Fred? Can you find this out? Sun On Wed, Feb 23, 2011 at 7:17 AM, Steve Ellcey <s...@cup.hp.com> wrote: > I am looking at bug #497 (https://bugs.open64.net/show_bug.cgi?id=497) and > created this small test case to show the problem: > > #include <stdio.h> > #include <stdint.h> > > int main() { > unsigned long long qw; > float f; > > qw = 0xFEA8C3DFBB282B2Dull; > f = (float)qw; > printf ("f = %e\n", f); > return 0; > } > > Gcc prints "f = 1.835013e+19" and Opencc prints "f = -9.661203e+16". > > > I then tracked the problem down to this code in wgen/wgen_expr.cxx where > we generate an ICVT instead of a UCVT: > > #if !defined(TARG_SL) > // bug 14430: Generate a CVT with the same signedness. > else if (MTYPE_signed(WN_rtype(wn0)) != MTYPE_signed(mtyp) && > MTYPE_bit_size(WN_rtype(wn0)) > MTYPE_bit_size(mtyp)) { > wn = WN_Cvt(Mtype_TransferSign(mtyp, WN_rtype(wn0)), mtyp, wn0); > } > #endif > > I assume bug 14430 is in the old pathscale database we don't have > access to? The problem here is that when converting a 64 bit unsigned > integer to a 32 bit float, this code is triggered and we generate an > ICVT instead of a UCVT and get the wrong answer. > > I would like to either remove this code (like is done for TARG_SL) or > restrict it to integer type conversions only (based on a guess that > the original bug involved only integer types). It is hard to know what > the right thing to do is without knowing what bug 14430 is. > > Does anyone know what the original bug was? Does anyone have an > opinion on the correct fix? > > Steve Ellcey > s...@cup.hp.com > > ------------------------------------------------------------------------------ > Free Software Download: Index, Search & Analyze Logs and other IT data in > Real-Time with Splunk. Collect, index and harness all the fast moving IT data > generated by your applications, servers and devices whether physical, virtual > or in the cloud. Deliver compliance at lower cost and gain new business > insights. http://p.sf.net/sfu/splunk-dev2dev > _______________________________________________ > Open64-devel mailing list > Open64-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/open64-devel >
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