From: Petar Jovanovic <mips32r2@gmail.com>
Date: Sun, 20 Jan 2013 18:16:45 +0000 (+0000)
Subject: mips: fix for mips-disassembler when branch is at block_size-2 position
X-Git-Tag: svn/VALGRIND_3_9_0^2~146
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=99cea0ae07b2ca1f439e1b8617a6cf7a127f19bc;p=thirdparty%2Fvalgrind.git

mips: fix for mips-disassembler when branch is at block_size-2 position

Check if the last instruction in the block is a branch or jump instruction
should happen only if the disassembler was not already stopped.
Incorrect conditional led to a boundary case in which jumps/branches were not
executed when placed on "max_insns - 2" position in the block.
none/tests/mips32/block_size test will be added to Valgrind to describe the case
and check for regressions in future.


git-svn-id: svn://svn.valgrind.org/vex/trunk@2648
---

diff --git a/VEX/priv/guest_mips_toIR.c b/VEX/priv/guest_mips_toIR.c
index f9fb4423a7..c6a458a703 100644
--- a/VEX/priv/guest_mips_toIR.c
+++ b/VEX/priv/guest_mips_toIR.c
@@ -3622,12 +3622,13 @@ static DisResult disInstr_MIPS_WRK ( Bool(*resteerOkFn) (/*opaque */void *,
 
    // On MIPS we need to check if the last instruction
    // in block is branch or jump
-   if ((vex_control.guest_max_insns - 1) == (delta+4)/4)
+   if (((vex_control.guest_max_insns - 1) == (delta + 4) / 4)
+       &&  (dres.whatNext != Dis_StopHere))
       if (branch_or_jump(guest_code + delta + 4)) {
          dres.whatNext = Dis_StopHere;
          dres.jk_StopHere = Ijk_Boring;
          putPC(mkU32(guest_PC_curr_instr + 4));
-   }
+      }
    dres.len = 4;
 
    DIP("\n");