Re: [patch] Enable power7 disassembling

[Peter Bergner <bergner@vnet.ibm.com>]

On Mon, 2009-03-02 at 22:04 +0100, Jan Kratochvil wrote:
> GDB has currently for PowerPC hardcoded disassembling `-Many' by the patch:
> http://sourceware.org/ml/gdb-patches/2007-02/msg00000.html
> http://sourceware.org/ml/gdb-cvs/2007-02/msg00061.html
> 
> ./gas/as-new -mpower7 -o ./gas/testsuite/gas/ppc/power7.o ./gas/testsuite/gas/ppc/power7.s
> objdump               -d ./gas/testsuite/gas/ppc/power7.o
>   20:   f0 64 28 50     .long 0xf0642850
> objdump -Mpower7      -d ./gas/testsuite/gas/ppc/power7.o
>   20:   f0 64 28 50     xxmrghd vs3,vs4,vs5
> objdump -Many         -d ./gas/testsuite/gas/ppc/power7.o
>   20:   f0 64 28 50     stfq    f3,10320(r4)

This is caused by primary opcode 60 being reused by POWER2 (which is
actually not a Power ISA supported processor) and POWER7 (which is).
The disassembler happily chooses the first matching instruction
it comes across in the opcode table, which happens to be POWER2's
stfq, so that's what we see.  I think it might make sense to
swap their order in the opcode table, so the processor more
likely to be used is listed first.

Alan, what do you think of the patch below?

Heh, I'll note that stfq doesn't even disassemble with -Mpower2,
since there is no code in ppc-dis.c that recognizes POWER2.
Ditto for a lot of other processor names.



> Therefore assuming there should be a new GDB option:
>   set powerpc disassembler-options power7
> which would still default to `any' as currently but one could override it.

This still might be a good idea.  I assume you could choose any
valid ppc processor name accepted by the disassembler here?
Eg, power4, power5, booke, etc.


Peter


opcodes/
	* ppc-opc.c (powerpc_opcodes): Reorder the opcode table so that
	instructions from newer processors are listed before older ones.

Index: opcodes/ppc-opc.c
===================================================================
RCS file: /cvs/src/src/opcodes/ppc-opc.c,v
retrieving revision 1.117
diff -u -p -r1.117 ppc-opc.c
--- opcodes/ppc-opc.c	26 Feb 2009 22:07:33 -0000	1.117
+++ opcodes/ppc-opc.c	3 Mar 2009 20:56:59 -0000
@@ -4560,8 +4560,8 @@ const struct powerpc_opcode powerpc_opco
 
 {"lhbrx",	X(31,790),	X_MASK,      COM,	PPCNONE,	{RT, RA0, RB}},
 
-{"lfqx",	X(31,791),	X_MASK,      POWER2,	PPCNONE,	{FRT, RA, RB}},
 {"lfdpx",	X(31,791),	X_MASK,      POWER6,	POWER7,		{FRT, RA, RB}},
+{"lfqx",	X(31,791),	X_MASK,      POWER2,	PPCNONE,	{FRT, RA, RB}},
 
 {"sraw",	XRC(31,792,0),	X_MASK,      PPCCOM,	PPCNONE,	{RA, RS, RB}},
 {"sra",		XRC(31,792,0),	X_MASK,      PWRCOM,	PPCNONE,	{RA, RS, RB}},
@@ -4638,8 +4638,8 @@ const struct powerpc_opcode powerpc_opco
 
 {"sthbrx",	X(31,918),	X_MASK,      COM,	PPCNONE,	{RS, RA0, RB}},
 
-{"stfqx",	X(31,919),	X_MASK,      POWER2,	PPCNONE,	{FRS, RA, RB}},
 {"stfdpx",	X(31,919),	X_MASK,      POWER6,	PPCNONE,	{FRS, RA, RB}},
+{"stfqx",	X(31,919),	X_MASK,      POWER2,	PPCNONE,	{FRS, RA, RB}},
 
 {"sraq",	XRC(31,920,0),	X_MASK,      M601,	PPCNONE,	{RA, RS, RB}},
 {"sraq.",	XRC(31,920,1),	X_MASK,      M601,	PPCNONE,	{RA, RS, RB}},
@@ -4801,12 +4801,12 @@ const struct powerpc_opcode powerpc_opco
 
