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2016-09-15fpu: add mechanism to check for invalid long double formatsAndrew Dutcher
All operations that take a floatx80 as an operand need to have their inputs checked for malformed encodings. In all of these cases, use the function floatx80_invalid_encoding to perform the check. If an invalid operand is found, raise an invalid operation exception, and then return either NaN (for fp-typed results) or the integer indefinite value (the minimum representable signed integer value, for int-typed results). For the non-quiet comparison operations, this touches adjacent code in order to pass style checks. Signed-off-by: Andrew Dutcher <andrew@andrewdutcher.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1471392895-17324-1-git-send-email-andrew@andrewdutcher.com [PMM: changed "1 << 63" to "1ULL << 63" to fix compile errors] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-08-15softfloat: Fix warn about implicit conversion from int to int8_tPranith Kumar
Change the flag type to 'uint8_t' to fix the implicit conversion error. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Message-id: 20160810185502.32015-1-bobby.prani@gmail.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-06-24softfloat: Handle snan_bit_is_one == 0 in MIPS pickNaNMulAdd()Aleksandar Markovic
Only for Mips platform, and only for cases when snan_bit_is_one is 0, correct the order of argument comparisons in pickNaNMulAdd(). For more info, see [1], page 53, section "3.5.3 NaN Propagation". [1] "MIPS Architecture for Programmers Volume IV-j: The MIPS32 SIMD Architecture Module", Imagination Technologies LTD, Revision 1.12, February 3, 2016 Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: Leon Alrae <leon.alrae@imgtec.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> [leon.alrae@imgtec.com: * reworded the subject of the patch * swapped if/else code blocks to match the commit description] Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
2016-06-24softfloat: For Mips only, correct default NaN valuesAleksandar Markovic
Only for Mips platform, and only for cases when snan_bit_is_one is 0, correct default NaN values (in their 16-, 32-, and 64-bit flavors). For more info, see [1], page 84, Table 6.3 "Value Supplied When a New Quiet NaN Is Created", and [2], page 52, Table 3.7 "Default NaN Encodings". [1] "MIPS Architecture For Programmers Volume II-A: The MIPS64 Instruction Set Reference Manual", Imagination Technologies LTD, Revision 6.04, November 13, 2015 [2] "MIPS Architecture for Programmers Volume IV-j: The MIPS32 SIMD Architecture Module", Imagination Technologies LTD, Revision 1.12, February 3, 2016 Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: Leon Alrae <leon.alrae@imgtec.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
2016-06-24softfloat: Clean code format in fpu/softfloat-specialize.hAleksandar Markovic
fpu/softfloat-specialize.h is the most critical file in SoftFloat library, since it handles numerous differences between platforms in relation to floating point arithmetics. This patch makes the code in this file more consistent format-wise, and hopefully easier to debug and maintain. Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
2016-06-24softfloat: Implement run-time-configurable meaning of signaling NaN bitAleksandar Markovic
This patch modifies SoftFloat library so that it can be configured in run-time in relation to the meaning of signaling NaN bit, while, at the same time, strictly preserving its behavior on all existing platforms. Background: In floating-point calculations, there is a need for denoting undefined or unrepresentable values. This is achieved by defining certain floating-point numerical values to be NaNs (which stands for "not a number"). For additional reasons, virtually all modern floating-point unit implementations use two kinds of NaNs: quiet and signaling. The binary representations of these two kinds of NaNs, as a rule, differ only in one bit (that bit is, traditionally, the first bit of mantissa). Up to 2008, standards for floating-point did not specify all details about binary representation of NaNs. More specifically, the meaning of the bit that is used for distinguishing between signaling and quiet NaNs was not strictly prescribed. (IEEE 754-2008 was the first floating-point standard that defined that meaning clearly, see [1], p. 35) As a result, different platforms took different approaches, and that presented considerable challenge for multi-platform emulators