diff options
| author | Richard Henderson <rth@twiddle.net> | 2013-02-25 11:41:40 -0800 |
|---|---|---|
| committer | Anthony Liguori <aliguori@us.ibm.com> | 2013-02-25 14:32:36 -0600 |
| commit | 08f4a0f7ee899c32bac91114e859d2687cbcf1d7 (patch) | |
| tree | 88edfe54d678c34f81f1c5b90a0dcf92613b768f | |
| parent | e77f083292916ba43b940fdacd2fc1001b750d1d (diff) | |
| download | qemu-08f4a0f7ee899c32bac91114e859d2687cbcf1d7.tar.gz | |
target-ppc: Fix SUBFE carry
While ~T0+T1+CF = T1-T0+CF-1 is true for the low 32-bits,
it does not produce the correct carry-out to bit 33. Do
exactly what the manual says.
Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
| -rw-r--r-- | target-ppc/translate.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/target-ppc/translate.c b/target-ppc/translate.c index f88644118b..80d5366d27 100644 --- a/target-ppc/translate.c +++ b/target-ppc/translate.c @@ -1120,14 +1120,15 @@ static inline void gen_op_arith_subf(DisasContext *ctx, TCGv ret, TCGv arg1, } if (add_ca) { - /* dest = ~arg1 + arg2 + ca = arg2 - arg1 + ca - 1. */ + /* dest = ~arg1 + arg2 + ca. */ if (compute_ca) { - TCGv zero; - tcg_gen_subi_tl(cpu_ca, cpu_ca, 1); + TCGv zero, inv1 = tcg_temp_new(); + tcg_gen_not_tl(inv1, arg1); zero = tcg_const_tl(0); tcg_gen_add2_tl(t0, cpu_ca, arg2, zero, cpu_ca, zero); - tcg_gen_sub2_tl(t0, cpu_ca, t0, cpu_ca, arg1, zero); + tcg_gen_add2_tl(t0, cpu_ca, t0, cpu_ca, inv1, zero); tcg_temp_free(zero); + tcg_temp_free(inv1); } else { tcg_gen_sub_tl(t0, arg2, arg1); tcg_gen_add_tl(t0, t0, cpu_ca); |