https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107013
Bug ID: 107013
Summary: Add fmin/fmax to RTL codes
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: guihaoc at gcc dot gnu.org
Target Milestone: ---
Could we add fmin/fmax to RTL codes so that the C standard fmin/fmax can be
represented in RTL without UNSPECs? Currently we only have smin/smax that are
not valid for NaNs, or when the sign of zeros is relevant.
C standard for fmax
F.10.9.2 The fmax functions
1 If just one argument is a NaN, the fmax functions return the other argument
(if both arguments are NaNs, the functions return a NaN).
2 The returned value is exact and is independent of the current rounding
direction mode.
3 The body of the fmax function might be374)
{ return (isgreaterequal(x, y) ||
isnan(y)) ? x : y; }
Footnotes
374) Ideally, fmax would be sensitive to the sign of zero, for example
fmax(-0.0, +0.0) would return +0; however, implementation in software might be
impractical.
