commit 663c93448e50599d411b2403585b90513dbf8e3a
author Vladimir Marko <vmarko@google.com> Wed Jul 22 11:28:14 2015 +0100
committer Vladimir Marko <vmarko@google.com> Wed Jul 22 13:36:35 2015 +0100
tree 0450ceef1764d17df8d2c08d0d0c471e5c74433b
parent e6e38ce021ef5e0d326d76172307c000e0e6fab3

ART: Fix Thumb2 literal fixup.

When processing a load literal during fixup, we use the
current code size to determine whether we need to add the
padding before literals. However, this may change by the end
of the fixup, yet we didn't recalculate to see if the load
literal is pushed out of range.

Instead of making the load literal fixup also depend on all
preceding fixups, add an extra pass over literals when we
need the padding and repeat the fixup loop if needed.

Change-Id: Ia21d660486167a2dcb1ad4afe8acc669b4af669d

compiler/utils/arm/assembler_thumb2.cc

diff --git a/compiler/utils/arm/assembler_thumb2.cc b/compiler/utils/arm/assembler_thumb2.cc
index 413b9ea..b499ddd 100644
--- a/compiler/utils/arm/assembler_thumb2.cc
+++ b/compiler/utils/arm/assembler_thumb2.cc
@@ -133,14 +133,27 @@
     AdjustFixupIfNeeded(&fixup, &current_code_size, &fixups_to_recalculate);
   }
   while (!fixups_to_recalculate.empty()) {
-    // Pop the fixup.
-    FixupId fixup_id = fixups_to_recalculate.front();
-    fixups_to_recalculate.pop_front();
-    Fixup* fixup = GetFixup(fixup_id);
-    DCHECK_NE(buffer_.Load<int16_t>(fixup->GetLocation()), 0);
-    buffer_.Store<int16_t>(fixup->GetLocation(), 0);
-    // See if it needs adjustment.
-    AdjustFixupIfNeeded(fixup, &current_code_size, &fixups_to_recalculate);
+    do {
+      // Pop the fixup.
+      FixupId fixup_id = fixups_to_recalculate.front();
+      fixups_to_recalculate.pop_front();
+      Fixup* fixup = GetFixup(fixup_id);
+      DCHECK_NE(buffer_.Load<int16_t>(fixup->GetLocation()), 0);
+      buffer_.Store<int16_t>(fixup->GetLocation(), 0);
+      // See if it needs adjustment.
+      AdjustFixupIfNeeded(fixup, &current_code_size, &fixups_to_recalculate);
+    } while (!fixups_to_recalculate.empty());
+
+    if ((current_code_size & 2) != 0 && !literals_.empty()) {
+      // If we need to add padding before literals, this may just push some out of range,
+      // so recalculate all load literals. This makes up for the fact that we don't mark
+      // load literal as a dependency of all previous Fixups even though it actually is.
+      for (Fixup& fixup : fixups_) {
+        if (fixup.IsLoadLiteral()) {
+          AdjustFixupIfNeeded(&fixup, &current_code_size, &fixups_to_recalculate);
+        }
+      }
+    }
   }
   if (kIsDebugBuild) {
     // Check that no fixup is marked as being in fixups_to_recalculate anymore.