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cmd/internal/obj/riscv: absorb rewriteMOV into instruction generation

Replace the now poorly named rewriteMOV function with a markRelocs function,
absorbing the MOV validation into the instruction generation code.

Change-Id: I6ae94553f7f300862c40310343ef0be8f44a4b0f
Reviewed-on: https://go-review.googlesource.com/c/go/+/344459
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This commit is contained in:
Joel Sing 2021-08-21 09:06:25 +00:00
parent f5bdbf311c
commit da790cccc5

View File

@ -218,64 +218,28 @@ func movToStore(mnemonic obj.As) obj.As {
}
}
// rewriteMOV rewrites MOV pseudo-instructions.
func rewriteMOV(ctxt *obj.Link, newprog obj.ProgAlloc, p *obj.Prog) {
// markRelocs marks an obj.Prog that specifies a MOV pseudo-instruction and
// requires relocation.
func markRelocs(p *obj.Prog) {
switch p.As {
case AMOV, AMOVB, AMOVH, AMOVW, AMOVBU, AMOVHU, AMOVWU, AMOVF, AMOVD:
default:
panic(fmt.Sprintf("%+v is not a MOV pseudo-instruction", p.As))
}
switch {
case p.From.Type == obj.TYPE_REG && p.To.Type == obj.TYPE_REG:
case p.From.Type == obj.TYPE_ADDR && p.To.Type == obj.TYPE_REG:
switch p.From.Name {
case obj.NAME_EXTERN, obj.NAME_STATIC:
p.Mark |= NEED_PCREL_ITYPE_RELOC
}
case p.From.Type == obj.TYPE_MEM && p.To.Type == obj.TYPE_REG:
switch p.From.Name {
case obj.NAME_AUTO, obj.NAME_NONE, obj.NAME_PARAM:
case obj.NAME_EXTERN, obj.NAME_STATIC:
p.Mark |= NEED_PCREL_ITYPE_RELOC
default:
ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
}
case p.From.Type == obj.TYPE_REG && p.To.Type == obj.TYPE_MEM:
switch p.As {
case AMOVBU, AMOVHU, AMOVWU:
ctxt.Diag("unsupported unsigned store at %v", p)
}
switch p.To.Name {
case obj.NAME_AUTO, obj.NAME_NONE, obj.NAME_PARAM:
case obj.NAME_EXTERN, obj.NAME_STATIC:
p.Mark |= NEED_PCREL_STYPE_RELOC
default:
ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
}
case p.From.Type == obj.TYPE_CONST:
if p.As != AMOV {
ctxt.Diag("%v: unsupported constant load", p)
}
if p.To.Type != obj.TYPE_REG {
ctxt.Diag("%v: constant load must target register", p)
}
case p.From.Type == obj.TYPE_ADDR:
if p.As != AMOV {
ctxt.Diag("%v: unsupported address load", p)
}
if p.To.Type != obj.TYPE_REG {
ctxt.Diag("%v: address load must target register", p)
}
switch p.From.Name {
case obj.NAME_AUTO, obj.NAME_NONE, obj.NAME_PARAM:
case obj.NAME_EXTERN, obj.NAME_STATIC:
p.Mark |= NEED_PCREL_ITYPE_RELOC
default:
ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
}
default:
ctxt.Diag("unsupported MOV at %v", p)
}
}
@ -641,14 +605,8 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
}
}
// Rewrite MOV pseudo-instructions. This cannot be done in
// progedit, as SP offsets need to be applied before we split
// up some of the Addrs.
for p := cursym.Func().Text; p != nil; p = p.Link {
switch p.As {
case AMOV, AMOVB, AMOVH, AMOVW, AMOVBU, AMOVHU, AMOVWU, AMOVF, AMOVD:
rewriteMOV(ctxt, newprog, p)
}
markRelocs(p)
}
// Compute instruction addresses. Once we do that, we need to check for
@ -1746,6 +1704,11 @@ func instructionsForMOV(p *obj.Prog) []*instruction {
switch {
case p.From.Type == obj.TYPE_CONST && p.To.Type == obj.TYPE_REG:
// Handle constant to register moves.
if p.As != AMOV {
p.Ctxt.Diag("%v: unsupported constant load", p)
return nil
}
low, high, err := Split32BitImmediate(ins.imm)
if err != nil {
p.Ctxt.Diag("%v: constant %d too large: %v", p, ins.imm, err)
@ -1769,6 +1732,10 @@ func instructionsForMOV(p *obj.Prog) []*instruction {
inss = append(inss, ins)
}
case p.From.Type == obj.TYPE_CONST && p.To.Type != obj.TYPE_REG:
p.Ctxt.Diag("%v: constant load must target register", p)
return nil
case p.From.Type == obj.TYPE_REG && p.To.Type == obj.TYPE_REG:
// Handle register to register moves.
switch p.As {
@ -1820,13 +1787,17 @@ func instructionsForMOV(p *obj.Prog) []*instruction {
insAUIPC := &instruction{as: AAUIPC, rd: ins.rd}
ins.as, ins.rs1, ins.rs2, ins.imm = movToLoad(p.As), ins.rd, obj.REG_NONE, 0
inss = []*instruction{insAUIPC, ins}
default:
p.Ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
return nil
}
case p.From.Type == obj.TYPE_REG && p.To.Type == obj.TYPE_MEM:
// Register to memory stores.
switch p.As {
case AMOVBU, AMOVHU, AMOVWU:
// rewriteMOV should have already added an error for these.
p.Ctxt.Diag("%v: unsupported unsigned store", p)
return nil
}
switch p.To.Name {
@ -1843,11 +1814,18 @@ func instructionsForMOV(p *obj.Prog) []*instruction {
insAUIPC := &instruction{as: AAUIPC, rd: REG_TMP}
ins.as, ins.rd, ins.rs1, ins.rs2, ins.imm = movToStore(p.As), REG_TMP, uint32(p.From.Reg), obj.REG_NONE, 0
inss = []*instruction{insAUIPC, ins}
default:
p.Ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
return nil
}
case p.From.Type == obj.TYPE_ADDR && p.To.Type == obj.TYPE_REG:
// MOV $sym+off(SP/SB), R
if p.As != AMOV {
p.Ctxt.Diag("%v: unsupported address load", p)
return nil
}
switch p.From.Name {
case obj.NAME_AUTO, obj.NAME_PARAM, obj.NAME_NONE:
inss = instructionsForOpImmediate(p, AADDI, addrToReg(p.From))
@ -1861,15 +1839,19 @@ func instructionsForMOV(p *obj.Prog) []*instruction {
insAUIPC := &instruction{as: AAUIPC, rd: ins.rd}
ins.as, ins.rs1, ins.rs2, ins.imm = AADDI, ins.rd, obj.REG_NONE, 0
inss = []*instruction{insAUIPC, ins}
}
default:
// If we get here with a MOV pseudo-instruction it is going to
// remain unhandled. For now we trust rewriteMOV to catch these.
switch p.As {
case AMOV, AMOVB, AMOVH, AMOVW, AMOVBU, AMOVHU, AMOVWU, AMOVF, AMOVD:
p.Ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
return nil
}
case p.From.Type == obj.TYPE_ADDR && p.To.Type != obj.TYPE_REG:
p.Ctxt.Diag("%v: address load must target register", p)
return nil
default:
p.Ctxt.Diag("%v: unsupported MOV", p)
return nil
}
return inss