cmd/internal/obj/arm64: pass obj.As to oaddi rather than an instruction

This simplifies callers, as they do not need to call opirr before calling oaddi.
Additionally, use appropriate types (int16) for registers, which avoids the need
to continually cast.

Change-Id: I8ca3807a97867ac49d63792f6922a18f35824448
Reviewed-on: https://go-review.googlesource.com/c/go/+/471520
Reviewed-by: Cherry Mui <[email protected]>
Run-TryBot: Joel Sing <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>

Author: 4a6f656c

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

@@ -3359,20 +3359,18 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		}
 		o1 = c.opirr(p, p.As)
 
-		rt := int(p.To.Reg)
+		rt, r := p.To.Reg, p.Reg
 		if p.To.Type == obj.TYPE_NONE {
 			if (o1 & Sbit) == 0 {
 				c.ctxt.Diag("ineffective ZR destination\n%v", p)
 			}
 			rt = REGZERO
 		}
-
-		r := int(p.Reg)
 		if r == obj.REG_NONE {
 			r = rt
 		}
 		v := c.regoff(&p.From)
-		o1 = c.oaddi(p, int32(o1), v, r, rt)
+		o1 = c.oaddi(p, p.As, v, rt, r)
 
 	case 3: /* op R<<n[,R],R (shifted register) */
 		o1 = c.oprrr(p, p.As)
@@ -3400,36 +3398,32 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		o1 |= (uint32(r&31) << 5) | uint32(rt&31)
 
 	case 4: /* mov $addcon, R; mov $recon, R; mov $racon, R; mov $addcon2, R */
-		rt := int(p.To.Reg)
-		r := int(o.param)
-
+		rt, r := p.To.Reg, o.param
 		if r == obj.REG_NONE {
 			r = REGZERO
 		} else if r == REGFROM {
-			r = int(p.From.Reg)
+			r = p.From.Reg
 		}
 		if r == obj.REG_NONE {
 			r = REGSP
 		}
 
 		v := c.regoff(&p.From)
-		var op int32
+		a := AADD
 		if v < 0 {
+			a = ASUB
 			v = -v
-			op = int32(c.opirr(p, ASUB))
-		} else {
-			op = int32(c.opirr(p, AADD))
 		}
 
-		if int(o.size(c.ctxt, p)) == 8 {
+		if o.size(c.ctxt, p) == 8 {
 			// NOTE: this case does not use REGTMP. If it ever does,
 			// remove the NOTUSETMP flag in optab.
-			o1 = c.oaddi(p, op, v&0xfff000, r, rt)
-			o2 = c.oaddi(p, op, v&0x000fff, rt, rt)
+			o1 = c.oaddi(p, a, v&0xfff000, rt, r)
+			o2 = c.oaddi(p, a, v&0x000fff, rt, rt)
 			break
 		}
 
-		o1 = c.oaddi(p, op, v, r, rt)
+		o1 = c.oaddi(p, a, v, rt, r)
 
 	case 5: /* b s; bl s */
 		o1 = c.opbra(p, p.As)
@@ -3889,9 +3883,9 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			c.ctxt.Diag("unexpected long move, op %v tab %v\n%v", p.As, o.as, p)
 		}
 
-		r := int(p.To.Reg)
+		r := p.To.Reg
 		if r == obj.REG_NONE {
-			r = int(o.param)
+			r = o.param
 		}
 
 		v := c.regoff(&p.To)
@@ -3910,7 +3904,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			goto storeusepool
 		}
 
-		o1 = c.oaddi(p, int32(c.opirr(p, AADD)), hi, r, REGTMP)
+		o1 = c.oaddi(p, AADD, hi, REGTMP, r)
 		o2 = c.olsr12u(p, c.opstr(p, p.As), ((v-hi)>>uint(s))&0xFFF, REGTMP, p.From.Reg)
 		break
 
