Thanks for the check Gabe.... I'll have some time next week to try to come up with a potential patch and try to update the tree...
On Wed, Dec 9, 2009 at 6:39 PM, Gabriel Michael Black <[email protected] > wrote: > I looked briefly at that change earlier, and I do think it's likely > that I broke it. I don't know how much time I'll have to dig into it > in the near future, but I'll put it on my short(ish :-/) list. > > Gabe > > Quoting Matt <[email protected]>: > > > Gabe, > > > > It looks like it was your changes that broke this. Do you have any > > insight on this? > > Thanks. > > > > On Fri, Dec 4, 2009 at 3:31 PM, Matt <[email protected]> wrote: > >> I'm having problems getting double-precision floating-point to work in > >> m5 for the MIPS isa. > >> > >> The 32-bit MIPS isa has 32 32-bit floating-point registers. > >> Double-precision floating-point numbers are stored in pairs of > >> floating-point registers. At least that's how I understand it. > >> > >> Simple floating point math used to work in m5 until changeset > >> 781969fbeca9. After the change, it seams that m5 does not read two > >> 32-bit floating point registers to get a double-precision > >> floating-point operand, but only one 32-bit floating-point register > >> (when it's simulating an add_d instruction, for example). This > >> results in incorrect floating point arithmetic. > >> > >> I have the following C program (compiled for MIPS) that exercises > >> the problem: > >> > >> #include<stdio.h> > >> > >> int main (void) > >> { > >> double x, y, z; > >> > >> x = 5.0; > >> y = 0.1; > >> > >> z = x + y; > >> > >> printf ("z = %lf\n", z); > >> > >> return 0; > >> } > >> > >> It should print "z = 5.1", but it doesn't because the simulation of > >> the floating-point addition is wrong. > >> > >> Can anyone tell me why this change was made that seems to break the > >> simulation of double-precision floating-point arithmetic in m5? > >> > >> Thanks. > >> > >> -- > >> Cheers, > >> Matt > >> > > > > > > > > -- > > Cheers, > > Matt > > > > > _______________________________________________ > m5-dev mailing list > [email protected] > http://m5sim.org/mailman/listinfo/m5-dev > -- - Korey
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