ppc/svp64: support svindex instruction

https://libre-soc.org/openpower/sv/
https://libre-soc.org/openpower/sv/remap/#svindex
https://libre-soc.org/openpower/isa/simplev/

gas/testsuite/gas/ppc/ppc.exp

@@ -159,3 +159,4 @@ run_dump_test "setvl"
 run_dump_test "svstep"
 run_dump_test "svshape"
 run_dump_test "svremap"
+run_dump_test "svindex"

gas/testsuite/gas/ppc/svindex.d

@@ -0,0 +1,16 @@
+#as: -mlibresoc
+#objdump: -dr -Mlibresoc
+
+.*:     file format .*
+
+
+Disassembly of section \.text:
+0+ <\.text>:
+.*:	(29 00 00 58|58 00 00 29) 	svindex 0,0,1,0,0,0,0
+.*:	(29 00 e0 5b|5b e0 00 29) 	svindex 31,0,1,0,0,0,0
+.*:	(29 00 1f 58|58 1f 00 29) 	svindex 0,31,1,0,0,0,0
+.*:	(29 f8 00 58|58 00 f8 29) 	svindex 0,0,32,0,0,0,0
+.*:	(29 06 00 58|58 00 06 29) 	svindex 0,0,1,3,0,0,0
+.*:	(29 01 00 58|58 00 01 29) 	svindex 0,0,1,0,1,0,0
+.*:	(a9 00 00 58|58 00 00 a9) 	svindex 0,0,1,0,0,1,0
+.*:	(69 00 00 58|58 00 00 69) 	svindex 0,0,1,0,0,0,1

gas/testsuite/gas/ppc/svindex.s

@@ -0,0 +1,8 @@
+svindex 0,0,1,0,0,0,0
+svindex 31,0,1,0,0,0,0
+svindex 0,31,1,0,0,0,0
+svindex 0,0,32,0,0,0,0
+svindex 0,0,1,3,0,0,0
+svindex 0,0,1,0,1,0,0
+svindex 0,0,1,0,0,1,0
+svindex 0,0,1,0,0,0,1

opcodes/ppc-opc.c

@@ -3509,6 +3509,7 @@ const struct powerpc_operand powerpc_operands[] =
 #define TO TBR + 1
 #define DUI TO
 #define SVme TO
+#define SVG TO
 #define TO_MASK (0x1f << 21)
   { 0x1f, 21, NULL, NULL, 0 },
 
@@ -3556,6 +3557,7 @@ const struct powerpc_operand powerpc_operands[] =
   /* The UIMM field in a VX form instruction.  */
 #define UIMM SIMM + 1
 #define DCTL UIMM
+#define rmm UIMM
   { 0x1f, 16, NULL, NULL, 0 },
 
   /* The 3-bit UIMM field in a VX form instruction.  */
@@ -3648,6 +3650,7 @@ const struct powerpc_operand powerpc_operands[] =
   /* The RMC or CY field in a Z23 form instruction.  */
 #define RMC A_L + 1
 #define CY RMC
+#define ew RMC
   { 0x3, 9, NULL, NULL, 0 },
 
 #define R RMC + 1
@@ -3836,12 +3839,15 @@ const struct powerpc_operand powerpc_operands[] =
   { 0x3f, 9, NULL, NULL, PPC_OPERAND_NONZERO },
 
 #define vf SVi + 1
+#define sk vf
   { 0x1, 6, NULL, NULL, 0 },
 
 #define vs vf + 1
+#define mm vs
   { 0x1, 7, NULL, NULL, 0 },
 
 #define ms vs + 1
+#define yx ms
   { 0x1, 8, NULL, NULL, 0 },
 
 #define SVLcr ms + 1
@@ -3854,6 +3860,7 @@ const struct powerpc_operand powerpc_operands[] =
   { 0x1f, 16, NULL, NULL, PPC_OPERAND_NONZERO },
 
 #define SVzd SVyd + 1
+#define SVd SVzd
   { 0x1f, 11, NULL, NULL, PPC_OPERAND_NONZERO },
 
 #define SVrm SVzd + 1
@@ -4758,6 +4765,12 @@ const unsigned int num_powerpc_operands = (sizeof (powerpc_operands)
    | (((uint64_t)(xop)) & 0x3f))
 #define SVRM_MASK	SVRM (0x3f, 0x3f)
 
+/* An SVI form instruction. */
+#define SVI(op, xop)				\
+  (OP (op)					\
+   | (((uint64_t)(xop)) & 0x3f))
+#define SVI_MASK	SVI (0x3f, 0x3f)
+
 /* The BO encodings used in extended conditional branch mnemonics.  */
 #define BODNZF	(0x0)
 #define BODNZFP	(0x1)
@@ -6835,6 +6848,8 @@ const struct powerpc_opcode powerpc_opcodes[] = {
 {"setvl",	SVL(22,27,0),	SVL_MASK,	SVP64,	PPCVLE,	{RT, RA, SVi, vf, vs, ms}},
 {"setvl.",	SVL(22,27,1),	SVL_MASK,	SVP64,	PPCVLE,	{RT, RA, SVi, vf, vs, ms}},
 
+{"svindex",	SVI(22,41),	SVI_MASK,	SVP64,	PPCVLE,	{SVG, rmm, SVd, ew, yx, mm, sk}},
+
 {"svremap",	SVRM(22,57),	SVRM_MASK,	SVP64,	PPCVLE,	{SVme, mi0, mi1, mi2, mo0, mo1, pst}},
 
 {"rotlw",	MME(23,31,0),	MMBME_MASK,  PPCCOM,	PPCVLE|EXT,	{RA, RS, RB}},