From 8d55cdc73b07dd56ae59a42bcc11cde82614334a Mon Sep 17 00:00:00 2001
From: Frank Mehnert <frank.mehnert@kernkonzept.com>
Date: Mon, 10 May 2021 00:00:00 +0000
Subject: [PATCH] ia32: add implementation for '__udivmoddi4()'

This function is implicitly required by code in jdb.cpp performing a
64-bit integer division on 32-bit systems. This function is required
by code generated with gcc-11. Code generated with older versions of
gcc was satisfied with the existing implementation for '__udivdi3'.

Also fix cosmetic issues in gcc_lib.c and add Doxygen documentation.

Change-Id: If5b44a9e98429c4fc3eacdd5af8bdaf33c9c2a8f
---
 src/lib/libk/gcc_lib.c | 49 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 41 insertions(+), 8 deletions(-)

diff --git a/src/lib/libk/gcc_lib.c b/src/lib/libk/gcc_lib.c
index e5626145..b121cb63 100644
--- a/src/lib/libk/gcc_lib.c
+++ b/src/lib/libk/gcc_lib.c
@@ -1,6 +1,8 @@
 
 unsigned long long __umoddi3(unsigned long long, unsigned long long);
 unsigned long long __udivdi3(unsigned long long, unsigned long long);
+unsigned long long __udivmoddi4(unsigned long long, unsigned long long,
+                                unsigned long long *);
 
 struct llmoddiv_t
 {
@@ -31,15 +33,15 @@ static struct llmoddiv_t llmoddiv(unsigned long long div, unsigned long long s)
   while (1)
     {
       if (div >= s)
-	{
-	  div -= s;
-	  i |= tmp;
-	}
+        {
+          div -= s;
+          i |= tmp;
+        }
       if (div == 0)
-	break;
+        break;
       tmp >>= 1;
       if (!tmp)
-	break;
+        break;
       s >>= 1;
     }
 
@@ -47,8 +49,39 @@ static struct llmoddiv_t llmoddiv(unsigned long long div, unsigned long long s)
 }
 
 
+/**
+ * 64-bit unsigned modulo for 32-bit machines.
+ *
+ * \param div  Dividend.
+ * \param s    Divisor.
+ * \return div / s.
+ */
 unsigned long long __umoddi3(unsigned long long div, unsigned long long s)
-{ return llmoddiv(div,s).mod; }
+{ return llmoddiv(div, s).mod; }
 
+/**
+ * 64-bit unsigned division for 32-bit machines.
+ *
+ * \param div  Dividend.
+ * \param s    Divisor.
+ * \return div / s.
+ */
 unsigned long long __udivdi3(unsigned long long div, unsigned long long s)
-{ return llmoddiv(div,s).div; }
+{ return llmoddiv(div, s).div; }
+
+/**
+ * 64-bit unsigned division + modulo for 32-bit machines.
+ *
+ * \param n       Dividend.
+ * \param d       Divisor.
+ * \param[out] r  Pointer to the result holding div % s.
+ * \return div / s.
+ */
+unsigned long long __udivmoddi4(unsigned long long div, unsigned long long s,
+                                unsigned long long *r)
+{
+  struct llmoddiv_t md = llmoddiv(div, s);
+  if (r)
+    *r = md.mod;
+  return md.div;
+}