cmd/internal/obj/arm64: fix assemble add/adds/sub/subs/cmp/cmn(extended register) bug

The current code encodes the wrong option value in the binary.

The fix reconstructs the function opxrrr() that does not encode the option
value into the binary value when arguments is sign or zero-extended register.

Add the relevant test cases and negative tests.

Fixes #23501
Change-Id: Ie5850ead2ad08d9a235a5664869aac5051762f1f
Reviewed-on: https://go-review.googlesource.com/88876
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/cmd/asm/internal/arch/arm64.go

@@ -123,6 +123,11 @@ func arm64RegisterNumber(name string, n int16) (int16, bool) {
 // ARM64RegisterExtension parses an ARM64 register with extension or arrangment.
 func ARM64RegisterExtension(a *obj.Addr, ext string, reg, num int16, isAmount, isIndex bool) error {
 	rm := uint32(reg)
+	if isAmount {
+		if num < 0 || num > 7 {
+			return errors.New("shift amount out of range")
+		}
+	}
 	switch ext {
 	case "UXTB":
 		if !isAmount {
@@ -134,7 +139,7 @@ func ARM64RegisterExtension(a *obj.Addr, ext string, reg, num int16, isAmount, i
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_UXTH + (num & 31) + int16(num<<5)
+		a.Reg = arm64.REG_UXTH + (reg & 31) + int16(num<<5)
 		a.Offset = int64(((rm & 31) << 16) | (1 << 13) | (uint32(num) << 10))
 	case "UXTW":
 		if !isAmount {

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

@@ -29,8 +29,20 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	ADD	R1<<22, R2, R3
 	ADD	R1->33, R2, R3
 	AND	R1@>33, R2, R3
-	ADD	R1.UXTB, R2, R3                 // 4360218b
-	ADD	R1.UXTB<<4, R2, R3              // 4370218b
+	ADD	R1.UXTB, R2, R3                 // 4300218b
+	ADD	R1.UXTB<<4, R2, R3              // 4310218b
+	ADDW	R2.SXTW, R10, R12               // 4cc1220b
+	ADD	R18.UXTX, R14, R17              // d161328b
+	ADDSW	R18.UXTW, R14, R17              // d141322b
+	ADDS	R12.SXTX, R3, R1                // 61e02cab
+	SUB	R19.UXTH<<4, R2, R21            // 553033cb
+	SUBW	R1.UXTX<<1, R3, R2              // 6264214b
+	SUBS	R3.UXTX, R8, R9                 // 096123eb
+	SUBSW	R17.UXTH, R15, R21              // f521316b
+	CMP	R2.SXTH, R13                    // bfa122eb
+	CMN	R1.SXTX<<2, R10                 // 5fe921ab
+	CMPW	R2.UXTH<<3, R11                 // 7f2d226b
+	CMNW	R1.SXTB, R9                     // 3f81212b
 	VADDP	V1.B16, V2.B16, V3.B16          // 43bc214e
 	VADDP	V1.S4, V2.S4, V3.S4             // 43bca14e
 	VADDP	V1.D2, V2.D2, V3.D2             // 43bce14e

src/cmd/asm/internal/asm/testdata/arm64error.s

@@ -10,4 +10,6 @@ TEXT errors(SB),$0
 	VST1	[V1.B16], (R8)(R13)    // ERROR "illegal combination"
 	VST1	[V1.B16], 9(R2)        // ERROR "illegal combination"
 	VLD1	8(R8)(R13), [V2.B16]   // ERROR "illegal combination"
+	ADD	R1.UXTB<<5, R2, R3     // ERROR "shift amount out of range 0 to 4"
+	ADDS	R1.UXTX<<7, R2, R3     // ERROR "shift amount out of range 0 to 4"
 	RET

