[gcc(refs/vendors/riscv/heads/gcc-13-with-riscv-opts)] RISC-V: Also accept constants for T-Head cond-move data input operands

[Jeff Law <law@gcc.gnu.org>]

https://gcc.gnu.org/g:1990eb1d2513349c153b38c069f678099e76185b

commit 1990eb1d2513349c153b38c069f678099e76185b
Author: Maciej W. Rozycki <macro@embecosm.com>
Date:   Wed Nov 22 01:18:27 2023 +0000

    RISC-V: Also accept constants for T-Head cond-move data input operands
    
    There is no need for the requirement for conditional-move data input
    operands to be stricter for T-Head targets than for short forward branch
    targets and limit them to registers only.  They are keyed according to
    the `sfb_alu_operand' predicate, which lets certain constants through.
    Such constants are already forced into a register for the `cons' operand
    in the analogous short forward branch case and we can force them for the
    `alt' operand and T-Head as well.  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 data input operands.
    
    (cherry picked from commit 566a2b3baa342c7e00b7de7112d92637baba9c75)

Diff:
---
 gcc/config/riscv/riscv.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index ac2e76f4bed..cdd1a4f9e25 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -4123,8 +4123,6 @@ riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
 
   if (TARGET_XTHEADCONDMOV
       && GET_MODE_CLASS (mode) == MODE_INT
-      && 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 || CONST_INT_P (op0))
       && (GET_MODE (op1) == mode || CONST_INT_P (op1))
@@ -4142,6 +4140,8 @@ riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
 	 cases for extensions which are more general than SFB.  But
 	 does mean we need to force CONS into a register at this point.  */
       cons = force_reg (mode, cons);
+      /* With XTheadCondMov we need to force ALT into a register too.  */
+      alt = force_reg (mode, alt);
       emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (mode,
 							  cond, cons, alt)));
       return true;