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>

1 files changed, 32 insertions, 16 deletions

diff --git a/src/cmd/internal/obj/arm64/asm7.go b/src/cmd/internal/obj/arm64/asm7.go
index fdf1fb565d..ca81238c93 100644
--- a/src/cmd/internal/obj/arm64/asm7.go
+++ b/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)