cmd/internal: add shift opcodes with shift operands on ppc64x

Some original shift opcodes for ppc64x expected an operand to be
a mask instead of a shift count, preventing some valid shift counts
from being written.

This adds new opcodes for shifts where needed, using mnemonics that
match the ppc64 asm and allowing the assembler to accept the full set
of valid shift counts.

Fixes #15016

Change-Id: Id573489f852038d06def279c13fd0523736878a7
Reviewed-on: https://go-review.googlesource.com/31853
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: David Chase <drchase@google.com>

src/cmd/asm/internal/asm/testdata/ppc64.s

@@ -594,6 +594,15 @@ label1:
 //	}
 	RLWMI	R1, R2, 4, 5, R3 // RLWMI	R1, R2, $201326592, R3
 
+
+// opcodes added with constant shift counts, not masks
+
+	RLDICR	$3, R2, $24, R4
+
+	RLDICL	$1, R2, $61, R6
+
+	RLDIMI  $7, R2, $52, R7
+
 //
 // load/store multiple
 //

src/cmd/internal/obj/ppc64/a.out.go

@@ -594,12 +594,18 @@ const (
 	ARFID
 	ARLDMI
 	ARLDMICC
+	ARLDIMI
+	ARLDIMICC
 	ARLDC
 	ARLDCCC
 	ARLDCR
 	ARLDCRCC
+	ARLDICR
+	ARLDICRCC
 	ARLDCL
 	ARLDCLCC
+	ARLDICL
+	ARLDICLCC
 	ASLBIA
 	ASLBIE
 	ASLBMFEE

src/cmd/internal/obj/ppc64/anames.go

@@ -286,12 +286,18 @@ var Anames = []string{
 	"RFID",
 	"RLDMI",
 	"RLDMICC",
+	"RLDIMI",
+	"RLDIMICC",
 	"RLDC",
 	"RLDCCC",
 	"RLDCR",
 	"RLDCRCC",
+	"RLDICR",
+	"RLDICRCC",
 	"RLDCL",
 	"RLDCLCC",
+	"RLDICL",
+	"RLDICLCC",
 	"SLBIA",
 	"SLBIE",
 	"SLBMFEE",

src/cmd/internal/obj/ppc64/asm9.go

@@ -139,6 +139,8 @@ var optab = []Optab{
 	{ARLDC, C_SCON, C_REG, C_LCON, C_REG, 29, 4, 0},
 	{ARLDCL, C_SCON, C_REG, C_LCON, C_REG, 29, 4, 0},
 	{ARLDCL, C_REG, C_REG, C_LCON, C_REG, 14, 4, 0},
+	{ARLDICL, C_REG, C_REG, C_LCON, C_REG, 14, 4, 0},
+	{ARLDICL, C_SCON, C_REG, C_LCON, C_REG, 14, 4, 0},
 	{ARLDCL, C_REG, C_NONE, C_LCON, C_REG, 14, 4, 0},
 	{AFADD, C_FREG, C_NONE, C_NONE, C_FREG, 2, 4, 0},
 	{AFADD, C_FREG, C_FREG, C_NONE, C_FREG, 2, 4, 0},
@@ -1484,6 +1486,8 @@ func buildop(ctxt *obj.Link) {
 
 		case ARLDMI:
 			opset(ARLDMICC, r0)
+			opset(ARLDIMI, r0)
+			opset(ARLDIMICC, r0)
 
 		case ARLDC:
 			opset(ARLDCCC, r0)
@@ -1493,6 +1497,11 @@ func buildop(ctxt *obj.Link) {
 			opset(ARLDCLCC, r0)
 			opset(ARLDCRCC, r0)
 
