[PATCH 14/44] RISC-V: Also invert the cond-move condition for GEU and LEU

[Maciej W. Rozycki]

Update `riscv_expand_conditional_move' and handle the missing GEU and 
LEU operators there, avoiding an extraneous conditional set operation, 
such as with this output:

        sgtu    a0,a0,a1
        seqz    a1,a0
        czero.eqz       a3,a3,a1
        czero.nez       a1,a2,a1
        or      a0,a1,a3

produced when optimizing for Zicond targets from:

int
movsigtu (int w, int x, int y, int z)
{
  return w > x ? y : z;
}

These operators can be inverted producing optimal code such as this:

        sgtu    a1,a0,a1
        czero.nez       a3,a3,a1
        czero.eqz       a1,a2,a1
        or      a0,a1,a3

which this change causes to happen.

        gcc/
        * config/riscv/riscv.cc (riscv_expand_conditional_move): Also 
        invert the condition for GEU and LEU.
---
 gcc/config/riscv/riscv.cc |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

gcc-riscv-expand-conditional-move-geu-leu.diff
Index: gcc/gcc/config/riscv/riscv.cc
===================================================================
--- gcc.orig/gcc/config/riscv/riscv.cc
+++ gcc/gcc/config/riscv/riscv.cc
@@ -4142,7 +4142,7 @@ riscv_expand_conditional_move (rtx dest,
          /* If riscv_expand_int_scc inverts the condition, then it will
             flip the value of INVERT.  We need to know where so that
             we can adjust it for our needs.  */
-         if (code == LE || code == GE)
+         if (code == LE || code == LEU || code == GE || code == GEU)
            invert_ptr = &invert;
 
          /* Emit an scc like instruction into a temporary