Reviewers: Kevin Millikin, fschneider, Message: Tested on all platorms. Strangely, on ARM, the TestValue context seems not to be propagated to the variable loads of y and z in z = (x ? y : z) && (!x ? y : z)
The ToBoolean call occurs after the control flow merge in the first ternary operator, not before it. This seems wrong (more efficient, but wrong). Description: Add conditional expressions (ternary choice operator) to fast compiler. Please review this at http://codereview.chromium.org/340058 SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/ Affected files: M src/compiler.cc M src/fast-codegen.cc Index: src/compiler.cc =================================================================== --- src/compiler.cc (revision 3191) +++ src/compiler.cc (working copy) @@ -625,7 +625,11 @@ void CodeGenSelector::VisitConditional(Conditional* expr) { - BAILOUT("Conditional"); + ProcessExpression(expr->condition(), Expression::kTest); + CHECK_BAILOUT; + ProcessExpression(expr->then_expression(), context_); + CHECK_BAILOUT; + ProcessExpression(expr->else_expression(), context_); } Index: src/fast-codegen.cc =================================================================== --- src/fast-codegen.cc (revision 3191) +++ src/fast-codegen.cc (working copy) @@ -380,7 +380,36 @@ void FastCodeGenerator::VisitConditional(Conditional* expr) { - UNREACHABLE(); + ASSERT_EQ(Expression::kTest, expr->condition()->context()); + ASSERT_EQ(expr->context(), expr->then_expression()->context()); + ASSERT_EQ(expr->context(), expr->else_expression()->context()); + + + Label true_case, false_case, done; + Label* saved_true = true_label_; + Label* saved_false = false_label_; + + true_label_ = &true_case; + false_label_ = &false_case; + Visit(expr->condition()); + true_label_ = saved_true; + false_label_ = saved_false; + + __ bind(&true_case); + Visit(expr->then_expression()); + // If control flow falls through Visit, jump to done. + if (expr->context() == Expression::kEffect || + expr->context() == Expression::kValue) { + __ jmp(&done); + } + + __ bind(&false_case); + Visit(expr->else_expression()); + // If control flow falls through Visit, merge it with true case here. + if (expr->context() == Expression::kEffect || + expr->context() == Expression::kValue) { + __ bind(&done); + } } --~--~---------~--~----~------------~-------~--~----~ v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev -~----------~----~----~----~------~----~------~--~---
