* configure.in: Check whether assembler supports section merging.

	* config.in: Rebuilt.
	* configure: Rebuilt.
	* varasm.c (variable_section, output_constant_pool): Pass alignment
	to SELECT_SECTION and SELECT_RTX_SECTION.
	(mergeable_string_section): New.
	(mergeable_constant_section): New.
	(default_elf_asm_named_section): Output SECTION_MERGE and
	SECTION_STRINGS flags plus SECTION_ENTSIZE entity size.
	* output.h (mergeable_string_section): New.
	(mergeable_constant_section): New.
	(SECTION_MERGE, SECTION_STRINGS, SECTION_ENTSIZE): Define.
	* toplev.c (flag_merge_constants): New.
	(f_options): Add -fmerge-constants and -fmerge-all-constants
	options.
	(toplev_main): Default to -fno-merge-constants if not optimizing.
	* flags.h (flag_merge_constants): Add extern.
	* invoke.texi (-fmerge-constants, -fmerge-all-constants): Document.
	* tm.texi (SELECT_SECTION, SELECT_RTX_SECTION): Document added third
	argument.
	* config/elfos.h (ASM_SECTION_START_OP, ASM_OUTPUT_SECTION_START):
	Define if assembler has working .subsection -1 support.
	(SELECT_RTX_SECTION, SELECT_SECTION): Add third macro argument.
	Put constant into special SHF_MERGE sections if the linker should
	attempt to merge duplicates.
	* config/ia64/sysv4.h (SELECT_RTX_SECTION, SELECT_SECTION): Add third
	macro argument.
	Put constant into special SHF_MERGE sections if the linker should
	attempt to merge duplicates.
	* config/alpha/elf.h: Likewise.
	(ASM_SECTION_START_OP, ASM_OUTPUT_SECTION_START): Define if assembler
	has working .subsection -1 support.
	* config/nextstep.h: Add third argument to SELECT_RTX_SECTION and
	SELECT_SECTION.
	* config/svr3.h: Likewise.
	* config/darwin.h: Likewise.
	* config/arm/aof.h: Likewise.
	* config/arm/linux-elf.h: Likewise.
	* config/avr/avr.h: Likewise.
	* config/c4x/c4x.h: Likewise.
	* config/d30v/d30v.h: Likewise.
	* config/i386/dgux.h: Likewise.
	* config/i386/osfrose.h: Likewise.
	* config/i386/sco5.h: Likewise.
	* config/i386/svr3gas.h: Likewise.
	* config/ia64/aix.h: Likewise.
	* config/m32r/m32r.h: Likewise.
	* config/m68k/m68k.h: Likewise.
	* config/m88k/dgux.h: Likewise.
	* config/m88k/m88k.h: Likewise.
	* config/mcore/mcore-pe.h: Likewise.
	* config/mips/mips.h: Likewise.
	* config/pa/pa.h: Likewise.
	* config/pa/pa-linux.h: Likewise.
	* config/romp/romp.h: Likewise.
	* config/rs6000/sysv4.h: Likewise.
	* config/rs6000/xcoff.h: Likewise.
	* config/s390/linux.h: Likewise.
	* config/sparc/sparc.h: Likewise.
	* config/sparc/sysv4.h: Likewise.
	* config/stormy16/stormy16.h: Likewise.
	* config/v850/v850.h: Likewise.
	* config/vax/vms.h: Likewise.
	* config/arm/arm.c (arm_elf_asm_named_section): Output SECTION_MERGE
	and SECTION_STRINGS flags plus SECTION_ENTSIZE entity size.
	* config/sparc/sparc.c (sparc_elf_asm_named_section): Use
	default_elf_asm_named_section for SHF_MERGE sections.

	* com.c (ffe_init_options): Default to -fmerge-all-constants
	if optimizing.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@45548 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 14 insertions, 7 deletions

diff --git a/gcc/config/ia64/sysv4.h b/gcc/config/ia64/sysv4.h
index 0abb7e8cd7e..54b5167363e 100644
--- a/gcc/config/ia64/sysv4.h
+++ b/gcc/config/ia64/sysv4.h
@@ -138,12 +138,12 @@ do {									\
 /* We override svr4.h so that we can support the sdata section.  */
 
 #undef SELECT_SECTION
-#define SELECT_SECTION(DECL,RELOC)					\
+#define SELECT_SECTION(DECL,RELOC,ALIGN)				\
 {									\
   if (TREE_CODE (DECL) == STRING_CST)					\
     {									\
       if (! flag_writable_strings)					\
-	const_section ();						\
+	mergeable_string_section ((DECL), (ALIGN), 0);			\
       else								\
 	data_section ();						\
     }									\
@@ -152,13 +152,20 @@ do {									\
       if (XSTR (XEXP (DECL_RTL (DECL), 0), 0)[0]			\
 	  == SDATA_NAME_FLAG_CHAR)					\
         sdata_section ();						\
-      /* ??? We need the extra ! RELOC check, because the default is to \
+      /* ??? We need the extra RELOC check, because the default is to	\
 	 only check RELOC if flag_pic is set, and we don't set flag_pic \
 	 (yet?).  */							\
-      else if (DECL_READONLY_SECTION (DECL, RELOC) && ! (RELOC))	\
+      else if (!DECL_READONLY_SECTION (DECL, RELOC) || (RELOC))		\
+	data_section ();						\
+      else if (flag_merge_constants < 2)				\
+	/* C and C++ don't allow different variables to share		\
+	   the same location.  -fmerge-all-constants allows		\
+	   even that (at the expense of not conforming).  */		\
 	const_section ();						\
+      else if (TREE_CODE (DECL_INITIAL (DECL)) == STRING_CST)		\
+	mergeable_string_section (DECL_INITIAL (DECL), (ALIGN), 0);	\
       else								\
-	data_section ();						\
+	mergeable_constant_section (DECL_MODE (DECL), (ALIGN), 0);	\
     }									\
   /* This could be a CONSTRUCTOR containing ADDR_EXPR of a VAR_DECL,	\
      in which case we can't put it in a shared library rodata.  */	\
@@ -172,7 +179,7 @@ do {									\
 
 extern unsigned int ia64_section_threshold;
 #undef SELECT_RTX_SECTION
-#define SELECT_RTX_SECTION(MODE, RTX)					\
+#define SELECT_RTX_SECTION(MODE, RTX, ALIGN)				\
 {									\
   if (GET_MODE_SIZE (MODE) > 0						\
       && GET_MODE_SIZE (MODE) <= ia64_section_threshold)		\
@@ -180,7 +187,7 @@ extern unsigned int ia64_section_threshold;
   else if (flag_pic && symbolic_operand ((RTX), (MODE)))		\
     data_section ();							\
   else									\
-    const_section ();							\
+    mergeable_constant_section ((MODE), (ALIGN), 0);			\
 }
 
 #undef EXTRA_SECTIONS