Having a separate, logical classifiation of numbers will
unify more error paths for different formats.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Use do_float_check_status directly, so that we don't get confused
about which return address we're using. And definitely don't use
helper_float_check_status.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The always_inline trick only works if the function is always
called from the outer-most helper. But it isn't, so pass in
the outer-most return address. There's no need for a switch
statement whose argument is always a constant. Unravel the
switch and goto via more helpers.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Memory operations have no side effects on fp state.
The use of a "real" conversions between float64 and float32
would raise exceptions for SNaN and out-of-range inputs.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Divide by zero, exception taken, leaves the destination register
unmodified. Therefore we must raise the exception before returning
from the respective helpers.
>From helper_fre, divide by zero exception not taken, return the
documented +/- 0.5.
At the same time, tidy the invalid exception checking so that we
rely on softfloat for initial argument validation, and select the
kind of invalid operand exception only when we know we must.
At the same time, pass and return float64 values directly rather
than bounce through the CPU_DoubleU union.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tidy the invalid exception checking so that we rely on softfloat for
initial argument validation, and select the kind of invalid operand
exception only when we know we must. Pass and return float64 values
directly rather than bounce through the CPU_DoubleU union.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tidy the invalid exception checking so that we rely on softfloat for
initial argument validation, and select the kind of invalid operand
exception only when we know we must. Pass and return float64 values
directly rather than bounce through the CPU_DoubleU union.
Note that because we know float_flag_invalid was set, we do not have
to re-check the signs of the infinities.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tidy the invalid exception checking so that we rely on softfloat for
initial argument validation, and select the kind of invalid operand
exception only when we know we must. Pass and return float64 values
directly rather than bounce through the CPU_DoubleU union.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Divide by zero, exception taken, leaves the destination register
unmodified. Therefore we must raise the exception before returning
from helper_fdiv. Move the check from do_float_check_status into
helper_fdiv.
At the same time, tidy the invalid exception checking so that we
rely on softfloat for initial argument validation, and select the
kind of invalid operand exception only when we know we must.
At the same time, pass and return float64 values directly rather
than bounce through the CPU_DoubleU union.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
While just setting the MSR bits is sufficient, we can tidy
the helper code by extracting the MSR test to a helper and
then forcing it true for user-only.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The FPSCR[FI] bit indicates if the last floating point instruction had a result that was rounded. Each consecutive floating point instruction is suppose to set this bit to the correct value. What currently happens is this bit is not set as often as it should be. I have verified that this is the behavior of a real PowerPC 950. This patch fixes that problem by deciding to set this bit after each floating point instruction.
https://www.pdfdrive.net/powerpc-microprocessor-family-the-programming-environments-for-32-e3087633.html
Page 63 in table 2-4 is where the description of this bit can be found.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Fix the helper_fpscr_clrbit() function so it correctly sets the FEX
and VX bits.
Determining the value for the Floating Point Status and Control
Register's (FPSCR) FEX bit is suppose to be done like this:
FEX = (VX & VE) | (OX & OE) | (UX & UE) | (ZX & ZE) | (XX & XE))
It is described as "the logical OR of all the floating-point exception
bits masked by their respective enable bits". It was not implemented
correctly. The value of FEX would stay on even when all other bits
were set to off.
The VX bit is described as "the logical OR of all of the invalid
operation exceptions". This bit was also not implemented correctly. It
too would stay on when all the other bits were set to off.
My main source of information is an IBM document called:
PowerPC Microprocessor Family:
The Programming Environments for 32-Bit Microprocessors
Page 62 is where the FPSCR information is located.
This is an older copy than the one I use but it is still very useful:
https://www.pdfdrive.net/powerpc-microprocessor-family-the-programming-environments-for-32-e3087633.html
I use a G3 and G5 iMac to compare bit values with QEMU. This patch
fixed all the problems I was having with these bits.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
[dwg: Re-wrapped commit message]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Only MIPS requires snan_bit_is_one to be variable. While we are
specializing softfloat behaviour, allow other targets to eliminate
this runtime check.