like QEMU. Mips platform represents the most complex case among QEMU-supported platforms regarding signaling NaN bit. Up to the Release 6 of Mips architecture, "1" in signaling NaN bit denoted signaling NaN, which is opposite to IEEE 754-2008 standard. From Release 6 on, Mips architecture adopted IEEE standard prescription, and "0" denotes signaling NaN. On top of that, Mips architecture for SIMD (also known as MSA, or vector instructions) also specifies signaling bit in accordance to IEEE standard. MSA unit can be implemented with both pre-Release 6 and Release 6 main processor units. QEMU uses SoftFloat library to implement various floating-point-related instructions on all platforms. The current QEMU implementation allows for defining meaning of signaling NaN bit during build time, and is implemented via preprocessor macro called SNAN_BIT_IS_ONE. On the other hand, the change in this patch enables SoftFloat library to be configured in run-time. This configuration is meant to occur during CPU initialization, at the moment when it is definitely known what desired behavior for particular CPU (or any additional FPUs) is. The change is implemented so that it is consistent with existing implementation of similar cases. This means that structure float_status is used for passing the information about desired signaling NaN bit on each invocation of SoftFloat functions. The additional field in float_status is called snan_bit_is_one, which supersedes macro SNAN_BIT_IS_ONE. IMPORTANT: This change is not meant to create any change in emulator behavior or functionality on any platform. It just provides the means for SoftFloat library to be used in a more flexible way - in other words, it will just prepare SoftFloat library for usage related to Mips platform and its specifics regarding signaling bit meaning, which is done in some of subsequent patches from this series. Further break down of changes: 1) Added field snan_bit_is_one to the structure float_status, and correspondent setter function set_snan_bit_is_one(). 2) Constants <float16|float32|float64|floatx80|float128>_default_nan (used both internally and externally) converted to functions <float16|float32|float64|floatx80|float128>_default_nan(float_status*). This is necessary since they are dependent on signaling bit meaning. At the same time, for the sake of code cleanup and simplicity, constants <floatx80|float128>_default_nan_<low|high> (used only internally within SoftFloat library) are removed, as not needed. 3) Added a float_status* argument to SoftFloat library functions XXX_is_quiet_nan(XXX a_), XXX_is_signaling_nan(XXX a_), XXX_maybe_silence_nan(XXX a_). This argument must be present in order to enable correct invocation of new version of functions XXX_default_nan(). (XXX is <float16|float32|float64|floatx80|float128> here) 4) Updated code for all platforms to reflect changes in SoftFloat library. This change is twofolds: it includes modifications of SoftFloat library functions invocations, and an addition of invocation of function set_snan_bit_is_one() during CPU initialization, with arguments that are appropriate for each particular platform. It was established that all platforms zero their main CPU data structures, so snan_bit_is_one(0) in appropriate places is not added, as it is not needed. [1] "IEEE Standard for Floating-Point Arithmetic", IEEE Computer Society, August 29, 2008. Signed-off-by: Thomas Schwinge <thomas@codesourcery.com> Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Tested-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> Reviewed-by: Leon Alrae <leon.alrae@imgtec.com> Tested-by: Leon Alrae <leon.alrae@imgtec.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> [leon.alrae@imgtec.com: * cherry-picked 2 chunks from patch #2 to fix compilation warnings] Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
2016-03-23target-tricore: Add FPU infrastructureBastian Koppelmann
This patch adds a file for all the FPU related helpers with all the includes, useful defines, and a function to update the status bits. Additionally it adds a mask for the rounding mode bits of PSW as well as all the opcodes for the FPU instructions. Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> Message-Id: <1457708597-3025-2-git-send-email-kbastian@mail.uni-paderborn.de>
2016-02-19fpu: Use plain 'int' rather than 'int_fast16_t' for exponentsPeter Maydell
