Use count-based profiling exclusively.

src/arm/deoptimizer-arm.cc

Index: src/arm/deoptimizer-arm.cc
diff --git a/src/arm/deoptimizer-arm.cc b/src/arm/deoptimizer-arm.cc
index 84acba287340bcb1b79b8f555939251099fbb518..dcebd558c5245a4f1ac7583ace8400686b7eb88b 100644
--- a/src/arm/deoptimizer-arm.cc
+++ b/src/arm/deoptimizer-arm.cc
@@ -114,7 +114,6 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
 }
 
 
-static const int32_t kBranchBeforeStackCheck = 0x2a000001;
 static const int32_t kBranchBeforeInterrupt =  0x5a000004;
 
 
@@ -123,24 +122,21 @@ void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
                                         Code* check_code,
                                         Code* replacement_code) {
   const int kInstrSize = Assembler::kInstrSize;
-  // The call of the stack guard check has the following form:
-  //  e1 5d 00 0c       cmp sp, <limit>
-  //  2a 00 00 01       bcs ok
+  // The back edge bookkeeping code matches the pattern:
+  //
+  //  <decrement profiling counter>
+  //  2a 00 00 01       bpl ok
   //  e5 9f c? ??       ldr ip, [pc, <stack guard address>]
   //  e1 2f ff 3c       blx ip
   ASSERT(Memory::int32_at(pc_after - kInstrSize) == kBlxIp);
   ASSERT(Assembler::IsLdrPcImmediateOffset(
       Assembler::instr_at(pc_after - 2 * kInstrSize)));
-  if (FLAG_count_based_interrupts) {
-    ASSERT_EQ(kBranchBeforeInterrupt,
-              Memory::int32_at(pc_after - 3 * kInstrSize));
-  } else {
-    ASSERT_EQ(kBranchBeforeStackCheck,
-              Memory::int32_at(pc_after - 3 * kInstrSize));
-  }
+  ASSERT_EQ(kBranchBeforeInterrupt,
+            Memory::int32_at(pc_after - 3 * kInstrSize));
 
   // We patch the code to the following form:
-  //  e1 5d 00 0c       cmp sp, <limit>
+  //
+  //  <decrement profiling counter>
   //  e1 a0 00 00       mov r0, r0 (NOP)
   //  e5 9f c? ??       ldr ip, [pc, <on-stack replacement address>]
   //  e1 2f ff 3c       blx ip
@@ -177,15 +173,9 @@ void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
 
   // Replace NOP with conditional jump.
   CodePatcher patcher(pc_after - 3 * kInstrSize, 1);
-  if (FLAG_count_based_interrupts) {
-    patcher.masm()->b(+16, pl);
-    ASSERT_EQ(kBranchBeforeInterrupt,
-              Memory::int32_at(pc_after - 3 * kInstrSize));
-  } else {
-    patcher.masm()->b(+4, cs);
-    ASSERT_EQ(kBranchBeforeStackCheck,
-              Memory::int32_at(pc_after - 3 * kInstrSize));
-  }
+  patcher.masm()->b(+16, pl);
+  ASSERT_EQ(kBranchBeforeInterrupt,
+            Memory::int32_at(pc_after - 3 * kInstrSize));
 
   // Replace the stack check address in the constant pool
   // with the entry address of the replacement code.