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[patch] bfd/*-h8300.c: Add comments about relaxation.
- From: Kazu Hirata <kazu at cs dot umass dot edu>
- To: binutils at sources dot redhat dot com
- Cc: anilp1 at KPITCummins dot com
- Date: Fri, 16 Jan 2004 18:36:12 -0500 (EST)
- Subject: [patch] bfd/*-h8300.c: Add comments about relaxation.
Hi,
Attached is a patch to add comments about relaxation.
Committed as obvious.
Kazu Hirata
2004-01-16 Kazu Hirata <kazu@cs.umass.edu>
* coff-h8300.c: Add comments about relaxation.
* elf32-h8300.c: Likewise.
Index: coff-h8300.c
===================================================================
RCS file: /cvs/src/src/bfd/coff-h8300.c,v
retrieving revision 1.26
diff -u -r1.26 coff-h8300.c
--- coff-h8300.c 12 Jan 2004 15:02:18 -0000 1.26
+++ coff-h8300.c 16 Jan 2004 23:29:42 -0000
@@ -940,15 +940,26 @@
break;
- /* A 16bit absolute mov.b that is now an 8bit absolute mov.b. */
+ /* 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_MOV16B2:
value = bfd_coff_reloc16_get_value (reloc, link_info, input_section);
- /* Sanity check. */
+ /* All instructions with R_H8_DIR16B2 start with 0x6a. */
if (data[dst_address - 2] != 0x6a)
abort ();
temp_code = data[src_address - 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;
@@ -956,15 +967,23 @@
switch (temp_code)
{
case 0x00:
+ /* This is mov.b @aa:16,Rd. */
data[dst_address - 2] = (data[src_address - 1] & 0xf) | 0x20;
break;
case 0x80:
+ /* This is mov.b Rs,@aa:16. */
data[dst_address - 2] = (data[src_address - 1] & 0xf) | 0x30;
break;
case 0x18:
+ /* This is a bit-maniputation instruction that stores one
+ bit into memory, one of "bclr", "bist", "bnot", "bset",
+ and "bst". */
data[dst_address - 2] = 0x7f;
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". */
data[dst_address - 2] = 0x7e;
break;
default:
@@ -975,15 +994,26 @@
src_address += 2;
break;
- /* Similarly for a 24bit mov.b */
+ /* 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_MOV24B2:
value = bfd_coff_reloc16_get_value (reloc, link_info, input_section);
- /* Sanity check. */
+ /* All instructions with R_MOV24B2 start with 0x6a. */
if (data[dst_address - 2] != 0x6a)
abort ();
temp_code = data[src_address - 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;
@@ -991,15 +1021,23 @@
switch (temp_code)
{
case 0x20:
+ /* This is mov.b @aa:24/32,Rd. */
data[dst_address - 2] = (data[src_address - 1] & 0xf) | 0x20;
break;
case 0xa0:
+ /* This is mov.b Rs,@aa:24/32. */
data[dst_address - 2] = (data[src_address - 1] & 0xf) | 0x30;
break;
case 0x38:
+ /* This is a bit-maniputation instruction that stores one
+ bit into memory, one of "bclr", "bist", "bnot", "bset",
+ and "bst". */
data[dst_address - 2] = 0x7f;
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". */
data[dst_address - 2] = 0x7e;
break;
default:
Index: elf32-h8300.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-h8300.c,v
retrieving revision 1.37
diff -u -r1.37 elf32-h8300.c
--- elf32-h8300.c 12 Jan 2004 15:02:18 -0000 1.37
+++ elf32-h8300.c 16 Jan 2004 23:29:43 -0000
@@ -659,6 +659,10 @@
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 @@
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 @@
/* 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 @@
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 @@
/* 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: