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authorKazu Hirata <kazu@codesourcery.com>2004-01-16 23:35:49 +0000
committerKazu Hirata <kazu@codesourcery.com>2004-01-16 23:35:49 +0000
commit9ed929751aa8416717c4e2ee7db6ad1b73435949 (patch)
treefaf080a3a0cd7796d476948e53b57b7261529bb8 /bfd/elf32-h8300.c
parentda09d74aafae4a5b0da4fe72760a832c547007b5 (diff)
downloadgdb-9ed929751aa8416717c4e2ee7db6ad1b73435949.tar.gz
* coff-h8300.c: Add comments about relaxation.
* elf32-h8300.c: Likewise.
Diffstat (limited to 'bfd/elf32-h8300.c')
-rw-r--r--bfd/elf32-h8300.c56
1 files changed, 50 insertions, 6 deletions
diff --git a/bfd/elf32-h8300.c b/bfd/elf32-h8300.c
index c803af176e9..e3529726e02 100644
--- a/bfd/elf32-h8300.c
+++ b/bfd/elf32-h8300.c
@@ -659,6 +659,10 @@ elf32_h8_merge_private_bfd_data (bfd *ibfd, bfd *obfd)
bCC:16 -> bCC:8 2 bytes
bsr:16 -> bsr:8 2 bytes
+ bset:16 -> bset:8 2 bytes
+ bset:24/32 -> bset:8 4 bytes
+ (also applicable to other bit manipulation instructions)
+
mov.b:16 -> mov.b:8 2 bytes
mov.b:24/32 -> mov.b:8 4 bytes
@@ -1000,8 +1004,15 @@ elf32_h8_relax_section (bfd *abfd, asection *sec,
break;
}
- /* This is a 16 bit absolute address in a "mov.b" insn, which may
- become an 8 bit absolute address if its in the right range. */
+ /* This is a 16-bit absolute address in one of the following
+ instructions:
+
+ "band", "bclr", "biand", "bild", "bior", "bist", "bixor",
+ "bld", "bnot", "bor", "bset", "bst", "btst", "bxor", and
+ "mov.b"
+
+ We may relax this into an 8-bit absolute address if it's in
+ the right range. */
case R_H8_DIR16A8:
{
bfd_vma value;
@@ -1021,28 +1032,41 @@ elf32_h8_relax_section (bfd *abfd, asection *sec,
/* Get the opcode. */
code = bfd_get_8 (abfd, contents + irel->r_offset - 2);
- /* Sanity check. */
+ /* All instructions with R_H8_DIR16A8 start with
+ 0x6a. */
if (code != 0x6a)
abort ();
temp_code = code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
+ /* If this is a mov.b instruction, clear the lower
+ nibble, which contains the source/destination
+ register number. */
if ((temp_code & 0x10) != 0x10)
temp_code &= 0xf0;
switch (temp_code)
{
case 0x00:
+ /* This is mov.b @aa:16,Rd. */
bfd_put_8 (abfd, (code & 0xf) | 0x20,
contents + irel->r_offset - 2);
break;
case 0x80:
+ /* This is mov.b Rs,@aa:16. */
bfd_put_8 (abfd, (code & 0xf) | 0x30,
contents + irel->r_offset - 2);
break;
case 0x18:
+ /* This is a bit-maniputation instruction that
+ stores one bit into memory, one of "bclr",
+ "bist", "bnot", "bset", and "bst". */
bfd_put_8 (abfd, 0x7f, contents + irel->r_offset - 2);
break;
case 0x10:
+ /* This is a bit-maniputation instruction that
+ loads one bit from memory, one of "band",
+ "biand", "bild", "bior", "bixor", "bld", "bor",
+ "btst", and "bxor". */
bfd_put_8 (abfd, 0x7e, contents + irel->r_offset - 2);
break;
default:
@@ -1068,8 +1092,15 @@ elf32_h8_relax_section (bfd *abfd, asection *sec,
break;
}
- /* This is a 24 bit absolute address in a "mov.b" insn, which may
- become an 8 bit absolute address if its in the right range. */
+ /* This is a 24-bit absolute address in one of the following
+ instructions:
+
+ "band", "bclr", "biand", "bild", "bior", "bist", "bixor",
+ "bld", "bnot", "bor", "bset", "bst", "btst", "bxor", and
+ "mov.b"
+
+ We may relax this into an 8-bit absolute address if it's in
+ the right range. */
case R_H8_DIR24A8:
{
bfd_vma value;
@@ -1089,29 +1120,42 @@ elf32_h8_relax_section (bfd *abfd, asection *sec,
/* Get the opcode. */
code = bfd_get_8 (abfd, contents + irel->r_offset - 2);
- /* Sanity check. */
+ /* All instructions with R_H8_DIR24A8 start with
+ 0x6a. */
if (code != 0x6a)
abort ();
temp_code = code = bfd_get_8 (abfd, contents + irel->r_offset - 1);
+ /* If this is a mov.b instruction, clear the lower
+ nibble, which contains the source/destination
+ register number. */
if ((temp_code & 0x30) != 0x30)
temp_code &= 0xf0;
switch (temp_code)
{
case 0x20:
+ /* This is mov.b @aa:24/32,Rd. */
bfd_put_8 (abfd, (code & 0xf) | 0x20,
contents + irel->r_offset - 2);
break;
case 0xa0:
+ /* This is mov.b Rs,@aa:24/32. */
bfd_put_8 (abfd, (code & 0xf) | 0x30,
contents + irel->r_offset - 2);
break;
case 0x38:
+ /* This is a bit-maniputation instruction that
+ stores one bit into memory, one of "bclr",
+ "bist", "bnot", "bset", and "bst". */
bfd_put_8 (abfd, 0x7f, contents + irel->r_offset - 2);
break;
case 0x30:
+ /* This is a bit-maniputation instruction that
+ loads one bit from memory, one of "band",
+ "biand", "bild", "bior", "bixor", "bld", "bor",
+ "btst", and "bxor". */
bfd_put_8 (abfd, 0x7e, contents + irel->r_offset - 2);
break;
default: