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tcg/ppc64: Fix zero extension code generation bug for ppc64 host

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The ppc64 code generation backend uses an rldicr (Rotate Left Double
Immediate and Clear Right) instruction to implement zero extension of
a 32 bit quantity to a 64 bit quantity (INDEX_op_ext32u_i64).  However
this is wrong - this instruction clears specified low bits of the
value, instead of high bits as we require for a zero extension.  It
should instead use an rldicl (Rotate Left Double Immediate and Clear
Left) instruction.

Presumably amongst other things, this causes the SLOF firmware image
used with -M pseries to not boot on a ppc64 host.

It appears this bug was exposed by commit
0bf1dbdcc935dfc220a93cd990e947e90706aec6 (tcg/ppc64: fix 16/32 mixup)
which enabled the use of the op_ext32u_i64 operation on the ppc64
backend.

Signed-off-by: Thomas Huth <thuth@de.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: malc <av1474@comtv.ru>
This commit is contained in:
Thomas Huth 2011-09-09 15:58:37 +10:00 committed by malc
parent 07ff2c4475
commit e89720b116
1 changed files with 1 additions and 1 deletions
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2
tcg/ppc64/tcg-target.c
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@ -1560,7 +1560,7 @@ static void tcg_out_op (TCGContext *s, TCGOpcode opc, const TCGArg *args,
break;
case INDEX_op_ext32u_i64:
tcg_out_rld (s, RLDICR, args[0], args[1], 0, 32);
tcg_out_rld (s, RLDICL, args[0], args[1], 0, 32);
break;
case INDEX_op_setcond_i32: