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| author | Yasmin Beatriz <yasmins@linux.ibm.com> | 2018-07-16 19:03:12 +0000 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2018-08-21 14:28:45 +1000 |
| commit | 56e0e961ec14f7f89f9d5f20e12b61b9510ed1ad (patch) | |
| tree | 0e3de82a4e1a87dada31ea99f4b4f6394c6dc912 /target | |
| parent | 86c0cab11aabb0c2a5cc76825bc05dfe2b367412 (diff) | |
| download | qemu-56e0e961ec14f7f89f9d5f20e12b61b9510ed1ad.zip qemu-56e0e961ec14f7f89f9d5f20e12b61b9510ed1ad.tar.gz qemu-56e0e961ec14f7f89f9d5f20e12b61b9510ed1ad.tar.bz2 | |
target/ppc: bcdsub fix sign when result is zero
When the result of bcdsub is equal to zero, the result sign may be
set to negative in some cases, and this does not follow the Power ISA
specifications as to decimal integer arithmetic instructions.
Signed-off-by: Yasmin Beatriz <yasmins@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'target')
| -rw-r--r-- | target/ppc/int_helper.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c index d52338e..ac7f92d 100644 --- a/target/ppc/int_helper.c +++ b/target/ppc/int_helper.c @@ -2747,6 +2747,9 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); zero = bcd_sub_mag(&result, a, b, &invalid, &overflow); cr = (sgna > 0) ? CRF_GT : CRF_LT; + } else if (bcd_cmp_mag(a, b) == 0) { + result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(0, ps); + zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); } else { result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgnb, ps); zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); |