CpuProfiler: fix for CollectDeoptEvents test on arm64

src/arm64/lithium-codegen-arm64.cc

Index: src/arm64/lithium-codegen-arm64.cc
diff --git a/src/arm64/lithium-codegen-arm64.cc b/src/arm64/lithium-codegen-arm64.cc
index ddc8731c9ff96ad767d5723d7108b7c67b60b2af..196a5400c38eab21051b53618454e00495f2dea4 100644
--- a/src/arm64/lithium-codegen-arm64.cc
+++ b/src/arm64/lithium-codegen-arm64.cc
@@ -864,55 +864,55 @@ bool LCodeGen::GenerateJumpTable() {
       // address and add an immediate offset.
       __ Mov(entry_offset, entry - base);
 
-      // The last entry can fall through into `call_deopt_entry`, avoiding a
-      // branch.
-      bool last_entry = (i + 1) == length;
-
       if (table_entry->needs_frame) {
         DCHECK(!info()->saves_caller_doubles());
-        if (!needs_frame.is_bound()) {
-          // This variant of deopt can only be used with stubs. Since we don't
-          // have a function pointer to install in the stack frame that we're
-          // building, install a special marker there instead.
-          DCHECK(info()->IsStub());
-
-          UseScratchRegisterScope temps(masm());
-          Register stub_marker = temps.AcquireX();
-          __ Bind(&needs_frame);
-          __ Mov(stub_marker, Smi::FromInt(StackFrame::STUB));
-          __ Push(lr, fp, cp, stub_marker);
-          __ Add(fp, __ StackPointer(), 2 * kPointerSize);
-          if (!last_entry) __ B(&call_deopt_entry);
-        } else {
-          // Reuse the existing needs_frame code.
-          __ B(&needs_frame);
-        }
+        // Save lr before Bl, fp will be adjusted in the needs_frame code.
+        __ Push(lr, fp, cp);

[jbramley, 2015/03/10 13:11:18]

We can save some space here by pushing (lr, fp) here, then (cp, stub_marker) at
needs_frame. ARM64 pushes registers in pairs, so pushing (a,b),(c,d) is more
space-efficient than pushing (a,b,c),(d).

The effect is probably small but I'll make a patch to address this, since there
is basically no cost.

(Sorry, I didn't see it at first.)

[loislo, 2015/03/10 14:42:18]

I'll do this in https://codereview.chromium.org/995813002/

+        // Reuse the existing needs_frame code.
+        __ Bl(&needs_frame);
       } else if (info()->saves_caller_doubles()) {
         DCHECK(info()->IsStub());
-        if (!restore_caller_doubles.is_bound()) {
-          __ Bind(&restore_caller_doubles);
-          RestoreCallerDoubles();
-          if (!last_entry) __ B(&call_deopt_entry);
-        } else {
-          // Reuse the existing restore_caller_doubles code.
-          __ B(&restore_caller_doubles);
-        }
+        // Reuse the existing restore_caller_doubles code.
+        __ Bl(&restore_caller_doubles);
       } else {
         // There is nothing special to do, so just continue to the second-level
         // table.
-        if (!last_entry) __ B(&call_deopt_entry);
+        __ Bl(&call_deopt_entry);
       }
 
+      bool last_entry = (i + 1) == length;
       masm()->CheckConstPool(false, last_entry);
     }
 
+    if (needs_frame.is_linked()) {
+      // This variant of deopt can only be used with stubs. Since we don't
+      // have a function pointer to install in the stack frame that we're
+      // building, install a special marker there instead.
+      DCHECK(info()->IsStub());
+
+      UseScratchRegisterScope temps(masm());
+      Register stub_marker = temps.AcquireX();
+      __ Bind(&needs_frame);
+      __ Mov(stub_marker, Smi::FromInt(StackFrame::STUB));
+      __ Push(stub_marker);
+      __ Add(fp, __ StackPointer(), 2 * kPointerSize);
+      if (restore_caller_doubles.is_linked()) {
+        __ B(&call_deopt_entry);
+      }
+    }
+
+    if (restore_caller_doubles.is_linked()) {
+      __ Bind(&restore_caller_doubles);
+      RestoreCallerDoubles();
+    }
+
     // Generate common code for calling the second-level deopt table.
     Register deopt_entry = temps.AcquireX();
     __ Bind(&call_deopt_entry);
     __ Mov(deopt_entry, Operand(reinterpret_cast<uint64_t>(base),
                                 RelocInfo::RUNTIME_ENTRY));
     __ Add(deopt_entry, deopt_entry, entry_offset);
-    __ Call(deopt_entry);
+    __ Br(deopt_entry);
   }
 
   // Force constant pool emission at the end of the deopt jump table to make
@@ -1152,7 +1152,7 @@ void LCodeGen::DeoptimizeIfMinusZero(DoubleRegister input, LInstruction* instr,
 
 void LCodeGen::DeoptimizeIfNotHeapNumber(Register object, LInstruction* instr) {
   __ CompareObjectMap(object, Heap::kHeapNumberMapRootIndex);
-  DeoptimizeIf(ne, instr, Deoptimizer::kNotHeapNumber);
+  DeoptimizeIf(ne, instr, Deoptimizer::kNotAHeapNumber);
 }