -407,7 +413,7 @@ void MCELFStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
     report_fatal_error(".bundle_align_mode should be only set once per file");
 }
 
-void MCELFStreamer::EmitBundleLock() {
+void MCELFStreamer::EmitBundleLock(bool AlignToEnd) {
   MCSectionData *SD = getCurrentSectionData();
 
   // Sanity checks
@@ -417,7 +423,8 @@ void MCELFStreamer::EmitBundleLock() {
   else if (SD->isBundleLocked())
     report_fatal_error("Nesting of .bundle_lock is forbidden");
 
-  SD->setBundleLocked(true);
+  SD->setBundleLockState(AlignToEnd ? MCSectionData::BundleLockedAlignToEnd :
+                                      MCSectionData::BundleLocked);
   SD->setBundleGroupBeforeFirstInst(true);
 }
 
@@ -432,7 +439,7 @@ void MCELFStreamer::EmitBundleUnlock() {
   else if (SD->isBundleGroupBeforeFirstInst())
     report_fatal_error("Empty bundle-locked group is forbidden");
 
-  SD->setBundleLocked(false);
+  SD->setBundleLockState(MCSectionData::NotBundleLocked);
 }
 
 void MCELFStreamer::FinishImpl() {