compiler: remove //go:volatile support

compiler/compiler.go

@@ -1086,12 +1086,7 @@ func (c *Compiler) parseInstr(frame *Frame, instr ssa.Instruction) {
 			// nothing to store
 			return
 		}
-		store := c.builder.CreateStore(llvmVal, llvmAddr)
-		valType := instr.Addr.Type().Underlying().(*types.Pointer).Elem()
-		if c.ir.IsVolatile(valType) {
-			// Volatile store, for memory-mapped registers.
-			store.SetVolatile(true)
-		}
+		c.builder.CreateStore(llvmVal, llvmAddr)
 	default:
 		c.addError(instr.Pos(), "unknown instruction: "+instr.String())
 	}
@@ -2505,7 +2500,7 @@ func (c *Compiler) parseUnOp(frame *Frame, unop *ssa.UnOp) (llvm.Value, error) {
 			return llvm.Value{}, c.makeError(unop.Pos(), "todo: unknown type for negate: "+unop.X.Type().Underlying().String())
 		}
 	case token.MUL: // *x, dereference pointer
-		valType := unop.X.Type().Underlying().(*types.Pointer).Elem()
+		unop.X.Type().Underlying().(*types.Pointer).Elem()
 		if c.targetData.TypeAllocSize(x.Type().ElementType()) == 0 {
 			// zero-length data
 			return c.getZeroValue(x.Type().ElementType()), nil
@@ -2525,10 +2520,6 @@ func (c *Compiler) parseUnOp(frame *Frame, unop *ssa.UnOp) (llvm.Value, error) {
 		} else {
 			c.emitNilCheck(frame, x, "deref")
 			load := c.builder.CreateLoad(x, "")
-			if c.ir.IsVolatile(valType) {
-				// Volatile load, for memory-mapped registers.
-				load.SetVolatile(true)
-			}
 			return load, nil
 		}
 	case token.XOR: // ^x, toggle all bits in integer

ir/ir.go

@@ -100,9 +100,6 @@ func NewProgram(lprogram *loader.Program, mainPath string) *Program {
 						}
 						for _, spec := range decl.Specs {
 							switch spec := spec.(type) {
-							case *ast.TypeSpec: // decl.Tok == token.TYPE
-								id := pkgInfo.Pkg.Path() + "." + spec.Name.Name
-								comments[id] = decl.Doc
 							case *ast.ValueSpec: // decl.Tok == token.VAR
 								for _, name := range spec.Names {
 									id := pkgInfo.Pkg.Path() + "." + name.Name
@@ -432,29 +429,6 @@ func (g *Global) CName() string {
 	return ""
 }
 
-// Return true if this named type is annotated with the //go:volatile pragma,
-// for volatile loads and stores.
-func (p *Program) IsVolatile(t types.Type) bool {
-	if t, ok := t.(*types.Named); !ok {
-		return false
-	} else {
-		if t.Obj().Pkg() == nil {
-			return false
-		}
-		id := t.Obj().Pkg().Path() + "." + t.Obj().Name()
-		doc := p.comments[id]
-		if doc == nil {
-			return false
-		}
-		for _, line := range doc.List {
-			if strings.TrimSpace(line.Text) == "//go:volatile" {
-				return true
-			}
-		}
-		return false
-	}
-}
-
 // Get all methods of a type.
 func getAllMethods(prog *ssa.Program, typ types.Type) []*types.Selection {
 	ms := prog.MethodSets.MethodSet(typ)