Implement method calls using relative BL on ARM.
Store the linker patches with each CompiledMethod instead of
keeping them in CompilerDriver. Reorganize oat file creation
to apply the patches as we're writing the method code. Add
framework for platform-specific relative call patches in the
OatWriter. Implement relative call patches for ARM.
Change-Id: Ie2effb3d92b61ac8f356140eba09dc37d62290f8
diff --git a/compiler/dex/quick/arm/call_arm.cc b/compiler/dex/quick/arm/call_arm.cc
index f6588fe..b721e02 100644
--- a/compiler/dex/quick/arm/call_arm.cc
+++ b/compiler/dex/quick/arm/call_arm.cc
@@ -20,6 +20,8 @@
#include "codegen_arm.h"
#include "dex/quick/mir_to_lir-inl.h"
#include "gc/accounting/card_table.h"
+#include "mirror/art_method.h"
+#include "mirror/object_array-inl.h"
#include "entrypoints/quick/quick_entrypoints.h"
namespace art {
@@ -499,4 +501,117 @@
NewLIR1(kThumbBx, rs_rARM_LR.GetReg());
}
+static bool ArmUseRelativeCall(CompilationUnit* cu, const MethodReference& target_method) {
+ // Emit relative calls only within a dex file due to the limited range of the BL insn.
+ return cu->dex_file == target_method.dex_file;
+}
+
+/*
+ * Bit of a hack here - in the absence of a real scheduling pass,
+ * emit the next instruction in static & direct invoke sequences.
+ */
+static int ArmNextSDCallInsn(CompilationUnit* cu, CallInfo* info,
+ int state, const MethodReference& target_method,
+ uint32_t unused,
+ uintptr_t direct_code, uintptr_t direct_method,
+ InvokeType type) {
+ Mir2Lir* cg = static_cast<Mir2Lir*>(cu->cg.get());
+ if (direct_code != 0 && direct_method != 0) {
+ switch (state) {
+ case 0: // Get the current Method* [sets kArg0]
+ if (direct_code != static_cast<uintptr_t>(-1)) {
+ cg->LoadConstant(cg->TargetPtrReg(kInvokeTgt), direct_code);
+ } else if (ArmUseRelativeCall(cu, target_method)) {
+ // Defer to linker patch.
+ } else {
+ cg->LoadCodeAddress(target_method, type, kInvokeTgt);
+ }
+ if (direct_method != static_cast<uintptr_t>(-1)) {
+ cg->LoadConstant(cg->TargetReg(kArg0, kRef), direct_method);
+ } else {
+ cg->LoadMethodAddress(target_method, type, kArg0);
+ }
+ break;
+ default:
+ return -1;
+ }
+ } else {
+ RegStorage arg0_ref = cg->TargetReg(kArg0, kRef);
+ switch (state) {
+ case 0: // Get the current Method* [sets kArg0]
+ // TUNING: we can save a reg copy if Method* has been promoted.
+ cg->LoadCurrMethodDirect(arg0_ref);
+ break;
+ case 1: // Get method->dex_cache_resolved_methods_
+ cg->LoadRefDisp(arg0_ref,
+ mirror::ArtMethod::DexCacheResolvedMethodsOffset().Int32Value(),
+ arg0_ref,
+ kNotVolatile);
+ // Set up direct code if known.
+ if (direct_code != 0) {
+ if (direct_code != static_cast<uintptr_t>(-1)) {
+ cg->LoadConstant(cg->TargetPtrReg(kInvokeTgt), direct_code);
+ } else if (ArmUseRelativeCall(cu, target_method)) {
+ // Defer to linker patch.
+ } else {
+ CHECK_LT(target_method.dex_method_index, target_method.dex_file->NumMethodIds());
+ cg->LoadCodeAddress(target_method, type, kInvokeTgt);
+ }
+ }
+ break;
+ case 2: // Grab target method*
+ CHECK_EQ(cu->dex_file, target_method.dex_file);
+ cg->LoadRefDisp(arg0_ref,
+ mirror::ObjectArray<mirror::Object>::OffsetOfElement(
+ target_method.dex_method_index).Int32Value(),
+ arg0_ref,
+ kNotVolatile);
+ break;
+ case 3: // Grab the code from the method*
+ if (direct_code == 0) {
+ // kInvokeTgt := arg0_ref->entrypoint
+ cg->LoadWordDisp(arg0_ref,
+ mirror::ArtMethod::EntryPointFromQuickCompiledCodeOffset().Int32Value(),
+ cg->TargetPtrReg(kInvokeTgt));
+ }
+ break;
+ default:
+ return -1;
+ }
+ }
+ return state + 1;
+}
+
+NextCallInsn ArmMir2Lir::GetNextSDCallInsn() {
+ return ArmNextSDCallInsn;
+}
+
+LIR* ArmMir2Lir::CallWithLinkerFixup(const MethodReference& target_method, InvokeType type) {
+ // For ARM, just generate a relative BL instruction that will be filled in at 'link time'.
+ // If the target turns out to be too far, the linker will generate a thunk for dispatch.
+ int target_method_idx = target_method.dex_method_index;
+ const DexFile* target_dex_file = target_method.dex_file;
+
+ // Generate the call instruction and save index, dex_file, and type.
+ // NOTE: Method deduplication takes linker patches into account, so we can just pass 0
+ // as a placeholder for the offset.
+ LIR* call = RawLIR(current_dalvik_offset_, kThumb2Bl, 0,
+ target_method_idx, WrapPointer(const_cast<DexFile*>(target_dex_file)), type);
+ AppendLIR(call);
+ call_method_insns_.push_back(call);
+ return call;
+}
+
+LIR* ArmMir2Lir::GenCallInsn(const MirMethodLoweringInfo& method_info) {
+ LIR* call_insn;
+ if (method_info.FastPath() && ArmUseRelativeCall(cu_, method_info.GetTargetMethod()) &&
+ (method_info.GetSharpType() == kDirect || method_info.GetSharpType() == kStatic) &&
+ method_info.DirectCode() == static_cast<uintptr_t>(-1)) {
+ call_insn = CallWithLinkerFixup(method_info.GetTargetMethod(), method_info.GetSharpType());
+ } else {
+ call_insn = OpReg(kOpBlx, TargetPtrReg(kInvokeTgt));
+ }
+ return call_insn;
+}
+
} // namespace art