diff options
author | Nick Clifton <nickc@redhat.com> | 2004-08-25 12:54:15 +0000 |
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committer | Nick Clifton <nickc@redhat.com> | 2004-08-25 12:54:15 +0000 |
commit | b18c562e39c5c3ee63032a9a0aa9b7571343fd58 (patch) | |
tree | 0a1ab4cf2ca014da6f955028f9410e6b59ce57e8 /bfd/elf32-msp430.c | |
parent | 61f5d0545d98ab8252082db2bf10cdd40af51cee (diff) | |
download | gdb-b18c562e39c5c3ee63032a9a0aa9b7571343fd58.zip gdb-b18c562e39c5c3ee63032a9a0aa9b7571343fd58.tar.gz gdb-b18c562e39c5c3ee63032a9a0aa9b7571343fd58.tar.bz2 |
Apply Dmitry Diky's patches to add relaxation to msp430.
Diffstat (limited to 'bfd/elf32-msp430.c')
-rw-r--r-- | bfd/elf32-msp430.c | 667 |
1 files changed, 569 insertions, 98 deletions
diff --git a/bfd/elf32-msp430.c b/bfd/elf32-msp430.c index dfe33bd..ba59cf7 100644 --- a/bfd/elf32-msp430.c +++ b/bfd/elf32-msp430.c @@ -25,41 +25,6 @@ #include "elf-bfd.h" #include "elf/msp430.h" -static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup - PARAMS ((bfd *, bfd_reloc_code_real_type)); - -static void msp430_info_to_howto_rela - PARAMS ((bfd *, arelent *, Elf_Internal_Rela *)); - -static asection *elf32_msp430_gc_mark_hook - PARAMS ((asection *, struct bfd_link_info *, Elf_Internal_Rela *, - struct elf_link_hash_entry *, Elf_Internal_Sym *)); - -static bfd_boolean elf32_msp430_gc_sweep_hook - PARAMS ((bfd *, struct bfd_link_info *, asection *, - const Elf_Internal_Rela *)); - -static bfd_boolean elf32_msp430_check_relocs - PARAMS ((bfd *, struct bfd_link_info *, asection *, - const Elf_Internal_Rela *)); - -static bfd_reloc_status_type msp430_final_link_relocate - PARAMS ((reloc_howto_type *, bfd *, asection *, bfd_byte *, - Elf_Internal_Rela *, bfd_vma)); - -static bfd_boolean elf32_msp430_relocate_section - PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, - Elf_Internal_Rela *, Elf_Internal_Sym *, asection **)); - -static void bfd_elf_msp430_final_write_processing - PARAMS ((bfd *, bfd_boolean)); - -static bfd_boolean elf32_msp430_object_p - PARAMS ((bfd *)); - -static void elf32_msp430_post_process_headers - PARAMS ((bfd *, struct bfd_link_info *)); - /* Use RELA instead of REL. */ #undef USE_REL @@ -71,7 +36,7 @@ static reloc_howto_type elf_msp430_howto_table[] = 32, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ - complain_overflow_bitfield, /* complain_on_overflow */ + complain_overflow_bitfield,/* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ "R_MSP430_NONE", /* name */ FALSE, /* partial_inplace */ @@ -85,7 +50,7 @@ static reloc_howto_type elf_msp430_howto_table[] = 32, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ - complain_overflow_bitfield, /* complain_on_overflow */ + complain_overflow_bitfield,/* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ "R_MSP430_32", /* name */ FALSE, /* partial_inplace */ @@ -100,7 +65,7 @@ static reloc_howto_type elf_msp430_howto_table[] = 10, /* bitsize */ TRUE, /* pc_relative */ 0, /* bitpos */ - complain_overflow_bitfield, /* complain_on_overflow */ + complain_overflow_bitfield,/* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ "R_MSP430_13_PCREL", /* name */ FALSE, /* partial_inplace */ @@ -119,7 +84,7 @@ static reloc_howto_type