There is no need for the requirement for conditional-move comparison
operands to be stricter for T-Head targets than for other targets and
limit them to registers only. Constants will be reloaded if required
just as with branches or other-target conditional-move operations and
there is no extra overhead specific to the T-Head case. This enables
more opportunities for a branchless sequence to be produced.
gcc/
* config/riscv/riscv.cc (riscv_expand_conditional_move): Also
accept constants for T-Head comparison operands.
---
gcc/config/riscv/riscv.cc | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
gcc-riscv-expand-conditional-move-thead-op.diff
Index: gcc/gcc/config/riscv/riscv.cc
===================================================================
--- gcc.orig/gcc/config/riscv/riscv.cc
+++ gcc/gcc/config/riscv/riscv.cc
@@ -4097,8 +4097,8 @@ riscv_expand_conditional_move (rtx dest,
&& reg_or_0_operand (cons, mode)
&& reg_or_0_operand (alt, mode)
&& (GET_MODE (op) == mode || GET_MODE (op) == E_VOIDmode)
- && GET_MODE (op0) == mode
- && GET_MODE (op1) == mode
+ && (GET_MODE (op0) == mode || CONST_INT_P (op0))
+ && (GET_MODE (op1) == mode || CONST_INT_P (op1))
&& (code == EQ || code == NE))
need_eq_ne_p = true;
