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MIPS16/GAS: Fix delay slot filling across frags 

Fix an assertion failure like:

test.s: Assembler messages:
test.s:3: Internal error!
Assertion failure in append_insn at .../gas/config/tc-mips.c:7523.
Please report this bug.

triggered by assembling MIPS16 code like:

hello:
	addiu	$4, $4, 4
	jr	$31

with the generation of a listing file enabled, e.g.:

$ as -mips16 -O2 -aln=test.lst

The cause of the problem is the lack of support for moving instructions
across frags in MIPS16 jump swapping, which triggers more easily with
listing enabled as in that case every instruction gets placed in its own
frag.  It would trigger even with listing disabled though if the
instruction to swap a MIPS16 jump with was unfortunately enough placed
as last in a frag that became full.

This scenario is already handled correctly with branch swapping in
regular MIPS and microMIPS code, so reuse it for MIPS16 code as well,
and now that all MIPS16 handling has become the same as the regular MIPS
and microMIPS cases remove MIPS16 special casing altogether.

This effectively complements:

commit 464ab0e55a
Author: Maciej W. Rozycki <macro@linux-mips.org>
Date:   Mon Aug 6 20:33:00 2012 +0000

<https://sourceware.org/ml/binutils/2012-08/msg00043.html>, ("MIPS/GAS:
Correct microMIPS branch swapping assertion") for the MIPS16 case.

The assertion itself was introduced with:

commit 1e91584932
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date:   Wed Mar 9 09:17:02 2005 +0000

<https://sourceware.org/ml/binutils/2005-03/msg00217.html>, ("Rework
MIPS nop-insertion code, add -mfix-vr4130 [5/11]"), but its introduction
merely noted our existing lack of support for MIPS16 jump swapping
across frags.

	gas/
	* config/tc-mips.c (append_insn) <APPEND_SWAP>: Do not special
	case MIPS16 handling.
	* testsuite/gas/mips/branch-swap-3.d: New test.
	* testsuite/gas/mips/branch-swap-4.d: New test.
	* testsuite/gas/mips/mips16@branch-swap-3.d: New test.
	* testsuite/gas/mips/mips16@branch-swap-4.d: New test.
	* testsuite/gas/mips/micromips@branch-swap-3.d: New test.
	* testsuite/gas/mips/micromips@branch-swap-4.d: New test.
	* testsuite/gas/mips/branch-swap-3.s: New test source.
	* testsuite/gas/mips/mips.exp: Run the new tests.
This commit is contained in:
Matthew Fortune 2016-06-30 15:02:20 +01:00 committed by Maciej W. Rozycki
parent 5e35670ba7
commit 99e7978bd2
10 changed files with 186 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
gas/ChangeLog
View File

@ -1,3 +1,17 @@
2016-06-30 Matthew Fortune <Matthew.Fortune@imgtec.com>
Maciej W. Rozycki <macro@imgtec.com>
* config/tc-mips.c (append_insn) <APPEND_SWAP>: Do not special
case MIPS16 handling.
* testsuite/gas/mips/branch-swap-3.d: New test.
* testsuite/gas/mips/branch-swap-4.d: New test.
* testsuite/gas/mips/mips16@branch-swap-3.d: New test.
* testsuite/gas/mips/mips16@branch-swap-4.d: New test.
* testsuite/gas/mips/micromips@branch-swap-3.d: New test.
* testsuite/gas/mips/micromips@branch-swap-4.d: New test.
* testsuite/gas/mips/branch-swap-3.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
2016-06-30 Maciej W. Rozycki <macro@imgtec.com>
* config/tc-mips.c (append_insn): Simplify non-MIPS16 branch

9
gas/config/tc-mips.c
View File

@ -7518,13 +7518,8 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
case APPEND_SWAP:
{
struct mips_cl_insn delay = history[0];
if (mips_opts.mips16)
{
know (delay.frag == ip->frag);
move_insn (ip, delay.frag, delay.where);
move_insn (&delay, ip->frag, ip->where + insn_length (ip));
}
else if (relaxed_branch || delay.frag != ip->frag)
if (relaxed_branch || delay.frag != ip->frag)
{
/* Add the delay slot instruction to the end of the
current frag and shrink the fixed part of the

