cmd/internal/obj/arm64: add register indexed FMOVS/FMOVD

This CL adds register indexed FMOVS/FMOVD.
FMOVS Fx, (Rn)(Rm)
FMOVS Fx, (Rn)(Rm<<2)
FMOVD Fx, (Rn)(Rm)
FMOVD Fx, (Rn)(Rm<<3)
FMOVS (Rn)(Rm), Fx
FMOVS (Rn)(Rm<<2), Fx
FMOVD (Rn)(Rm), Fx
FMOVD (Rn)(Rm<<3), Fx

Change-Id: Id76de6a4be96b64cf79d7e9a1962d9d49cb462f2
Reviewed-on: https://go-review.googlesource.com/123995
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/cmd/asm/internal/asm/testdata/arm64.s

@@ -164,6 +164,15 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	MOVB	(R29)(R30), R14                 // MOVB	(R29)(R30*1), R14                // ae6bbe38
 	MOVB	R4, (R2)(R6.SXTX)               // 44e82638
 
+	FMOVS	(R2)(R6), F4       // FMOVS (R2)(R6*1), F4    // 446866bc
+	FMOVS	(R2)(R6<<2), F4                               // 447866bc
+	FMOVD	(R2)(R6), F4       // FMOVD (R2)(R6*1), F4    // 446866fc
+	FMOVD	(R2)(R6<<3), F4                               // 447866fc
+	FMOVS	F4, (R2)(R6)       // FMOVS F4, (R2)(R6*1)    // 446826bc
+	FMOVS	F4, (R2)(R6<<2)                               // 447826bc
+	FMOVD	F4, (R2)(R6)       // FMOVD F4, (R2)(R6*1)    // 446826fc
+	FMOVD	F4, (R2)(R6<<3)                               // 447826fc
+
 //	LTYPE1 imsr ',' spreg ','
 //	{
 //		outcode($1, &$2, $4, &nullgen);

src/cmd/internal/obj/arm64/asm7.go

@@ -519,12 +519,16 @@ var optab = []Optab{
 	{AMOVH, C_ROFF, C_NONE, C_NONE, C_REG, 98, 4, 0, 0, 0},
 	{AMOVB, C_ROFF, C_NONE, C_NONE, C_REG, 98, 4, 0, 0, 0},
 	{AMOVBU, C_ROFF, C_NONE, C_NONE, C_REG, 98, 4, 0, 0, 0},
+	{AFMOVS, C_ROFF, C_NONE, C_NONE, C_FREG, 98, 4, 0, 0, 0},
+	{AFMOVD, C_ROFF, C_NONE, C_NONE, C_FREG, 98, 4, 0, 0, 0},
 
 	/* store with extended register offset */
 	{AMOVD, C_REG, C_NONE, C_NONE, C_ROFF, 99, 4, 0, 0, 0},
 	{AMOVW, C_REG, C_NONE, C_NONE, C_ROFF, 99, 4, 0, 0, 0},
 	{AMOVH, C_REG, C_NONE, C_NONE, C_ROFF, 99, 4, 0, 0, 0},
 	{AMOVB, C_REG, C_NONE, C_NONE, C_ROFF, 99, 4, 0, 0, 0},
+	{AFMOVS, C_FREG, C_NONE, C_NONE, C_ROFF, 99, 4, 0, 0, 0},
+	{AFMOVD, C_FREG, C_NONE, C_NONE, C_ROFF, 99, 4, 0, 0, 0},
 
 	/* pre/post-indexed/signed-offset load/store register pair
 	   (unscaled, signed 10-bit quad-aligned and long offset) */
@@ -2540,11 +2544,11 @@ func (c *ctxt7) checkShiftAmount(p *obj.Prog, a *obj.Addr) {
 		if amount != 1 && amount != 0 {
 			c.ctxt.Diag("invalid index shift amount: %v", p)
 		}
-	case AMOVW, AMOVWU:
+	case AMOVW, AMOVWU, AFMOVS:
 		if amount != 2 && amount != 0 {
 			c.ctxt.Diag("invalid index shift amount: %v", p)
 		}
-	case AMOVD:
+	case AMOVD, AFMOVD:
 		if amount != 3 && amount != 0 {
 			c.ctxt.Diag("invalid index shift amount: %v", p)
 		}