atrosinenko added inline comments.

================
Comment at: compiler-rt/test/builtins/Unit/divdf3_test.c:80
+    // divisor is 1.0 as UQ1.31
+    if (test__divdf3(0x1.0p+0, 0x1.00000001p+0, UINT64_C(0x3fefffffffe00000)))
       return 1;
----------------
sepavloff wrote:
> atrosinenko wrote:
> > sepavloff wrote:
> > > Is 0x1.00000001p+0 equal to 1.0 in UQ1.31?
> > Divisor is `1.(31 zeroes)1` after restoring the implicit bit, so it is 
> > **truncated** to 1.0 as UQ1.31. Instead of counting bits carefully, it 
> > would probably be better to add several tests with the `1` bit shifted 1-2 
> > places left/right as well as if the divisor is round up instead of 
> > truncating - //just in case//. :) So, with table-driven test it would 
> > probably be simpler to not make extra assumptions on the implementation.
> > Divisor is 1.(31 zeroes)1
> 
> So it is **not** `1.0` and the comment is misleading. Try rewording the 
> comment to avoid confusion. Maybe `divisor is truncated to 1.0 in UQ1.31` or 
> something like that. 
Now got it, thank you.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D84932/new/

https://reviews.llvm.org/D84932

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