@@ -3919,7 +3913,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			c.ctxt.Diag("REGTMP used in large offset store: %v", p)
 		}
 		o1 = c.omovlit(AMOVD, p, &p.To, REGTMP)
-		o2 = c.olsxrr(p, int32(c.opstrr(p, p.As, false)), int(p.From.Reg), r, REGTMP)
+		o2 = c.olsxrr(p, int32(c.opstrr(p, p.As, false)), int(p.From.Reg), int(r), REGTMP)
 
 	case 31: /* movT L(R), R -> ldrT */
 		// if offset L can be split into hi+lo, and both fit into instructions, do
@@ -3933,9 +3927,9 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			c.ctxt.Diag("unexpected long move, op %v tab %v\n%v", p.As, o.as, p)
 		}
 
-		r := int(p.From.Reg)
+		r := p.From.Reg
 		if r == obj.REG_NONE {
-			r = int(o.param)
+			r = o.param
 		}
 
 		v := c.regoff(&p.From)
@@ -3954,7 +3948,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			goto loadusepool
 		}
 
-		o1 = c.oaddi(p, int32(c.opirr(p, AADD)), hi, r, REGTMP)
+		o1 = c.oaddi(p, AADD, hi, REGTMP, r)
 		o2 = c.olsr12u(p, c.opldr(p, p.As), ((v-hi)>>uint(s))&0xFFF, REGTMP, p.To.Reg)
 		break
 
@@ -3963,7 +3957,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			c.ctxt.Diag("REGTMP used in large offset load: %v", p)
 		}
 		o1 = c.omovlit(AMOVD, p, &p.From, REGTMP)
-		o2 = c.olsxrr(p, int32(c.opldrr(p, p.As, false)), int(p.To.Reg), r, REGTMP)
+		o2 = c.olsxrr(p, int32(c.opldrr(p, p.As, false)), int(p.To.Reg), int(r), REGTMP)
 
 	case 32: /* mov $con, R -> movz/movn */
 		o1 = c.omovconst(p.As, p, &p.From, int(p.To.Reg))
@@ -4234,13 +4228,12 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		if op&Sbit != 0 {
 			c.ctxt.Diag("can not break addition/subtraction when S bit is set", p)
 		}
-		rt := int(p.To.Reg)
-		r := int(p.Reg)
+		rt, r := p.To.Reg, p.Reg
 		if r == obj.REG_NONE {
 			r = rt
 		}
-		o1 = c.oaddi(p, int32(op), c.regoff(&p.From)&0x000fff, r, rt)
-		o2 = c.oaddi(p, int32(op), c.regoff(&p.From)&0xfff000, rt, rt)
+		o1 = c.oaddi(p, p.As, c.regoff(&p.From)&0x000fff, rt, r)
+		o2 = c.oaddi(p, p.As, c.regoff(&p.From)&0xfff000, rt, rt)
 
 	case 50: /* sys/sysl */
 		o1 = c.opirr(p, p.As)
@@ -7097,17 +7090,20 @@ func (c *ctxt7) opstrr(p *obj.Prog, a obj.As, extension bool) uint32 {
 	return 0
 }
 
-func (c *ctxt7) oaddi(p *obj.Prog, o1 int32, v int32, r int, rt int) uint32 {
+func (c *ctxt7) oaddi(p *obj.Prog, a obj.As, v int32, rd, rn int16) uint32 {
+	op := c.opirr(p, a)
+
 	if (v & 0xFFF000) != 0 {
 		if v&0xFFF != 0 {
 			c.ctxt.Diag("%v misuses oaddi", p)
 		}
 		v >>= 12
-		o1 |= 1 << 22
+		op |= 1 << 22
 	}
 
-	o1 |= ((v & 0xFFF) << 10) | (int32(r&31) << 5) | int32(rt&31)
-	return uint32(o1)
+	op |= (uint32(v&0xFFF) << 10) | (uint32(rn&31) << 5) | uint32(rd&31)
+
+	return op
 }
 
 func (c *ctxt7) oaddi12(p *obj.Prog, v int32, rd, rn int16) uint32 {
@@ -7120,7 +7116,7 @@ func (c *ctxt7) oaddi12(p *obj.Prog, v int32, rd, rn int16) uint32 {
 		a = ASUB
 		v = -v
 	}
-	return c.oaddi(p, int32(c.opirr(p, a)), v, int(rn), int(rd))
+	return c.oaddi(p, a, v, rd, rn)
 }
 
 /*