Use the plain 'int' type rather than 'int_fast16_t' for handling exponents. Exponents don't need to be exactly 16 bits, so using int16_t for them would confuse more than it clarified. This should be a safe change because int_fast16_t semantics permit use of 'int' (and on 32-bit glibc that is what you get). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Message-id: 1453807806-32698-4-git-send-email-peter.maydell@linaro.org
2016-02-19fpu: Use plain 'int' rather than 'int_fast16_t' for shift countsPeter Maydell
Use the plain 'int' type rather than 'int_fast16_t' for shift counts in the various shift related functions, since we don't actually care about the size of the integer at all here, and using int16_t would be confusing. This should be a safe change because int_fast16_t semantics permit use of 'int' (and on 32-bit glibc that is what you get). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Message-id: 1453807806-32698-3-git-send-email-peter.maydell@linaro.org
2016-02-19fpu: Remove use of int_fast16_t in conversions to int16Peter Maydell
Make the functions which convert floating point to 16 bit integer return int16_t rather than int_fast16_t, and correspondingly use int_fast16_t in their internal implementations where appropriate. (These functions are used only by the ARM target.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Message-id: 1453807806-32698-2-git-send-email-peter.maydell@linaro.org
2016-02-04all: Clean up includesPeter Maydell
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: 1454089805-5470-16-git-send-email-peter.maydell@linaro.org
2016-01-22softfloat: fix return type of roundAndPackFloat16pull-softfloat-20160122Aurelien Jarno
The roundAndPackFloat16 function should return a float16 value, not a float32 one. Fix that. Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1452700993-6570-1-git-send-email-aurelien@aurel32.net Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-01-22fpu: Replace int8 typedef with int8_tPeter Maydell
Replace the int8 softfloat-specific typedef with int8_t. This change was made with find include hw fpu target-* -name '*.[ch]' | xargs sed -i -e 's/\bint8\b/int8_t/g' together with manual removal of the typedef definition, and manual undoing of various mis-hits. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Acked-by: Leon Alrae <leon.alrae@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Message-id: 1452603315-27030-6-git-send-email-peter.maydell@linaro.org
2016-01-22fpu: Replace uint32 typedef with uint32_tPeter Maydell
Replace the uint32 softfloat-specific typedef with uint32_t. This change was made with find include hw fpu target-* -name '*.[ch]' | xargs sed -i -e 's/\buint32\b/uint32_t/g' together with manual removal of the typedef definition, manual undoing of various mis-hits, and another couple of fixes found via test compilation. All the uses in hw/ were using the wrong type by mistake. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Acked-by: Leon Alrae <leon.alrae@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Message-id: 1452603315-27030-5-git-send-email-peter.maydell@linaro.org
2016-01-22fpu: Replace int32 typedef with int32_tPeter Maydell
Replace the int32 softfloat-specific typedef with int32_t. This change was made with find hw include fpu target-* -name '*.[ch]' | xargs sed -i -e 's/\bint32\b/int32_t/g' together with manual removal of the typedef definition, and manual undoing of some mis-hits where macro arguments were being used for token pasting rather than as a type. The uses in hw/ipmi/ should not have been using this type at all. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Acked-by: Leon Alrae <leon.alrae@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Message-id: 1452603315-27030-4-git-send-email-peter.maydell@linaro.org
2016-01-22fpu: Replace uint64 typedef with uint64_tPeter Maydell
Replace the uint64 softfloat-specific typedef with uint64_t. This change was made with find include fpu target-* -name '*.[ch]' | xargs sed -i -e 's/\buint64\b/uint64_t/g' together with manual removal of the typedef definition, and manual undoing of some mis-hits where macro arguments were being used for token pasting rather than as a type. Note that the target-mips/kvm.c and target-s390x/kvm.c changes are fixing code that should not have been using the uint64 type in the first place. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Acked-by: Leon Alrae <leon.alrae@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Message-id: 1452603315-27030-3-git-send-email-peter.maydell@linaro.org
2016-01-22fpu: Replace int64 typedef with int64_tPeter Maydell
Replace the int64 softfloat-specific typedef with int64_t. This change was made with find include fpu target-* -name '*.[ch]' | xargs sed -i -e 's/\bint64\b/int64_t/g' together with manual removal of the typedef definition, and manual undoing of some mis-hits where macro arguments were being used for token pasting rather than as a type. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Acked-by: Leon Alrae <leon.alrae@imgtec.com> Message-id: 1452603315-27030-2-git-send-email-peter.maydell@linaro.org
2015-06-05target-s390x: define default NaN valuesAurelien Jarno
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-02-06softfloat: expand out STATUS macroPeter Maydell
Expand out and remove the STATUS macro. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2015-02-06softfloat: expand out STATUS_VARPeter Maydell
Expand out and remove the STATUS_VAR macro. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2015-02-06softfloat: Expand out the STATUS_PARAM macroPeter Maydell
Expand out STATUS_PARAM wherever it is used and delete the definition. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2015-01-29softfloat: Clarify license statusPeter Maydell
The code in the softfloat source files is under a mixture of licenses: the original code and many changes from QEMU contributors are under the base SoftFloat-2a license; changes from Stefan Weil and RedHat employees are GPLv2-or-later; changes from Fabrice Bellard are under the BSD license. Clarify this in the comments at the top of each affected source file, including a statement about the assumed licensing for future contributions, so we don't need to remember to ask patch submitters explicitly to pick a license. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Andreas Färber <afaerber@suse.de> Acked-by: Aurelien Jarno <aurelien@aurel32.net> Acked-by: Avi Kivity <avi.kivity@gmail.com> Acked-by: Ben Taylor <bentaylor.solx86@gmail.com> Acked-by: Blue Swirl <blauwirbel@gmail.com> Acked-by: Christophe Lyon <christophe.lyon@st.com> Acked-by: Fabrice Bellard <fabrice@bellard.org> Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Juan Quintela <quintela@redhat.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: Paul Brook <paul@codesourcery.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Richard Henderson <rth@twiddle.net> Acked-by: Richard Sandiford <rdsandiford@googlemail.com> Acked-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1421073508-23909-5-git-send-email-peter.maydell@linaro.org
2015-01-29softfloat: Revert and reimplement remaining parts of b645bb4885 and 5a6932d51dPeter Maydell
Revert the parts of commits b645bb4885 and 5a6932d51d which are still in the codebase and under a SoftFloat-2b license. Reimplement support for architectures where the most significant bit in the mantissa is 1 for a signaling NaN rather than a quiet NaN, by adding handling for SNAN_BIT_IS_ONE being set to the functions which test values for NaN-ness. This includes restoring the bugfixes lost in the reversion where some of the float*_is_quiet_nan() functions were returning true for both signaling and quiet NaNs. [This is a mechanical squashing together of two separate "revert" and "reimplement" patches.] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1421073508-23909-4-git-send-email-peter.maydell@linaro.org
2015-01-29softfloat: Revert and reimplement remaining portions of 75d62a5856 and ↵Peter Maydell
3430b0be36f Revert the remaining portions of commits 75d62a5856 and 3430b0be36f which are under a SoftFloat-2b license, ie the functions uint64_to_float32() and uint64_to_float64(). (The float64_to_uint64() and float64_to_uint64_round_to_zero() functions were completely rewritten in commits fb3ea83aa and 0a87a3107d so can stay.) Reimplement from scratch the uint64_to_float64() and uint64_to_float32() conversion functions. [This is a mechanical squashing together of two separate "revert" and "reimplement" patches.] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1421073508-23909-3-git-send-email-peter.maydell@linaro.org
2015-01-29softfloat: Apply patch corresponding to rebasing to softfloat-2aPeter Maydell
This commit applies the changes to master which correspond to replacing commit 158142c2c2df with a set of changes made by: * taking the SoftFloat-2a release * mechanically transforming the block comment style * reapplying Fabrice's original changes from 158142c2c2df This commit was created by: diff -u 158142c2c2df import-sf-2a patch -p1 --fuzz 10 <../relicense-patch.txt (where import-sf-2a is the branch resulting from the changes above). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1421073508-23909-2-git-send-email-peter.maydell@linaro.org
