similar to: [LLVMdev] Soft floating point support

APFloat is derived from C code using fixed width storage for the matntissa. When converting to C++ I changed it to variable- width storage for space efficiency and generality reasons. Unfortunately this leads to a complication during float->float conversions that I missed that isn't present when using fixed width storage. Dale - I think this solves the issue correctly whilst preserving

Hi All, APFloat::fusedMultiplyAdd currently computes the wrong signed zero when small negative results are truncated back to zero in standard precision. The following snippet handles the signedness in fusedMultiplyAdd: /* If two numbers add (exactly) to zero, IEEE 754 decrees it is a positive zero unless rounding to minus infinity, except that adding two like-signed zeroes gives that

Hi Mehdi, Thanks for the feedback. I think the comment is fine - the problem is just that the original conditional didn't exactly match it. With the addition of the underflow check I believe the condition now matches the comment: The sign is only tweaked if the result of the addition is exactly zero, rather than a small result that truncates to zero. CC'ing llvm-commits, where this email

Hola LLVMers, I'm getting a crash when using ConstantFP::get. I can repro it by adding one line to the Fibonacci example program: int main(int argc, char **argv) { int n = argc > 1 ? atol(argv[1]) : 24; // Create some module to put our function into it. Module *M = new Module("test"); // We are about to create the "fib" function: Function

It's in debug. I'm having a look at the assembler it's producing right now and it's definitely a little odd for what should be a simple assignment in zeroSignificand. ________________________________ From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Dale Johannesen Sent: Wednesday, September 05, 2007 2:39 PM To: LLVM Developers Mailing

On Sep 5, 2007, at 2:21 PM, Chuck Rose III wrote: > Hola LLVMers, > > > > I’m getting a crash when using ConstantFP::get. > > > > I can repro it by adding one line to the Fibonacci example program: > > > > int main(int argc, char **argv) { > > int n = argc > 1 ? atol(argv[1]) : 24; > > > > // Create some module to put our function

Hola Dale, I spent some time walking through what's going on with a friend of mine from VStudio. Category is given 2 bits in the APFloat class definition. It's sign extending the enum value for the comparisons when it loads it out of the class, so the 2 becomes a -2 and the comparison fails. He sent me a piece of code which I might be able to use to force the issue. I'll update

Neil Booth wrote: > Talin wrote:- > >> On the other hand, writing an interpreter means duplicating a lot of >> the functionality that's already in LLVM. For example, consider just >> the problem of float to int conversions: >> >> char B[ (int)3.0 ]; >> >> Generating code for this is relatively simple; Converting >> arbitrary-sized

Talin wrote:- > On the other hand, writing an interpreter means duplicating a lot of > the functionality that's already in LLVM. For example, consider just > the problem of float to int conversions: > > char B[ (int)3.0 ]; > > Generating code for this is relatively simple; Converting > arbitrary-sized APFloats to arbitrary-sized APInts isn't quite as >

Talin wrote:- > Well, I may be using it wrong. But looking at APFloat.h, I see four > functions that purport to convert to integer: > > opStatus convertToInteger(integerPart *, unsigned int, bool, > roundingMode) const; > opStatus convertFromSignExtendedInteger(const integerPart *, > unsigned int, >

More questions on the best way to write a compiler using LLVM: Lets say I have a struct definition that looks like this: const int imageSize = 77; struct A { char B[align(imageSize)]; } ...where 'imageSize' is some small inline function that rounds up to a power of two or something. (A common requirement for textures on 3d graphics cards.) Now, clearly the compiler

Hi Sanjay, Thanks, I saw this flag and it's definitely should be considered, but it appeared to me to be static characteristic of target platform. I'm not sure how appropriate it would be to change its value from a front-end. It says "Has", while optional flag would rather say "Uses" meaning that implementation cares about floating point exceptions. Regards, Sergey

On Sep 5, 2007, at 5:08 PM, Chuck Rose III wrote: > Hola Dale, > > > > I spent some time walking through what’s going on with a friend of > mine from VStudio. Category is given 2 bits in the APFloat class > definition. It’s sign extending the enum value for the comparisons > when it loads it out of the class, so the 2 becomes a -2 and the > comparison fails.