https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126691
Bug ID: 126691
Summary: Add roundeven to the rounding family lists
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Keywords: easyhack, missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: ktkachov at gcc dot gnu.org
Target Milestone: ---
Two rules collapse a rounding function applied to an already integral value,
one for the function applied to itself and one for any integer valued
operand. Both list six of the seven rounding functions. roundeven, added as
a builtin in 2019, was never added to either
#include <math.h>
double f (double x) { return __builtin_roundeven (__builtin_floor (x)); }
double g (int n) { return __builtin_roundeven ((double) n); }
Clang for aarch64 generates just:
f:
frintm d0, d0
ret
g:
scvtf d0, w0
ret