elf_msp430_howto_table[] = bfd_elf_generic_reloc, /* special_function */ "R_MSP430_16", /* name */ FALSE, /* partial_inplace */ - 0xffff, /* src_mask */ + 0, /* src_mask */ 0xffff, /* dst_mask */ FALSE), /* pcrel_offset */ @@ -134,7 +99,7 @@ static reloc_howto_type elf_msp430_howto_table[] = bfd_elf_generic_reloc, /* special_function */ "R_MSP430_16_PCREL", /* name */ FALSE, /* partial_inplace */ - 0xffff, /* src_mask */ + 0, /* src_mask */ 0xffff, /* dst_mask */ TRUE), /* pcrel_offset */ @@ -162,10 +127,40 @@ static reloc_howto_type elf_msp430_howto_table[] = 0, /* bitpos */ complain_overflow_dont,/* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ - "R_MSP430_16_PCREL_BYTE", /* name */ + "R_MSP430_16_PCREL_BYTE",/* name */ FALSE, /* partial_inplace */ 0xffff, /* src_mask */ 0xffff, /* dst_mask */ + TRUE), /* pcrel_offset */ + + /* A 13 bit PC relative relocation for complicated polymorphs. */ + HOWTO (R_MSP430_2X_PCREL, /* type */ + 1, /* rightshift */ + 2, /* size (0 = byte, 1 = short, 2 = long) */ + 10, /* bitsize */ + TRUE, /* pc_relative */ + 0, /* bitpos */ + complain_overflow_bitfield,/* complain_on_overflow */ + bfd_elf_generic_reloc, /* special_function */ + "R_MSP430_2X_PCREL", /* name */ + FALSE, /* partial_inplace */ + 0xfff, /* src_mask */ + 0xfff, /* dst_mask */ + TRUE), /* pcrel_offset */ + + /* A 16 bit relaxable relocation for command address. */ + HOWTO (R_MSP430_RL_PCREL, /* type */ + 1, /* rightshift */ + 1, /* size (0 = byte, 1 = short, 2 = long) */ + 16, /* bitsize */ + TRUE, /* pc_relative */ + 0, /* bitpos */ + complain_overflow_dont,/* complain_on_overflow */ + bfd_elf_generic_reloc, /* special_function */ + "R_MSP430_RL_PCREL", /* name */ + FALSE, /* partial_inplace */ + 0, /* src_mask */ + 0xffff, /* dst_mask */ TRUE) /* pcrel_offset */ }; @@ -179,20 +174,21 @@ struct msp430_reloc_map static const struct msp430_reloc_map msp430_reloc_map[] = { - {BFD_RELOC_NONE, R_MSP430_NONE}, - {BFD_RELOC_32, R_MSP430_32}, - {BFD_RELOC_MSP430_10_PCREL, R_MSP430_10_PCREL}, - {BFD_RELOC_16, R_MSP430_16_BYTE}, - {BFD_RELOC_MSP430_16_PCREL, R_MSP430_16_PCREL}, - {BFD_RELOC_MSP430_16, R_MSP430_16}, + {BFD_RELOC_NONE, R_MSP430_NONE}, + {BFD_RELOC_32, R_MSP430_32}, + {BFD_RELOC_MSP430_10_PCREL, R_MSP430_10_PCREL}, + {BFD_RELOC_16, R_MSP430_16_BYTE}, + {BFD_RELOC_MSP430_16_PCREL, R_MSP430_16_PCREL}, + {BFD_RELOC_MSP430_16, R_MSP430_16}, {BFD_RELOC_MSP430_16_PCREL_BYTE, R_MSP430_16_PCREL_BYTE}, - {BFD_RELOC_MSP430_16_BYTE, R_MSP430_16_BYTE} + {BFD_RELOC_MSP430_16_BYTE, R_MSP430_16_BYTE}, + {BFD_RELOC_MSP430_2X_PCREL, R_MSP430_2X_PCREL}, + {BFD_RELOC_MSP430_RL_PCREL, R_MSP430_RL_PCREL} }; static reloc_howto_type * -bfd_elf32_bfd_reloc_type_lookup (abfd, code) - bfd *abfd ATTRIBUTE_UNUSED; - bfd_reloc_code_real_type code; +bfd_elf32_bfd_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED, + bfd_reloc_code_real_type code) { unsigned int i; @@ -206,10 +202,9 @@ bfd_elf32_bfd_reloc_type_lookup (abfd, code) /* Set the howto pointer for an MSP430 ELF reloc. */ static void -msp430_info_to_howto_rela (abfd, cache_ptr, dst) - bfd *abfd ATTRIBUTE_UNUSED; - arelent *cache_ptr; - Elf_Internal_Rela *dst; +msp430_info_to_howto_rela (bfd * abfd ATTRIBUTE_UNUSED, + arelent * cache_ptr, + Elf_Internal_Rela * dst) { unsigned int r_type; @@ -219,12 +214,11 @@ msp430_info_to_howto_rela (abfd, cache_ptr, dst) } static asection * -elf32_msp430_gc_mark_hook (sec, info, rel, h, sym) - asection *sec; - struct bfd_link_info *info ATTRIBUTE_UNUSED; - Elf_Internal_Rela *rel; - struct elf_link_hash_entry *h; - Elf_Internal_Sym *sym; +elf32_msp430_gc_mark_hook (asection * sec, + struct bfd_link_info * info ATTRIBUTE_UNUSED, + Elf_Internal_Rela * rel, + struct elf_link_hash_entry * h, + Elf_Internal_Sym * sym) { if (h != NULL) { @@ -252,11 +246,10 @@ elf32_msp430_gc_mark_hook (sec, info, rel, h, sym) } static bfd_boolean -elf32_msp430_gc_sweep_hook (abfd, info, sec, relocs) - bfd *abfd ATTRIBUTE_UNUSED; - struct bfd_link_info *info ATTRIBUTE_UNUSED; - asection *sec ATTRIBUTE_UNUSED; - const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED; +elf32_msp430_gc_sweep_hook (bfd * abfd ATTRIBUTE_UNUSED, + struct bfd_link_info * info ATTRIBUTE_UNUSED, + asection * sec ATTRIBUTE_UNUSED, + const Elf_Internal_Rela * relocs ATTRIBUTE_UNUSED) { /* We don't use got and plt entries for msp430. */ return TRUE; @@ -267,11 +260,8 @@ elf32_msp430_gc_sweep_hook (abfd, info, sec, relocs) virtual table relocs for gc. */ static bfd_boolean -elf32_msp430_check_relocs (abfd, info, sec, relocs) - bfd *abfd; - struct bfd_link_info *info; - asection *sec; - const Elf_Internal_Rela *relocs; +elf32_msp430_check_relocs (bfd * abfd, struct bfd_link_info * info, + asection * sec, const Elf_Internal_Rela * relocs) { Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes, **sym_hashes_end; @@ -308,14 +298,9 @@ elf32_msp430_check_relocs (abfd, info, sec, relocs) routines, but a few relocs, we have to do them ourselves. */ static bfd_reloc_status_type -msp430_final_link_relocate (howto, input_bfd, input_section, - contents, rel, relocation) - reloc_howto_type *howto; - bfd *input_bfd; - asection *input_section; - bfd_byte *contents; - Elf_Internal_Rela *rel; - bfd_vma relocation; +msp430_final_link_relocate (reloc_howto_type * howto, bfd * input_bfd, + asection * input_section, bfd_byte * contents, + Elf_Internal_Rela * rel, bfd_vma relocation) { bfd_reloc_status_type r = bfd_reloc_ok; bfd_vma x; @@ -347,7 +332,37 @@ msp430_final_link_relocate (howto, input_bfd, input_section, bfd_put_16 (input_bfd, x, contents); break; + case R_MSP430_2X_PCREL: + contents += rel->r_offset; + srel = (bfd_signed_vma) relocation; + srel += rel->r_addend; + srel -= rel->r_offset; + srel -= 2; /* Branch instructions add 2 to the PC... */ + srel -= (input_section->output_section->vma + + input_section->output_offset); + + if (srel & 1) + return bfd_reloc_outofrange; + + /* MSP430 addresses commands as words. */ + srel >>= 1; + + /* Check for an overflow. */ + if (srel < -512 || srel > 511) + return bfd_reloc_overflow; + + x = bfd_get_16 (input_bfd, contents); + x = (x & 0xfc00) | (srel & 0x3ff); + bfd_put_16 (input_bfd, x, contents); + /* Handle second jump instruction. */ + x = bfd_get_16 (input_bfd, contents - 2); + srel += 1; + x = (x & 0xfc00) | (srel & 0x3ff); + bfd_put_16 (input_bfd, x, contents - 2); + break; + case R_MSP430_16_PCREL: + case R_MSP430_RL_PCREL: contents += rel->r_offset; srel = (bfd_signed_vma) relocation; srel += rel->r_addend; @@ -404,16 +419,14 @@ msp430_final_link_relocate (howto, input_bfd, input_section, /* Relocate an MSP430 ELF section. */ static bfd_boolean -elf32_msp430_relocate_section (output_bfd, info, input_bfd, input_section, - contents, relocs, local_syms, local_sections) - bfd *output_bfd ATTRIBUTE_UNUSED; - struct bfd_link_info *info; - bfd *input_bfd; - asection *input_section; - bfd_byte *contents; - Elf_Internal_Rela *relocs; - Elf_Internal_Sym *local_syms; - asection **local_sections; +elf32_msp430_relocate_section (bfd * output_bfd ATTRIBUTE_UNUSED, + struct bfd_link_info * info, + bfd * input_bfd, + asection * input_section, + bfd_byte * contents, + Elf_Internal_Rela * relocs, + Elf_Internal_Sym * local_syms, + asection ** local_sections) { Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; @@ -520,9 +533,8 @@ elf32_msp430_relocate_section (output_bfd, info, input_bfd, input_section, number. */ static void -bfd_elf_msp430_final_write_processing (abfd, linker) - bfd *abfd; - bfd_boolean linker ATTRIBUTE_UNUSED; +bfd_elf_msp430_final_write_processing (bfd * abfd, + bfd_boolean linker ATTRIBUTE_UNUSED) { unsigned long val; @@ -594,8 +606,7 @@ bfd_elf_msp430_final_write_processing (abfd, linker) /* Set the right machine number. */ static bfd_boolean -elf32_msp430_object_p (abfd) - bfd *abfd; +elf32_msp430_object_p (bfd * abfd) { int e_set = bfd_mach_msp14; @@ -669,11 +680,10 @@ elf32_msp430_object_p (abfd) } static void -elf32_msp430_post_process_headers (abfd, link_info) - bfd *abfd; - struct bfd_link_info *link_info ATTRIBUTE_UNUSED; +elf32_msp430_post_process_headers (bfd * abfd, + struct bfd_link_info * link_info ATTRIBUTE_UNUSED) { - Elf_Internal_Ehdr *i_ehdrp; /* ELF file header, internal form. */ + Elf_Internal_Ehdr * i_ehdrp; /* ELF file header, internal form. */ i_ehdrp = elf_elfheader (abfd); @@ -684,6 +694,466 @@ elf32_msp430_post_process_headers (abfd, link_info) i_ehdrp->e_ident[EI_OSABI] = ELFOSABI_STANDALONE; } +/* These functions handle relaxing for the msp430. + Relaxation required only in two cases: + - Bad hand coding like jumps from one section to another or + from file to file. + - Sibling calls. This will affect onlu 'jump label' polymorph. Without + relaxing this enlarges code by 2 bytes. Sibcalls implemented but + do not work in gcc's port by the reason I do not know. + Anyway, if a relaxation required, user should pass -relax option to the + linker. + + There are quite a few relaxing opportunities available on the msp430: + + ================================================================ + + 1. 3 words -> 1 word + + eq == jeq label jne +4; br lab + ne != jne label jeq +4; br lab + lt < jl label jge +4; br lab + ltu < jlo label lhs +4; br lab + ge >= jge label jl +4; br lab + geu >= jhs label jlo +4; br lab + + 2. 4 words -> 1 word + + ltn < jn jn +2; jmp +4; br lab + + 3. 4 words -> 2 words + + gt > jeq +2; jge label jeq +6; jl +4; br label + gtu > jeq +2; jhs label jeq +6; jlo +4; br label + + 4. 