Provide a distinct contents for semBogus and semPPCDoubleDouble in order
to prevent compilers from collapsing them to a single memory address,
while we heavily rely on every semantic having distinct address.
This happens if insecure optimization collapsing identical values is
enabled. As a result, APFloats of semBogus are indistinguishable from
semPPCDoubleDouble -- and whenever the move constructor is used, the old
value beings being incorrectly recognized as a semPPCDoubleDouble.
Since the values in semPPCDoubleDouble are not used anywhere,
we can easily solve this issue via altering the value of one of the
fields and therefore ensuring that the collapse can not occur.
Differential Revision: https://reviews.llvm.org/D28112
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290896 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
I looked at libgcc's implementation (which is based on the paper,
Software for Doubled-Precision Floating-Point Computations", by Seppo Linnainmaa,
ACM TOMS vol 7 no 3, September 1981, pages 272-283.) and made it generic to
arbitrary IEEE floats.
Differential Revision: https://reviews.llvm.org/D26817
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289472 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286060 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285351 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285105 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253254 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248195 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245999 91177308-0d34-0410-b5e6-96231b3b80d8
Michal Gorny
Tim Shen
Stephan Bergmann
Sylvestre Ledru
Mehdi Amini
Duncan P. N. Exon Smith
Eugene Zelenko
Matt Arsenault
Richard Trieu
Stephen Canon
JF Bastien
Benjamin Kramer
Tamas Berghammer