cmd/asm: add support for bdnz/bdz extended mnemonics on PPC64

Support BDNZ and BDZ mnemonics, they are commonly used
POWER instructions. The raw BC mnemonic is not easy
to read.

Likewise, cleanup code surrounding these changes.

Change-Id: I72f1dad5013f7856bd0dd320bfb17b5a9f3c69ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/390696
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Trust: Paul Murphy <murp@ibm.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/cmd/asm/internal/arch/ppc64.go b/src/cmd/asm/internal/arch/ppc64.go
index 3139665ba55c581f00f71b89db303673e4b7a5eb..616e189b1a8ac09f2a50828acdb69e564c91e957 100644 (file)
--- a/src/cmd/asm/internal/arch/ppc64.go
+++ b/src/cmd/asm/internal/arch/ppc64.go
@@ -15,7 +15,7 @@ import (
 
 func jumpPPC64(word string) bool {
        switch word {
-       case "BC", "BCL", "BEQ", "BGE", "BGT", "BL", "BLE", "BLT", "BNE", "BR", "BVC", "BVS", "CALL", "JMP":
+       case "BC", "BCL", "BEQ", "BGE", "BGT", "BL", "BLE", "BLT", "BNE", "BR", "BVC", "BVS", "BDNZ", "BDZ", "CALL", "JMP":
                return true
        }
        return false

diff --git a/src/cmd/asm/internal/asm/testdata/ppc64.s b/src/cmd/asm/internal/asm/testdata/ppc64.s
index c140fd025a64e8117754db20842bffe3e714b3ff..5452668791d205522e35d9e45def10612331bbf9 100644 (file)
--- a/src/cmd/asm/internal/asm/testdata/ppc64.s
+++ b/src/cmd/asm/internal/asm/testdata/ppc64.s
@@ -751,17 +751,23 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
        MOVD XER, R3                    // 7c6102a6
        MOVFL CR3, CR1                  // 4c8c0000
 
-       MOVW CR0, R1                    // 7c380026
-       MOVW CR7, R1                    // 7c301026
-       MOVW CR, R1                     // 7c200026
-
-       MOVW R1, CR                     // 7c2ff120
-       MOVFL R1, CR                    // 7c2ff120
-       MOVW R1, CR2                    // 7c320120
-       MOVFL R1, CR2                   // 7c320120
-       MOVFL R1, $255                  // 7c2ff120
-       MOVFL R1, $1                    // 7c301120
-       MOVFL R1, $128                  // 7c380120
-       MOVFL R1, $3                    // 7c203120
+       MOVW CR0, R1                    // 7c380026
+       MOVW CR7, R1                    // 7c301026
+       MOVW CR, R1                     // 7c200026
+
+       MOVW R1, CR                     // 7c2ff120
+       MOVFL R1, CR                    // 7c2ff120
+       MOVW R1, CR2                    // 7c320120
+       MOVFL R1, CR2                   // 7c320120
+       MOVFL R1, $255                  // 7c2ff120
+       MOVFL R1, $1                    // 7c301120
+       MOVFL R1, $128                  // 7c380120
+       MOVFL R1, $3                    // 7c203120
+
+       // Verify supported bdnz/bdz encodings.
+       BC 16,0,0(PC)                   // BC $16,R0,0(PC) // 42000000
+       BDNZ 0(PC)                      // 42000000
+       BDZ 0(PC)                       // 42400000
+       BC 18,0,0(PC)                   // BC $18,R0,0(PC) // 42400000
 
        RET

diff --git a/src/cmd/internal/obj/ppc64/a.out.go b/src/cmd/internal/obj/ppc64/a.out.go
index 1e74e64a29fb5ff0089632923935cfe76dd21c0b..25081efcee8b3156479ae62a2e26991bef5e1c5d 100644 (file)
--- a/src/cmd/internal/obj/ppc64/a.out.go
+++ b/src/cmd/internal/obj/ppc64/a.out.go
@@ -362,13 +362,14 @@ const (
        BI_LT  = 0
        BI_GT  = 1
        BI_EQ  = 2
-       BI_OVF = 3
+       BI_FU  = 3
 )
 
 // Common values for the BO field.
 
