cmd/asm: add s390x 'rotate then ... selected bits' instructions

This CL adds the following instructions, useful for shifting/rotating
and masking operations:

 * RNSBG - rotate then and selected bits
 * ROSBG - rotate then or selected bits
 * RXSBG - rotate then exclusive or selected bits
 * RISBG - rotate then insert selected bits

It also adds the 'T' (test), 'Z' (zero), 'H' (high), 'L' (low) and
'N' (no test) variants of these instructions as appropriate.

Operands are ordered as: I₃, I₄, I₅, R₂, R₁.

Key: I₃=start, I₄=end, I₅=amount, R₂=source, R₁=destination

Change-Id: I200d12287e1df7447f37f4919da5e9a93d27c792
Reviewed-on: https://go-review.googlesource.com/c/go/+/159357
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

5 files changed, 95 insertions, 0 deletions

diff --git a/src/cmd/asm/internal/asm/asm.go b/src/cmd/asm/internal/asm/asm.go
index 3d99af6889..d83cfb2284 100644
--- a/src/cmd/asm/internal/asm/asm.go
+++ b/src/cmd/asm/internal/asm/asm.go
@@ -789,6 +789,12 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 			prog.To = a[4]
 			break
 		}
+		if p.arch.Family == sys.S390X {
+			prog.From = a[0]
+			prog.RestArgs = []obj.Addr{a[1], a[2], a[3]}
+			prog.To = a[4]
+			break
+		}
 		p.errorf("can't handle %s instruction with 5 operands", op)
 		return
 	case 6:
diff --git a/src/cmd/asm/internal/asm/testdata/s390x.s b/src/cmd/asm/internal/asm/testdata/s390x.s
index fbe1203aaa..713ad12aca 100644
--- a/src/cmd/asm/internal/asm/testdata/s390x.s
+++ b/src/cmd/asm/internal/asm/testdata/s390x.s
@@ -182,6 +182,21 @@ TEXT main·foo(SB),DUPOK|NOSPLIT,$16-0 // TEXT main.foo(SB), DUPOK|NOSPLIT, $16-
 	XORW	(R1), R2              // 57201000
 	XORW	-1(R1), R2            // e3201fffff57
 
+	RNSBG	$0, $31, $32, R1, R2  // ec21001f2054
+	RXSBG	$17, $8, $16, R3, R4  // ec4311081057
+	ROSBG	$9, $24, $11, R5, R6  // ec6509180b56
+	RNSBGT	$0, $31, $32, R7, R8  // ec87801f2054
+	RXSBGT	$17, $8, $16, R9, R10 // eca991081057
+	ROSBGT	$9, $24, $11, R11, R0 // ec0b89180b56
+	RISBG	$0, $31, $32, R1, R2  // ec21001f2055
+	RISBGN	$17, $8, $16, R3, R4  // ec4311081059
+	RISBGZ	$9, $24, $11, R5, R6  // ec6509980b55
+	RISBGNZ	$0, $31, $32, R7, R8  // ec87009f2059
+	RISBHG	$17, $8, $16, R9, R10 // eca91108105d
+	RISBLG	$9, $24, $11, R11, R0 // ec0b09180b51
+	RISBHGZ	$17, $8, $16, R9, R10 // eca91188105d
+	RISBLGZ	$9, $24, $11, R11, R0 // ec0b09980b51
+
 	LAA	R1, R2, 524287(R3)    // eb213fff7ff8
 	LAAG	R4, R5, -524288(R6)   // eb54600080e8
 	LAAL	R7, R8, 8192(R9)      // eb87900002fa
diff --git a/src/cmd/internal/obj/s390x/a.out.go b/src/cmd/internal/obj/s390x/a.out.go
index fb246cbc47..d11a3834b0 100644
--- a/src/cmd/internal/obj/s390x/a.out.go
+++ b/src/cmd/internal/obj/s390x/a.out.go
@@ -289,6 +289,20 @@ const (
 	ASRAD
 	ARLL
 	ARLLG
+	ARNSBG
+	ARXSBG
+	AROSBG
+	ARNSBGT
+	ARXSBGT
+	AROSBGT
+	ARISBG
+	ARISBGN
+	ARISBGZ
+	ARISBGNZ
+	ARISBHG
+	ARISBLG
+	ARISBHGZ
+	ARISBLGZ
 
