https://bugs.kde.org/show_bug.cgi?id=386945
--- Comment #59 from Mark Wielaard <m...@klomp.org> ---
The last two patches get rid of the invalid loads for the power8 vsx inlined
strcmp sequences, but still leave us with conditional jumps depending on
undefined values.
The issue is that we will hit the following:
10000624: 99 1e 20 7c lxvd2x vs33,0,r3
10000628: 99 fe 00 7c lxvd2x vs32,0,r31
1000062c: 8c 03 a0 11 vspltisw v13,0
10000630: 00 00 40 39 li r10,0
10000634: 06 00 81 11 vcmpequb v12,v1,v0
10000638: 06 68 01 10 vcmpequb v0,v1,v13
1000063c: 57 65 00 f0 xxlorc vs32,vs32,vs44
10000640: 06 6c 20 10 vcmpequb. v1,v0,v13
10000644: 78 00 98 40 bge cr6,100006bc <main+0x13c>
The bge depends on the cr6 flag which is set as a result of comparing the
result of the vcmpequb. on two possibly not completely defined vectors.
This is done in set_AV_CR6 () in guest_ppc_toIR.c:
/* Set the CR6 flags following an AltiVec compare operation.
* NOTE: This also works for VSX single-precision compares.
* */
static void set_AV_CR6 ( IRExpr* result, Bool test_all_ones )
Called as set_AV_CR6( mkexpr(vD), True ); after interpreting the vcmpequb as
assign( vD, binop(Iop_CmpEQ8x16, mkexpr(vA), mkexpr(vB)) );
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