2017-07-07 18:31 GMT+04:00 Georg-Johann Lay <a...@gjlay.de>: > Hi, > > this patch addresses a very old issue, the non-optimal > generation of ISR prologues and epilogues. > > As GAS now provides the __gcc_isr pseudo instruction to > overcome some problems, see > > https://sourceware.org/bugzilla/show_bug.cgi?id=21683 > > this can now be used to address PR20296. > > > This patch does: > > * Add a configure test if GAS supports __gcc_isr and -mgcc-isr. > > * Add new option -mgas-isr-prologues to switch on / off > generating of __gcc_isr in ISR prologues / epilogues. > > * Switch on the feature per default except for -O0 and -Og. > > * Add a new no_gccisr function attribute to disable __gcc_isr > generation for individual ISRs. > > * Add a new pass .avr-gasisr that filters out situations where > __gcc_isr is not appropriate. > > * Extend prologue and epilogue generation to emit __gcc_isr chunks > during prologue and epilogue(s). > > * Implement final_postscan_insn to emit final __gcc_isr Done chunk. > > * Add -mgcc-isr to ASM_SPEC if appropriate. > > > We currently have only 3 torture tests for ISRs, namely > > gcc.target/avr/torture/isr-*.c > > All these tests PASS when > > * Run with -mgas-isr-prologues > * Run with -mno-gas-isr-prologues > * Run for: atmega8 atmega64 atmega103 atmega2560 atmega128 atxmega128a1 > attiny40 > > Ok for trunk?
Please apply. > > Johann > > PR target/20296 > PR target/81268 > * configure.ac [target=avr]: Add GAS check for -mgcc-isr. > (HAVE_AS_AVR_MGCCISR_OPTION): If so, AC_DEFINE it. > * config.in: Regenerate. > * configure: Regenerate. > > * doc/extend.texi (AVR Function Attributes) <no_gccisr>: Document > it. > * doc/invoke.texi (AVR Options) <-mgas-isr-prologues>: Document it. > > * config/avr/avr.opt (-mgas-isr-prologues): New option and... > (TARGET_GASISR_PROLOGUES): ...target mask. > * common/config/avr/avr-common.c > (avr_option_optimization_table) [OPT_LEVELS_1_PLUS_NOT_DEBUG]: > Set -mgas-isr-prologues. > * config/avr/avr-passes.def (avr_pass_maybe_gasisr): Add > INSERT_PASS_BEFORE for it. > * config/avr/avr-protos.h (make_avr_pass_maybe_gasisr): New proto. > * config/avr/avr.c (avr_option_override) > [!HAVE_AS_AVR_MGCCISR_OPTION]: Unset TARGET_GASISR_PROLOGUES. > (avr_no_gccisr_function_p, avr_hregs_split_lsb): New static > functions. > (avr_attribute_table) <no_gccisr>: Add new function attribute. > (avr_set_current_function) <is_no_gccisr>: Init machine field. > (avr_pass_data_gasisr, avr_pass_maybe_gasisr): New pass data > and rtl_opt_pass. > (make_avr_pass_maybe_gasisr): New function. > (emit_push_sfr) <treg>: Add argument to function and use it > instead of TMP_REG. > (avr_expand_prologue) [machine->gasisr.maybe]: Emit gasisr insn > and set machine->gasisr.yes. > (avr_expand_epilogue) [machine->gasisr.yes]: Similar. > (avr_asm_function_end_prologue) [machine->gasisr.yes]: Add > __gcc_isr.n_pushed to .L__stack_usage. > (TARGET_ASM_FINAL_POSTSCAN_INSN): Define to... > (avr_asm_final_postscan_insn): ...this new static function. > * config/avr/avr.h (machine_function) > <is_no_gccisr, use_L__stack_usage>: New fields. > <gasisr, gasisr.yes, gasisr.maybe, gasisr.regno>: New fields. > * config/avr/avr.md (UNSPECV_GASISR): Add unspecv enum. > (GASISR_Prologue, GASISR_Epilogue, GASISR_Done): New > define_constants. > (gasisr, *gasisr): New expander and insn. > * config/avr/gen-avr-mmcu-specs.c (print_mcu) > [HAVE_AS_AVR_MGCCISR_OPTION]: Print asm_gccisr spec. > * config/avr/specs.h (ASM_SPEC) <asm_gccisr>: Add sub spec.
