[GIT PULL] alpha: soft-fp tininess fix for v7.4

[GIT PULL] alpha: soft-fp tininess fix for v7.4

[Matt Turner]

Hi Linus,

This is one alpha FP emulation fix, sent separately from Magnus's alpha
pull because it also touches include/math-emu/, which powerpc, sh and
sparc use as well. Magnus Cc'd the maintainers of those architectures on
the patch in September and I followed up in October, but no one has
replied, so there is no ack from outside alpha.

The change for them should be nil: the new _FP_TININESS_AFTER_ROUNDING
macro defaults to 0, and the new code in _FP_PACK_CANONICAL is guarded
by it, so the compiler drops it on the other architectures. Only alpha
sets it to 1.

The two other patches from the same series went in for v7.3.

Thread: https://lore.kernel.org/r/20260803-alpha-fp-exceptions-v1-0-c99d75608e60@gmail.com

The following changes since commit c03c1a14507dfaf8b856c2608f9ac216021fc222:

  Linux 7.3 (2026-10-18 13:14:58 -1000)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha.git alpha-fixes-v7.4

for you to fetch changes up to b74843b38da8f1186fd7d447646c835b47096a15:

  alpha: determine tininess after rounding in the FP emulation (2026-10-20 21:38:52 -0400)

----------------------------------------------------------------
alpha: Fixes for v7.4

Make the FP emulation determine tininess after rounding, as the hardware
does.  soft-fp always determined it before rounding, so an operation that
trapped for software completion could report an underflow the same
operation would not report when it did not trap.  glibc's math testsuite
catches the disagreement.

This adds _FP_TININESS_AFTER_ROUNDING to the shared soft-fp code in
include/math-emu/, as glibc's copy already has, and sets it only for
alpha.  It defaults to zero, so powerpc, sh and sparc are unchanged.

This is the last patch of a three-patch series; the first two were
merged for v7.3.

----------------------------------------------------------------
Matt Turner (1):
      alpha: determine tininess after rounding in the FP emulation

 arch/alpha/include/asm/sfp-machine.h |  4 ++++
 include/math-emu/op-common.h         | 23 +++++++++++++++++++++--
 include/math-emu/soft-fp.h           |  8 ++++++++
 3 files changed, 33 insertions(+), 2 deletions(-)

Re: [GIT PULL] alpha: soft-fp tininess fix for v7.4

[pr-tracker-bot]

The pull request you sent on Tue, 20 Oct 2026 22:03:42 -0400:

> https://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha.git alpha-fixes-v7.4

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/979fac3eaaa02fa887c7dfe6509248b21dca3872

Thank you!

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