From 55548603b88ccf0babd081bd636c73ca164da919 Mon Sep 17 00:00:00 2001
From: iximeow <me@iximeow.net>
Date: Wed, 19 Jun 2024 10:46:49 -0700
Subject: hoist set_len calls to have fewer live values

---
 src/long_mode/display.rs | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)

(limited to 'src/long_mode')

diff --git a/src/long_mode/display.rs b/src/long_mode/display.rs
index a60b2fd..0188361 100644
--- a/src/long_mode/display.rs
+++ b/src/long_mode/display.rs
@@ -555,6 +555,10 @@ impl DisplaySink for alloc::string::String {
 
             let mut rem = new_bytes.len() as isize;
 
+            // set_len early because there is no way to avoid the following asm!() writing that
+            // same number of bytes into buf
+            buf.set_len(buf.len() + new_bytes.len());
+
             core::arch::asm!(
                 "6:",
                 "cmp {rem:e}, 16",
@@ -598,8 +602,6 @@ impl DisplaySink for alloc::string::String {
                 buf = out(reg) _,
                 options(nostack),
             );
-
-            buf.set_len(buf.len() + new_bytes.len());
         }
         /*
         for i in 0..new_bytes.len() {
@@ -633,6 +635,10 @@ impl DisplaySink for alloc::string::String {
 
             let mut rem = new_bytes.len() as isize;
 
+            // set_len early because there is no way to avoid the following asm!() writing that
+            // same number of bytes into buf
+            buf.set_len(buf.len() + new_bytes.len());
+
             core::arch::asm!(
                 "7:",
                 "cmp {rem:e}, 8",
@@ -667,8 +673,6 @@ impl DisplaySink for alloc::string::String {
                 buf = out(reg) _,
                 options(nostack),
             );
-
-            buf.set_len(buf.len() + new_bytes.len());
         }
         /*
         for i in 0..new_bytes.len() {
@@ -702,6 +706,10 @@ impl DisplaySink for alloc::string::String {
 
             let mut rem = new_bytes.len() as isize;
 
+            // set_len early because there is no way to avoid the following asm!() writing that
+            // same number of bytes into buf
+            buf.set_len(buf.len() + new_bytes.len());
+
             core::arch::asm!(
                 "8:",
                 "cmp {rem:e}, 4",
@@ -729,8 +737,6 @@ impl DisplaySink for alloc::string::String {
                 buf = out(reg) _,
                 options(nostack),
             );
-
-            buf.set_len(buf.len() + new_bytes.len());
         }
         /*
         for i in 0..new_bytes.len() {
@@ -926,6 +932,10 @@ impl DisplaySink for BigEnoughString {
 
             let mut rem = new_bytes.len() as isize;
 
+            // set_len early because there is no way to avoid the following asm!() writing that
+            // same number of bytes into buf
+            buf.set_len(buf.len() + new_bytes.len());
+
             core::arch::asm!(
                 "6:",
                 "cmp {rem:e}, 16",
@@ -969,8 +979,6 @@ impl DisplaySink for BigEnoughString {
                 buf = out(reg) _,
                 options(nostack),
             );
-
-            buf.set_len(buf.len() + new_bytes.len());
         }
         /*
         for i in 0..new_bytes.len() {
@@ -1002,6 +1010,10 @@ impl DisplaySink for BigEnoughString {
 
             let mut rem = new_bytes.len() as isize;
 
+            // set_len early because there is no way to avoid the following asm!() writing that
+            // same number of bytes into buf
+            buf.set_len(buf.len() + new_bytes.len());
+
             core::arch::asm!(
                 "7:",
                 "cmp {rem:e}, 8",
@@ -1036,8 +1048,6 @@ impl DisplaySink for BigEnoughString {
                 buf = out(reg) _,
                 options(nostack),
             );
-
-            buf.set_len(buf.len() + new_bytes.len());
         }
         /*
         for i in 0..new_bytes.len() {
@@ -1069,6 +1079,10 @@ impl DisplaySink for BigEnoughString {
 
             let mut rem = new_bytes.len() as isize;
 
+            // set_len early because there is no way to avoid the following asm!() writing that
+            // same number of bytes into buf
+            buf.set_len(buf.len() + new_bytes.len());
+
             core::arch::asm!(
                 "8:",
                 "cmp {rem:e}, 4",
@@ -1096,8 +1110,6 @@ impl DisplaySink for BigEnoughString {
                 buf = out(reg) _,
                 options(nostack),
             );
-
-            buf.set_len(buf.len() + new_bytes.len());
         }
         /*
         for i in 0..new_bytes.len() {
-- 
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