2014-10-14softfloat: add functions corresponding to IEEE-2008 min/maxNumMagLeon Alrae
Add abs argument to the existing softfloat minmax() function and define new float{32,64}_{min,max}nummag functions. minnummag(x,y) returns x if |x| < |y|, returns y if |y| < |x|, otherwise minnum(x,y) maxnummag(x,y) returns x if |x| > |y|, returns y if |y| > |x|, otherwise maxnum(x,y) Signed-off-by: Leon Alrae <leon.alrae@imgtec.com> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
2014-06-23fpu: softfloat: drop INLINE macroLuiz Capitulino
This commit expands all uses of the INLINE macro and drop it. The reason for this is to avoid clashes with external libraries with bad name conventions and also because renaming keywords is not a good practice. PS: I'm fine with this change to be licensed under softfloat-2a or softfloat-2b. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-08softfloat: Introduce float32_to_uint64_round_to_zeroTom Musta
This change adds the float32_to_uint64_round_to_zero function to the softfloat library. This function fills out the complement of float32 to INT round-to-zero conversion rountines, where INT is {int32_t, uint32_t, int64_t, uint64_t}. This contribution can be licensed under either the softfloat-2a or -2b license. Signed-off-by: Tom Musta <tommusta@gmail.com> Tested-by: Tom Musta <tommusta@gmail.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-03-17softfloat: export squash_input_denormal functionsAlex Bennée
I need these available outside of softfloat for some of the reciprocal processing in aarch64 helper functions. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 1394822294-14837-20-git-send-email-peter.maydell@linaro.org
2014-02-20softfloat: Support halving the result of muladd operationPeter Maydell
The ARMv8 instruction set includes a fused floating point reciprocal square root step instruction which demands an "(x * y + z) / 2" fused operation. Support this by adding a flag to the softfloat muladd operations which requests that the result is halved before rounding. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Add support for ties-away roundingPeter Maydell
IEEE754-2008 specifies a new rounding mode: "roundTiesToAway: the floating-point number nearest to the infinitely precise result shall be delivered; if the two nearest floating-point numbers bracketing an unrepresentable infinitely precise result are equally near, the one with larger magnitude shall be delivered." Implement this new mode (it is needed for ARM). The general principle is that the required code is exactly like the ties-to-even code, except that we do not need to do the "in case of exact tie clear LSB to round-to-even", because the rounding operation naturally causes the exact tie to round up in magnitude. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Refactor code handling various rounding modesPeter Maydell
Refactor the code in various functions which calculates rounding increments given the current rounding mode, so that instead of a set of nested if statements we have a simple switch statement. This will give us a clean place to add the case for the new tiesAway rounding mode. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Add float16 <=> float64 conversion functionsPeter Maydell
Add the conversion functions float16_to_float64() and float64_to_float16(), which will be needed for the ARM A64 instruction set. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Factor out RoundAndPackFloat16 and NormalizeFloat16SubnormalPeter Maydell
In preparation for adding conversions between float16 and float64, factor out code currently done inline in the float16<=>float32 conversion functions into functions RoundAndPackFloat16 and NormalizeFloat16Subnormal along the lines of the existing versions for the other float types. Note that we change the handling of zExp from the inline code to match the API of the other RoundAndPackFloat functions; however we leave the positioning of the binary point between bits 22 and 23 rather than shifting it up to the high end of the word. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Provide complete set of accessors for fp statePeter Maydell
Tidy up the get/set accessors for the fp state to add missing ones and make them all inline in softfloat.h rather than some inline and some not. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Fix float64_to_uint32_round_to_zeroTom Musta
The float64_to_uint32_round_to_zero routine is incorrect. For example, the following test pattern: 425F81378DC0CD1F / 0x1.f81378dc0cd1fp+38 will erroneously set the inexact flag. This patch re-implements the routine to use the float64_to_uint64_round_to_zero routine. If saturation occurs we ignore any flags set by the conversion function and raise only Invalid. This contribution can be licensed under either the softfloat-2a or -2b license. Signed-off-by: Tom Musta <tommusta@gmail.com> Message-id: 1387397961-4894-6-git-send-email-tommusta@gmail.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Fix float64_to_uint32Tom Musta
The float64_to_uint32 has several flaws: - for numbers between 2**32 and 2**64, the inexact exception flag may get incorrectly set. In this case, only the invalid flag should be set. test pattern: 425F81378DC0CD1F / 0x1.f81378dc0cd1fp+38 - for numbers between 2**63 and 2**64, incorrect results may be produced: test pattern: 43EAAF73F1F0B8BD / 0x1.aaf73f1f0b8bdp+63 This patch re-implements float64_to_uint32 to re-use the float64_to_uint64 routine (instead of float64_to_int64). For the saturation case, we ignore any flags which the conversion routine has set and raise only the invalid flag. This contribution can be licensed under either the softfloat-2a or -2b license. Signed-off-by: Tom Musta <tommusta@gmail.com> Message-id: 1387397961-4894-5-git-send-email-tommusta@gmail.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Fix float64_to_uint64_round_to_zeroTom Musta
The float64_to_uint64_round_to_zero routine is incorrect. For example, the following test pattern: 46697351FF4AEC29 / 0x1.97351ff4aec29p+103 currently produces 8000000000000000 instead of FFFFFFFFFFFFFFFF. This patch re-implements the routine to temporarily force the rounding mode and use the float64_to_uint64 routine. This contribution can be licensed under either the softfloat-2a or -2b license. Signed-off-by: Tom Musta <tommusta@gmail.com> Message-id: 1387397961-4894-4-git-send-email-tommusta@gmail.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Add float32_to_uint64()Tom Musta
This patch adds the float32_to_uint64() routine, which converts a 32-bit floating point number to an unsigned 64 bit number. This contribution can be licensed under either the softfloat-2a or -2b license. Signed-off-by: Tom Musta <tommusta@gmail.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> [PMM: removed harmless but silly int64_t casts] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Fix factor 2 error for scalbn on denormal inputsPeter Maydell
If the input to float*_scalbn() is denormal then it represents a number 0.[mantissabits] * 2^(1-exponentbias) (and the actual exponent field is all zeroes). This means that when we convert it to our unpacked encoding the unpacked exponent must be one greater than for a normal number, which represents 1.[mantissabits] * 2^(e-exponentbias) for an exponent field e. This meant we were giving answers too small by a factor of 2 for all denormal inputs. Note that the float-to-int routines also have this behaviour of not adjusting the exponent for denormals; however there it is harmless because denormals will all convert to integer zero anyway. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Only raise Invalid when conversions to int are out of rangePeter Maydell
We implement a number of float-to-integer conversions using conversion to an integer type with a wider range and then a check against the narrower range we are actually converting to. If we find the result to be out of range we correctly raise the Invalid exception, but we must also suppress other exceptions which might have been raised by the conversion function we called. This won't throw away exceptions we should have preserved, because for the 'core' exception flags the IEEE spec mandates that the only valid combinations of exception that can be raised by a single operation are Inexact + Overflow and Inexact + Underflow. For the non-IEEE softfloat flag for input denormals, we can guarantee that that flag won't have been set for out of range float-to-int conversions because a squashed denormal by definition goes to plus or minus zero, which is always in range after conversion to integer zero. This bug has been fixed for some of the float-to-int conversion routines by previous patches; fix it for the remaining functions as well, so that they all restore the pre-conversion status flags prior to raising Invalid. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Fix float64_to_uint64Tom Musta