4 words -> 2 words and 2 labels + + leu <= jeq label; jlo label jeq +2; jhs +4; br label + le <= jeq label; jl label jeq +2; jge +4; br label + ================================================================= + + codemap for first cases is (labels masked ): + eq: 0x2002,0x4010,0x0000 -> 0x2400 + ne: 0x2402,0x4010,0x0000 -> 0x2000 + lt: 0x3402,0x4010,0x0000 -> 0x3800 + ltu: 0x2c02,0x4010,0x0000 -> 0x2800 + ge: 0x3802,0x4010,0x0000 -> 0x3400 + geu: 0x2802,0x4010,0x0000 -> 0x2c00 + + second case: + ltn: 0x3001,0x3c02,0x4010,0x0000 -> 0x3000 + + third case: + gt: 0x2403,0x3802,0x4010,0x0000 -> 0x2401,0x3400 + gtu: 0x2403,0x2802,0x4010,0x0000 -> 0x2401,0x2c00 + + fourth case: + leu: 0x2401,0x2c02,0x4010,0x0000 -> 0x2400,0x2800 + le: 0x2401,0x3402,0x4010,0x0000 -> 0x2400,0x3800 + + Unspecified case :) + jump: 0x4010,0x0000 -> 0x3c00. */ + +#define NUMB_RELAX_CODES 12 +static struct rcodes_s +{ + int f0, f1; /* From code. */ + int t0, t1; /* To code. */ + int labels; /* Position of labels: 1 - one label at first + word, 2 - one at second word, 3 - two + labels at both. */ + int cdx; /* Words to match. */ + int bs; /* Shrink bytes. */ + int off; /* Offset from old label for new code. */ + int ncl; /* New code length. */ +} rcode[] = +{/* lab,cdx,bs,off,ncl */ + { 0x0000, 0x0000, 0x3c00, 0x0000, 1, 0, 2, 2, 2}, /* jump */ + { 0x0000, 0x2002, 0x2400, 0x0000, 1, 1, 4, 4, 2}, /* eq */ + { 0x0000, 0x2402, 0x2000, 0x0000, 1, 1, 4, 4, 2}, /* ne */ + { 0x0000, 0x3402, 0x3800, 0x0000, 1, 1, 4, 4, 2}, /* lt */ + { 0x0000, 0x2c02, 0x2800, 0x0000, 1, 1, 4, 4, 2}, /* ltu */ + { 0x0000, 0x3802, 0x3400, 0x0000, 1, 1, 4, 4, 2}, /* ge */ + { 0x0000, 0x2802, 0x2c00, 0x0000, 1, 1, 4, 4, 2}, /* geu */ + { 0x3001, 0x3c02, 0x3000, 0x0000, 1, 2, 6, 6, 2}, /* ltn */ + { 0x2403, 0x3802, 0x2401, 0x3400, 2, 2, 4, 6, 4}, /* gt */ + { 0x2403, 0x2802, 0x2401, 0x2c00, 2, 2, 4, 6, 4}, /* gtu */ + { 0x2401, 0x2c02, 0x2400, 0x2800, 3, 2, 4, 6, 4}, /* leu , 2 labels */ + { 0x2401, 0x2c02, 0x2400, 0x2800, 3, 2, 4, 6, 4}, /* le , 2 labels */ + { 0, 0, 0, 0, 0, 0, 0, 0, 0} +}; + +/* Return TRUE if a symbol exists at the given address. */ + +static bfd_boolean +msp430_elf_symbol_address_p (bfd * abfd, + asection * sec, + Elf_Internal_Sym * isym, + bfd_vma addr) +{ + Elf_Internal_Shdr *symtab_hdr; + unsigned int sec_shndx; + Elf_Internal_Sym *isymend; + struct elf_link_hash_entry **sym_hashes; + struct elf_link_hash_entry **end_hashes; + unsigned int symcount; + + sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec); + + /* Examine all the local symbols. */ + symtab_hdr = &elf_tdata (abfd)->symtab_hdr; + for (isymend = isym + symtab_hdr->sh_info; isym < isymend; isym++) + if (isym->st_shndx == sec_shndx && isym->st_value == addr) + return TRUE; + + symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym) + - symtab_hdr->sh_info); + sym_hashes = elf_sym_hashes (abfd); + end_hashes = sym_hashes + symcount; + for (; sym_hashes < end_hashes; sym_hashes++) + { + struct elf_link_hash_entry *sym_hash = *sym_hashes; + + if ((sym_hash->root.type == bfd_link_hash_defined + || sym_hash->root.type == bfd_link_hash_defweak) + && sym_hash->root.u.def.section == sec + && sym_hash->root.u.def.value == addr) + return TRUE; + } + + return FALSE; +} + +/* Delete some bytes from a section while relaxing. */ + +static bfd_boolean +msp430_elf_relax_delete_bytes (bfd * abfd, asection * sec, bfd_vma addr, + int count) +{ + Elf_Internal_Shdr *symtab_hdr; + unsigned int sec_shndx; + bfd_byte *contents; + Elf_Internal_Rela *irel; + Elf_Internal_Rela *irelend; + Elf_Internal_Rela *irelalign; + bfd_vma