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

@@ -2362,7 +2362,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			r = rt
 		}
 		if p.To.Type != obj.TYPE_NONE && (p.To.Reg == REGSP || r == REGSP) {
-			o2 = c.opxrrr(p, p.As)
+			o2 = c.opxrrr(p, p.As, false)
 			o2 |= REGTMP & 31 << 16
 			o2 |= LSL0_64
 		} else {
@@ -2591,11 +2591,16 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		o1 |= (REGZERO & 31 << 5) | uint32(rt&31)
 
 	case 27: /* op Rm<<n[,Rn],Rd (extended register) */
-		o1 = c.opxrrr(p, p.As)
 
 		if (p.From.Reg-obj.RBaseARM64)&REG_EXT != 0 {
+			amount := (p.From.Reg >> 5) & 7
+			if amount > 4 {
+				c.ctxt.Diag("shift amount out of range 0 to 4: %v", p)
+			}
+			o1 = c.opxrrr(p, p.As, true)
 			o1 |= uint32(p.From.Offset) /* includes reg, op, etc */
 		} else {
+			o1 = c.opxrrr(p, p.As, false)
 			o1 |= uint32(p.From.Reg&31) << 16
 		}
 		rt := int(p.To.Reg)
@@ -2755,7 +2760,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		if !(o1 != 0) {
 			break
 		}
-		o2 = c.opxrrr(p, AADD)
+		o2 = c.opxrrr(p, AADD, false)
 		o2 |= REGTMP & 31 << 16
 		o2 |= LSL0_64
 		r := int(p.From.Reg)
@@ -3122,7 +3127,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			r = rt
 		}
 		if p.To.Type != obj.TYPE_NONE && (p.To.Reg == REGSP || r == REGSP) {
-			o2 = c.opxrrr(p, p.As)
+			o2 = c.opxrrr(p, p.As, false)
 			o2 |= REGTMP & 31 << 16
 			o2 |= LSL0_64
 		} else {
@@ -3373,7 +3378,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		}
 
 		o1 = c.omovlit(AMOVD, p, &p.From, REGTMP)
-		o2 = c.opxrrr(p, AADD)
+		o2 = c.opxrrr(p, AADD, false)
 		o2 |= (REGTMP & 31) << 16
 		o2 |= uint32(r&31) << 5
 		o2 |= uint32(REGTMP & 31)
@@ -3426,7 +3431,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 			o3 |= 2 << 23
 		}
 		o1 = c.omovlit(AMOVD, p, &p.To, REGTMP)
-		o2 = c.opxrrr(p, AADD)
+		o2 = c.opxrrr(p, AADD, false)
 		o2 |= REGTMP & 31 << 16
 		o2 |= uint32(r&31) << 5
 		o2 |= uint32(REGTMP & 31)
@@ -4518,33 +4523,44 @@ func (c *ctxt7) opbit(p *obj.Prog, a obj.As) uint32 {
 }
 
 /*
- * add/subtract extended register
+ * add/subtract sign or zero-extended register
  */
-func (c *ctxt7) opxrrr(p *obj.Prog, a obj.As) uint32 {
+func (c *ctxt7) opxrrr(p *obj.Prog, a obj.As, extend bool) uint32 {
+	extension := uint32(0)
+	if !extend {
+		switch a {
+		case AADD, ACMN, AADDS, ASUB, ACMP, ASUBS:
+			extension = LSL0_64
+
+		case AADDW, ACMNW, AADDSW, ASUBW, ACMPW, ASUBSW:
+			extension = LSL0_32
+		}
+	}
+
 	switch a {
 	case AADD:
-		return S64 | 0<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_64
+		return S64 | 0<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | extension
 
 	case AADDW:
-		return S32 | 0<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32
+		return S32 | 0<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | extension
 
 	case ACMN, AADDS:
-		return S64 | 0<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_64
+		return S64 | 0<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | extension
 
 	case ACMNW, AADDSW:
-		return S32 | 0<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32
+		return S32 | 0<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | extension
 
 	case ASUB:
-		return S64 | 1<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_64
+		return S64 | 1<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | extension
 
 	case ASUBW:
-		return S32 | 1<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32
+		return S32 | 1<<30 | 0<<29 | 0x0b<<24 | 0<<22 | 1<<21 | extension
 
 	case ACMP, ASUBS:
-		return S64 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_64
+		return S64 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | extension
 
 	case ACMPW, ASUBSW:
-		return S32 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | LSL0_32
+		return S32 | 1<<30 | 1<<29 | 0x0b<<24 | 0<<22 | 1<<21 | extension
 	}
 
 	c.ctxt.Diag("bad opxrrr %v\n%v", a, p)