Commit Graph

17 Commits

Author SHA1 Message Date
David Neto
2937538210
Fix undef behaviour in hex float parsing (#5025)
When the parser saw more significant hex digits than fit in
the target type, it would compute a nonsensical shift amount, resulting
in undefined behaviour.

Now, drop the excess bits, effectively truncating the significand.

Also guard against overflow of the exponent in the extraordinary (and untested)
case where we see more than, for example, 2**(32-4+1) significant hex digits
for a 32-bit float, or 2**(16-4+1) significant hex digits for a 16-bit
float.

Also guard against overflow of the indexing counting the number of
significant bits.  When that would occur silently drop any further
significant bits.  (Untested)

Avoid hex floats in C++ code. It's a C++17 feature.

Fixes: #4724
2022-12-19 15:46:57 -05:00
David Neto
8dc0030ecb
spirv-as: Avoid overflow when parsing exponents on hex floats (#4874)
* spirv-as: Avoid overflow when parsing exponents on hex floats

When an exponent is so large that it would overflow the int
type in the parser, saturate the exponent.
This allows extremely large exponents, and saturates
to infinity when the exponent is positive, and zero when the exponent
is negative.

Fixes #4721.

* Avoid unexpected narrowing conversions from arithmetic operations

Co-authored-by: Alastair F. Donaldson <alastair.donaldson@imperial.ac.uk>
2022-07-28 09:40:07 -04:00
Alastair Donaldson
1f3f0f185b
Avoid uninitialised read when parsing hex float (#4646)
Ensures that when an attempt to read a floating-point value from an
input stream fails, the recieving variable for the read does not end up
uninitialised.

Fixes OSS-Fuzz:40432
Fixes #4644
2021-12-08 11:09:25 -05:00
David Neto
7e860e3831
fix parsing of bad binary exponents in hex floats (#4501)
- The binary exponent must have some decimal digits
- A + or - after the binary exponent digits should not be interpreted as
  part of the binary exponent.

Fixes: #4500
2021-09-03 12:27:12 -04:00
Steven Perron
72d4e5414b
Change HexFloat to work with gcc8. (#2109)
When we want to set a the value of a HexFloat to inf or nan, we
construct the specific bit pattern in an appropriately sized integer.
That integer is copied to a FloatProxy object through a memcpy.  GCC8
complains about the memcpy because it is overwriting a private member of
the class.

The original solution worked well because the template to the HexFloat
could be anything.  However, we only used some instantiation of FloatProxy,
which has a construction from that takes its uint_type, so I decided to use
that constructor instead of the memcpy.  This puts an extra requirement
on the templace for HexFloat, but it will be fine for us.

Part of #1541.
2018-11-26 15:47:48 -05:00
dan sinclair
eda2cfbe12
Cleanup includes. (#1795)
This Cl cleans up the include paths to be relative to the top level
directory. Various include-what-you-use fixes have been added.
2018-08-03 15:06:09 -04:00
dan sinclair
58a6876cee
Rewrite include guards (#1793)
This CL rewrites the include guards to make PRESUBMIT.py include guard
check happy.
2018-08-03 08:05:33 -04:00
dan sinclair
76e0bde196 Move utils/ to spvtools::utils
Currently the utils/ folder uses both spvutils:: and spvtools::utils.
This CL changes the namespace to consistenly be spvtools::utils to match
the rest of the codebase.
2018-07-06 16:47:46 -04:00
Neil Roberts
57a2441791 hex_float: Use max_digits10 for the float precision
CPPreference.com has this description of digits10:

“The value of std::numeric_limits<T>::digits10 is the number of
 base-10 digits that can be represented by the type T without change,
 that is, any number with this many significant decimal digits can be
 converted to a value of type T and back to decimal form, without
 change due to rounding or overflow.”

This means that any number with this many digits can be represented
accurately in the corresponding type. A change in any digit in a
number after that may or may not cause it a different bitwise
representation. Therefore this isn’t necessarily enough precision to
accurately represent the value in text. Instead we need max_digits10
which has the following description:

“The value of std::numeric_limits<T>::max_digits10 is the number of
 base-10 digits that are necessary to uniquely represent all distinct
 values of the type T, such as necessary for
 serialization/deserialization to text.”

The patch includes a test case in hex_float_test which tries to do a
round-robin conversion of a number that requires more than 6 decimal
places to be accurately represented. This would fail without the
patch.

