[Qemu-devel] [PATCH] Fix Alpha ret instruction

[Vince Weaver <vince@csl.cornell.edu>]

Hopefully pine doesn't corrupt this patch, I've had problems recently.

For an alpha "ret" instruction, of the type
     ret $26

The return was being ignored.  This is because in translate.c
register $26 (the return address) was being over-written with the current 
PC before it could be jumped to.  Thus the ret was ignored.

This patch just re-orders things so the return address is processed before 
it is over-written with the current PC.



Index: target-alpha/translate.c
===================================================================
--- target-alpha/translate.c	(revision 5636)
+++ target-alpha/translate.c	(working copy)
@@ -1634,12 +1634,13 @@
          break;
  #endif
      case 0x1A:
-        if (ra != 31)
-            tcg_gen_movi_i64(cpu_ir[ra], ctx->pc);
          if (rb != 31)
              tcg_gen_andi_i64(cpu_pc, cpu_ir[rb], ~3);
          else
              tcg_gen_movi_i64(cpu_pc, 0);
+        if (ra != 31)
+            tcg_gen_movi_i64(cpu_ir[ra], ctx->pc);
+
          /* Those four jumps only differ by the branch prediction hint */
          switch (fn2) {
          case 0x0: