sh.c (SH_ATTRIBUTES): Define.

	* config/sh/sh.c (SH_ATTRIBUTES): Define.
	(SYMBOL_FLAG_FUNCVEC_FUNCTION): Define.
	(print_operand): Handle resbank in %@ operand code.
	(sh_encode_section_info): New.
	(push_regs): Add conditions for resbank.
	(sh_expand_epilogue): Likewise.
	(sh_insert_attributes): Likewise.
	(sh_attribute_table): Likewise.
	(sh_handle_resbank_handler_attribute): New.
	(sh2a_handle_function_vector_handler_attribute): New.
	(sh2a_is_function_vector_call): New.
	(sh2a_get_function_vector_number): New.
	(sh2a_function_vector_p): New.
	(sh_cfun_resbank_handler_p): New.
	* config/sh/sh.md (calli): Emit jsr/n if possible.
	(calli_tbr_rel): New.
	(calli_pcrel): Emit jsr/n if possible.
	(return_i): Emit rts/n if possible.
	(call_valuei_tbr_rel): New.
	(call_valuei_pcrel): Add condition for SH2A target.
	(call_value): Likewise.
	* config/sh/sh-protos.h (sh_cfun_resbank_handler_p): Declare.
	(sh2a_get_function_vector_number): Likewise.
	(sh2a_is_function_vector_call): Likewise.
	* doc/extend.texi: Document TBR relative addressing of SH2A.
	(resbank): Add description for SH2A.

	* gcc.target/sh/sh2a-resbank.c: New test.
	* gcc.target/sh/sh2a-tbr-jump.c: New test.
	* gcc.target/sh/sh2a-jsrn.c: New test.
	* gcc.target/sh/sh2a-rtsn.c: New test.


Co-Authored-By: Jayant R Sonar <jayant.sonar@kpitcummins.com>
Co-Authored-By: Naveen.H.S <naveen.hs@kpitcummins.com>

From-SVN: r133513

1 files changed, 31 insertions, 1 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index b28d9df..1fa7fc2 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -2299,16 +2299,33 @@ is used.  @xref{C Dialect Options,,Options
 Controlling C Dialect}.
 
 @item function_vector
-@cindex calling functions through the function vector on H8/300, M16C, and M32C processors
+@cindex calling functions through the function vector on H8/300, M16C, M32C and SH2A processors
 Use this attribute on the H8/300, H8/300H, and H8S to indicate that the specified
 function should be called through the function vector.  Calling a
 function through the function vector will reduce code size, however;
 the function vector has a limited size (maximum 128 entries on the H8/300
 and 64 entries on the H8/300H and H8S) and shares space with the interrupt vector.
 
+In SH2A target, this attribute declares a function to be called using the
+TBR relative addressing mode.  The argument to this attribute is the entry
+number of the same function in a vector table containing all the TBR
+relative addressable functions.  For the successful jump, register TBR
+should contain the start address of this TBR relative vector table.
+In the startup routine of the user application, user needs to care of this
+TBR register initialization.  The TBR relative vector table can have at
+max 256 function entries.  The jumps to these functions will be generated
+using a SH2A specific, non delayed branch instruction JSR/N @@(disp8,TBR).
 You must use GAS and GLD from GNU binutils version 2.7 or later for
 this attribute to work correctly.
 
+Please refer the example of M16C target, to see the use of this
+attribute while declaring a function,
+
+In an application, for a function being called once, this attribute will
+save at least 8 bytes of code; and if other successive calls are being
+made to the same function, it will save 2 bytes of code per each of these
+calls.
+
 On M16C/M32C targets, the @code{function_vector} attribute declares a
 special page subroutine call function. Use of this attribute reduces
 the code size by 2 bytes for each call generated to the
@@ -2722,6 +2739,19 @@ number of registers available if used in conjunction with the
 attribute is incompatible with nested functions; this is considered a
 hard error.
 
+@item resbank
+@cindex @code{resbank} attribute
+On the SH2A target, this attribute enables the high-speed register
+saving and restoration using a register bank for @code{interrupt_handler}
+routines.  Saving to the bank is performed automatcially after the CPU
+accepts an interrupt that uses a register bank.
+
+The nineteen 32-bit registers comprising general register R0 to R14,
+control register GBR, and system registers MACH, MACL, and PR and the
+vector table address offset are saved into a register bank.  Register
+banks are stacked in first-in last-out (FILO) sequence.  Restoration
+from the bank is executed by issuing a RESBANK instruction.
+
 @item returns_twice
 @cindex @code{returns_twice} attribute
 The @code{returns_twice} attribute tells the compiler that a function may