 	// floating point
 	AFABS
diff --git a/src/cmd/internal/obj/s390x/anames.go b/src/cmd/internal/obj/s390x/anames.go
index 3a21e90ab1..a9bdfcafe9 100644
--- a/src/cmd/internal/obj/s390x/anames.go
+++ b/src/cmd/internal/obj/s390x/anames.go
@@ -60,6 +60,20 @@ var Anames = []string{
 	"SRAD",
 	"RLL",
 	"RLLG",
+	"RNSBG",
+	"RXSBG",
+	"ROSBG",
+	"RNSBGT",
+	"RXSBGT",
+	"ROSBGT",
+	"RISBG",
+	"RISBGN",
+	"RISBGZ",
+	"RISBGNZ",
+	"RISBHG",
+	"RISBLG",
+	"RISBHGZ",
+	"RISBLGZ",
 	"FABS",
 	"FADD",
 	"FADDS",
diff --git a/src/cmd/internal/obj/s390x/asmz.go b/src/cmd/internal/obj/s390x/asmz.go
index f4f2317e1e..5cd4dca2a2 100644
--- a/src/cmd/internal/obj/s390x/asmz.go
+++ b/src/cmd/internal/obj/s390x/asmz.go
@@ -196,6 +196,7 @@ var optab = []Optab{
 	Optab{i: 7, as: ASLD, a1: C_REG, a2: C_REG, a6: C_REG},
 	Optab{i: 7, as: ASLD, a1: C_SCON, a2: C_REG, a6: C_REG},
 	Optab{i: 7, as: ASLD, a1: C_SCON, a6: C_REG},
+	Optab{i: 13, as: ARNSBG, a1: C_SCON, a3: C_SCON, a4: C_SCON, a5: C_REG, a6: C_REG},
 
 	// compare and swap
 	Optab{i: 79, as: ACSG, a1: C_REG, a2: C_REG, a6: C_SOREG},
@@ -953,6 +954,20 @@ func buildop(ctxt *obj.Link) {
 			opset(ASRAW, r)
 			opset(ARLL, r)
 			opset(ARLLG, r)
+		case ARNSBG:
+			opset(ARXSBG, r)
+			opset(AROSBG, r)
+			opset(ARNSBGT, r)
+			opset(ARXSBGT, r)
+			opset(AROSBGT, r)
+			opset(ARISBG, r)
+			opset(ARISBGN, r)
+			opset(ARISBGZ, r)
+			opset(ARISBGNZ, r)
+			opset(ARISBHG, r)
+			opset(ARISBLG, r)
+			opset(ARISBHGZ, r)
+			opset(ARISBLGZ, r)
 		case ACSG:
 			opset(ACS, r)
 		case ASUB:
@@ -2993,6 +3008,37 @@ func (c *ctxtz) asmout(p *obj.Prog, asm *[]byte) {
 			zRXY(opxy, uint32(r1), uint32(x2), uint32(b2), uint32(d2), asm)
 		}
 
+	case 13: // rotate, followed by operation
+		r1 := p.To.Reg
+		r2 := p.RestArgs[2].Reg
+		i3 := uint8(p.From.Offset)        // start
+		i4 := uint8(p.RestArgs[0].Offset) // end
+		i5 := uint8(p.RestArgs[1].Offset) // rotate amount
+		switch p.As {
+		case ARNSBGT, ARXSBGT, AROSBGT:
+			i3 |= 0x80 // test-results
+		case ARISBGZ, ARISBGNZ, ARISBHGZ, ARISBLGZ:
+			i4 |= 0x80 // zero-remaining-bits
+		}
+		var opcode uint32
+		switch p.As {
+		case ARNSBG, ARNSBGT:
+			opcode = op_RNSBG
+		case ARXSBG, ARXSBGT:
+			opcode = op_RXSBG
+		case AROSBG, AROSBGT:
+			opcode = op_ROSBG
+		case ARISBG, ARISBGZ:
+			opcode = op_RISBG
+		case ARISBGN, ARISBGNZ:
+			opcode = op_RISBGN
+		case ARISBHG, ARISBHGZ:
+			opcode = op_RISBHG
+		case ARISBLG, ARISBLGZ:
+			opcode = op_RISBLG
+		}
+		zRIE(_f, uint32(opcode), uint32(r1), uint32(r2), 0, uint32(i3), uint32(i4), 0, uint32(i5), asm)
+
 	case 15: // br/bl (reg)
 		r := p.To.Reg
 		if p.As == ABCL || p.As == ABL {