toaddr; + Elf_Internal_Sym *isym; + Elf_Internal_Sym *isymend; + struct elf_link_hash_entry **sym_hashes; + struct elf_link_hash_entry **end_hashes; + unsigned int symcount; + + sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec); + + contents = elf_section_data (sec)->this_hdr.contents; + + /* The deletion must stop at the next ALIGN reloc for an aligment + power larger than the number of bytes we are deleting. */ + + irelalign = NULL; + toaddr = sec->size; + + irel = elf_section_data (sec)->relocs; + irelend = irel + sec->reloc_count; + + /* Actually delete the bytes. */ + memmove (contents + addr, contents + addr + count, + (size_t) (toaddr - addr - count)); + sec->size -= count; + + /* Adjust all the relocs. */ + for (irel = elf_section_data (sec)->relocs; irel < irelend; irel++) + /* Get the new reloc address. */ + if ((irel->r_offset > addr && irel->r_offset < toaddr)) + irel->r_offset -= count; + + /* Adjust the local symbols defined in this section. */ + symtab_hdr = & elf_tdata (abfd)->symtab_hdr; + isym = (Elf_Internal_Sym *) symtab_hdr->contents; + for (isymend = isym + symtab_hdr->sh_info; isym < isymend; isym++) + if (isym->st_shndx == sec_shndx + && isym->st_value > addr && isym->st_value < toaddr) + isym->st_value -= count; + + /* Now adjust the global symbols defined in this section. */ + symcount = (symtab_hdr->sh_size / sizeof (Elf32_External_Sym) + - symtab_hdr->sh_info); + sym_hashes = elf_sym_hashes (abfd); + end_hashes = sym_hashes + symcount; + for (; sym_hashes < end_hashes; sym_hashes++) + { + struct elf_link_hash_entry *sym_hash = *sym_hashes; + + if ((sym_hash->root.type == bfd_link_hash_defined + || sym_hash->root.type == bfd_link_hash_defweak) + && sym_hash->root.u.def.section == sec + && sym_hash->root.u.def.value > addr + && sym_hash->root.u.def.value < toaddr) + sym_hash->root.u.def.value -= count; + } + + return TRUE; +} + + +static bfd_boolean +msp430_elf_relax_section (bfd * abfd, asection * sec, + struct bfd_link_info * link_info, + bfd_boolean * again) +{ + Elf_Internal_Shdr * symtab_hdr; + Elf_Internal_Rela * internal_relocs; + Elf_Internal_Rela * irel; + Elf_Internal_Rela * irelend; + bfd_byte * contents = NULL; + Elf_Internal_Sym * isymbuf = NULL; + + /* Assume nothing changes. */ + *again = FALSE; + + /* We don't have to do anything for a relocatable link, if + this section does not have relocs, or if this is not a + code section. */ + if (link_info->relocatable + || (sec->flags & SEC_RELOC) == 0 + || sec->reloc_count == 0 || (sec->flags & SEC_CODE) == 0) + return TRUE; + + symtab_hdr = & elf_tdata (abfd)->symtab_hdr; + + /* Get a copy of the native relocations. */ + internal_relocs = + _bfd_elf_link_read_relocs (abfd, sec, NULL, NULL, link_info->keep_memory); + if (internal_relocs == NULL) + goto error_return; + + /* Walk through them looking for relaxing opportunities. */ + irelend = internal_relocs + sec->reloc_count; + for (irel = internal_relocs; irel < irelend; irel++) + { + bfd_vma symval; + + /* If this isn't something that can be relaxed, then ignore + this reloc. */ + if (ELF32_R_TYPE (irel->r_info) != (int) R_MSP430_RL_PCREL) + continue; + + /* Get the section contents if we haven't done so already. */ + if (contents == NULL) + { + /* Get