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cmd/internal/obj/riscv: clean up lowerJALR

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This cleans up the last of the direct obj.Prog rewriting, removing lowerJALR
and replacing it with correct handling for AJALR during instruction encoding.

Change-Id: Ieea125bde30d4c0edd2d9ed1e50160543aa8f330
Reviewed-on: https://go-review.googlesource.com/c/go/+/249077
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Joel Sing <joel@sing.id.au>
This commit is contained in:
Joel Sing 2020-08-19 03:07:26 +10:00
parent 7f24142b7b
commit 0dde60a5fe
1 changed files with 9 additions and 34 deletions
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43
src/cmd/internal/obj/riscv/obj.go
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@ -58,30 +58,14 @@ func jalrToSym(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc, lr int16) *ob
p.As = AJALR
p.From.Type = obj.TYPE_REG
p.From.Reg = lr
p.From.Sym = to.Sym
p.Reg = 0
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_TMP
lowerJALR(p)
p.To.Sym = to.Sym
return p
}
// lowerJALR normalizes a JALR instruction.
func lowerJALR(p *obj.Prog) {
if p.As != AJALR {
panic("lowerJALR: not a JALR")
}
// JALR gets parsed like JAL - the linkage pointer goes in From,
// and the target is in To. However, we need to assemble it as an
// I-type instruction, so place the linkage pointer in To, the
// target register in Reg, and the offset in From.
p.Reg = p.To.Reg
p.From, p.To = p.To, p.From
p.From.Type, p.From.Reg = obj.TYPE_CONST, obj.REG_NONE
}
// progedit is called individually for each *obj.Prog. It normalizes instruction
// formats and eliminates as many pseudo-instructions as possible.
func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
@ -125,7 +109,6 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
switch p.As {
case obj.AJMP:
// Turn JMP into JAL ZERO or JALR ZERO.
// p.From is actually an _output_ for this instruction.
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_ZERO
@ -136,7 +119,6 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
switch p.To.Name {
case obj.NAME_NONE:
p.As = AJALR
lowerJALR(p)
case obj.NAME_EXTERN:
// Handled in preprocess.
default:
@ -154,14 +136,10 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
p.As = AJALR
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_LR
lowerJALR(p)
default:
ctxt.Diag("unknown destination type %+v in CALL: %v", p.To.Type, p)
}
case AJALR:
lowerJALR(p)
case obj.AUNDEF:
p.As = AEBREAK
@ -454,7 +432,7 @@ func containsCall(sym *obj.LSym) bool {
case obj.ACALL:
return true
case AJAL, AJALR:
if p.To.Type == obj.TYPE_REG && p.To.Reg == REG_LR {
if p.From.Type == obj.TYPE_REG && p.From.Reg == REG_LR {
return true
}
}
@ -731,11 +709,9 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
p = jalrToSym(ctxt, p, newprog, REG_ZERO)
} else {
p.As = AJALR
p.From.Type = obj.TYPE_CONST
p.From.Offset = 0
p.Reg = REG_LR
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_ZERO
p.From = obj.Addr{Type: obj.TYPE_REG, Reg: REG_ZERO}
p.Reg = 0
p.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_LR}
}
// "Add back" the stack removed in the previous instruction.
@ -917,9 +893,8 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
// it is reserved by SSA.
jmp := obj.Appendp(p, newprog)
jmp.As = AJALR
jmp.From = obj.Addr{Type: obj.TYPE_CONST, Offset: 0}
jmp.To = p.From
jmp.Reg = REG_TMP
jmp.From = p.From
jmp.To = obj.Addr{Type: obj.TYPE_REG, Reg: REG_TMP}
// p.From is not generally valid, however will be
// fixed up in the next loop.
@ -1801,8 +1776,8 @@ func instructionsForProg(p *obj.Prog) []*instruction {
inss := []*instruction{ins}
switch ins.as {
case AJAL:
ins.rd, ins.rs2 = uint32(p.From.Reg), obj.REG_NONE
case AJAL, AJALR:
ins.rd, ins.rs1, ins.rs2 = uint32(p.From.Reg), uint32(p.To.Reg), obj.REG_NONE
ins.imm = p.To.Offset
case ABEQ, ABEQZ, ABGE, ABGEU, ABGEZ, ABGT, ABGTU, ABGTZ, ABLE, ABLEU, ABLEZ, ABLT, ABLTU, ABLTZ, ABNE, ABNEZ: