• Milad Fa's avatar
    PPC/s390: [ext-code-space] Add InterpreterEntryTrampolineForProfiling builtin · 30d6b245
    Milad Fa authored
    Port 1067c6ac
    
    Original Commit Message:
    
        ... - a code range size agnostic version of InterpreterEntryTrampoline
        builtin. The new builtin is fully compatible with the default version
        and used as a template for creating interpreter entry trampoline
        Code objects when --interpreted-frames-native-stack is enabled.
    
        This CL introduces a new assembler option "position_independent_code"
        which affects the way builtin calls are generated.
        This mode is enabled only for InterpreterEntryTrampolineForProfiling.
    
        Motivation:
    
        * InterpreterEntryTrampoline uses RelocInfo::CODE_TARGET for calling
          other builtins which requires the code range to be small enough to
          allow PC-relative jumps/calls between Code objects. This is the
          reason why --interpreted-frames-native-stack was not supported on
          arm and might not work on arm64 because the code range is bigger
          than the max PC-relative distance for call/jump instructions.
          The new builtin calls other builtins via builtins entry table which
          makes the code fully relocatable and usable for any code range size.
    
        * RelocInfo::CODE_TARGET requires a target code to be materialized
          as a Code object which contradicts the Code-less builtins goal.
    
        * The --interpreted-frames-native-stack is rarely used in the wild but
          we have to pay the price of deserializing InterpreterEntryTrampoline
          builtin as a Code object which consumes address space in the code
          range and thus limits the number of V8 isolates that can be created
          because of code range exhaustion. Now the pointer compression cage
          becomes the limiting factor instead of the code range.
    
        * We can remove complicated logic of Factory::CopyCode() and respective
          support on GC side.
    
    R=ishell@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
    BUG=
    LOG=N
    
    Change-Id: I2ed5edbffc5c33717f4becf8370369f7a4d000fb
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3816765Reviewed-by: 's avatarJunliang Yan <junyan@redhat.com>
    Commit-Queue: Milad Farazmand <mfarazma@redhat.com>
    Cr-Commit-Position: refs/heads/main@{#82317}
    30d6b245
macro-assembler-ppc.cc 140 KB