cached copy if it exists. */ + if (elf_section_data (sec)->this_hdr.contents != NULL) + contents = elf_section_data (sec)->this_hdr.contents; + else if (! bfd_malloc_and_get_section (abfd, sec, &contents)) + goto error_return; + } + + /* Read this BFD's local symbols if we haven't done so already. */ + if (isymbuf == NULL && symtab_hdr->sh_info != 0) + { + isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents; + if (isymbuf == NULL) + isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr, + symtab_hdr->sh_info, 0, + NULL, NULL, NULL); + if (isymbuf == NULL) + goto error_return; + } + + /* Get the value of the symbol referred to by the reloc. */ + if (ELF32_R_SYM (irel->r_info) < symtab_hdr->sh_info) + { + /* A local symbol. */ + Elf_Internal_Sym *isym; + asection *sym_sec; + + isym = isymbuf + ELF32_R_SYM (irel->r_info); + if (isym->st_shndx == SHN_UNDEF) + sym_sec = bfd_und_section_ptr; + else if (isym->st_shndx == SHN_ABS) + sym_sec = bfd_abs_section_ptr; + else if (isym->st_shndx == SHN_COMMON) + sym_sec = bfd_com_section_ptr; + else + sym_sec = bfd_section_from_elf_index (abfd, isym->st_shndx); + symval = (isym->st_value + + sym_sec->output_section->vma + sym_sec->output_offset); + } + else + { + unsigned long indx; + struct elf_link_hash_entry *h; + + /* An external symbol. */ + indx = ELF32_R_SYM (irel->r_info) - symtab_hdr->sh_info; + h = elf_sym_hashes (abfd)[indx]; + BFD_ASSERT (h != NULL); + + if (h->root.type != bfd_link_hash_defined + && h->root.type != bfd_link_hash_defweak) + /* This appears to be a reference to an undefined + symbol. Just ignore it--it will be caught by the + regular reloc processing. */ + continue; + + symval = (h->root.u.def.value + + h->root.u.def.section->output_section->vma + + h->root.u.def.section->output_offset); + } + + /* For simplicity of coding, we are going to modify the section + contents, the section relocs, and the BFD symbol table. We + must tell the rest of the code not to free up this + information. It would be possible to instead create a table + of changes which have to be made, as is done in coff-mips.c; + that would be more work, but would require less memory when + the linker is run. */ + + /* Try to turn a 16bit pc-relative branch into a 10bit pc-relative + branch. */ + /* Paranoia? paranoia... */ + if (ELF32_R_TYPE (irel->r_info) == (int) R_MSP430_RL_PCREL) + { + bfd_vma value = symval; + + /* Deal with pc-relative gunk. */ + value -= (sec->output_section->vma + sec->output_offset); + value -= irel->r_offset; + value += irel->r_addend; + + /* See if the value will fit in 10 bits, note the high value is + 1016 as the target will be two bytes closer if we are + able to relax. */ + if ((long) value < 1016 && (long) value > -1016) + { + int code0 = 0, code1 = 0, code2 = 0; + int i; + struct rcodes_s *rx; + + /* Get the opcode. */ + if (irel->r_offset >= 6) + code0 = bfd_get_16 (abfd, contents + irel->r_offset - 6); + + if (irel->r_offset >= 4) + code1 = bfd_get_16 (abfd, contents + irel->r_offset - 4); + + code2 = bfd_get_16 (abfd, contents + irel->r_offset - 2); + + if (code2 != 0x4010) + continue; + + /* Check r4 and r3. */ + for (i = NUMB_RELAX_CODES - 1; i >= 0; i--) + { + rx = &rcode[i]; + if (rx->cdx == 2 && rx->f0 == code0 && rx->f1 == code1) + break; + else if (rx->cdx == 1 && rx->f1 == code1) + break; + else if (rx->cdx == 0) /* This is an unconditional jump. */ + break; + } + + /* Check labels: + .Label0: ; we do not care about this label + jeq +6 + .Label1: ; make sure there is no label here + jl +4 + .Label2: ; make sure there is no label here + br .Label_dst + + So, if there is .Label1 or .Label2 we cannot relax this code. + This actually should not happen, cause for relaxable + instructions we use RL_PCREL reloc instead of 16_PCREL. + Will change this in the future. */ + + if (rx->cdx > 0 + && msp430_elf_symbol_address_p (abfd, sec, isymbuf, + irel->r_offset - 2)) + continue; + if (rx->cdx > 1 + && msp430_elf_symbol_address_p (abfd, sec, isymbuf, + irel->r_offset - 4)) + continue; + + /* Note that we've changed the relocs, section contents, etc. */ + elf_section_data (sec)->relocs = internal_relocs; + elf_section_data (sec)->this_hdr.contents = contents; + symtab_hdr->contents = (unsigned char *) isymbuf; + + /* Fix the relocation's type. */ + if (rx->labels == 3) /* Handle special cases. */ + irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info), + R_MSP430_2X_PCREL); + else + irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info), + R_MSP430_10_PCREL); + + /* Fix the opcode right way. */ + bfd_put_16 (abfd, rx->t0, contents + irel->r_offset - rx->off); + if (rx->t1) + bfd_put_16 (abfd, rx->t1, + contents + irel->r_offset - rx->off + 2); + + /* Delete bytes. */ + if (!msp430_elf_relax_delete_bytes (abfd, sec, + irel->r_offset - rx->off + + rx->ncl, rx->bs)) + goto error_return; + + /* Handle unconditional jumps. */ + if (rx->cdx == 0) + irel->r_offset -= 2; + + /* That will change things, so, we should relax again. + Note that this is not required, and it may be slow. */ + *again = TRUE; + } + } + } + + if (isymbuf != NULL && symtab_hdr->contents != (unsigned char *) isymbuf) + { + if (!link_info->keep_memory) + free (isymbuf); + else + { + /* Cache the symbols for elf_link_input_bfd. */ + symtab_hdr->contents = (unsigned char *) isymbuf; + } + } + + if (contents != NULL + && elf_section_data (sec)->this_hdr.contents != contents) + { + if (!link_info->keep_memory) + free (contents); + else + { + /* Cache the section contents for elf_link_input_bfd. */ + elf_section_data (sec)->this_hdr.contents = contents; + } + } + + if (internal_relocs != NULL + && elf_section_data (sec)->relocs != internal_relocs) + free (internal_relocs); + + return TRUE; + +error_return: + if (isymbuf != NULL && symtab_hdr->contents != (unsigned char *) isymbuf) + free (isymbuf); + if (contents != NULL + && elf_section_data (sec)->this_hdr.contents != contents) + free (contents); + if (internal_relocs != NULL + && elf_section_data (sec)->relocs != internal_relocs) + free (internal_relocs); + + return FALSE; +} + #define ELF_ARCH bfd_arch_msp430 #define ELF_MACHINE_CODE EM_MSP430 @@ -703,5 +1173,6 @@ elf32_msp430_post_process_headers (abfd, link_info) #define elf_backend_final_write_processing bfd_elf_msp430_final_write_processing #define elf_backend_object_p elf32_msp430_object_p #define elf_backend_post_process_headers elf32_msp430_post_process_headers +#define bfd_elf32_bfd_relax_section msp430_elf_relax_section #include "elf32-target.h" |