2009-04-09 Catherine Moore <clm@codesourcery.com>

* config/tc-mips.c (mips_fix_24k): Declare.
        (check_for_24k_errata): New.
        (mips_cleanup): Call check_for_24k_errata.
        (start_noreorder): Likewise.
        (md_mips_end): Likewise.
        (s_change_sec): Likewise.
        (s_change_section): Likewise.
        (append_insn): Call check_for_24k_errata.  Prevent
        ERET/DERET instructions from being moved into delay
        slots.
        (OPTION_FIX_24K): New.
        (OPTION_NO_FIX_24k) New.
        (md_longopts): Add "mfix-24k" and "mno-fix-24k".
        (md_parse_option): Handle fix-24k options.
        (md_show_usage): Display fix-24k options.
        * doc/c-mips.texi: Document.
        * testsuite/gas/mips/mips.exp: Run new tests.
        * testsuite/gas/mips/eret.s: New test.
        * testsuite/gas/mips/eret.d: New test output.
        * testsuite/gas/mips/eret.l: New test output.
This commit is contained in:
Catherine Moore 2009-04-09 15:55:59 +00:00
parent ef699244c2
commit 6a32d87432
7 changed files with 232 additions and 3 deletions

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@ -1,3 +1,26 @@
2009-04-09 Catherine Moore <clm@codesourcery.com>
* config/tc-mips.c (mips_fix_24k): Declare.
(check_for_24k_errata): New.
(mips_cleanup): Call check_for_24k_errata.
(start_noreorder): Likewise.
(md_mips_end): Likewise.
(s_change_sec): Likewise.
(s_change_section): Likewise.
(append_insn): Call check_for_24k_errata. Prevent
ERET/DERET instructions from being moved into delay
slots.
(OPTION_FIX_24K): New.
(OPTION_NO_FIX_24k) New.
(md_longopts): Add "mfix-24k" and "mno-fix-24k".
(md_parse_option): Handle fix-24k options.
(md_show_usage): Display fix-24k options.
* doc/c-mips.texi: Document.
* testsuite/gas/mips/mips.exp: Run new tests.
* testsuite/gas/mips/eret.s: New test.
* testsuite/gas/mips/eret.d: New test output.
* testsuite/gas/mips/eret.l: New test output.
2009-04-09 Adam Nemet <anemet@caviumnetworks.com>
* config/tc-mips.c (mips_dwarf2_addr_size): Use HAVE_64BIT_OBJECTS

