On 9/18/26 6:54 AM, Milan Tripkovic wrote:
Fix a missed optimization where conditional zeroes based on
less-than-or-equal
and greater-than comparisons against immediates generate redundant
Immediate loads.
Add define_split patterns to optimize these if_then_else operations.
Introduce the gt_to_le code attribute to map greater-than conditions to
Less-than-or-equal.
This enables the patterns to utilize the sle_operand predicate, safely
splitting the
operations into slti or sltiu evaluations followed by czero.nez or
czero.eqz
Instructions.
ASM Before:
li a5,100
sgt a0,a0,a5 // sgtu a0,a0,a5
czero.nez a0,a1,a0 // czero.eqz a0,a1,a0
ASM after:
slti a0,a0,101 // sltiu a0,a0,101
czero.eqz a0,a1,a0 // czero.nez a0,a1,a0
Also, add a new regression test to cover this optimization and
update an existing test to prevent false alarms due to the new
instruction sequence.
2026-09-18 Milan Tripkovic <[email protected]>
Gcc/ChangeLog:
*config/riscv/iterators.md (leu): Map gt to le
*config/riscv/zicond.md: Add define_split patterns
Gcc/testsuite/ChangeLog:
*gcc.target/riscv/czero-bext.c: Change scan assembler
*gcc.target/riscv/pr127374.c: New test.
THanks! I've pushed this to the trunk.
jeff
