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;  \
><td>
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<div class='path'>path: <a href='/guix/log/?id=da3c8a963f83c044568d99921480259eaa26a923'>root</a>/<a href='/guix/log/etc?id=da3c8a963f83c044568d99921480259eaa26a923'>etc</a>/<a href='/guix/log/etc/upgrade-manifest.scm?id=da3c8a963f83c044568d99921480259eaa26a923'>upgrade-manifest.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/etc/upgrade-manifest.scm?id=da3c8a963f83c044568d99921480259eaa26a923&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-12-02 11:55:09 +0100'>2024-12-02</span></td><td><a href='/guix/commit/etc/upgrade-manifest.scm?id=fb4100293545b30a7eef0b7f3b9bab024d0984a6'>maint: Run ‘etc/upgrade-manifest.scm’ in a UTF-8 locale.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/upgrade-manifest.scm: Add calls to ‘setlocale’ to force a UTF-8
locale.

Change-Id: Ia567a1e08124d9eab7fb32f3363681a8f37431b1
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2024-12-01 20:14:16 +0100'>2024-12-01</span></td><td><a href='/guix/commit/etc/upgrade-manifest.scm?id=858dd7e721d69a6087375395037a86640418f1fb'>etc: Add upgrade manifest.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/scripts/build.scm (dependents): Export.
* etc/upgrade-manifest.scm: New file.
* Makefile.am (EXTRA_DIST): Add it.

Change-Id: I1b2a2ebd09e559c68da9f25772bf33caacb4c031
</span></span></td><td>Ludovic Courtès</td></tr>