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@ -760,6 +760,9 @@ static int mips_fix_vr4120;
/* ...likewise -mfix-vr4130. */
static int mips_fix_vr4130;
/* ...likewise -mfix-24k. */
static int mips_fix_24k;
/* We don't relax branches by default, since this causes us to expand
`la .l2 - .l1' if there's a branch between .l1 and .l2, because we
fail to compute the offset before expanding the macro to the most
@ -1789,6 +1792,85 @@ reg_lookup (char **s, unsigned int types, unsigned int *regnop)
return reg >= 0;
}
#define INSN_ERET 0x42000018
#define INSN_DERET 0x4200001f
/* Implement the ERET/DERET Errata for MIPS 24k.
If an ERET/DERET is encountered in a noreorder block,
warn if the ERET/DERET is followed by a branch instruction.
Also warn if the ERET/DERET is the last instruction in the
noreorder block.
IF an ERET/DERET is in a reorder block and is followed by a
branch instruction, insert a nop. */
static void
check_for_24k_errata (struct mips_cl_insn *insn, int eret_ndx)
{
bfd_boolean next_insn_is_branch = FALSE;
/* eret_ndx will be -1 for the last instruction in a section
and the ERET/DERET will be in insn, not history. */
if (insn
&& eret_ndx == -1
&& (insn->insn_opcode == INSN_ERET
|| insn->insn_opcode == INSN_DERET)
&& insn->noreorder_p)
{
as_warn (_("ERET and DERET must be followed by a NOP on the 24K."));
return;
}
if (history[eret_ndx].insn_opcode != INSN_ERET
&& history[eret_ndx].insn_opcode != INSN_DERET)
return;
if (!insn)
{
if (history[eret_ndx].noreorder_p)
as_warn (_("ERET and DERET must be followed by a NOP on the 24K."));
return;
}
next_insn_is_branch = ((insn->insn_opcode == INSN_ERET)
|| (insn->insn_opcode == INSN_DERET)
|| (insn->insn_mo->pinfo
& (INSN_UNCOND_BRANCH_DELAY
| INSN_COND_BRANCH_DELAY
| INSN_COND_BRANCH_LIKELY)));
if (next_insn_is_branch && history[eret_ndx].noreorder_p)
{
as_warn (_("ERET and DERET must be followed by a NOP on the 24K."));
return;
}
/* Emit nop if the next instruction is a branch. */
if (next_insn_is_branch)
{
long nop_where, br_where;
struct frag *nop_frag, *br_frag;
struct mips_cl_insn br_insn, nop_insn;
emit_nop ();
nop_insn = history[eret_ndx - 1];
nop_frag = history[eret_ndx - 1].frag;
nop_where = history[eret_ndx - 1].where;
br_insn = history[eret_ndx];
br_frag = history[eret_ndx].frag;
br_where = history[eret_ndx].where;
move_insn (&nop_insn, br_frag, br_where);
move_insn (&br_insn, nop_frag, nop_where);
history[eret_ndx-1] = br_insn;
history[eret_ndx] = nop_insn;
}
}
/* Return TRUE if opcode MO is valid on the currently selected ISA and
architecture. If EXPANSIONP is TRUE then this check is done while
expanding a macro. Use is_opcode_valid_16 for MIPS16 opcodes. */
@ -2074,6 +2156,9 @@ md_begin (void)
void
md_mips_end (void)
{
if (mips_fix_24k)
check_for_24k_errata ((struct mips_cl_insn *) &history[0], -1);
if (! ECOFF_DEBUGGING)
md_obj_end ();
}
@ -2705,6 +2790,7 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
bfd_reloc_code_real_type *reloc_type)
{
unsigned long prev_pinfo, pinfo;
int hndx_24k = 0;
relax_stateT prev_insn_frag_type = 0;
bfd_boolean relaxed_branch = FALSE;
segment_info_type *si = seg_info (now_seg);
@ -3238,7 +3324,11 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
|| (mips_opts.mips16 && history[0].fixp[0])
/* If the previous instruction is a sync, sync.l, or
sync.p, we can not swap. */
|| (prev_pinfo & INSN_SYNC))
|| (prev_pinfo & INSN_SYNC)
/* If the previous instruction is an ERET or
DERET, avoid the swap. */
|| (history[0].insn_opcode == INSN_ERET)
|| (history[0].insn_opcode == INSN_DERET))
{
if (mips_opts.mips16
&& (pinfo & INSN_UNCOND_BRANCH_DELAY)
@ -3258,6 +3348,8 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
slot, and bump the destination address. */
insert_into_history (0, 1, ip);
emit_nop ();
if (mips_fix_24k)
hndx_24k++;
}
if (mips_relax.sequence)
@ -3297,7 +3389,14 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
/* If that was an unconditional branch, forget the previous
insn information. */
if (pinfo & INSN_UNCOND_BRANCH_DELAY)
mips_no_prev_insn ();
{
/* Check for eret/deret before clearing history. */
if (mips_fix_24k)
check_for_24k_errata (
(struct mips_cl_insn *) &history[hndx_24k],
hndx_24k+1);
mips_no_prev_insn ();
}
}
else if (pinfo & INSN_COND_BRANCH_LIKELY)
{
@ -3307,6 +3406,8 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
the next instruction. */
insert_into_history (0, 1, ip);
emit_nop ();
if (mips_fix_24k)
hndx_24k++;
}
else
insert_into_history (0, 1, ip);
@ -3314,6 +3415,10 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
else
insert_into_history (0, 1, ip);
if (mips_fix_24k)
check_for_24k_errata ((struct mips_cl_insn *) &history[hndx_24k],
hndx_24k+1);
/* We just output an insn, so the next one doesn't have a label. */
mips_clear_insn_labels ();
}
@ -3400,6 +3505,9 @@ start_noreorder (void)
static void
end_noreorder (void)
{
if (mips_fix_24k)
check_for_24k_errata (NULL, 0);
mips_opts.noreorder--;
if (mips_opts.noreorder == 0 && prev_nop_frag != NULL)
{
@ -11175,7 +11283,9 @@ enum options
OPTION_M3900,
OPTION_NO_M3900,
OPTION_M7000_HILO_FIX,
OPTION_MNO_7000_HILO_FIX,
OPTION_MNO_7000_HILO_FIX,
OPTION_FIX_24K,
OPTION_NO_FIX_24K,
OPTION_FIX_VR4120,
OPTION_NO_FIX_VR4120,
OPTION_FIX_VR4130,
@ -11268,6 +11378,8 @@ struct option md_longopts[] =
{"mno-fix-vr4120", no_argument, NULL, OPTION_NO_FIX_VR4120},
{"mfix-vr4130", no_argument, NULL, OPTION_FIX_VR4130},
{"mno-fix-vr4130", no_argument, NULL, OPTION_NO_FIX_VR4130},
{"mfix-24k", no_argument, NULL, OPTION_FIX_24K},
{"mno-fix-24k", no_argument, NULL, OPTION_NO_FIX_24K},
/* Miscellaneous options. */
{"trap", no_argument, NULL, OPTION_TRAP},
@ -11521,6 +11633,14 @@ md_parse_option (int c, char *arg)
mips_opts.ase_smartmips = 0;
break;
case OPTION_FIX_24K:
mips_fix_24k = 1;
break;
case OPTION_NO_FIX_24K:
mips_fix_24k = 0;
break;
case OPTION_FIX_VR4120:
mips_fix_vr4120 = 1;
break;
@ -12468,6 +12588,10 @@ s_change_sec (int sec)
#endif
mips_emit_delays ();
if (mips_fix_24k)
check_for_24k_errata ((struct mips_cl_insn *) &history[0], -1);
switch (sec)
{
case 't':
@ -12526,6 +12650,9 @@ s_change_section (int ignore ATTRIBUTE_UNUSED)
if (!IS_ELF)
return;
if (mips_fix_24k)
check_for_24k_errata ((struct mips_cl_insn *) &history[0], -1);
section_name = input_line_pointer;
c = get_symbol_end ();
if (c)
@ -15457,6 +15584,7 @@ MIPS options:\n\
fprintf (stream, _("\
-mfix-vr4120 work around certain VR4120 errata\n\
-mfix-vr4130 work around VR4130 mflo/mfhi errata\n\
-mfix-24k insert a nop after ERET and DERET instructions\n\
-mgp32 use 32-bit GPRs, regardless of the chosen ISA\n\
-mfp32 use 32-bit FPRs, regardless of the chosen ISA\n\
-msym32 assume all symbols have 32-bit values\n\