+		case ARLDICL:
+			opset(ARLDICLCC, r0)
+			opset(ARLDICR, r0)
+			opset(ARLDICRCC, r0)
+
 		case AFMOVD:
 			opset(AFMOVDCC, r0)
 			opset(AFMOVDU, r0)
@@ -2107,22 +2116,34 @@ func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
 			r = int(p.To.Reg)
 		}
 		d := vregoff(ctxt, p.From3)
-		var mask [2]uint8
-		maskgen64(ctxt, p, mask[:], uint64(d))
 		var a int
 		switch p.As {
+
+		// These opcodes expect a mask operand that has to be converted into the
+		// appropriate operand.  The way these were defined, not all valid masks are possible.
+		// Left here for compatibility in case they were used or generated.
 		case ARLDCL, ARLDCLCC:
+			var mask [2]uint8
+			maskgen64(ctxt, p, mask[:], uint64(d))
+
 			a = int(mask[0]) /* MB */
 			if mask[1] != 63 {
 				ctxt.Diag("invalid mask for rotate: %x (end != bit 63)\n%v", uint64(d), p)
 			}
 
 		case ARLDCR, ARLDCRCC:
+			var mask [2]uint8
+			maskgen64(ctxt, p, mask[:], uint64(d))
+
 			a = int(mask[1]) /* ME */
 			if mask[0] != 0 {
 				ctxt.Diag("invalid mask for rotate: %x (start != 0)\n%v", uint64(d), p)
 			}
 
+		// These opcodes use a shift count like the ppc64 asm, no mask conversion done
+		case ARLDICR, ARLDICRCC, ARLDICL, ARLDICLCC:
+			a = int(d)
+
 		default:
 			ctxt.Diag("unexpected op in rldc case\n%v", p)
 			a = 0
@@ -2403,6 +2424,11 @@ func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
 		v := regoff(ctxt, &p.From)
 
 		d := vregoff(ctxt, p.From3)
+
+		// Original opcodes had mask operands which had to be converted to a shift count as expected by
+		// the ppc64 asm.
+		switch p.As {
+		case ARLDMI, ARLDMICC:
 			var mask [2]uint8
 			maskgen64(ctxt, p, mask[:], uint64(d))
 			if int32(mask[1]) != (63 - v) {
@@ -2417,6 +2443,15 @@ func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
 				o1 |= 1 << 5 /* mb[5] is top bit */
 			}
 
+		// Opcodes with shift count operands.
+		case ARLDIMI, ARLDIMICC:
+			o1 = AOP_RRR(opirr(ctxt, p.As), uint32(p.Reg), uint32(p.To.Reg), (uint32(v) & 0x1F))
+			o1 |= (uint32(d) & 31) << 6
+			if v&0x20 != 0 {
+				o1 |= 1 << 1
+			}
+		}
+
 	case 31: /* dword */
 		d := vregoff(ctxt, &p.From)
 
@@ -3340,6 +3375,15 @@ func oprrr(ctxt *obj.Link, a obj.As) uint32 {
 	case ARLDCR:
 		return OPVCC(30, 9, 0, 0)
 
+	case ARLDICL:
+		return OPVCC(30, 0, 0, 0)
+	case ARLDICLCC:
+		return OPVCC(30, 0, 0, 1)
+	case ARLDICR:
+		return OPVCC(30, 0, 0, 0) | 2<<1 // rldicr
+	case ARLDICRCC:
+		return OPVCC(30, 0, 0, 1) | 2<<1 // rldicr.
+
 	case ASYSCALL:
 		return OPVCC(17, 1, 0, 0)
 
@@ -3771,7 +3815,10 @@ func opirr(ctxt *obj.Link, a obj.As) uint32 {
 		return OPVCC(30, 0, 0, 0) | 3<<2 /* rldimi */
 	case ARLDMICC:
 		return OPVCC(30, 0, 0, 1) | 3<<2
-
+	case ARLDIMI:
+		return OPVCC(30, 0, 0, 0) | 3<<2 /* rldimi */
+	case ARLDIMICC:
+		return OPVCC(30, 0, 0, 1) | 3<<2
 	case ARLWNM:
 		return OPVCC(21, 0, 0, 0) /* rlwinm */
 	case ARLWNMCC: