ARM: VIXL32: Keep jump table base label within range of adr.
Macro assembler instructions between adr and the jump table base label
could cause literal pool or veneer emission, which would push the jump
table start out of adr range. Such a large emission is highly unlikely,
but possible, so prevent this by using an ExactAssemblyScope.
Test: export ART_USE_VIXL_ARM_BACKEND=true && test-art-target
Change-Id: I46a038e452e197d73206b415376b5f2246388317
diff --git a/compiler/optimizing/code_generator_arm_vixl.cc b/compiler/optimizing/code_generator_arm_vixl.cc
index ffaf18f..fe2c49d 100644
--- a/compiler/optimizing/code_generator_arm_vixl.cc
+++ b/compiler/optimizing/code_generator_arm_vixl.cc
@@ -7679,15 +7679,21 @@
vixl32::Register jump_offset = temps.Acquire();
// Load jump offset from the table.
- __ Adr(table_base, jump_table->GetTableStartLabel());
- __ Ldr(jump_offset, MemOperand(table_base, key_reg, vixl32::LSL, 2));
+ {
+ const size_t jump_size = switch_instr->GetNumEntries() * sizeof(int32_t);
+ ExactAssemblyScope aas(GetVIXLAssembler(),
+ (vixl32::kMaxInstructionSizeInBytes * 4) + jump_size,
+ CodeBufferCheckScope::kMaximumSize);
+ __ adr(table_base, jump_table->GetTableStartLabel());
+ __ ldr(jump_offset, MemOperand(table_base, key_reg, vixl32::LSL, 2));
- // Jump to target block by branching to table_base(pc related) + offset.
- vixl32::Register target_address = table_base;
- __ Add(target_address, table_base, jump_offset);
- __ Bx(target_address);
+ // Jump to target block by branching to table_base(pc related) + offset.
+ vixl32::Register target_address = table_base;
+ __ add(target_address, table_base, jump_offset);
+ __ bx(target_address);
- jump_table->EmitTable(codegen_);
+ jump_table->EmitTable(codegen_);
+ }
}
}
void LocationsBuilderARMVIXL::VisitArmDexCacheArraysBase(HArmDexCacheArraysBase* base) {
