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Unified Diff: src/arm/fast-codegen-arm.cc

Issue 354024: Emitting the common return sequence in the top-level compiler in one function... (Closed) Base URL: http://v8.googlecode.com/svn/branches/bleeding_edge/
Patch Set: '' Created 11 years, 1 month ago
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Index: src/arm/fast-codegen-arm.cc
===================================================================
--- src/arm/fast-codegen-arm.cc (revision 3211)
+++ src/arm/fast-codegen-arm.cc (working copy)
@@ -102,26 +102,51 @@
// body.
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
}
- { Comment cmnt(masm_, "Return sequence");
- if (return_label_.is_bound()) {
- __ b(&return_label_);
- } else {
- __ bind(&return_label_);
- SetReturnPosition(fun);
- if (FLAG_trace) {
- // Push the return value on the stack as the parameter.
- // Runtime::TraceExit returns its parameter in r0.
- __ push(r0);
- __ CallRuntime(Runtime::kTraceExit, 1);
- }
- __ RecordJSReturn();
- __ mov(sp, fp);
- __ ldm(ia_w, sp, fp.bit() | lr.bit());
- int num_parameters = function_->scope()->num_parameters();
- __ add(sp, sp, Operand((num_parameters + 1) * kPointerSize));
- __ Jump(lr);
+ EmitReturnSequence(function_->end_position());
+}
+
+
+void FastCodeGenerator::EmitReturnSequence(int position) {
+ Comment cmnt(masm_, "[ Return sequence");
+ if (return_label_.is_bound()) {
+ __ b(&return_label_);
+ } else {
+ __ bind(&return_label_);
+ if (FLAG_trace) {
+ // Push the return value on the stack as the parameter.
+ // Runtime::TraceExit returns its parameter in r0.
+ __ push(r0);
+ __ CallRuntime(Runtime::kTraceExit, 1);
}
+#ifdef DEBUG
+ // Add a label for checking the size of the code used for returning.
+ Label check_exit_codesize;
+ masm_->bind(&check_exit_codesize);
+#endif
+ CodeGenerator::RecordPositions(masm_, position);
+ __ RecordJSReturn();
+ __ mov(sp, fp);
+ __ ldm(ia_w, sp, fp.bit() | lr.bit());
+ int num_parameters = function_->scope()->num_parameters();
+ __ add(sp, sp, Operand((num_parameters + 1) * kPointerSize));
+ __ Jump(lr);
}
+#ifdef DEBUG
+ // Check that the size of the code used for returning matches what is
+ // expected by the debugger. The add instruction above is an addressing
+ // mode 1 instruction where there are restrictions on which immediate values
+ // can be encoded in the instruction and which immediate values requires
+ // use of an additional instruction for moving the immediate to a temporary
+ // register.
+ int expected_return_sequence_length = CodeGenerator::kJSReturnSequenceLength;
+ if (!masm_->ImmediateFitsAddrMode1Instruction((num_parameters + 1) *
+ kPointerSize)) {
+ // Additional mov instruction generated.
+ expected_return_sequence_length++;
+ }
+ ASSERT_EQ(expected_return_sequence_length,
+ masm_->InstructionsGeneratedSince(&check_exit_codesize));
+#endif
}
@@ -259,7 +284,6 @@
void FastCodeGenerator::VisitReturnStatement(ReturnStatement* stmt) {
Comment cmnt(masm_, "[ ReturnStatement");
- SetStatementPosition(stmt);
Expression* expr = stmt->expression();
// Complete the statement based on the type of the subexpression.
if (expr->AsLiteral() != NULL) {
@@ -269,21 +293,7 @@
Visit(expr);
__ pop(r0);
}
- if (return_label_.is_bound()) {
- __ b(&return_label_);
- } else {
- __ bind(&return_label_);
- if (FLAG_trace) {
- __ push(r0);
- __ CallRuntime(Runtime::kTraceExit, 1);
- }
- __ RecordJSReturn();
- __ mov(sp, fp);
- __ ldm(ia_w, sp, fp.bit() | lr.bit());
- int num_parameters = function_->scope()->num_parameters();
- __ add(sp, sp, Operand((num_parameters + 1) * kPointerSize));
- __ Jump(lr);
- }
+ EmitReturnSequence(stmt->statement_pos());
}
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