cmd/internal/obj/riscv: simplify rewriteMOV

Rewrite and simplify the rewriteMOV function in preparation for eliminating it
entirely. Improve some error messages in the process.

Change-Id: Id9a77be5174d46cc23651930c2e9068ee6555690
Reviewed-on: https://go-review.googlesource.com/c/go/+/344458
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>

diff --git a/src/cmd/asm/internal/asm/testdata/riscv64error.s b/src/cmd/asm/internal/asm/testdata/riscv64error.s
index b09a1c7a8c969e9b4497311e7cf88fda89b3e5f9..238552565bdd2f6fe1fe1f9769f7020403a6a5a7 100644 (file)
--- a/src/cmd/asm/internal/asm/testdata/riscv64error.s
+++ b/src/cmd/asm/internal/asm/testdata/riscv64error.s
@@ -3,12 +3,12 @@
 // license that can be found in the LICENSE file.
 
 TEXT errors(SB),$0
-       MOV     $errors(SB), (X5)               // ERROR "unsupported addr MOV"
-       MOV     $8(SP), (X5)                    // ERROR "unsupported addr MOV"
-       MOVB    $8(SP), X5                      // ERROR "unsupported addr MOV"
-       MOVH    $8(SP), X5                      // ERROR "unsupported addr MOV"
-       MOVW    $8(SP), X5                      // ERROR "unsupported addr MOV"
-       MOVF    $8(SP), X5                      // ERROR "unsupported addr MOV"
+       MOV     $errors(SB), (X5)               // ERROR "address load must target register"
+       MOV     $8(SP), (X5)                    // ERROR "address load must target register"
+       MOVB    $8(SP), X5                      // ERROR "unsupported address load"
+       MOVH    $8(SP), X5                      // ERROR "unsupported address load"
+       MOVW    $8(SP), X5                      // ERROR "unsupported address load"
+       MOVF    $8(SP), X5                      // ERROR "unsupported address load"
        MOV     $1234, 0(SP)                    // ERROR "constant load must target register"
        MOV     $1234, 8(SP)                    // ERROR "constant load must target register"
        MOV     $0, 0(SP)                       // ERROR "constant load must target register"

diff --git a/src/cmd/internal/obj/riscv/obj.go b/src/cmd/internal/obj/riscv/obj.go
index 1140542739013fc8ed73a9f33f40195411c90628..443f761ad91ce07734251b1f693726036f3b6f7f 100644 (file)
--- a/src/cmd/internal/obj/riscv/obj.go
+++ b/src/cmd/internal/obj/riscv/obj.go
@@ -226,51 +226,32 @@ func rewriteMOV(ctxt *obj.Link, newprog obj.ProgAlloc, p *obj.Prog) {
                panic(fmt.Sprintf("%+v is not a MOV pseudo-instruction", p.As))
        }
 
-       switch p.From.Type {
-       case obj.TYPE_MEM:
-               switch p.From.Name {
-               case obj.NAME_AUTO, obj.NAME_PARAM, obj.NAME_NONE:
-                       if p.To.Type != obj.TYPE_REG {
-                               ctxt.Diag("unsupported load for %v", p)
-                       }
+       switch {
+       case p.From.Type == obj.TYPE_REG && p.To.Type == obj.TYPE_REG:
 
+       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 obj.TYPE_REG:
-               switch p.To.Type {
-               case obj.TYPE_REG:
-                       switch p.As {
-                       case AMOV, AMOVB, AMOVH, AMOVW, AMOVBU, AMOVHU, AMOVWU, AMOVF, AMOVD:
-                       default:
-                               ctxt.Diag("unsupported register-register move at %v", p)
-                       }
-
-               case obj.TYPE_MEM:
-                       switch p.As {
-                       case AMOVBU, AMOVHU, AMOVWU:
-                               ctxt.Diag("unsupported unsigned store at %v", p)
-                               return
-                       }
-                       switch p.To.Name {
-                       case obj.NAME_AUTO, obj.NAME_PARAM, obj.NAME_NONE:
-
-                       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_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 MOV at %v", p)
+                       ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
                }
 
-       case obj.TYPE_CONST:
+       case p.From.Type == obj.TYPE_CONST:
                if p.As != AMOV {
                        ctxt.Diag("%v: unsupported constant load", p)
                }
@@ -278,18 +259,19 @@ func rewriteMOV(ctxt *obj.Link, newprog obj.ProgAlloc, p *obj.Prog) {
                        ctxt.Diag("%v: constant load must target register", p)
                }
 
-       case obj.TYPE_ADDR:
-               if p.To.Type != obj.TYPE_REG || p.As != AMOV {
-                       ctxt.Diag("unsupported addr MOV at %v", 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_PARAM, obj.NAME_NONE:
-
+               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("bad addr MOV from name %v at %v", p.From.Name, p)
+                       ctxt.Diag("unsupported name %d for %v", p.From.Name, p)
                }
 
        default: