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From: Christian B. <bor...@de...> - 2011-12-28 12:13:21
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Just some comments on the generic things. > General: how much has this been checked out by the s390 folks > (Florian, Christian, Divya) ? I have reviewed the proposal IBM-internally before Carl pushed that out (several things were added and clarified for s390). There might be some problems still hiding, since we have not yet started with decimal floating point for valgrind on s390, but most aspects should be covered or at least mentioned (like PFPO). > General: please give a reference, including URL, to a publically available > standard that defines the basic arithmetic (IEEE 754-2008 ?) Yes decimal floating point on power and s390 follows 754-2008 as far as I know. [...] >> D128: 128-bit decimal floating point format. These >> values use a pair of two 64 bit floating point registers (F64). The >> instruction only references the first register of the register pair. The >> second register is implied. > > As per comments above, the comments re the PPC register layouts isn't > directly relevant to what you need in the IR. (I don't care; I just want > to be sure we have our concepts straight here) I think your concepts are the same. Carl was just describing the whole stack. In the end the register pair thing might boil down to the same logic as for F128 on s390: two loads. (see get_fpr_pair in VEX/priv/guest_s390_toIR.c) |