On 1/1/25 2:16 PM, Keith Packard wrote:
I thought I had sent all of my m68k soft float fixes along last year,
but it looks like I managed to leave some out. I had been building
my toolchain from a private repo (oops), which masked my mistake. We're
fixing that by automatically building toolchains from upstream source
with a list of patches now, so this "shouldn't" happen again. Now to
drive that list of patches to zero.
0001-libgcc-m68k-Fixes-for-soft-float.patch
From 1a3e403603f5a687724c7e2f6625debc3d23d934 Mon Sep 17 00:00:00 2001
From: Keith Packard<kei...@keithp.com>
Date: Sun, 29 Dec 2024 01:42:29 -0800
Subject: [PATCH] libgcc/m68k: Fixes for soft float
Fix __extenddfxf2:
* Remove bogus denorm handling block which would never execute --
the converted exp value is always positive as EXCESSX > EXCESSD.
* Compute the whole significand in dl instead of doing part of it in
ldl.
* Mask off exponent from dl.l.upper so the denorm shift test
works.
* Insert the hidden one bit into dl.l.upper as needed.
Fix __truncxfdf2 denorm handling. All that is required is to shift the
significand right by the correct amount; it already has all of the
necessary bits set including the explicit one. Compute the shift
amount, then perform the wide shift across both elements of the
significand.
Fix __fixxfsi:
* The value was off by a factor of two as the significand contains
32 bits, not 31 so we need to shift by one more than the equivalent
code in __fixdfsi.
* Simplify the code having realized that the lower 32 bits of the
significand can never appear in the results.
Return positive qNaN instead of negative. For floats, qNaN is 0x7fff_ffff. For
doubles, qNaN is 0x7fff_ffff_ffff_ffff.
Return correctly signed zero on float and double divide underflow. This means
that Ld$underflow now expects d7 to contain the sign bit, just like the other
return paths.
Signed-off-by: Keith Packard<kei...@keithp.com>
Thanks. I pushed this to the trunk.
jeff
