ARM: Add literal pool blocking to position critical code.

src/arm/full-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 55 matching lines @@
     ASSERT(patch_site_.is_bound() == info_emitted_);
   }
 
   // When initially emitting this ensure that a jump is always generated to skip
   // the inlined smi code.
   void EmitJumpIfNotSmi(Register reg, Label* target) {
     ASSERT(!patch_site_.is_bound() && !info_emitted_);
     Assembler::BlockConstPoolScope block_const_pool(masm_);
     __ bind(&patch_site_);
     __ cmp(reg, Operand(reg));
-    // Don't use b(al, ...) as that might emit the constant pool right after the
-    // branch. After patching when the branch is no longer unconditional
-    // execution can continue into the constant pool.
     __ b(eq, target);  // Always taken before patched.
   }
 
   // When initially emitting this ensure that a jump is never generated to skip
   // the inlined smi code.
   void EmitJumpIfSmi(Register reg, Label* target) {
     ASSERT(!patch_site_.is_bound() && !info_emitted_);
     Assembler::BlockConstPoolScope block_const_pool(masm_);
     __ bind(&patch_site_);
     __ cmp(reg, Operand(reg));
     __ b(ne, target);  // Never taken before patched.
   }
 
   void EmitPatchInfo() {
+    // Block literal pool emission whilst recording patch site information.
+    Assembler::BlockConstPoolScope block_const_pool(masm_);
     if (patch_site_.is_bound()) {
       int delta_to_patch_site = masm_->InstructionsGeneratedSince(&patch_site_);
       Register reg;
       reg.set_code(delta_to_patch_site / kOff12Mask);
       __ cmp_raw_immediate(reg, delta_to_patch_site % kOff12Mask);
 #ifdef DEBUG
       info_emitted_ = true;
 #endif
     } else {
       __ nop();  // Signals no inlined code.
@@ skipping 234 matching lines @@
 }
 
 
 static const int kMaxBackEdgeWeight = 127;
 static const int kBackEdgeDistanceDivisor = 142;
 
 
 void FullCodeGenerator::EmitStackCheck(IterationStatement* stmt,
                                        Label* back_edge_target) {
   Comment cmnt(masm_, "[ Stack check");
+  // Block literal pools whilst emitting stack check code.
+  Assembler::BlockConstPoolScope block_const_pool(masm_);
   Label ok;
 
   if (FLAG_count_based_interrupts) {
     int weight = 1;
     if (FLAG_weighted_back_edges) {
       ASSERT(back_edge_target->is_bound());
       int distance = masm_->SizeOfCodeGeneratedSince(back_edge_target);
       weight = Min(kMaxBackEdgeWeight,
                    Max(1, distance / kBackEdgeDistanceDivisor));
     }
@@ skipping 4177 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM