Commit Graph

2 Commits

Author SHA1 Message Date
Pirama Arumuga Nainar 4a39e80809 Fix incorrect truncation at the overflow boundary
Summary:
This patch fixes incorrect truncation when the input wider value is
exactly 2^dstBits.  For that value, the overflow to infinity is not
correctly handled.  The fix is to replace a strict '>' with '>='.

Currently,
__truncdfsf2(340282366900000000000000000000000000000.0) returns infinity
__truncdfsf2(340282366920938463463374607431768211456.0) returns 0
__truncdfsf2(400000000000000000000000000000000000000.0) returns infinity

Likewise, __truncdfhf2 and __truncsfhf2 (and consequently gnu_f2h_ieee)
are discontinuous at 65536.0.

This patch adds tests for all three cases, along with adding a missing
header include to fp_test.h.

Reviewers: joerg, ab, srhines

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10594

llvm-svn: 240450
2015-06-23 20:24:53 +00:00
Ahmed Bougacha f1ac850e77 [Builtins] Implement half-precision conversions.
Mostly uninteresting, except:
- in __extendXfYf2, when checking if the number is normal, the old
  code relied on the unsignedness of src_rep_t, which is a problem
  when sizeof(src_rep_t) < sizeof(int): the result gets promoted to
  int, the signedness of which breaks the comparison.
  I added an explicit cast; it shouldn't affect other types.
- we can't pass __fp16, so src_t and src_rep_t are the same.
- the gnu_*_ieee symbols are simply duplicated definitions, as aliases
  are problematic on mach-o (where only weak aliases are supported;
  that's not what we want).

Differential Revision: http://reviews.llvm.org/D9693

llvm-svn: 237161
2015-05-12 18:33:42 +00:00