From 13b910f01a9869acc68af1e34e57177b0be8f777 Mon Sep 17 00:00:00 2001
From: Markku Rossi <mtr@iki.fi>
Date: Sat, 3 Aug 2024 11:31:20 +0200
Subject: [PATCH] Pointer fixes.

---
 compiler/ast/ssagen.go                        |  6 ++--
 compiler/ssa/value.go                         | 29 +++++++++++++++++++
 .../internal/edwards25519/ed25519.mpcl        | 10 ++-----
 3 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/compiler/ast/ssagen.go b/compiler/ast/ssagen.go
index cbc6d352..435cc8cc 100644
--- a/compiler/ast/ssagen.go
+++ b/compiler/ast/ssagen.go
@@ -2261,11 +2261,11 @@ func (ast *Copy) SSA(block *ssa.Block, ctx *Codegen, gen *ssa.Generator) (
 		return nil, nil, ast.errf(ctx, ast.Src, "got multivalue %T", ast.Src)
 	}
 	src := v[0]
-	srcType := src.IndirectType()
-	if !srcType.Type.Array() {
+	src = src.Indirect(block, gen)
+	if !src.Type.Type.Array() {
 		return nil, nil, ast.errf(ctx, ast.Src, "got %v", src.Type)
 	}
-	if !dst.Type.ElementType.Equal(*srcType.ElementType) {
+	if !dst.Type.ElementType.Equal(*src.Type.ElementType) {
 		return nil, nil, ctx.Errorf(ast,
 			"arguments to copy have different element types: %s and %s",
 			dst.Type.ElementType, src.Type.ElementType)
diff --git a/compiler/ssa/value.go b/compiler/ssa/value.go
index f402974f..530508c5 100644
--- a/compiler/ssa/value.go
+++ b/compiler/ssa/value.go
@@ -84,6 +84,35 @@ func (v Value) IndirectType() types.Info {
 	return v.Type
 }
 
+// Indirect returns Value that v points to. If v is not a pointer,
+// Indirect returns v.
+func (v Value) Indirect(block *Block, gen *Generator) Value {
+	if v.Type.Type != types.TPtr {
+		return v
+	}
+
+	// Get container value.
+	b, ok := v.PtrInfo.Bindings.Get(v.PtrInfo.Name)
+	if !ok {
+		panic("Value.Indirect: could not find pointer target")
+	}
+	cv := b.Value(block, gen)
+
+	if v.PtrInfo.ContainerType.Type != types.TStruct {
+		return cv
+	}
+
+	// Get struct field value.
+	elType := *v.Type.ElementType
+	ev := gen.AnonVal(elType)
+	fromConst := gen.Constant(int64(v.PtrInfo.Offset), types.Undefined)
+	toConst := gen.Constant(int64(v.PtrInfo.Offset+elType.Bits),
+		types.Undefined)
+	block.AddInstr(NewSliceInstr(cv, fromConst, toConst, ev))
+
+	return ev
+}
+
 // ContainerType returs the pointer container type of the value. For
 // non-pointer values, this returns the value type itself.
 func (v Value) ContainerType() types.Info {
diff --git a/pkg/crypto/ed25519/internal/edwards25519/ed25519.mpcl b/pkg/crypto/ed25519/internal/edwards25519/ed25519.mpcl
index 29b5814f..695d0e2b 100644
--- a/pkg/crypto/ed25519/internal/edwards25519/ed25519.mpcl
+++ b/pkg/crypto/ed25519/internal/edwards25519/ed25519.mpcl
@@ -1,6 +1,6 @@
 // -*- go -*-
 //
-// Copyright (c) 2020-2023 Markku Rossi
+// Copyright (c) 2020-2024 Markku Rossi
 //
 // Ed25519 signature algorithm in MPCL. This file is derived from the
 // crypto/ed25519/internal/edwards25519 package of Go 1.16.9. The
@@ -24,9 +24,7 @@ type FieldElement [10]int32
 var zero FieldElement
 
 func FeZero(fe *FieldElement) {
-	for i := 0; i < len(fe); i++ {
-		fe[i] = zero[i]
-	}
+	copy(fe[:], zero[:])
 }
 
 func FeOne(fe *FieldElement) {
@@ -61,9 +59,7 @@ func FeSub(dst, a, b *FieldElement) {
 }
 
 func FeCopy(dst, src *FieldElement) {
-	for i := 0; i < len(dst); i++ {
-		dst[i] = src[i]
-	}
+	copy(dst[:], src[:])
 }
 
 // Replace (f,g) with (g,g) if b == 1;