 {"psq_l",	OP(56),		OP_MASK,     PPCPS,	PPCNONE,	{FRT,PSD,RA,PSW,PSQ}},
 
+{"lfdp",	OP(57),		OP_MASK,     POWER6,	POWER7,		{FRT, D, RA0}},
+
 {"lfqu",	OP(57),		OP_MASK,     POWER2,	PPCNONE,	{FRT, D, RA0}},
 
 {"psq_lu",	OP(57),		OP_MASK,     PPCPS,	PPCNONE,	{FRT,PSD,RA,PSW,PSQ}},
 
-{"lfdp",	OP(57),		OP_MASK,     POWER6,	POWER7,		{FRT, D, RA0}},
-
 {"ld",		DSO(58,0),	DS_MASK,     PPC64,	PPCNONE,	{RT, DS, RA0}},
 {"ldu",		DSO(58,1),	DS_MASK,     PPC64,	PPCNONE,	{RT, DS, RAL}},
 {"lwa",		DSO(58,2),	DS_MASK,     PPC64,	PPCNONE,	{RT, DS, RA0}},
@@ -4921,10 +4921,6 @@ const struct powerpc_opcode powerpc_opco
 {"fcfidus",	XRC(59,974,0),	XRA_MASK,    POWER7,	PPCNONE,	{FRT, FRB}},
 {"fcfidus.",	XRC(59,974,1),	XRA_MASK,    POWER7,	PPCNONE,	{FRT, FRB}},
 
-{"stfq",	OP(60),		OP_MASK,     POWER2,	PPCNONE,	{FRS, D, RA}},
-
-{"psq_st",	OP(60),		OP_MASK,     PPCPS,	PPCNONE,	{FRS,PSD,RA,PSW,PSQ}},
-
 {"xxsldwi",	XX3(60,2),	XX3SHW_MASK, PPCVSX,	PPCNONE,	{XT6, XA6, XB6, SHW}},
 {"xxsel",	XX4(60,3),	XX4_MASK,    PPCVSX,	PPCNONE,	{XT6, XA6, XB6, XC6}},
 {"xxspltd",	XX3(60,10),	XX3DM_MASK,  PPCVSX,	PPCNONE,	{XT6, XA6, XB6S, DMEX}},
@@ -5067,12 +5063,16 @@ const struct powerpc_opcode powerpc_opco
 {"xvcvsxddp",	XX2(60,504),	XX2_MASK,    PPCVSX,	PPCNONE,	{XT6, XB6}},
 {"xvnegdp",	XX2(60,505),	XX2_MASK,    PPCVSX,	PPCNONE,	{XT6, XB6}},
 
-{"psq_stu",	OP(61),		OP_MASK,     PPCPS,	PPCNONE,	{FRS,PSD,RA,PSW,PSQ}},
+{"stfq",	OP(60),		OP_MASK,     POWER2,	PPCNONE,	{FRS, D, RA}},
 
-{"stfqu",	OP(61),		OP_MASK,     POWER2,	PPCNONE,	{FRS, D, RA}},
+{"psq_st",	OP(60),		OP_MASK,     PPCPS,	PPCNONE,	{FRS,PSD,RA,PSW,PSQ}},
 
 {"stfdp",	OP(61),		OP_MASK,     POWER6,	PPCNONE,	{FRT, D, RA0}},
 
+{"stfqu",	OP(61),		OP_MASK,     POWER2,	PPCNONE,	{FRS, D, RA}},
+
+{"psq_stu",	OP(61),		OP_MASK,     PPCPS,	PPCNONE,	{FRS,PSD,RA,PSW,PSQ}},
+
 {"std",		DSO(62,0),	DS_MASK,     PPC64,	PPCNONE,	{RS, DS, RA0}},
 {"stdu",	DSO(62,1),	DS_MASK,     PPC64,	PPCNONE,	{RS, DS, RAS}},
 {"stq",		DSO(62,2),	DS_MASK,     POWER4,	PPCNONE,	{RSQ, DS, RA0}},