38
gas/testsuite/gas/mips/branch-swap-3.d Normal file
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@ -0,0 +1,38 @@
#objdump: -dr -M reg-names=numeric
#as: -32 -O2 -aln=branch-swap-lst.lst
#name: MIPS branch swapping with assembler listing
#source: branch-swap-3.s
# Check delay slot filling with a listing file works
.*: +file format .*mips.*
Disassembly of section \.text:
[0-9a-f]+ <test>:
[ 0-9a-f]+: 0c000000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS_26 func
[ 0-9a-f]+: 00408025 move \$16,\$2
[ 0-9a-f]+: 0c000000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS_26 func
[ 0-9a-f]+: 26300001 addiu \$16,\$17,1
[ 0-9a-f]+: 0c000000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS_26 func
[ 0-9a-f]+: 26300001 addiu \$16,\$17,1
[ 0-9a-f]+: 0c000000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS_26 func
[ 0-9a-f]+: 26303fff addiu \$16,\$17,16383
[ 0-9a-f]+: 0c000000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS_26 func
[ 0-9a-f]+: 26303fff addiu \$16,\$17,16383
[ 0-9a-f]+: 03e0000[89] jr \$31
[ 0-9a-f]+: 00408025 move \$16,\$2
[ 0-9a-f]+: 03e0000[89] jr \$31
[ 0-9a-f]+: 26300001 addiu \$16,\$17,1
[ 0-9a-f]+: 03e0000[89] jr \$31
[ 0-9a-f]+: 26300001 addiu \$16,\$17,1
[ 0-9a-f]+: 03e0000[89] jr \$31
[ 0-9a-f]+: 26303fff addiu \$16,\$17,16383
[ 0-9a-f]+: 03e0000[89] jr \$31
[ 0-9a-f]+: 26303fff addiu \$16,\$17,16383
\.\.\.

30
gas/testsuite/gas/mips/branch-swap-3.s Normal file
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@ -0,0 +1,30 @@
.text
test:
move $16, $2
jal func
addiu $16, $17, 1
jal func
addiu $16, $17, foo
jal func
addiu $16, $17, 0x3fff
jal func
addiu $16, $17, bar
jal func
move $16, $2
jr $31
addiu $16, $17, 1
jr $31
addiu $16, $17, foo
jr $31
addiu $16, $17, 0x3fff
jr $31
addiu $16, $17, bar
jr $31
.set foo, 1
.set bar, 0x3fff
# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
.space 16
.align 4, 0

5
gas/testsuite/gas/mips/branch-swap-4.d Normal file
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@ -0,0 +1,5 @@
#objdump: -dr -M reg-names=numeric
#as: -32 -O2
#name: MIPS branch swapping without assembler listing
#source: branch-swap-3.s
#dump: branch-swap-3.d

40
gas/testsuite/gas/mips/micromips@branch-swap-3.d Normal file
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@ -0,0 +1,40 @@
#objdump: -dr -M reg-names=numeric
#as: -32 -O2 -aln=branch-swap-lst.lst
#name: MIPS branch swapping with assembler listing
#source: branch-swap-3.s
# Check delay slot filling with a listing file works (microMIPS)
.*: +file format .*mips.*
Disassembly of section \.text:
[0-9a-f]+ <test>:
[ 0-9a-f]+: 0e02 move \$16,\$2
[ 0-9a-f]+: f400 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MICROMIPS_26_S1 func
[ 0-9a-f]+: 0000 0000 nop
[ 0-9a-f]+: 6c10 addiu \$16,\$17,1
[ 0-9a-f]+: f400 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MICROMIPS_26_S1 func
[ 0-9a-f]+: 0000 0000 nop
[ 0-9a-f]+: f400 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MICROMIPS_26_S1 func
[ 0-9a-f]+: 3211 0001 addiu \$16,\$17,1
[ 0-9a-f]+: f400 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MICROMIPS_26_S1 func
[ 0-9a-f]+: 3211 3fff addiu \$16,\$17,16383
[ 0-9a-f]+: f400 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MICROMIPS_26_S1 func
[ 0-9a-f]+: 3211 3fff addiu \$16,\$17,16383
[ 0-9a-f]+: 459f jr \$31
[ 0-9a-f]+: 0e02 move \$16,\$2
[ 0-9a-f]+: 459f jr \$31
[ 0-9a-f]+: 6c10 addiu \$16,\$17,1
[ 0-9a-f]+: 459f jr \$31
[ 0-9a-f]+: 3211 0001 addiu \$16,\$17,1
[ 0-9a-f]+: 459f jr \$31
[ 0-9a-f]+: 3211 3fff addiu \$16,\$17,16383
[ 0-9a-f]+: 459f jr \$31
[ 0-9a-f]+: 3211 3fff addiu \$16,\$17,16383
\.\.\.

