Support LoongArch architecture (lp64 ABIs)

meson.build

@@ -88,6 +88,8 @@ elif arch == 'aarch64'
 	bitness = 64
 elif arch == 'riscv64'
 	bitness = 64
+elif arch == 'loongarch64'
+	bitness = 64
 else
 	error('Architecture "@0@" is not supported.'.format(arch))
 endif

src/asm/trampoline-loongarch64.S

@@ -0,0 +1,49 @@
+/*
+ * Dear user,
+ *
+ * this file has been released under the Romantic WTF public license.
+ * I hereby grant you an irrevocable license to do
+ * WHAT THE GENTLE CARESS YOU WANT TO
+ * with this lovely code.
+ *
+ * -- Alexey Sheplyakov <[email protected]>
+ *
+ * P.S.: Even though I poured my heart into this work I cannot provide any
+ *       warranty regarding its fitness for any purpose. You acknowledge
+ *       that I will not be held liable for any damage its use could incur.
+ */
+
+#include "config.h"
+#include "mangling.h"
+
+#ifdef ASSEMBLER_SUPPORTS_HIDDEN
+.hidden MANGLE(bxfi_trampoline)
+#endif
+.globl MANGLE(bxfi_trampoline)
+MANGLE(bxfi_trampoline):
+/* All LoongArch instructions are 4 bytes long.
+ * The destination address is next to the trampoline code.
+ * Thus the destination address is at current PC + 12 bytes
+ * for the trampoline code is the following 3 instructions:
+ */
+    pcaddu12i	$t0, 0
+    ld.d	$t0, $t0, 0xc
+    jirl	$ra, $t0, 0
+
+.align 1
+
+#ifdef ASSEMBLER_SUPPORTS_HIDDEN
+.hidden MANGLE(bxfi_trampoline_addr)
+#endif
+.globl MANGLE(bxfi_trampoline_addr)
+MANGLE(bxfi_trampoline_addr):
+addr_data:
+.fill 8, 1, 0
+
+#ifdef ASSEMBLER_SUPPORTS_HIDDEN
+.hidden MANGLE(bxfi_trampoline_end)
+#endif
+.globl MANGLE(bxfi_trampoline_end)
+MANGLE(bxfi_trampoline_end):
+
+#include "stackfix.h"