Copied from Debian.

From: Dave Martin
Subject: "rsc" doesnt exist anymore in thumb2

diff --git a/fixed.h b/fixed.h
index 4b58abf..ba4bc26 100644
--- a/fixed.h
+++ b/fixed.h
@@ -275,12 +275,25 @@ mad_fixed_t mad_f_mul_inline(mad_fixed_t x, mad_fixed_t y)
 	 : "+r" (lo), "+r" (hi)  \
 	 : "%r" (x), "r" (y))
 
+#ifdef __thumb__
+/* In Thumb-2, the RSB-immediate instruction is only allowed with a zero
+	operand.  If needed this code can also support Thumb-1 
+	(simply append "s" to the end of the second two instructions). */
+#  define MAD_F_MLN(hi, lo)  \
+    asm ("rsbs        %0, %0, #0\n\t"  \
+	 "sbc   %1, %1, %1\n\t"  \
+	 "sub   %1, %1, %2"  \
+	 : "+&r" (lo), "=&r" (hi)  \
+	 : "r" (hi)  \
+	 : "cc")
+#else /* ! __thumb__ */
 #  define MAD_F_MLN(hi, lo)  \
     asm ("rsbs	%0, %2, #0\n\t"  \
 	 "rsc	%1, %3, #0"  \
-	 : "=r" (lo), "=r" (hi)  \
+	 : "=&r" (lo), "=r" (hi)  \
 	 : "0" (lo), "1" (hi)  \
 	 : "cc")
+#endif /* __thumb__ */
 
 #  define mad_f_scale64(hi, lo)  \
     ({ mad_fixed_t __result;  \
ut/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=24e08f8f1d31e1ef380084599d348e6551424aad'>refs</a><a class='active' href='/guix/log/tests/go.scm'>log</a><a href='/guix/tree/tests/go.scm?id=24e08f8f1d31e1ef380084599d348e6551424aad'>tree</a><a href='/guix/commit/tests/go.scm?id=24e08f8f1d31e1ef380084599d348e6551424aad'>commit</a><a href='/guix/diff/tests/go.scm?id=24e08f8f1d31e1ef380084599d348e6551424aad'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/go.scm'>
<input type='hidden' name='id' value='24e08f8f1d31e1ef380084599d348e6551424aad'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=24e08f8f1d31e1ef380084599d348e6551424aad'>root</a>/<a href='/guix/log/tests?id=24e08f8f1d31e1ef380084599d348e6551424aad'>tests</a>/<a href='/guix/log/tests/go.scm?id=24e08f8f1d31e1ef380084599d348e6551424aad'>go.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/go.scm?id=24e08f8f1d31e1ef380084599d348e6551424aad&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-12-16 18:05:58 +0200'>2023-12-16</span></td><td><a href='/guix/commit/tests/go.scm?id=6aade039e1007b5fece031d80aade43e108768a4'>guix: import: Report go version for go importer.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/go.scm (go-package, go.mod-go-version): New procedures.
(go-module-&gt;guix-package): Add the #:go keyword in the generated package
definition if the required go is newer than the default go.
* tests/go.scm (mock-http-get): Use gexps for package arguments.

Change-Id: I8d005740a442330ac307a40a53764c803ceffc4f
</span></span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2021-09-28 22:00:47 +0200'>2021-09-28</span></td><td><a href='/guix/commit/tests/go.scm?id=770ae098604d0bd9f21d625e8959e6c7ced3c36f'>tests: go: Fix typo.</a><span class='msg-avail'>...<span class='msg-tooltip'>* tests/go.scm (fixture-go-mod-unparseable): Rename this…
(fixture-go-mod-unparsable): …to this.  Adjust the only caller.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-09-01 23:41:42 +0200'>2021-09-01</span></td><td><a href='/guix/commit/tests/go.scm?id=be13e2be08feb88d868f911d8f55b0451fe15e10'>import: go: Improve error handling.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/go.scm (go-module-&gt;guix-package*): Handle errors, remove
memoize.
(go-module-recursive-import): Remove 'guard', add memoize.
* guix/scripts/import/go.scm (guix-import-go): Adjust.
* tests/go.scm: Adjust.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>zimoun</td></tr>