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@ -182,6 +182,10 @@ all problems in hand-written assembler code.
@itemx -no-mfix-vr4130
Insert nops to work around the VR4130 @samp{mflo}/@samp{mfhi} errata.
@item -mfix-24k
@itemx -no-mfix-24k
Insert nops to work around the 24K @samp{eret}/@samp{deret} errata.
@item -m4010
@itemx -no-m4010
Generate code for the LSI @sc{r4010} chip. This tells the assembler to

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@ -0,0 +1,41 @@
#objdump: -d
#name: MIPS eret disassembly
#as: -mfix-24k -march=24kc --no-warn
.*\.o: file format .*mips.*
Disassembly of section \.text:
00000000 <\.text>:
0: 240c0000 li t4,0
4: 42000018 eret
8: 00000000 nop
c: 10000003 b 0x1c
10: 00000000 nop
14: 240a0003 li t2,3
18: 42000018 eret
1c: 24040000 li a0,0
20: 4200001f deret
24: 00000000 nop
28: 116afffa beq t3,t2,0x14
2c: 00000000 nop
30: 4200001f deret
34: 00000000 nop
38: 42000018 eret
3c: 00000000 nop
40: 42000018 eret
44: 00000000 nop
48: 1000fff4 b 0x1c
4c: 00000000 nop
50: 240c0004 li t4,4
54: 4200001f deret
58: 240c0003 li t4,3
5c: 42000018 eret
60: 10000005 b 0x78
64: 240c0003 li t4,3
68: 42000018 eret
6c: 00000000 nop
70: 10000001 b 0x78
74: 240c0003 li t4,3
78: 240c0003 li t4,3
7c: 42000018 eret

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@ -0,0 +1,3 @@
.*\.s: Assembler messages:
.*\.s:20: Warning: ERET and DERET must be followed by a NOP on the 24K\.
.*\.s:27: Warning: ERET and DERET must be followed by a NOP on the 24K\.

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@ -0,0 +1,27 @@
.text
li $t4, 0
eret
b 2f
1: li $t2, 3
eret
2: li $a0, 0
deret
beq $t3,$t2,1b
deret
eret
eret
b 2b
.set noreorder
li $t4, 4
deret
li $t4, 3
eret
b 1f
li $t4, 3
eret
nop
b 1f
li $t4, 3
1: li $t4, 3
eret

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@ -436,6 +436,9 @@ if { [istarget mips*-*-vxworks*] } {
} else {
run_dump_test "jal"
}
run_dump_test "eret"
run_list_test "eret" "-mfix-24k -march=24kc" "MIPS eret warnings"
if $elf { run_dump_test "jal-svr4pic" }
if $elf { run_dump_test "jal-xgot" }
run_list_test_arches "jal-range" "-32" [mips_arch_list_matching mips1]