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Yongbok Kim <yongbok.kim@mips.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Alexander Graf <agraf@suse.de>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
As cpu.h is another typically widely included file which doesn't need
full access to the softfloat API we can remove the includes from here
as well. Where they do need types it's typically for float_status and
the rounding modes so we move that to softfloat-types.h as well.
As a result of not having softfloat in every cpu.h call we now need to
add it to various helpers that do need the full softfloat.h
definitions.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[For PPC parts]
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Use the helper routine float[32,64]_maddsub_update_excp() in VSX_MADD
macro.
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Adds FPU_MADDSUB_UPDATE macro, this will be used for other routines
having float32/16
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Current order of checking does not confirm with the spec
(ISA 3.0: MultiplyAddDP page-469). Change the order and make them
independent of each other.
For example: a = infinity, b = zero, c = SNaN, this should set both
VXIMZ and VXNAN
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Use the softfloat api for fused multiply-add.
Introduce routine to set the FPSCR flags VXNAN, VXIMZ nad VMISI.
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xscvqpudz: VSX Scalar truncate & Convert Quad-Precision format to
Unsigned Doubleword format
xscvqpuwz: VSX Scalar truncate & Convert Quad-Precision format to
Unsigned Word format
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xsaddqpo: VSX Scalar Add Quad-Precision using round to Odd
xsmulqo: VSX Scalar Multiply Quad-Precision using round to Odd
xsdivqpo: VSX Scalar Divide Quad-Precision using round to Odd
xscvqpdpo: VSX Scalar round & Convert Quad-Precision format to
Double-Precision format using round to Odd
xssqrtqpo: VSX Scalar Square Root Quad-Precision using round to Odd
xssubqpo: VSX Scalar Subtract Quad-Precision using round to Odd
In addition, fix the invalid bitmask in the instruction encoding
of xssqrtqp[o].
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
CC: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xststdcsp: VSX Scalar Test Data Class Single-Precision
xststdcdp: VSX Scalar Test Data Class Double-Precision
xststdcqp: VSX Scalar Test Data Class Quad-Precision
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xvtstdcsp: VSX Vector Test Data Class Single-Precision
xvtstdcdp: VSX Vector Test Data Class Double-Precision
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xvcvhpsp: VSX Vector Convert Half Precision to Single Precision
xvcvsphp: VSX Vector Convert Single Precision to Half Precision
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xscvsdqp: VSX Scalar Convert Signed Doubleword format to
Quad-Precision format
xscvudqp: VSX Scalar Convert Unsigned Doubleword format to
Quad-Precision format
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xscmpoqp, xscmpuqp & xscmpexpqp were added before f128 field was
introduced in ppc_vsr_t. Now that we have it, use it instead of
generating the 128 bit float using two 64bit fields.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xscvqpsdz: VSX Scalar truncate & Convert Quad-Precision format to
Signed Doubleword format
xscvqpswz: VSX Scalar truncate & Convert Quad-Precision format to
Signed Word format
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xscvqpdp: VSX Scalar round & Convert Quad-Precision format to
Double-Precision format
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xscvdpqp: VSX Scalar Convert Double-Precision format to
Quad-Precision format
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Use correct FP precision when setting FPRF in FP conversion helpers
instead of always assuming float64 precision.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
xscvdphp: VSX Scalar round & Convert Double-Precision format to
Half-Precision format
xscvhpdp: VSX Scalar Convert Half-Precision format to
Double-Precision format
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Since helper_compute_fprf() works on float64 argument, rename it
to helper_compute_fprf_float64(). Also use a macro to generate
helper_compute_fprf_float64() so that float128 version of the same
helper can be introduced easily later.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Replace isden() by float64_is_zero_or_denormal() so that code in
helper_compute_fprf() can be reused to work with float128 argument.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Use float64 argument instead of unit64_t in helper_compute_fprf()
This allows code in helper_compute_fprf() to be reused later to
work with float128 argument too.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The structure and corresponding defines and functions need to be used
outside of fpu_helper.c as well.
Add u8, u16, u32 and Int128 to the structure.
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
