cmd/internal/obj/s390x: remove support for stores of global addresses

This CL removes support for MOVD instructions that store the address
of a global variable. For example:

  MOVD $main·a(SB), (R1)
  MOVD $main·b(SB), main·c(SB)

These instructions are emulated and the new backend doesn't need them
(the stores now always go through an intermediate register).

Change-Id: I3a1bcb3f19c5096ad0426afd76d35a4d7975733b
Reviewed-on: https://go-review.googlesource.com/30720
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/cmd/internal/obj/s390x/asmz.go b/src/cmd/internal/obj/s390x/asmz.go
index 91d5d6c261db446bc62a00bb0a936ef97568a2bc..1658a6def702235e11e3a20f21bd2873db368337 100644 (file)
--- a/src/cmd/internal/obj/s390x/asmz.go
+++ b/src/cmd/internal/obj/s390x/asmz.go
@@ -76,19 +76,16 @@ var optab = []Optab{
        Optab{AMOVBZ, C_DCON, C_NONE, C_NONE, C_REG, 3, 0},
 
        // store constant
-       Optab{AMOVD, C_SYMADDR, C_NONE, C_NONE, C_ADDR, 73, 0},
        Optab{AMOVD, C_LCON, C_NONE, C_NONE, C_ADDR, 73, 0},
        Optab{AMOVW, C_LCON, C_NONE, C_NONE, C_ADDR, 73, 0},
        Optab{AMOVWZ, C_LCON, C_NONE, C_NONE, C_ADDR, 73, 0},
        Optab{AMOVBZ, C_LCON, C_NONE, C_NONE, C_ADDR, 73, 0},
        Optab{AMOVB, C_LCON, C_NONE, C_NONE, C_ADDR, 73, 0},
-       Optab{AMOVD, C_SYMADDR, C_NONE, C_NONE, C_LAUTO, 72, REGSP},
        Optab{AMOVD, C_LCON, C_NONE, C_NONE, C_LAUTO, 72, REGSP},
        Optab{AMOVW, C_LCON, C_NONE, C_NONE, C_LAUTO, 72, REGSP},
        Optab{AMOVWZ, C_LCON, C_NONE, C_NONE, C_LAUTO, 72, REGSP},
        Optab{AMOVB, C_LCON, C_NONE, C_NONE, C_LAUTO, 72, REGSP},
        Optab{AMOVBZ, C_LCON, C_NONE, C_NONE, C_LAUTO, 72, REGSP},
-       Optab{AMOVD, C_SYMADDR, C_NONE, C_NONE, C_LOREG, 72, 0},
        Optab{AMOVD, C_LCON, C_NONE, C_NONE, C_LOREG, 72, 0},
        Optab{AMOVW, C_LCON, C_NONE, C_NONE, C_LOREG, 72, 0},
        Optab{AMOVWZ, C_LCON, C_NONE, C_NONE, C_LOREG, 72, 0},
@@ -3296,7 +3293,7 @@ func asmout(ctxt *obj.Link, asm *[]byte) {
                        zRIL(_a, zopril(ctxt, p.As), uint32(p.From.Reg), uint32(v), asm)
                }
 
-       case 72: // mov $constant/$addr mem
+       case 72: // mov $constant mem
                v := regoff(ctxt, &p.From)
                d := regoff(ctxt, &p.To)
                r := p.To.Reg
@@ -3304,23 +3301,7 @@ func asmout(ctxt *obj.Link, asm *[]byte) {
                if r == 0 {
                        r = o.param
                }
-               if p.From.Sym != nil {
-                       zRIL(_b, op_LARL, REGTMP, 0, asm)
-                       if v&0x1 != 0 {
-                               v -= 1
-                               zRX(op_LA, REGTMP, REGTMP, 0, 1, asm)
-                       }
-                       addrilreloc(ctxt, p.From.Sym, int64(v))
-                       if d < -DISP20/2 || d >= DISP20/2 {
-                               zRIL(_a, op_LGFI, REGTMP2, uint32(d), asm)
-                               if x != 0 {
-                                       zRRE(op_AGR, REGTMP2, uint32(x), asm)
-                               }
-                               d = 0
-                               x = REGTMP2
-                       }
-                       zRXY(zopstore(ctxt, p.As), REGTMP, uint32(x), uint32(r), uint32(d), asm)
-               } else if int32(int16(v)) == v && x == 0 {
+               if int32(int16(v)) == v && x == 0 {
                        if d < 0 || d >= DISP12 {
                                if r == REGTMP || r == REGTMP2 {
                                        zRIL(_a, op_AGFI, uint32(r), uint32(d), asm)
@@ -3374,16 +3355,7 @@ func asmout(ctxt *obj.Link, asm *[]byte) {
                }
                zRIL(_b, op_LARL, REGTMP, uint32(d), asm)
                addrilreloc(ctxt, p.To.Sym, int64(d))
-               if p.From.Sym != nil {
-                       zRIL(_b, op_LARL, REGTMP2, 0, asm)
-                       a := uint32(0)
-                       if v&0x1 != 0 {
-                               v -= 1
-                               zRX(op_LA, REGTMP2, REGTMP2, 0, 1, asm)
-                       }
-                       addrilrelocoffset(ctxt, p.From.Sym, int64(v), sizeRIL)
-                       zRXY(zopstore(ctxt, p.As), REGTMP2, 0, REGTMP, a, asm)
-               } else if int32(int16(v)) == v {
+               if int32(int16(v)) == v {
                        var opcode uint32
                        switch p.As {
                        case AMOVD: