* [PATCH] MIPS/GAS: Fix register use annotation of ALNV.PS
@ 2011-02-25 1:06 Maciej W. Rozycki
2011-02-26 9:40 ` Richard Sandiford
0 siblings, 1 reply; 3+ messages in thread
From: Maciej W. Rozycki @ 2011-02-25 1:06 UTC (permalink / raw)
To: binutils; +Cc: Richard Sandiford
Hi,
The ALNV.PS instruction lacks register use annotation for its general
register argument. As a result it can be reordered into a branch delay
slot even if it reads a register that the branch writes. Here's a fix.
Regression-tested with the mips-sde-elf and mips-gnu-linux targets. OK
to apply?
2011-02-25 Maciej W. Rozycki <macro@codesourcery.com>
opcodes/
* mips-opc.c (mips_builtin_opcodes): Correct register use
annotation of "alnv.ps".
gas/testsuite/
* gas/mips/alnv_ps-swap.d: New test for ALNV.PS instruction
branch swapping.
* gas/mips/alnv_ps-swap.s: Source for the new test.
* gas/mips/mips.exp: Run the new test.
Maciej
binutils-mips-opcode-alnv.diff
Index: binutils-fsf-trunk-quilt/opcodes/mips-opc.c
===================================================================
--- binutils-fsf-trunk-quilt.orig/opcodes/mips-opc.c 2011-02-24 23:46:08.000000000 +0000
+++ binutils-fsf-trunk-quilt/opcodes/mips-opc.c 2011-02-24 23:46:09.000000000 +0000
@@ -297,7 +297,7 @@ const struct mips_opcode mips_builtin_op
{"alni.ob", "X,Y,Z,O", 0x78000018, 0xff00003f, WR_D|RD_S|RD_T|FP_D, 0, MX|SB1 },
{"alni.ob", "D,S,T,%", 0x48000018, 0xff00003f, WR_D|RD_S|RD_T, 0, N54 },
{"alni.qh", "X,Y,Z,O", 0x7800001a, 0xff00003f, WR_D|RD_S|RD_T|FP_D, 0, MX },
-{"alnv.ps", "D,V,T,s", 0x4c00001e, 0xfc00003f, WR_D|RD_S|RD_T|FP_D, 0, I5_33 },
+{"alnv.ps", "D,V,T,s", 0x4c00001e, 0xfc00003f, WR_D|RD_S|RD_T|RD_s|FP_D, 0, I5_33 },
{"alnv.ob", "X,Y,Z,s", 0x78000019, 0xfc00003f, WR_D|RD_S|RD_T|RD_s|FP_D, 0, MX|SB1 },
{"alnv.qh", "X,Y,Z,s", 0x7800001b, 0xfc00003f, WR_D|RD_S|RD_T|RD_s|FP_D, 0, MX },
{"and", "d,v,t", 0x00000024, 0xfc0007ff, WR_d|RD_s|RD_t, 0, I1 },
Index: binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/alnv_ps-swap.d
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/alnv_ps-swap.d 2011-02-24 23:46:09.000000000 +0000
@@ -0,0 +1,39 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS ALNV.PS instruction branch swapping
+#as: -32
+
+# Check that a register dependency between ALNV.PS and the following
+# branch prevents from branch swapping.
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+[0-9a-f]+ <[^>]*> 1000ffff b 0+0000 <foo>
+[0-9a-f]+ <[^>]*> 4c60111e alnv\.ps \$f4,\$f2,\$f0,v1
+[0-9a-f]+ <[^>]*> 0411fffd bal 0+0000 <foo>
+[0-9a-f]+ <[^>]*> 4c60111e alnv\.ps \$f4,\$f2,\$f0,v1
+[0-9a-f]+ <[^>]*> 0470fffb bltzal v1,0+0000 <foo>
+[0-9a-f]+ <[^>]*> 4c60111e alnv\.ps \$f4,\$f2,\$f0,v1
+[0-9a-f]+ <[^>]*> 0060f809 jalr v1
+[0-9a-f]+ <[^>]*> 4c60111e alnv\.ps \$f4,\$f2,\$f0,v1
+[0-9a-f]+ <[^>]*> 00602009 jalr a0,v1
+[0-9a-f]+ <[^>]*> 4c60111e alnv\.ps \$f4,\$f2,\$f0,v1
+[0-9a-f]+ <[^>]*> 4c60111e alnv\.ps \$f4,\$f2,\$f0,v1
+[0-9a-f]+ <[^>]*> 03e01809 jalr v1,ra
+[0-9a-f]+ <[^>]*> 00000000 nop
+[0-9a-f]+ <[^>]*> 1000fff2 b 0+0000 <foo>
+[0-9a-f]+ <[^>]*> 4fe0111e alnv\.ps \$f4,\$f2,\$f0,ra
+[0-9a-f]+ <[^>]*> 4fe0111e alnv\.ps \$f4,\$f2,\$f0,ra
+[0-9a-f]+ <[^>]*> 0411ffef bal 0+0000 <foo>
+[0-9a-f]+ <[^>]*> 00000000 nop
+[0-9a-f]+ <[^>]*> 4fe0111e alnv\.ps \$f4,\$f2,\$f0,ra
+[0-9a-f]+ <[^>]*> 0470ffec bltzal v1,0+0000 <foo>
+[0-9a-f]+ <[^>]*> 00000000 nop
+[0-9a-f]+ <[^>]*> 4fe0111e alnv\.ps \$f4,\$f2,\$f0,ra
+[0-9a-f]+ <[^>]*> 0060f809 jalr v1
+[0-9a-f]+ <[^>]*> 00000000 nop
+[0-9a-f]+ <[^>]*> 00602009 jalr a0,v1
+[0-9a-f]+ <[^>]*> 4fe0111e alnv\.ps \$f4,\$f2,\$f0,ra
+[0-9a-f]+ <[^>]*> 03e01809 jalr v1,ra
+[0-9a-f]+ <[^>]*> 4fe0111e alnv\.ps \$f4,\$f2,\$f0,ra
+ \.\.\.