 const (
        BO_BCTR    = 16 // decrement ctr, branch on ctr != 0
+       BO_NOTBCTR = 18 // decrement ctr, branch on ctr == 0
        BO_BCR     = 12 // branch on cr value
        BO_BCRBCTR = 8  // decrement ctr, branch on ctr != 0 and cr value
        BO_NOTBCR  = 4  // branch on not cr value
@@ -480,9 +481,11 @@ const (
        ABGT
        ABLE // not GT = L/E/U
        ABLT
-       ABNE // not EQ = L/G/U
-       ABVC // Unordered-clear
-       ABVS // Unordered-set
+       ABNE  // not EQ = L/G/U
+       ABVC  // Branch if float not unordered (also branch on not summary overflow)
+       ABVS  // Branch if float unordered (also branch on summary overflow)
+       ABDNZ // Decrement CTR, and branch if CTR != 0
+       ABDZ  // Decrement CTR, and branch if CTR == 0
        ACMP
        ACMPU
        ACMPEQB

diff --git a/src/cmd/internal/obj/ppc64/anames.go b/src/cmd/internal/obj/ppc64/anames.go
index 0da73ca91ed6c9f8d1036e94c481c918ddc39f12..7521a92ab4d35c1b47389e9a3cfac07b8e894d9a 100644 (file)
--- a/src/cmd/internal/obj/ppc64/anames.go
+++ b/src/cmd/internal/obj/ppc64/anames.go
@@ -42,6 +42,8 @@ var Anames = []string{
        "BNE",
        "BVC",
        "BVS",
+       "BDNZ",
+       "BDZ",
        "CMP",
        "CMPU",
        "CMPEQB",

diff --git a/src/cmd/internal/obj/ppc64/asm9.go b/src/cmd/internal/obj/ppc64/asm9.go
index 70ce9050b698fdeefd49a8112f656fa662795c46..50c9b37f02fa262669a8c901c99ca57dd0c7659a 100644 (file)
--- a/src/cmd/internal/obj/ppc64/asm9.go
+++ b/src/cmd/internal/obj/ppc64/asm9.go
@@ -305,6 +305,7 @@ var optab = []Optab{
        {as: ABC, a1: C_SCON, a2: C_REG, a6: C_LR, type_: 18, size: 4},
        {as: ABC, a1: C_SCON, a2: C_REG, a6: C_CTR, type_: 18, size: 4},
        {as: ABC, a6: C_ZOREG, type_: 15, size: 8},
+       {as: ABDNZ, a6: C_SBRA, type_: 16, size: 4},
        {as: ASYNC, type_: 46, size: 4},
        {as: AWORD, a1: C_LCON, type_: 40, size: 4},
        {as: ADWORD, a1: C_64CON, type_: 31, size: 8},
@@ -1778,6 +1779,9 @@ func buildop(ctxt *obj.Link) {
                case ABC:
                        opset(ABCL, r0)
 
+               case ABDNZ:
+                       opset(ABDZ, r0)
+
                case AEXTSB: /* op Rs, Ra */
                        opset(AEXTSBCC, r0)
 
@@ -4875,21 +4879,25 @@ func (c *ctxt9) opirr(a obj.As) uint32 {
                return OPVCC(16, 0, 0, 0) | 1
 
        case ABEQ:
-               return AOP_RRR(16<<26, 12, 2, 0)
+               return AOP_RRR(16<<26, BO_BCR, BI_EQ, 0)
        case ABGE:
-               return AOP_RRR(16<<26, 4, 0, 0)
+               return AOP_RRR(16<<26, BO_NOTBCR, BI_LT, 0)
        case ABGT:
-               return AOP_RRR(16<<26, 12, 1, 0)
+               return AOP_RRR(16<<26, BO_BCR, BI_GT, 0)
        case ABLE:
-               return AOP_RRR(16<<26, 4, 1, 0)
+               return AOP_RRR(16<<26, BO_NOTBCR, BI_GT, 0)
        case ABLT:
-               return AOP_RRR(16<<26, 12, 0, 0)
+               return AOP_RRR(16<<26, BO_BCR, BI_LT, 0)
        case ABNE:
-               return AOP_RRR(16<<26, 4, 2, 0)
+               return AOP_RRR(16<<26, BO_NOTBCR, BI_EQ, 0)
        case ABVC:
-               return AOP_RRR(16<<26, 4, 3, 0) // apparently unordered-clear
+               return AOP_RRR(16<<26, BO_NOTBCR, BI_FU, 0)
        case ABVS:
-               return AOP_RRR(16<<26, 12, 3, 0) // apparently unordered-set
+               return AOP_RRR(16<<26, BO_BCR, BI_FU, 0)
+       case ABDZ:
+               return AOP_RRR(16<<26, BO_NOTBCTR, 0, 0)
+       case ABDNZ:
+               return AOP_RRR(16<<26, BO_BCTR, 0, 0)
 
        case ACMP:
                return OPVCC(11, 0, 0, 0) | 1<<21 /* L=1 */