Sadly this also breaks a bunch of other tests. Some of the tests in
hex_float_test use ldexp and then compare it with a value which is not
the same as the one returned by ldexp but instead is the value rounded
to 6 decimals. Others use values that are not evenly representable as
a binary floating fraction but then happened to generate the same
value when rounded to 6 decimals. Where the actual value didn’t seem
to matter these have been changed with different values that can be
represented as a binary fraction.
2018-04-03 12:53:10 -04:00
Alan Baker
802cf053c7 Merge arithmetic with non-trivial constant operands
Adding basis of arithmetic merging

* Refactored constant collection in ConstantManager
* New rules:
 * consecutive negates
 * negate of arithmetic op with a constant
 * consecutive muls
 * reciprocal of div

* Removed IRContext::CanFoldFloatingPoint
 * replaced by Instruction::IsFloatingPointFoldingAllowed
* Fixed some bad tests
* added some header comments

Added PerformIntegerOperation

* minor fixes to constants and tests
* fixed IntMultiplyBy1 to work with 64 bit ints
* added tests for integer mul merging

Adding test for vector integer multiply merging

Adding support for merging integer add and sub through negate

* Added tests

Adding rules to merge mult with preceding divide

* Has a couple tests, but needs more
* Added more comments

Fixed bug in integer division folding

* Will no longer merge through integer division if there would be a
remainder in the division
* Added a bunch more tests

Adding rules to merge divide and multiply through divide

* Improved comments
* Added tests

Adding rules to handle mul or div of a negation

* Added tests

Changes for review

* Early exit if no constants are involved in more functions
* fixed some comments
* removed unused declaration
* clarified some logic

Adding new rules for add and subtract

* Fold adds of adds, subtracts or negates
* Fold subtracts of adds, subtracts or negates
* Added tests
2018-02-27 13:02:13 -05:00
Andrew Woloszyn
e543b195df Removed warnings from hex_float.h
Bitcasting FloatProxy<->uint_type was hitting a warning
with g++8.0.1. Replace bitcasts with new casting traits for FloatProxy.
2018-02-16 21:15:51 -05:00
Andrew Woloszyn
d7f199b5d4 Hack around bug in gcc-4.8.1 templates.
This keeps the previous behavior for other compilers that will
throw warnings on a negative shift operation, but works around
the internal compiler error in GCC.
2017-10-06 10:26:17 -04:00
qining
1773b95737 Pull out the number parsing logic
Pull out the number parsing logic from
AssemblyContext::binaryEncodeNumericLiteral() to utilities.

The new utility function: `ParseAndEncodeNumber()` now accepts:
  * number text to parse
  * number type
  * a emit function, which is a function which will be called with each
    parsed uint32 word.
  * a pointer to std::string to be overwritten with error messages.
    (pass nullptr if expect no error message)
and returns:
  * an enum result type to indicate the status

Type/Structs moved to utility:
  * template<typename T> class ClampToZeroIfUnsignedType

New type:
* enum EncodeNumberStatus: success or error code
* NumberType: hold the number type information for the number to be parsed.
 * several helper functions are also added for NumberType.

Functions moved to utility:
  * Helpers:
    * template<typename T> checkRangeAndIfHexThenSignExtend() -> CheckRangeAndIfHex....()
  * Interfaces:
    * template<typename T> parseNumber() -> ParseNumber()
    * binaryEncodeIntegerLiteral() -> ParseAndEncodeIntegerNumber()
    * binaryEncodeFloatingPointLiteral() -> ParseAndEncodeFloatingPointNumber()
    * binaryEncodeNumericLiteral() -> ParseAndEncodeNumber()

Tests added/moved to test/ParseNumber.cpp, including tests for:
* ParseNumber(): This is moved from TextToBinary.cpp to ParseNumber.cpp
* ParseAndEncodeIntegerNumber(): New added
* ParseAndEncodeFloatingPointNumber(): New added
* ParseAndEncodeNumber(): New added

Note that the error messages are kept almost the same as before, but
they may be inappropriate for an utility function. Those will be fixed
in another CL.
2016-09-08 18:42:54 -04:00
David Neto
9fc8658ef3 Relicense SPIRV-Tools under Apache 2.0
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/383

Finalize v2016.4
2016-09-02 10:00:29 -04:00
Jamie Madill
34cb0035fd Fix several warnings exposed in MSVS 2015.
diagnostic.cpp:
- unreachable code

operand.cpp
- conversion between int and uint32_t
- unreachable code

hex_float.h:
- conversion from 'const int' to 'unsigned int'
- unreachable code

validate_id.cpp
- forcing value to bool 'true' or 'false'

validate_types.cpp:
- forcing value to bool 'true' or 'false'
2016-04-29 18:02:01 -04:00
Lei Zhang
712bed0227 Fix issues reported by cppcheck.
Remove code not being used, add explicit to constructors, and
add missing fields in constructors.
2016-02-25 16:16:28 -05:00
David Neto
5a70335bf1 Rearrange headers
Now we have public headers arranged as follows:
$SPIRV_TOOLS_ROOT/include/spirv-tools/libspirv.h
$SPIRV_TOOLS_ROOT/include/spirv/spirv.h
$SPIRV_TOOLS_ROOT/include/spirv/GLSL.std.450.h
$SPIRV_TOOLS_ROOT/include/spirv/OpenCL.std.h

A project should use -I$SPIRV_TOOLS_ROOT/include
and then #include "spirv-tools/libspirv.h"

The headers from the SPIR-V Registry can be accessed as "spirv/spirv."
for example.

The install target should also install the headers from the SPIR-V
Registry.  The libspirv.h header is broken otherwise.

The SPIRV-Tools library depends on the headers from the SPIR-V Registry.

The util/bitutils.h and util/hex_float.h are pulled into the internal
source tree.  Those are not part of the public API to SPIRV-Tools.
2016-02-17 14:49:44 -05:00