ChangeLog

2016-01-08  Filip Pizlo  <fpizlo@apple.com>

        FTL B3 fails to realize that binary snippets might choose to omit their fast path

        https://bugs.webkit.org/show_bug.cgi?id=152901

        Reviewed by NOBODY (OOPS!).

        This reduces the number of failures from 99 to 35.

        * ftl/FTLLowerDFGToLLVM.cpp:

        (JSC::FTL::DFG::LowerDFGToLLVM::emitBinarySnippet):

2016-01-08  Saam barati  <sbarati@apple.com>

        restoreCalleeSavesFromVMCalleeSavesBuffer should use the scratch register

194772

Source/JavaScriptCore/ftl/FTLLowerDFGToLLVM.cpp

@@private:

                Box<CCallHelpers::JumpList> exceptions =

                    exceptionHandle->scheduleExitCreation(params)->jumps(jit);

7577

                auto generator = Box<BinaryArithOpGenerator>::create(

                    leftOperand, rightOperand, JSValueRegs(params[0].gpr()),

                    JSValueRegs(params[1].gpr()), JSValueRegs(params[2].gpr()),

@@private:

                    scratchFPRUsage == NeedScratchFPR ? params.fpScratch(2) : InvalidFPRReg);

                generator->generateFastPath(jit);

7585 generator->endJumpList().link(&jit);

7586 CCallHelpers::Label done = jit.label();

75877585

                params.addLatePath(

                    [=] (CCallHelpers& jit) {

                        AllowMacroScratchRegisterUsage allowScratch(jit);

                if (generator->didEmitFastPath()) {

                    generator->endJumpList().link(&jit);

                    CCallHelpers::Label done = jit.label();

                    params.addLatePath(

                        [=] (CCallHelpers& jit) {

                            AllowMacroScratchRegisterUsage allowScratch(jit);

75917593

                        generator->slowPathJumpList().link(&jit);

                        callOperation(

                            *state, params.unavailableRegisters(), jit, node->origin.semantic,

                            exceptions.get(), slowPathFunction, params[0].gpr(),

                            params[1].gpr(), params[2].gpr());

                        jit.jump().linkTo(done, &jit);

                    });

                            generator->slowPathJumpList().link(&jit);

                            callOperation(

                                *state, params.unavailableRegisters(), jit, node->origin.semantic,

                                exceptions.get(), slowPathFunction, params[0].gpr(),

                                params[1].gpr(), params[2].gpr());

                            jit.jump().linkTo(done, &jit);

                        });

                } else {

                    callOperation(

                        *state, params.unavailableRegisters(), jit, node->origin.semantic,

                        exceptions.get(), slowPathFunction, params[0].gpr(), params[1].gpr(),

                        params[2].gpr());

                }

            });

        setJSValue(patchpoint);

194748