From: Paul E. Murphy <murp@ibm.com>
Date: Tue, 3 Nov 2020 22:59:25 +0000 (-0600)
Subject: cmd/asm: fix rlwnm reg,reg,const,reg encoding on ppc64
X-Git-Tag: go1.16beta1~332
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=5ed81a3d14aa4eda5de87d7fe074b4c913b58511;p=gostls13.git

cmd/asm: fix rlwnm reg,reg,const,reg encoding on ppc64

The wrong value for the first reg parameter was selected.
Likewise the wrong opcode was selected.  This should match
rlwnm (rrr type), not rlwinm (irr type).

Similarly, fix the optab matching rules so clrlslwi does
not match reg,reg,const,reg arguments.  This is not a valid
operand combination for clrlslwi.

Fixes #42368

Change-Id: I4eb16d45a760b9fd3f497ef9863f82465351d39f
Reviewed-on: https://go-review.googlesource.com/c/go/+/267421
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Lynn Boger <laboger@linux.vnet.ibm.com>
---

diff --git a/src/cmd/asm/internal/asm/testdata/ppc64.s b/src/cmd/asm/internal/asm/testdata/ppc64.s
index 2b1191c44b..8f6eb14f73 100644
--- a/src/cmd/asm/internal/asm/testdata/ppc64.s
+++ b/src/cmd/asm/internal/asm/testdata/ppc64.s
@@ -282,7 +282,9 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	RLWMI $7, R3, $65535, R6        // 50663c3e
 	RLWMICC $7, R3, $65535, R6      // 50663c3f
 	RLWNM $3, R4, $7, R6            // 54861f7e
+	RLWNM R3, R4, $7, R6            // 5c861f7e
 	RLWNMCC $3, R4, $7, R6          // 54861f7f
+	RLWNMCC R3, R4, $7, R6          // 5c861f7f
 	RLDMI $0, R4, $7, R6            // 7886076c
 	RLDMICC $0, R4, $7, R6          // 7886076d
 	RLDIMI $0, R4, $7, R6           // 788601cc
diff --git a/src/cmd/internal/obj/ppc64/asm9.go b/src/cmd/internal/obj/ppc64/asm9.go
index 090fefb4d8..775d27d8e8 100644
--- a/src/cmd/internal/obj/ppc64/asm9.go
+++ b/src/cmd/internal/obj/ppc64/asm9.go
@@ -174,6 +174,7 @@ var optab = []Optab{
 	{ASRAD, C_SCON, C_NONE, C_NONE, C_REG, 56, 4, 0},
 	{ARLWMI, C_SCON, C_REG, C_LCON, C_REG, 62, 4, 0},
 	{ARLWMI, C_REG, C_REG, C_LCON, C_REG, 63, 4, 0},
+	{ACLRLSLWI, C_SCON, C_REG, C_LCON, C_REG, 62, 4, 0},
 	{ARLDMI, C_SCON, C_REG, C_LCON, C_REG, 30, 4, 0},
 	{ARLDC, C_SCON, C_REG, C_LCON, C_REG, 29, 4, 0},
 	{ARLDCL, C_SCON, C_REG, C_LCON, C_REG, 29, 4, 0},
@@ -1911,7 +1912,6 @@ func buildop(ctxt *obj.Link) {
 			opset(ARLWMICC, r0)
 			opset(ARLWNM, r0)
 			opset(ARLWNMCC, r0)
-			opset(ACLRLSLWI, r0)
 
 		case ARLDMI:
 			opset(ARLDMICC, r0)
@@ -2010,6 +2010,7 @@ func buildop(ctxt *obj.Link) {
 			AADDEX,
 			ACMPEQB,
 			AECIWX,
+			ACLRLSLWI,
 			obj.ANOP,
 			obj.ATEXT,
 			obj.AUNDEF,
@@ -3413,25 +3414,10 @@ func (c *ctxt9) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		}
 
 	case 63: /* rlwmi b,s,$mask,a */
-		v := c.regoff(&p.From)
-		switch p.As {
-		case ACLRLSLWI:
-			n := c.regoff(p.GetFrom3())
-			if n > v || v >= 32 {
-				// Message will match operands from the ISA even though in the
-				// code it uses 'v'
-				c.ctxt.Diag("Invalid n or b for CLRLSLWI: %x %x\n%v", v, n, p)
-			}
-			// This is an extended mnemonic described in the ISA C.8.2
-			// clrlslwi ra,rs,b,n -> rlwinm ra,rs,n,b-n,31-n
-			// It generates the rlwinm directly here.
-			o1 = OP_RLW(OP_RLWINM, uint32(p.To.Reg), uint32(p.Reg), uint32(n), uint32(v-n), uint32(31-n))
-		default:
-			var mask [2]uint8
-			c.maskgen(p, mask[:], uint32(c.regoff(p.GetFrom3())))
-			o1 = AOP_RRR(c.opirr(p.As), uint32(p.Reg), uint32(p.To.Reg), uint32(v))
-			o1 |= (uint32(mask[0])&31)<<6 | (uint32(mask[1])&31)<<1
-		}
+		var mask [2]uint8
+		c.maskgen(p, mask[:], uint32(c.regoff(p.GetFrom3())))
+		o1 = AOP_RRR(c.oprrr(p.As), uint32(p.Reg), uint32(p.To.Reg), uint32(p.From.Reg))
+		o1 |= (uint32(mask[0])&31)<<6 | (uint32(mask[1])&31)<<1
 
 	case 64: /* mtfsf fr[, $m] {,fpcsr} */
 		var v int32