elf_arm_tdata (output_bfd)->no_enum_size_warning = no_enum_warn;
}
-/* The thumb form of a long branch is a bit finicky, because the offset
- encoding is split over two fields, each in it's own instruction. They
- can occur in any order. So given a thumb form of long branch, and an
- offset, insert the offset into the thumb branch and return finished
- instruction.
-
- It takes two thumb instructions to encode the target address. Each has
- 11 bits to invest. The upper 11 bits are stored in one (identified by
- H-0.. see below), the lower 11 bits are stored in the other (identified
- by H-1).
-
- Combine together and shifted left by 1 (it's a half word address) and
- there you have it.
-
- Op: 1111 = F,
- H-0, upper address-0 = 000
- Op: 1111 = F,
- H-1, lower address-0 = 800
-
- They can be ordered either way, but the arm tools I've seen always put
- the lower one first. It probably doesn't matter. krk@cygnus.com
-
- XXX: Actually the order does matter. The second instruction (H-1)
- moves the computed address into the PC, so it must be the second one
- in the sequence. The problem, however is that whilst little endian code
- stores the instructions in HI then LOW order, big endian code does the
- reverse. nickc@cygnus.com. */
-
-#define LOW_HI_ORDER 0xF800F000
-#define HI_LOW_ORDER 0xF000F800
-
-static insn32
-insert_thumb_branch (insn32 br_insn, int rel_off)
-{
- unsigned int low_bits;
- unsigned int high_bits;
-
- BFD_ASSERT ((rel_off & 1) != 1);
-
- rel_off >>= 1; /* Half word aligned address. */
- low_bits = rel_off & 0x000007FF; /* The bottom 11 bits. */
- high_bits = (rel_off >> 11) & 0x000007FF; /* The top 11 bits. */
-
- if ((br_insn & LOW_HI_ORDER) == LOW_HI_ORDER)
- br_insn = LOW_HI_ORDER | (low_bits << 16) | high_bits;
- else if ((br_insn & HI_LOW_ORDER) == HI_LOW_ORDER)
- br_insn = HI_LOW_ORDER | (high_bits << 16) | low_bits;
- else
- /* FIXME: abort is probably not the right call. krk@cygnus.com */
- abort (); /* Error - not a valid branch instruction form. */
+/* Replace the target offset of a Thumb bl or b.w instruction. */
- return br_insn;
+static void
+insert_thumb_branch (bfd *abfd, long int offset, bfd_byte *insn)
+{
+ bfd_vma upper;
+ bfd_vma lower;
+ int reloc_sign;
+
+ BFD_ASSERT ((offset & 1) == 0);
+
+ upper = bfd_get_16 (abfd, insn);
+ lower = bfd_get_16 (abfd, insn + 2);
+ reloc_sign = (offset < 0) ? 1 : 0;
+ upper = (upper & ~(bfd_vma) 0x7ff)
+ | ((offset >> 12) & 0x3ff)
+ | (reloc_sign << 10);
+ lower = (lower & ~(bfd_vma) 0x2fff)
+ | (((!((offset >> 23) & 1)) ^ reloc_sign) << 13)
+ | (((!((offset >> 22) & 1)) ^ reloc_sign) << 11)
+ | ((offset >> 1) & 0x7ff);
+ bfd_put_16 (abfd, upper, insn);
+ bfd_put_16 (abfd, lower, insn + 2);
}
{
asection * s = 0;
bfd_vma my_offset;
- unsigned long int tmp;
long int ret_offset;
struct elf_link_hash_entry * myh;
struct elf32_arm_link_hash_table * globals;
/* Biassing for PC-relative addressing. */
- 8;
- tmp = bfd_get_32 (input_bfd, hit_data
- - input_section->vma);
-
- bfd_put_32 (output_bfd,
- (bfd_vma) insert_thumb_branch (tmp, ret_offset),
- hit_data - input_section->vma);
+ insert_thumb_branch (input_bfd, ret_offset, hit_data - input_section->vma);
return TRUE;
}
projects / binutils-gdb.git / commitdiff