Microblaze Target: PIC data text relative

2018-04-30 Andrew Sadek  <andrew.sadek.se@gmail.com>

gcc/ChangeLog:
	* config/microblaze/microblaze.opt: add new option -mpic-data-text-rel.
	* config/microblaze/microblaze-protos.h (microblaze_constant_address_p):
	Add declaration.
	* gcc/config/microblaze/microblaze.h (microblaze_constant_address_p):
	CONSTANT_ADDRESS_P definition to microblaze_constant_address_p.
	* config/microblaze/microblaze.c (TARGET_PIC_DATA_TEXT_REL):
	New addressing mode for data-text relative position indepenedent code.
	(microblaze_classify_unspec): add 'UNSPEC_TEXT' case ->
	'ADDRESS_SYMBOLIC_TXT_REL'.
	(microblaze_classify_address): Add handling for UNSPEC + CONST_INT.
	(microblaze_legitimate_pic_operand): Exclude function calls from
	pic operands in case of TARGET_PIC_DATA_TEXT_REL option.
	(microblaze_legitimize_address): Generate 'UNSPEC_TEXT' for all possible
	addresses cases.
	(microblaze_address_insns): Add 'ADDRESS_SYMBOLIC_TXT_REL' case.
	(print_operand): Add 'ADDRESS_SYMBOLIC_TXT_REL' case.
	(print_operand_address): Add 'ADDRESS_SYMBOLIC_TXT_REL' case + handling
	for 'address + offset'.
	(microblaze_expand_prologue): Add new function prologue call for
	'r20' assignation.
	(microblaze_asm_generate_pic_addr_dif_vec): Override new target hook
	'TARGET_ASM_GENERATE_PIC_ADDR_DIFF_VEC' to disable address diff vector
	table in case of TARGET_PIC_DATA_TEXT_REL.
	(expand_pic_symbol_ref): Add handling for 'UNSPEC_TEXT'.
	* gcc/config/microblaze/microblaze.md (TARGET_PIC_DATA_TEXT_REL):
	Add new macros 'UNSPEC_TEXT',
	'UNSPEC_SET_TEXT' + add rule for setting r20 in function prologue
	+ exclude function calls from 'UNSPEC_PLT' in case of data text
	relative mode.
	* doc/tm.texi.in (TARGET_ASM_GENERATE_PIC_ADDR_DIFF_VEC): Add
	new target hook for generating address diff vector tables in case of
	flag_pic.
	* doc/tm.texi : Regenerate.
	* stmt.c (TARGET_ASM_GENERATE_PIC_ADDR_DIFF_VEC): Append new condition
	'targetm.asm_out.generate_pic_addr_diff_vec' to flag_pic in case
	of addr diff vector generation.
	* target.def (TARGET_ASM_GENERATE_PIC_ADDR_DIFF_VEC): Add
	target hook definition.
	* targhooks.h, gcc/targhooks.c (TARGET_ASM_GENERATE_PIC_ADDR_DIFF_VEC):
	Add default function for generate_pic_addr_diff_vec -> flag_pic.
	* doc/invoke.texi (Add new pic option): Add new microblaze pic
	option for data text relative.

testsuite/ChangeLog:
	* gcc.target/microblaze/others/data_var1.c: Include
	PIC case of r20 base register.
	* gcc.target/microblaze/others/data_var2.c: Ditto.
	* gcc.target/microblaze/others/picdtr.c: Add new
	test case for -mpic-is-data-text-relative.
	* gcc.target/microblaze/others/sdata_var1.c: Add
	* gcc.target/microblaze/others/sdata_var2.c: Ditto.
	* gcc.target/microblaze/others/sdata_var3.c: Ditto.
	* gcc.target/microblaze/others/sdata_var4.c: Ditto.
	* gcc.target/microblaze/others/sdata_var5.c: Ditto.
	* gcc.target/microblaze/others/sdata_var6.c: Ditto.
	* gcc.target/microblaze/others/string_cst1_gpopt.c:	Ditto.
	* gcc.target/microblaze/others/string_cst2_gpopt.c: Ditto.

From-SVN: r259758

3 files changed, 18 insertions, 1 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 4441591..e45f467 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -867,7 +867,8 @@ Objective-C and Objective-C++ Dialects}.
 -mmemcpy  -mxl-soft-mul  -mxl-soft-div  -mxl-barrel-shift @gol
 -mxl-pattern-compare  -mxl-stack-check  -mxl-gp-opt  -mno-clearbss @gol
 -mxl-multiply-high  -mxl-float-convert  -mxl-float-sqrt @gol
--mbig-endian  -mlittle-endian  -mxl-reorder  -mxl-mode-@var{app-model}}
+-mbig-endian  -mlittle-endian  -mxl-reorder  -mxl-mode-@var{app-model}
+-mpic-data-is-text-relative}
 
 @emph{MIPS Options}
 @gccoptlist{-EL  -EB  -march=@var{arch}  -mtune=@var{arch} @gol
@@ -20113,6 +20114,12 @@ Select application model @var{app-model}.  Valid models are
 @item executable
 normal executable (default), uses startup code @file{crt0.o}.
 
+@item -mpic-data-is-text-relative
+@opindex mpic-data-is-text-relative
+Assume that the displacement between the text and data segments is fixed
+at static link time.  This allows data to be referenced by offset from start of
+text address instead of GOT since PC-relative addressing is not supported.
+
 @item xmdstub
 for use with Xilinx Microprocessor Debugger (XMD) based
 software intrusive debug agent called xmdstub. This uses startup file
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index bd8b917..9d92ed1 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -7491,6 +7491,14 @@ when the target cannot support (some kinds of) dynamic relocations
 in read-only sections even in executables.
 @end deftypefn
 
+@deftypefn {Target Hook} bool TARGET_ASM_GENERATE_PIC_ADDR_DIFF_VEC (void)
+Return true to generate ADDR_DIF_VEC table
+or false to generate ADDR_VEC table for jumps in case of -fPIC.
+
+The default version of this function returns true if flag_pic
+equals true and false otherwise
+@end deftypefn
+
 @deftypefn {Target Hook} {section *} TARGET_ASM_SELECT_SECTION (tree @var{exp}, int @var{reloc}, unsigned HOST_WIDE_INT @var{align})
 Return the section into which @var{exp} should be placed.  You can
 assume that @var{exp} is either a @code{VAR_DECL} node or a constant of
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index b020714..5732a2a 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -4922,6 +4922,8 @@ This macro is irrelevant if there is no separate readonly data section.
 
 @hook TARGET_ASM_RELOC_RW_MASK
 
+@hook TARGET_ASM_GENERATE_PIC_ADDR_DIFF_VEC
+
 @hook TARGET_ASM_SELECT_SECTION
 
 @defmac USE_SELECT_SECTION_FOR_FUNCTIONS