Re: [PATCH] ARM half-precision floating point, 6/8 (ARM backend details)

[Paolo Bonzini <bonzini at gnu dot org>]

In fix_trunchfsi2 and fix_trunchfdi2:

> +	(fix:SI (fix:HF (match_operand:HF 1 "general_operand"  ""))))]

I know this is not used, but to be precise this would be float_extend:SF
instead of fix:HF.

> +FLOAT_MODE (HF, 2, 0);

This can probably go in the machine-independent parts.


Also, I came across the bug you fix in part 2 for my cond-optab work.

> 2009-04-15  Sandra Loosemore  <sandra@codesourcery.com>
> 
>     gcc/
>     * optabs.c (prepare_float_lib_cmp):  Test that the comparison,
>     swapped, and reversed optabs exist before trying to use them.

This will actually be unnecessary after the cond-optab merge.  The bug
here is that can_compare_p tries widening the operand and says "we can
do UNLT by going through SFmode", so that UNLT is not split into
UNORDERED and LT.  Then however prepare_cmp_insn does not try widening
and prepare_float_lib_cmp crashes when it tries HFmode because UNLT does
not have a libcall and hence an optab.  On the branch, widening is tried
before libcalls, which works.

If I beat you to committing the branch, I'll ask you to try reverting
that part.  If (as it is likely) you're first, I'll test whether I can
change this to an assert.

Paolo