Index: binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/alnv_ps-swap.s
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/alnv_ps-swap.s 2011-02-24 23:46:09.000000000 +0000
@@ -0,0 +1,33 @@
+# Source file to test branch swapping with the ALNV.PS instruction.
+
+ .text
+foo:
+ alnv.ps $f4, $f2, $f0, $3
+ b foo
+ alnv.ps $f4, $f2, $f0, $3
+ bal foo
+ alnv.ps $f4, $f2, $f0, $3
+ bltzal $3, foo
+ alnv.ps $f4, $f2, $f0, $3
+ jalr $3
+ alnv.ps $f4, $f2, $f0, $3
+ jalr $4, $3
+ alnv.ps $f4, $f2, $f0, $3
+ jalr $3, $31
+
+ alnv.ps $f4, $f2, $f0, $31
+ b foo
+ alnv.ps $f4, $f2, $f0, $31
+ bal foo
+ alnv.ps $f4, $f2, $f0, $31
+ bltzal $3, foo
+ alnv.ps $f4, $f2, $f0, $31
+ jalr $3
+ alnv.ps $f4, $f2, $f0, $31
+ jalr $4, $3
+ alnv.ps $f4, $f2, $f0, $31
+ jalr $3, $31
+
+# Force at least 8 (non-delay-slot) zero bytes, to make 'objdump' print ...
+ .align 2
+ .space 8
Index: binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/mips.exp
===================================================================
--- binutils-fsf-trunk-quilt.orig/gas/testsuite/gas/mips/mips.exp 2011-02-24 23:46:09.000000000 +0000
+++ binutils-fsf-trunk-quilt/gas/testsuite/gas/mips/mips.exp 2011-02-24 23:46:09.000000000 +0000
@@ -983,6 +983,9 @@ if { [istarget mips*-*-vxworks*] } {
run_dump_test "mips32-sync"
run_dump_test_arches "mips32r2-sync" \
[mips_arch_list_matching mips32r2]
+ run_dump_test_arches "alnv_ps-swap" [lsort -dictionary -unique [concat \
+ [mips_arch_list_matching mips5] \
+ [mips_arch_list_matching mips32r2] ] ]
if $has_newabi { run_dump_test "cfi-n64-1" }
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] MIPS/GAS: Fix register use annotation of ALNV.PS
2011-02-25 1:06 [PATCH] MIPS/GAS: Fix register use annotation of ALNV.PS Maciej W. Rozycki
@ 2011-02-26 9:40 ` Richard Sandiford
2011-02-28 16:39 ` Maciej W. Rozycki
0 siblings, 1 reply; 3+ messages in thread
From: Richard Sandiford @ 2011-02-26 9:40 UTC (permalink / raw)
To: Maciej W. Rozycki; +Cc: binutils
"Maciej W. Rozycki" <macro@codesourcery.com> writes:
> The ALNV.PS instruction lacks register use annotation for its general
> register argument. As a result it can be reordered into a branch delay
> slot even if it reads a register that the branch writes. Here's a fix.
Ouch. So easily done. Did someone find out the hard way, or was this
just by inspection?
> 2011-02-25 Maciej W. Rozycki <macro@codesourcery.com>
>
> opcodes/
> * mips-opc.c (mips_builtin_opcodes): Correct register use
> annotation of "alnv.ps".
>
> gas/testsuite/
> * gas/mips/alnv_ps-swap.d: New test for ALNV.PS instruction
> branch swapping.
> * gas/mips/alnv_ps-swap.s: Source for the new test.
> * gas/mips/mips.exp: Run the new test.
OK, thanks.
Richard
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] MIPS/GAS: Fix register use annotation of ALNV.PS
2011-02-26 9:40 ` Richard Sandiford
@ 2011-02-28 16:39 ` Maciej W. Rozycki
0 siblings, 0 replies; 3+ messages in thread
From: Maciej W. Rozycki @ 2011-02-28 16:39 UTC (permalink / raw)
To: Richard Sandiford; +Cc: binutils
On Sat, 26 Feb 2011, Richard Sandiford wrote:
> > The ALNV.PS instruction lacks register use annotation for its general
> > register argument. As a result it can be reordered into a branch delay
> > slot even if it reads a register that the branch writes. Here's a fix.
>
> Ouch. So easily done. Did someone find out the hard way, or was this
> just by inspection?
The microMIPS version of ALNV.PS is enough of an oddball that I couldn't
resist checking we've got the standard version right either. ;)
> > 2011-02-25 Maciej W. Rozycki <macro@codesourcery.com>
> >
> > opcodes/
> > * mips-opc.c (mips_builtin_opcodes): Correct register use
> > annotation of "alnv.ps".
> >
> > gas/testsuite/
> > * gas/mips/alnv_ps-swap.d: New test for ALNV.PS instruction
> > branch swapping.
> > * gas/mips/alnv_ps-swap.s: Source for the new test.
> > * gas/mips/mips.exp: Run the new test.
>
> OK, thanks.
It's now in, thanks.
Maciej
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-02-25 1:06 [PATCH] MIPS/GAS: Fix register use annotation of ALNV.PS Maciej W. Rozycki
2011-02-26 9:40 ` Richard Sandiford
2011-02-28 16:39 ` Maciej W. Rozycki
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