diff --git a/VEX/priv/guest_ppc_toIR.c b/VEX/priv/guest_ppc_toIR.c

index e16e837..a8d4926 100644

--- a/VEX/priv/guest_ppc_toIR.c

+++ b/VEX/priv/guest_ppc_toIR.c

@@ -29356,62 +29356,70 @@ DisResult disInstr_PPC_WRK (

    decode_noF:

       vassert(!allow_F);

-      vex_printf("disInstr(ppc): found the Floating Point instruction 0x%x that\n"

-		 "can't be handled by Valgrind on this host.  This instruction\n"

-		 "requires a host that supports Floating Point instructions.\n",

-		 theInstr);

+      if (sigill_diag)

+         vex_printf("disInstr(ppc): found the Floating Point instruction 0x%x that\n"

+		    "can't be handled by Valgrind on this host.  This instruction\n"

+		    "requires a host that supports Floating Point instructions.\n",

+		    theInstr);

       goto not_supported;

    decode_noV:

       vassert(!allow_V);

-      vex_printf("disInstr(ppc): found an AltiVec or an e500 instruction 0x%x\n"

-		 "that can't be handled by Valgrind.  If this instruction is an\n"

-		 "Altivec instruction, Valgrind must be run on a host that supports"

-		 "AltiVec instructions.  If the application was compiled for e500, then\n"

-		 "unfortunately Valgrind does not yet support e500 instructions.\n",

-		 theInstr);

+      if (sigill_diag)

+         vex_printf("disInstr(ppc): found an AltiVec or an e500 instruction 0x%x\n"

+		    "that can't be handled by Valgrind.  If this instruction is an\n"

+		    "Altivec instruction, Valgrind must be run on a host that supports"

+		    "AltiVec instructions.  If the application was compiled for e500, then\n"

+		    "unfortunately Valgrind does not yet support e500 instructions.\n",

+		    theInstr);

       goto not_supported;

    decode_noVX:

       vassert(!allow_VX);

-      vex_printf("disInstr(ppc): found the instruction 0x%x that is defined in the\n"

-		 "Power ISA 2.06 ABI but can't be handled by Valgrind on this host.\n"

-		 "This instruction \nrequires a host that supports the ISA 2.06 ABI.\n",

-		 theInstr);

+      if (sigill_diag)

+         vex_printf("disInstr(ppc): found the instruction 0x%x that is defined in the\n"

+		    "Power ISA 2.06 ABI but can't be handled by Valgrind on this host.\n"

+		    "This instruction \nrequires a host that supports the ISA 2.06 ABI.\n",

+		    theInstr);

       goto not_supported;

    decode_noFX:

       vassert(!allow_FX);

-      vex_printf("disInstr(ppc): found the General Purpose-Optional instruction 0x%x\n"

-		 "that can't be handled by Valgrind on this host. This instruction\n"

-		 "requires a host that supports the General Purpose-Optional instructions.\n",

-		 theInstr);

+      if (sigill_diag)

+         vex_printf("disInstr(ppc): found the General Purpose-Optional instruction 0x%x\n"

+		    "that can't be handled by Valgrind on this host. This instruction\n"

+		    "requires a host that supports the General Purpose-Optional instructions.\n",

+		    theInstr);

       goto not_supported;

    decode_noGX:

       vassert(!allow_GX);

-      vex_printf("disInstr(ppc): found the Graphics-Optional instruction 0x%x\n"

-		 "that can't be handled by Valgrind on this host. This instruction\n"

-		 "requires a host that supports the Graphic-Optional instructions.\n",

-		 theInstr);

+      if (sigill_diag)

+         vex_printf("disInstr(ppc): found the Graphics-Optional instruction 0x%x\n"

+		    "that can't be handled by Valgrind on this host. This instruction\n"

+		    "requires a host that supports the Graphic-Optional instructions.\n",

+		    theInstr);

       goto not_supported;

    decode_noDFP:

       vassert(!allow_DFP);

-      vex_printf("disInstr(ppc): found the decimal floating point (DFP) instruction 0x%x\n"

-		 "that can't be handled by Valgrind on this host.  This instruction\n"

-		 "requires a host that supports DFP instructions.\n",

-		 theInstr);

+      if (sigill_diag)

+         vex_printf("disInstr(ppc): found the decimal floating point (DFP) instruction 0x%x\n"

+		    "that can't be handled by Valgrind on this host.  This instruction\n"

+		    "requires a host that supports DFP instructions.\n",

+		    theInstr);

       goto not_supported;

    decode_noP8:

       vassert(!allow_isa_2_07);

-      vex_printf("disInstr(ppc): found the Power 8 instruction 0x%x that can't be handled\n"

-		 "by Valgrind on this host.  This instruction requires a host that\n"

-		 "supports Power 8 instructions.\n",

-		 theInstr);

+      if (sigill_diag)

+         vex_printf("disInstr(ppc): found the Power 8 instruction 0x%x that can't be handled\n"

+		    "by Valgrind on this host.  This instruction requires a host that\n"

+		    "supports Power 8 instructions.\n",

+		    theInstr);

       goto not_supported;

    decode_noP9:

       vassert(!allow_isa_3_0);

-      vex_printf("disInstr(ppc): found the Power 9 instruction 0x%x that can't be handled\n"

-                 "by Valgrind on this host.  This instruction requires a host that\n"

-		 "supports Power 9 instructions.\n",

-		 theInstr);

+      if (sigill_diag)

+         vex_printf("disInstr(ppc): found the Power 9 instruction 0x%x that can't be handled\n"

+                    "by Valgrind on this host.  This instruction requires a host that\n"

+		    "supports Power 9 instructions.\n",

+		    theInstr);

       goto not_supported;

    decode_failure: