Summary:
Fixes PR30869.
In D25977 I meant to change all functions that care about lifetime. I
changed constructors, factory functions, but I missed member/free
functions that return new instances. This patch changes them.
Reviewers: hfinkel, kbarton, echristo, joerg
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D26269
llvm-svn: 286060
Summary:
This patch adds DoubleAPFloat mode to APFloat.
Now, an APFloat with semantics PPCDoubleDouble will have DoubleAPFloat layout
(APFloat.U.Double), which contains two underlying APFloats as
PPCDoubleDoubleImpl and IEEEdouble semantics. Currently the IEEEdouble APFloat
is not used, and the first APFloat behaves exactly the same before this change.
This patch consists of three kinds of logics:
1) Construction and destruction of APFloat. Now the ctors, dtor, assign
opertors and factory functions construct different underlying layout
based on the semantics passed in.
2) s/IEEE/getIEEE()/ for normal, lifetime-unrelated computation functions.
These functions only access Floats[0] in DoubleAPFloat, which is the
same as today's semantic.
3) A "Double dispatch" function, APFloat::convert. Converting between two
different layouts requires appropriate logic.
Neither of these change the external behavior.
Reviewers: hfinkel, kbarton, echristo, iteratee
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D25977
llvm-svn: 285351
Summary:
The intention is to make APFloat an interface class, so that later I can add a second implementation class DoubleAPFloat to correctly implement PPCDoubleDouble semantic. The interface of IEEEFloat is not public, and can be simplified (currently it's exactly the same as the old APFloat), but that belongs to a separate patch.
DoubleAPFloat should look like:
class DoubleAPFloat {
const fltSemantics *Semantics;
std::unique_ptr<APFloat> APFloats; // Two heap-allocated APFloats.
};
There is no functional change, nor public interface change.
Reviewers: hfinkel, chandlerc, iteratee, echristo, kbarton
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D25536
llvm-svn: 285105
Some Include What You Use suggestions were used too.
Use anonymous namespaces in source files.
Differential revision: http://reviews.llvm.org/D18778
llvm-svn: 265454
Useful utility function; this wasn't too hard to do before, but also wasn't
obviously discoverable. Make it explicit. Reviewed offline by Michael
Gottesman.
llvm-svn: 253254
Because mod is always exact, this function should have never taken a rounding mode argument. The actual implementation still has issues, which I'll look at resolving in a subsequent patch.
llvm-svn: 248195
Summary: Adds accessor functions for all the fields in llvm::fltSemantics. This will be used in MergeFunctions to order two APFloats with different semanatics.
Author: jrkoenig
Reviewers: jfb
Subscribers: dschuff, llvm-commits
Differential revision: http://reviews.llvm.org/D12253
llvm-svn: 245999
The newly added function returns the size of the specified floating
point semantics in bits.
Differential revision: http://reviews.llvm.org/D8413
llvm-svn: 241793
The patch is generated using this command:
tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
llvm/lib/
Thanks to Eugene Kosov for the original patch!
llvm-svn: 240137
Simplify boolean expressions using `true` and `false` with `clang-tidy`
Patch by Richard Thomson - I dropped the parens and != 0 test, for
consistency with other patches/tests like this, but I'm open to the
notion that we should add the explicit non-zero test in all these sort
of cases (non-bool assigned to a bool).
Differential Revision: http://reviews.llvm.org/D8526
llvm-svn: 233004
This patch adds a check for underflow when truncating results back to lower
precision at the end of an FMA. The additional sign handling logic in
APFloat::fusedMultiplyAdd should only be performed when the result of the
addition step of the FMA (in full precision) is exactly zero, not when the
result underflows to zero.
Unit tests for this case and related signed zero FMA results are included.
Fixes <rdar://problem/18925551>.
llvm-svn: 225123
As detailed at http://llvm.org/PR20728, due to an internal overflow in
APFloat::multiplySignificand the APFloat::fusedMultiplyAdd method can return
incorrect results for x87DoubleExtended (x86_fp80) values. This commonly
manifests as incorrect constant folding of libm fmal calls on x86. E.g.
fmal(1.0L, 1.0L, 3.0L) == 0.0L (should be 4.0L)
This patch fixes PR20728 by adding an extra bit to the significand for
intermediate results of APFloat::multiplySignificand, avoiding the overflow.
llvm-svn: 222374
Reapply r216913, a fix for PR20832 by Andrea Di Biagio. The commit was reverted
because of buildbot failures, and credit goes to Ulrich Weigand for isolating
the underlying issue (which can be confirmed by Valgrind, which does helpfully
light up like the fourth of July). Uli explained the problem with the original
patch as:
It seems the problem is calling multiplySignificand with an addend of category
fcZero; that is not expected by this routine. Note that for fcZero, the
significand parts are simply uninitialized, but the code in (or rather, called
from) multiplySignificand will unconditionally access them -- in effect using
uninitialized contents.
This version avoids using a category == fcZero addend within
multiplySignificand, which avoids this problem (the Valgrind output is also now
clean).
Original commit message:
[APFloat] Fixed a bug in method 'fusedMultiplyAdd'.
When folding a fused multiply-add builtin call, make sure that we propagate the
correct result in the case where the addend is zero, and the two other operands
are finite non-zero.
Example:
define double @test() {
%1 = call double @llvm.fma.f64(double 7.0, double 8.0, double 0.0)
ret double %1
}
Before this patch, the instruction simplifier wrongly folded the builtin call
in function @test to constant 'double 7.0'.
With this patch, method 'fusedMultiplyAdd' correctly evaluates the multiply and
propagates the expected result (i.e. 56.0).
Added test fold-builtin-fma.ll with the reproducible from PR20832 plus extra
test cases to verify the behavior of method 'fusedMultiplyAdd' in the presence
of NaN/Inf operands.
This fixes PR20832.
llvm-svn: 219708
When folding a fused multiply-add builtin call, make sure that we propagate the
correct result in the case where the addend is zero, and the two other operands
are finite non-zero.
Example:
define double @test() {
%1 = call double @llvm.fma.f64(double 7.0, double 8.0, double 0.0)
ret double %1
}
Before this patch, the instruction simplifier wrongly folded the builtin call
in function @test to constant 'double 7.0'.
With this patch, method 'fusedMultiplyAdd' correctly evaluates the multiply and
propagates the expected result (i.e. 56.0).
Added test fold-builtin-fma.ll with the reproducible from PR20832 plus extra
test cases to verify the behavior of method 'fusedMultiplyAdd' in the presence
of NaN/Inf operands.
This fixes PR20832.
Differential Revision: http://reviews.llvm.org/D5152
llvm-svn: 216913
Because we don't have a separate negate( ) function, 0 - NaN does double-duty as the IEEE-754 negate( ) operation, which (unlike most FP ops) *does* attach semantic meaning to the signbit of NaN.
llvm-svn: 210428
This is a re-commit of r189442; I'll follow up with clang changes.
The previous default was almost, but not quite enough digits to
represent a floating-point value in a manner which preserves the
representation when it's read back in. The larger default is much
less confusing.
I spent some time looking into printing exactly the right number of
digits if a precision isn't specified, but it's kind of complicated,
and I'm not really sure I understand what APFloat::toString is supposed
to output for FormatPrecision != 0 (or maybe the current API specification
is just silly, not sure which). I have a WIP patch if anyone is interested.
llvm-svn: 189624
The previous default was almost, but not quite enough digits to
represent a floating-point value in a manner which preserves the
representation when it's read back in. The larger default is much
less confusing.
I spent some time looking into printing exactly the right number of
digits if a precision isn't specified, but it's kind of complicated,
and I'm not really sure I understand what APFloat::toString is supposed
to output for FormatPrecision != 0 (or maybe the current API specification
is just silly, not sure which). I have a WIP patch if anyone is interested.
llvm-svn: 189442
IEEE-754R 1.4 Exclusions states that IEEE-754R does not specify the
interpretation of the sign of NaNs. In order to remove an irrelevant
variable that most floating point implementations do not use,
standardize add, sub, mul, div, mod so that operating anything with
NaN always yields a positive NaN.
In a later commit I am going to update the APIs for creating NaNs so
that one can not even create a negative NaN.
llvm-svn: 187314
Zeroing the significand of a floating point number does not necessarily cause a
floating point number to become finite non zero. For instance, if one has a NaN,
zeroing the significand will cause it to become +/- infinity.
llvm-svn: 187313
There were a couple of different loops that were not handling
'.' correctly in APFloat::convertFromHexadecimalString; these mistakes
could lead to assertion failures and incorrect rounding for overlong
hex float literals.
Fixes PR16643.
llvm-svn: 186539
Sylvestre Ledru