Implement call0 ABI for xtensa

Programming / Compilers / GCC - jcmvbkbc [138bc75d-0d04-0410-961f-82ee72b054a4] - 3 March 2015 11:44 UTC

call0 is an ABI that doesn't use register windows.

2015-03-03 Max Filippov

gcc/
- config/xtensa/constraints.md ("a" constraint): Include stack pointer in case of call0 ABI. ("q" constraint): Make empty in case of call0 ABI. ("D" constraint): Include stack pointer in case of call0 ABI.
- config/xtensa/xtensa-protos.h (xtensa_set_return_address, xtensa_expand_epilogue, xtensa_regno_to_class): Add new function prototypes.
- config/xtensa/xtensa.c (xtensa_callee_save_size): New
variable. (xtensa_regno_to_class): Make it a local variable in the function xtensa_regno_to_class. (xtensa_function_epilogue, TARGET_ASM_FUNCTION_EPILOGUE): Remove macro, function prototype and implementation. (reg_nonleaf_alloc_order): Make it a local variable in the function order_regs_for_local_alloc. (xtensa_conditional_register_usage): New function. (TARGET_CONDITIONAL_REGISTER_USAGE): Define macro. (xtensa_valid_move): Allow direct moves to stack pointer register in call0 ABI. (xtensa_setup_frame_addresses): Only spill register windows in windowed ABI. (xtensa_emit_call): Emit call(x)8 or call(x)0 in windowed and call0 ABI respectively. (xtensa_function_arg_1): Only mark a7 register for copying in windowed ABI. (xtensa_call_save_reg): New function. (compute_frame_size): Add space for callee saved register storage to the frame size in call0 ABI. (xtensa_expand_prologue): Generate code to set up stack frame and save callee-saved registers in call0 ABI. (xtensa_expand_epilogue): New function. (xtensa_set_return_address): New function. (xtensa_return_addr): Calculate return address in call0 ABI. (xtensa_builtin_saveregs): Only mark a7 register for copying and emit copying code in windowed ABI. (order_regs_for_local_alloc): Add preferred register allocation order for non-leaf function in call0 ABI. (xtensa_static_chain): Add atatic chain passing for call0 ABI. (xtensa_asm_trampoline_template): Add trampoline generation for call0 ABI. (xtensa_trampoline_init): Add trampoline initialization for call0 ABI. (xtensa_conditional_register_usage, xtensa_regno_to_class): New functions.
- config/xtensa/xtensa.h (TARGET_WINDOWED_ABI): New macro. (TARGET_CPU_CPP_BUILTINS): Add built-in define for call0 ABI. (CALL_USED_REGISTERS): Modify to encode both windowed and call0 ABI call-used registers. (HARD_FRAME_POINTER_REGNUM): Add frame pointer for call0 ABI. (INCOMING_REGNO, OUTGOING_REGNO): Use argument unchanged in call0 ABI. (REG_CLASS_CONTENTS): Include all registers into the preferred reload registers set, adjust the set in the xtensa_conditional_register_usage. (xtensa_regno_to_class): Drop variable declaration. (REGNO_REG_CLASS): Redefine to use xtensa_regno_to_class function. (WINDOW_SIZE): Define as 8 or 0 for windowed and call0 ABI respectively. (FUNCTION_PROFILER): Add _mcount call for call0 ABI. (TRAMPOLINE_SIZE): Define trampoline size for call0 ABI. (RETURN_ADDR_IN_PREVIOUS_FRAME): Define to 0 in call0 ABI. (ASM_OUTPUT_POOL_PROLOGUE): Always generate literal pool location in call0 ABI. (EH_RETURN_STACKADJ_RTX): New definition, use a10 for passing stack adjustment size when handling exception. (CRT_CALL_STATIC_FUNCTION): Add definition for call0 ABI.
- config/xtensa/xtensa.md (A9_REG, UNSPECV_BLOCKAGE): New definitions. ("return" pattern): Generate ret.n/ret in call0 ABI. ("epilogue" pattern): Expand epilogue. ("nonlocal_goto" pattern): Use default in call0 ABI. ("eh_return" pattern): Move implementation to eh_set_a0_windowed, emit eh_set_a0_* depending on ABI. ("eh_set_a0_windowed" pattern): Former eh_return pattern. ("eh_set_a0_call0", "blockage"): New patterns.

libgcc/
- config/xtensa/lib2funcs.S (__xtensa_libgcc_window_spill, __xtensa_nonlocal_goto): Don't compile for call0 ABI. (__xtensa_sync_caches): Only use entry and retw in windowed ABI, use ret in call0 ABI.
- config/xtensa/t-windowed: New file.
- libgcc/config/xtensa/t-xtensa (LIB2ADDEH): Move to t-windowed.
- libgcc/configure: Regenerated.
- libgcc/configure.ac: Check if xtensa target is configured for windowed ABI and thus needs to use custom unwind code.

b89c671 Implement call0 ABI for xtensa
gcc/ChangeLog | 80 +++++
gcc/config/xtensa/constraints.md | 6 +-
gcc/config/xtensa/xtensa-protos.h | 3 +
gcc/config/xtensa/xtensa.c | 561 +++++++++++++++++++++++++++--------
gcc/config/xtensa/xtensa.h | 67 +++--
gcc/config/xtensa/xtensa.md | 48 ++-
libgcc/ChangeLog | 13 +
libgcc/config/xtensa/lib2funcs.S | 10 +
libgcc/config/xtensa/linux-unwind.h | 3 +
libgcc/config/xtensa/t-windowed | 2 +
libgcc/config/xtensa/t-xtensa | 3 -
libgcc/configure | 21 ++
libgcc/configure.ac | 16 +
13 files changed, 679 insertions(+), 154 deletions(-)

Upstream: gcc.gnu.org

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