The idea is, that if an ieee 754 float is divided by a power of two, we can
turn the division into a cheaper multiplication. This function sees if we can
get an exact multiplicative inverse for a divisor and returns it if possible.
This is the hard part of PR9587.
I tested many inputs against llvm-gcc's frotend implementation of this
optimization and didn't find any difference. However, floating point is the
land of weird edge cases, so any review would be appreciated.
llvm-svn: 128545
makes valgrind stop complaining about uninitialized variables being read when it
accesses a bitfield (category) that shares its bits with these variables.
llvm-svn: 127871
clang's -Wuninitialized-experimental warning.
While these don't look like real bugs, clang's
-Wuninitialized-experimental analysis is stricter
than GCC's, and these fixes have the benefit
of being general nice cleanups.
llvm-svn: 124073
zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.
llvm-svn: 121120
payloads. APFloat's internal folding routines always make QNaNs now,
instead of sometimes making QNaNs and sometimes SNaNs depending on the
type.
llvm-svn: 97364
cut the significand down to the desired precision *before* entering the
core divmod loop. Makes the overall algorithm logarithmic in the exponent.
There's still a lot of room for improvement here, but this gets the
performance back down to acceptable-for-diagnostics levels, even for
long doubles.
negligible, even on long doubles.
llvm-svn: 92130
smallest-normalized-magnitude values in a given FP semantics.
Provide an APFloat-to-string conversion which I am quite ready to admit could
be much more efficient.
llvm-svn: 92126
This adds location info for all llvm_unreachable calls (which is a macro now) in
!NDEBUG builds.
In NDEBUG builds location info and the message is off (it only prints
"UREACHABLE executed").
llvm-svn: 75640
Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.
llvm-svn: 75379
same as a normal i80 {low64, high16} rather
than its own {high64, low16}. A depressing number
of places know about this; I think I got them all.
Bitcode readers and writers convert back to the old
form to avoid breaking compatibility.
llvm-svn: 67562
Cleanup some warning.
Remark: when struct/class are declared differently than they are defined, this make problem for VC++ since it seems to mangle class differently that struct. These error are very hard to understand and find. So please, try to keep your definition/declaration in sync.
Only tested with VS2008. hope it does not break anything. feel free to revert.
llvm-svn: 64554
ASCII IR; loading and storing these can change the
bits of NaNs on some hosts. Remove or add warnings
at a few other places using host floating point;
this is a bad thing to do in general.
llvm-svn: 62712
since -0.0 can't be represented as an int.
This prevents llvm from reducing -0.0 to a
load-and-convert of int 0. Fixes
ieee.exp/mzero[2356].c in gcc testsuite.
llvm-svn: 57224
are Inexact. (These are not Inexact as defined
by IEEE754, but that seems like a reasonable way
to abstract what happens: information is lost.)
llvm-svn: 57218
returning an std::string by value, it fills in a SmallString/SmallVector
passed in. This significantly reduces string thrashing in some cases.
More specifically, this:
- Adds an operator<< and a print method for APInt that allows you to
directly send them to an ostream.
- Reimplements APInt::toString to be much simpler and more efficient
algorithmically in addition to not thrashing strings quite as much.
This speeds up llvm-dis on kc++ by 7%, and may also slightly speed up the
asmprinter. This also fixes a bug I introduced into the asmwriter in a
previous patch w.r.t. alias printing.
llvm-svn: 54873
ppc long double, which doesn't work.
This may break some stuff temporarily, but I want to
avoid the propagation of code that assumes this works.
llvm-svn: 49983
Added member template "Add" to FoldingSetNodeID that allows "adding" arbitrary
objects to a profile via dispatch to FoldingSetTrait<T>::Profile().
Removed FoldingSetNodeID::AddAPFloat and FoldingSetNodeID::APInt, as their
functionality is now replaced using the above mentioned member template.
llvm-svn: 46957
memory rather than in a copy of the APFloat. This avoids problems
when the destination is wider than our significand and is cleaner.
Also provide deterministic values in all cases where conversion
fails, namely zero for NaNs and the minimal or maximal value
respectively for underflow or overflow.
llvm-svn: 43626
integer conversion. In some such cases this makes us one or two orders
of magnitude faster than NetBSD's libc. Glibc seems to have a similar
fast path.
Also, tighten up some upper bounds to save a bit of memory.
llvm-svn: 42984
from user input strings.
Such conversions are more intricate and subtle than they may appear;
it is unlikely I have got it completely right first time. I would
appreciate being informed of any bugs and incorrect roundings you
might discover.
llvm-svn: 42912
No compile-time support for constant operations yet,
just format transformations. Make readers and
writers work. Split constants into 2 doubles in
Legalize.
llvm-svn: 42865
It used to modify its argument in-place.
This interface is saner and the implementation more efficient. It will
be needed for decimal->binary conversion.
llvm-svn: 42733
input. APInt unfortunately zero-extends signed integers, so Dale
modified the function to expect zero-extended input. Make this
assumption explicit in the function name.
llvm-svn: 42732
Eli Friedman