These will be used to implement new decimal floating point
instructions from Power ISA 3.1.
The remainder is now returned directly by divu128/divs128,
freeing up phigh to receive the high 64 bits of the quotient.
Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211025191154.350831-4-luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In preparation for changing the divu128/divs128 implementations
to allow for quotients larger than 64 bits, move the div-by-zero
and overflow checks to the callers.
Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211025191154.350831-2-luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The previous code didn't detect overflows if the high 64-bit
of the dividend were equal to the 64-bit divisor. In that case,
64 bits wouldn't be enough to hold the quotient.
Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210910112624.72748-2-luis.pires@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Implements 128-bit left shift and right shift as well as their
testcases. By design, shift silently mods by 128, so the caller is
responsible to assert the shift range if necessary.
Left shift sets the overflow flag if any non-zero digit is shifted out.
Examples:
ulshift(&low, &high, 250, &overflow);
equivalent: n << 122
urshift(&low, &high, -2);
equivalent: n << 126
Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[dwg: Added test-shift128 to .gitignore]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It is not possible to implement functions in host-utils.c for
architectures with quadwords because the guard is implemented in the
Makefile. This patch move the guard out of the Makefile to the
implementation file.
Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-6-git-send-email-peter.maydell@linaro.org
This patch adds the Divide Doubleword Extended instructions.
The implementation builds on the unsigned helper provided in
the previous patch.
Signed-off-by: Tom Musta <tommusta@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Alexander Graf <agraf@suse.de>
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>
The new formulation makes better use of add-with-carry type insns
that the host may have. Use gcc's sign adjustment trick to avoid
having to perform a 128-bit negation.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Replace some x86_64 specific inline assembly with something that
all 64-bit hosts ought to optimize well. At worst this becomes
a call to the gcc __multi3 routine, which is no worse than our
implementation in util/host-utils.c.
With gcc 4.7, we get identical code generation for x86_64. We
now get native multiplication on ia64 and s390x hosts. With minor
improvements to gcc we can get it for ppc64 as well.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