The comment preceding the float64_to_uint64 routine suggests that the implementation is broken. And this is, indeed, the case. This patch properly implements the conversion of a 64-bit floating point number to an unsigned, 64 bit integer. This contribution can be licensed under either the softfloat-2a or -2b license. Signed-off-by: Tom Musta <tommusta@gmail.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Make the int-to-float functions take exact-width typesPeter Maydell
Currently the int-to-float functions take types which are specified as "at least X bits wide", rather than "exactly X bits wide". This is confusing and unhelpful since it means that the callers have to include an explicit cast to [u]intXX_t to ensure the correct behaviour. Fix them all to take the exactly-X-bits-wide types instead. Note that this doesn't change behaviour at all since at the moment we happen to define the 'int32' and 'uint32' types as exactly 32 bits wide, and the 'int64' and 'uint64' types as exactly 64 bits wide. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Add float to 16bit integer conversions.Will Newton
ARMv8 requires support for converting 32 and 64bit floating point values to signed and unsigned 16bit integers. Signed-off-by: Will Newton <will.newton@linaro.org> [PMM: updated not to incorrectly set Inexact for Invalid inputs] Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2014-01-08softfloat: Fix exception flag handling for float32_to_float16()Peter Maydell
Our float32 to float16 conversion routine was generating the correct numerical answers, but not always setting the right set of exception flags. Fix this, mostly by rearranging the code to more closely resemble RoundAndPackFloat*, and in particular: * non-IEEE halfprec always raises Invalid for input NaNs * we need to check for the overflow case before underflow * we weren't getting the tininess-detected-after-rounding case correct (somewhat academic since only ARM uses halfprec and it is always tininess-detected-before-rounding) * non-IEEE halfprec overflow raises only Invalid, not Invalid + Inexact * we weren't setting Inexact when we should Also add some clarifying comments about what the code is doing. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
2013-12-10softfloat: Add minNum() and maxNum() functions to softfloat.Will Newton
Add floatnn_minnum() and floatnn_maxnum() functions which are equivalent to the minNum() and maxNum() functions from IEEE 754-2008. They are similar to min() and max() but differ in the handling of QNaN arguments. Signed-off-by: Will Newton <will.newton@linaro.org> Message-id: 1386158099-9239-5-git-send-email-will.newton@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2013-12-10softfloat: Remove unused argument from MINMAX macro.Will Newton
The nan_exp argument is not used, so remove it. Signed-off-by: Will Newton <will.newton@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1386158099-9239-4-git-send-email-will.newton@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2013-06-10softfloat: Fix shift128Right for shift counts 64..127Peter Maydell
shift128Right would give the wrong result for a shift count between 64 and 127. This was never noticed because all of our uses of this function are guaranteed not to use shift counts in this range. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1370186269-24353-1-git-send-email-peter.maydell@linaro.org Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-15fpu: Correct edgecase in float64_muladdPeter Maydell
In handling float64_muladd, if we end up doing a subtraction of the product and c, and the 128 bit result of this subtraction happens to have its most significant bit in bit 63, we weren't handling this correctly when attempting to normalize to put the most significant bit into bit 126. We would end up doing a right shift by a negative number (undefined behaviour in C) so at best we would return an incorrect result to the guest. MSB in bit 63 has to be handled as a special case separately from MSB in 0..62 and MSB in 63..126. (MSB in 127 is not possible.) Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2013-01-26softfloat: Handle float_muladd_negate_c when product is zeroRichard Sandiford
Honour float_muladd_negate_c in the case where the product is zero and c is nonzero. Previously we would fail to negate c. Seen in (and tested against) the gfortran testsuite on MIPS. Signed-off-by: Richard Sandiford <rdsandiford@googlemail.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>