invoke.texi (SPARC options): Add -mflat.

gcc/
	* doc/invoke.texi (SPARC options): Add -mflat.
	* config/sparc/sparc.opt: Likewise.
	* config/sparc/sparc-protos.h (sparc_expand_epilogue): Add parameter.
	(sparc_flat_expand_prologue): Declare.
	(sparc_flat_expand_epilogue): Likewise.
	* config/sparc/sparc.h (CPP_CPU_SPEC): Do not handle -msoft-float.
	(CPP_ENDIAN_SPEC): Replace with...
	(CPP_OTHER_SPEC): ...this.  Also handle -mflat and -msoft-float.
	(CPP_SPEC): Adjust to above change.
	(EXTRA_SPECS): Likewise.
	(SPARC_INCOMING_INT_ARG_FIRST): Add TARGET_FLAT handling.
	(INCOMING_REGNO): Likewise.
	(OUTGOING_REGNO): Likewise.
	(LOCAL_REGNO): Likewise.
	(SETUP_FRAME_ADDRESSES): Likewise.
	(FIXED_REGISTERS): Set 0 for %fp.
	(CALL_USED_REGISTERS): Likewise.
	(INITIAL_ELIMINATION_OFFSET): Pass current_function_is_leaf.
	(EXIT_IGNORE_STACK): Define to 1 unconditionally.
	(RETURN_ADDR_REGNUM): Define.
	(RETURN_ADDR_RTX): Use it.
	(INCOMING_RETURN_ADDR_REGNUM): Define.
	(INCOMING_RETURN_ADDR_RTX): Use it.
	(DWARF_FRAME_RETURN_COLUMN): Likewise.
	(EH_RETURN_REGNUM): Define.
	(EH_RETURN_STACKADJ_RTX): Use it.
	(EH_RETURN_HANDLER_RTX): Delete.
	(EPILOGUE_USES): Use them and add TARGET_FLAT handling.
	* config/sparc/sparc.c (apparent_fsize, actual_fsize, num_gfregs):
	Delete.
	(struct machine_function): Add frame_size, apparent_frame_size,
	frame_base_reg, frame_base_offset, n_global_fp_regs and
	save_local_in_regs_p fields.
	(sparc_frame_size, sparc_apparent_frame_size, sparc_frame_base_reg,
	sparc_frame_base_offset, sparc_n_global_fp_regs,
	sparc_save_local_in_regs_p): New macros.
	(sparc_option_override): Error out if -fcall-saved-REG is specified
	for Out registers.
	(eligible_for_restore_insn): Fix formatting.
	(eligible_for_return_delay): Likewise.  Add TARGET_FLAT handling.
	(eligible_for_sibcall_delay): Likewise.
	(RTX_OK_FOR_OFFSET_P, RTX_OK_FOR_OLO10_P): Add MODE parameter.
	(sparc_legitimate_address_p): Adjust to above change.
	(save_global_or_fp_reg_p): New predicate.
	(return_addr_reg_needed_p): Likewise.
	(save_local_or_in_reg_p): Likewise.
	(sparc_compute_frame_size): Use them.  Add TARGET_FLAT handling.
	(SORR_SAVE, SORR_RESTORE): Delete.
	(sorr_pred_t): New typedef.
	(sorr_act_t): New enum.
	(save_or_restore_regs): Rename to...
	(emit_save_or_restore_regs): ...this.  Change type of LOW and HIGH
	parameters, remove ACTION parameter, add LEAF_FUNCTION_P, SAVE_P,
	ACTION_TRUE and ACTION_FALSE parameters.  Implement more general
	mechanism.  Add CFI information for double-word saves in 32-bit mode.
	(emit_adjust_base_to_offset): New function extracted from...
	(emit_save_or_restore_regs): ...this.  Rename the rest to...
	(emit_save_or_restore_regs_global_fp_regs): ...this.
	(emit_save_or_restore_regs_local_in_regs): New function.
	(gen_create_flat_frame_[123]): New functions.
	(sparc_expand_prologue): Use SIZE local variable.  Adjust.
	(sparc_flat_expand_prologue): New function.
	(sparc_asm_function_prologue): Add TARGET_FLAT handling.
	(sparc_expand_epilogue): Use SIZE local variable.  Adjust.
	(sparc_flat_expand_epilogue): New function.
	(sparc_can_use_return_insn_p): Add TARGET_FLAT handling.
	(output_return): Likewise.
	(output_sibcall): Likewise.
	(sparc_output_mi_thunk): Likewise.
	(sparc_frame_pointer_required): Likewise.
	(sparc_conditional_register_usage): If TARGET_FLAT, disable the leaf
	function optimization.
	* config/sparc/sparc.md (flat): New attribute.
	(prologue): Add TARGET_FLAT handling.
	(save_register_window): Disable if TARGET_FLAT.
	(create_flat_frame_[123]): New patterns.
	(epilogue): Add TARGET_FLAT handling.
	(sibcall_epilogue): Likewise.
	(eh_return): New expander.
	(eh_return_internal): New insn and splitter.
	(return_internal): Add TARGET_FLAT handling.
	(untyped_return): Remove bogus test and use RETURN_ADDR_REGNUM.
	(save_stack_nonlocal): Use RETURN_ADDR_REGNUM.
	(nonlocal_goto): Add TARGET_FLAT handling.
	* config/sparc/t-elf: Add -mflat multilib.
	* config/sparc/t-leon: Likewise.
libgcc/
	* config/sparc/linux-unwind.h (STACK_BIAS): Define.
	(sparc64_fallback_frame_state): Use it.
	(sparc64_frob_update_context): Further adjust context.
	* config/sparc/sol2-unwind.h (sparc64_frob_update_context): Likewise.
	* config/sparc/sol2-ci.S: Add TARGET_FLAT handling.
	* config/sparc/sol2-cn.S: Likewise.

Co-Authored-By: Laurent Rougé <laurent.rouge@menta.fr>

From-SVN: r174897

1 files changed, 14 insertions, 1 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 0069f78..fee3a2f 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -863,7 +863,7 @@ See RS/6000 and PowerPC Options.
 -mtune=@var{cpu-type} @gol
 -mcmodel=@var{code-model} @gol
 -m32  -m64  -mapp-regs  -mno-app-regs @gol
--mfaster-structs  -mno-faster-structs @gol
+-mfaster-structs  -mno-faster-structs  -mflat  -mno-flat @gol
 -mfpu  -mno-fpu  -mhard-float  -msoft-float @gol
 -mhard-quad-float  -msoft-quad-float @gol
 -mlittle-endian @gol
@@ -17043,6 +17043,19 @@ To be fully SVR4 ABI compliant at the cost of some performance loss,
 specify @option{-mno-app-regs}.  You should compile libraries and system
 software with this option.
 
+@item -mflat
+@itemx -mno-flat
+@opindex mflat
+@opindex mno-flat
+With @option{-mflat}, the compiler does not generate save/restore instructions
+and uses a ``flat'' or single register window model.  This model is compatible
+with the regular register window model.  The local registers and the input
+registers (0--5) are still treated as ``call-saved'' registers and will be
+saved on the stack as needed.
+
+With @option{-mno-flat} (the default), the compiler generates save/restore
+instructions (except for leaf functions).  This is the normal operating mode.
+
 @item -mfpu
 @itemx -mhard-float
 @opindex mfpu