5
gas/testsuite/gas/mips/micromips@branch-swap-4.d Normal file
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@ -0,0 +1,5 @@
#objdump: -dr -M reg-names=numeric
#as: -32 -O2
#name: MIPS branch swapping without assembler listing
#source: branch-swap-3.s
#dump: micromips@branch-swap-3.d

3
gas/testsuite/gas/mips/mips.exp
View File

@ -575,6 +575,9 @@ if { [istarget mips*-*-vxworks*] } {
"MIPS branch swapping ($count)"
}
run_dump_test_arches "branch-swap-3" [mips_arch_list_all]
run_dump_test_arches "branch-swap-4" [mips_arch_list_all]
run_dump_test "branch-section-1"
run_dump_test "branch-section-2"
run_dump_test "branch-section-3"

44
gas/testsuite/gas/mips/mips16@branch-swap-3.d Normal file
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@ -0,0 +1,44 @@
#objdump: -dr -M reg-names=numeric
#as: -32 -O2 -aln=branch-swap-lst.lst
#name: MIPS branch swapping with assembler listing
#source: branch-swap-3.s
# Check delay slot filling with a listing file works (MIPS16)
.*: +file format .*mips.*
Disassembly of section \.text:
[0-9a-f]+ <test>:
[ 0-9a-f]+: 1800 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS16_26 func
[ 0-9a-f]+: 6702 move \$16,\$2
[ 0-9a-f]+: 1800 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS16_26 func
[ 0-9a-f]+: 4101 addiu \$16,\$17,1
[ 0-9a-f]+: 4101 addiu \$16,\$17,1
[ 0-9a-f]+: 1800 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS16_26 func
[ 0-9a-f]+: 6500 nop
[ 0-9a-f]+: f7f7 410f addiu \$16,\$17,16383
[ 0-9a-f]+: 1800 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS16_26 func
[ 0-9a-f]+: 6500 nop
[ 0-9a-f]+: f7f7 410f addiu \$16,\$17,16383
[ 0-9a-f]+: 1800 0000 jal 0 <test>
[ ]*[0-9a-f]+: R_MIPS16_26 func
[ 0-9a-f]+: 6500 nop
[ 0-9a-f]+: e820 jr \$31
[ 0-9a-f]+: 6702 move \$16,\$2
[ 0-9a-f]+: e820 jr \$31
[ 0-9a-f]+: 4101 addiu \$16,\$17,1
[ 0-9a-f]+: 4101 addiu \$16,\$17,1
[ 0-9a-f]+: e820 jr \$31
[ 0-9a-f]+: 6500 nop
[ 0-9a-f]+: f7f7 410f addiu \$16,\$17,16383
[ 0-9a-f]+: e820 jr \$31
[ 0-9a-f]+: 6500 nop
[ 0-9a-f]+: f7f7 410f addiu \$16,\$17,16383
[ 0-9a-f]+: e820 jr \$31
[ 0-9a-f]+: 6500 nop
\.\.\.

5
gas/testsuite/gas/mips/mips16@branch-swap-4.d Normal file
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@ -0,0 +1,5 @@
#objdump: -dr -M reg-names=numeric
#as: -32 -O2
#name: MIPS branch swapping without assembler listing
#source: branch-swap-3.s
#dump: mips16@branch-swap-3.d