@@ -1074,6 +1074,7 @@ HAVE_LIST="

     VirtualAlloc

     winsock2_h

     xform_asm

+    xmm_clobbers

     yasm

 "

@@ -2585,6 +2586,9 @@ EOF

     check_asm ebx_available '""::"b"(0)' &&

         check_asm ebx_available '"":::"%ebx"'

+    # check whether xmm clobbers are supported

+    check_asm xmm_clobbers '"":::"%xmm0"'

+

     # check whether more than 10 operands are supported

     check_cc <<EOF && enable ten_operands

 int main(void) {

@@ -75,4 +75,24 @@ typedef int x86_reg;

 #    define BROKEN_RELOCATIONS 1

 #endif

+/*

+ * If gcc is not set to support sse (-msse) it will not accept xmm registers

+ * in the clobber list for inline asm. XMM_CLOBBERS takes a list of xmm

+ * registers to be marked as clobbered and evaluates to nothing if they are

+ * not supported, or to the list itself if they are supported. Since a clobber

+ * list may not be empty, XMM_CLOBBERS_ONLY should be used if the xmm

+ * registers are the only in the clobber list.

+ * For example a list with "eax" and "xmm0" as clobbers should become:

+ * : XMM_CLOBBERS("xmm0",) "eax"

+ * and a list with only "xmm0" should become:

+ * XMM_CLOBBERS_ONLY("xmm0")

+ */

+#if HAVE_XMM_CLOBBERS

+#    define XMM_CLOBBERS(...)        __VA_ARGS__

+#    define XMM_CLOBBERS_ONLY(...) : __VA_ARGS__

+#else

+#    define XMM_CLOBBERS(...)

+#    define XMM_CLOBBERS_ONLY(...)

+#endif

+

 #endif /* AVUTIL_X86_CPU_H */