https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119629
Bug ID: 119629
Summary: mismatch between [power9-64] builtins and their
instructions
Product: gcc
Version: 14.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: aoliva at gcc dot gnu.org
Target Milestone: ---
cmpeqb's conditions are TARGET_P9_MISC && TARGET_64BIT, but the conditions that
enable the expansion of __builtin_scalar_byte_in_set are those of [power9-64],
namely TARGET_MODULE && TARGET_POWERPC64. On a powerpc-elf standard build,
TARGET_POWERPC64 is enabled, but TARGET_64BIT isn't, and so
gcc.target/powerpc/byte-in-set-2.c fails to compile with an ICE (instruction
not recognized) instead of the expected error.
This raises a number of problems:
- instructions and expanders for these builtins don't have their conditions
tested, so they must necessarily follow from the builtin conditions, and this
case clearly isn't
- TARGET_64BIT seems to imply TARGET_POWERPC64, but TARGET_POWERPC64 doesn't
imply TARGET_64BIT
- TARGET_MODULO isn't used very often in conditions in the .md file, but it can
be controlled independently from TARGET_P9_MISC
- the groupings of builtins doesn't seem to correspond to the conditions of
instructions that implement them
- the misuse of TARGET_64BIT in cmpeqb alone makes me worry that other
instructions guarded by it may have the same condition mismatch problem.
cfuged seems to be one of those, and [power10-64] accepts TARGET_POWERPC64
instead. there may be more.
it looks like a review by someone familiar with this port and these
instructions would probably be useful
