From bb73dfea8892bb8f36a9c6e5ae55ceec6093d420 Mon Sep 17 00:00:00 2001
From: Daniel Egger <daniel@eggers-club.de>
Date: Sun, 28 Jul 2019 16:59:34 +0200
Subject: [PATCH] Join the bits muching into a single line to improve dev
 builds

Also this rectifies many of the tons of
https://rust-lang.github.io/rust-clippy/master/index.html#identity_op
lints we're getting.

Signed-off-by: Daniel Egger <daniel@eggers-club.de>
---
 CHANGELOG.md             |  2 ++
 src/generate/register.rs | 38 ++++++++++++++++++++++++++++----------
 2 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7c645fc2..770958bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 
 - Break ultra-long single line output into multiple lines for better usability
+- Joined field write proxy into a single line to help dev builds
+- Elimated useless 0 shifts to reduce generated code size and fix a clippy lint
 
 ### Fixed
 
diff --git a/src/generate/register.rs b/src/generate/register.rs
index e31e0041..7e6d35d6 100644
--- a/src/generate/register.rs
+++ b/src/generate/register.rs
@@ -323,7 +323,7 @@ pub fn fields(
 
         let bits = &f.bits;
         let mask = &f.mask;
-        let offset = &f.offset;
+        let offset: usize = f.offset.parse().unwrap();
         let fty = &f.ty;
 
         let lookup_results = lookup(
@@ -341,8 +341,15 @@ pub fn fields(
             } else {
                 quote! { as #fty }
             };
-            let value = quote! {
-                ((self.bits >> #offset) & #mask) #cast
+            let value = if offset != 0 {
+                let offset = &f.offset;
+                quote! {
+                    ((self.bits >> #offset) & #mask) #cast
+                }
+            } else {
+                quote! {
+                    (self.bits & #mask) #cast
+                }
             };
 
             if let Some((evs, base)) = lookup_filter(&lookup_results, Usage::Read) {
@@ -720,13 +727,24 @@ pub fn fields(
                 });
             }
 
-            proxy_items.push(quote! {
-                ///Writes raw bits to the field
-                #[inline(always)]
-                pub #unsafety fn #bits(self, value: #fty) -> &'a mut W {
-                    self.w.bits &= !(#mask << #offset);
-                    self.w.bits |= ((value as #rty) & #mask) << #offset;
-                    self.w
+            proxy_items.push(if offset != 0 {
+                let offset = &f.offset;
+                quote! {
+                    ///Writes raw bits to the field
+                    #[inline(always)]
+                    pub #unsafety fn #bits(self, value: #fty) -> &'a mut W {
+                        self.w.bits = (self.w.bits & !(#mask << #offset)) | (((value as #rty) & #mask) << #offset);
+                        self.w
+                    }
+                }
+            } else {
+                quote! {
+                    ///Writes raw bits to the field
+                    #[inline(always)]
+                    pub #unsafety fn #bits(self, value: #fty) -> &'a mut W {
+                        self.w.bits = (self.w.bits & !#mask) | ((value as #rty) & #mask);
+                        self.w
+                    }
                 }
             });