Bug 270794

Created attachment 58861 [details]
Patch to fix this bug

Bug # 267630 adds support for the IBM POWER7.  There's a very minor bug in the patch attached to that bug report that causes a problem running the 'jm-insns' program in none/tests/ppc{32|64}.  The problem only shows up under the following conditions:
  1. Running on an IBM processor without Altivec support (e.g., POWER5)
  2. Building with a new enough compiler that recognizes the '-mvsx' flag
  3. Running the jm-insns testcase without the test harness, as follows:
        ./vg-in-place --tool=none none/tests/ppc{32|64}/jm-insns -a

Invoking the testcase this way will result in an ugly message:
---------
==3958== Process terminating with default action of signal 4 (SIGILL)
==3958==  Illegal opcode at address 0x568D64C
==3958==    at 0x100074B8: main (jm-insns.c:4422)
---------

... versus the slightly more user-friendly message that would be expected in this situation:
---------
disInstr(ppc): declined to decode an AltiVec insn.
disInstr(ppc): unhandled instruction: 0x7C0048CE
                 primary 31(0x1F), secondary 206(0xCE)
==3924== valgrind: Unrecognised instruction at address 0x10004254.
==3924==    at 0x10004254: main (jm-insns.c:4422)
---------

On the other hand, if you invoke the "jm-insns -a" testcase using the test harness as follows:
  perl tests/vg_tests none/tests/ppc{32|64}/jm-vmx

... the prereq check for VMX support will return false and the testcase won't be run at all.