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author | Tom Musta <tommusta@gmail.com> | 2014-01-07 10:05:51 -0600 |
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committer | Alexander Graf <agraf@suse.de> | 2014-03-05 03:06:39 +0100 |
commit | 98d1eb2748e84f9e3118d1bd2495f0cc917ac18d (patch) | |
tree | 7768c567eff4633cb49b55878c29dc4580dc45de /util | |
parent | a824bc191a90d86980a9ed090cb1d1219faaf8e7 (diff) | |
download | hqemu-98d1eb2748e84f9e3118d1bd2495f0cc917ac18d.zip hqemu-98d1eb2748e84f9e3118d1bd2495f0cc917ac18d.tar.gz |
target-ppc: Add ISA2.06 divdeu[o] Instructions
This patch adds the Divide Doubleword Extended Unsigned
instructions. This instruction requires dividing a 128-bit
value by a 64 bit value. Since 128 bit integer division is
not supported in TCG, a helper is used. An architecture
independent 128-bit division routine is added to host-utils.
Signed-off-by: Tom Musta <tommusta@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
[agraf: use ||]
Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'util')
-rw-r--r-- | util/host-utils.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/util/host-utils.c b/util/host-utils.c index f0784d6..37c1706 100644 --- a/util/host-utils.c +++ b/util/host-utils.c @@ -86,4 +86,42 @@ void muls64 (uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b) } *phigh = rh; } + +/* Unsigned 128x64 division. Returns 1 if overflow (divide by zero or */ +/* quotient exceeds 64 bits). Otherwise returns quotient via plow and */ +/* remainder via phigh. */ +int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor) +{ + uint64_t dhi = *phigh; + uint64_t dlo = *plow; + unsigned i; + uint64_t carry = 0; + + if (divisor == 0) { + return 1; + } else if (dhi == 0) { + *plow = dlo / divisor; + *phigh = dlo % divisor; + return 0; + } else if (dhi > divisor) { + return 1; + } else { + + for (i = 0; i < 64; i++) { + carry = dhi >> 63; + dhi = (dhi << 1) | (dlo >> 63); + if (carry || (dhi >= divisor)) { + dhi -= divisor; + carry = 1; + } else { + carry = 0; + } + dlo = (dlo << 1) | carry; + } + + *plow = dlo; + *phigh = dhi; + return 0; + } +} #endif /* !CONFIG_INT128 */ |