[gcc r16-6387] RISC-V: Combine vec_duplicate + vmsleu.vv to vmsleu.vx on GR2VR cost

[Pan Li]

https://gcc.gnu.org/g:678d0e035025b32e73398c8102f0dd150173b014

commit r16-6387-g678d0e035025b32e73398c8102f0dd150173b014
Author: Pan Li <pan2.li@intel.com>
Date:   Sun Dec 21 20:07:43 2025 +0800

    RISC-V: Combine vec_duplicate + vmsleu.vv to vmsleu.vx on GR2VR cost
    
    This patch would like to combine the vec_duplicate + vmsleu.wv to the
    vmsleu.vx.  From example as below code.  The related pattern will depend
    on the cost of vec_duplicate from GR2VR.  Then the late-combine will
    take action if the cost of GR2VR is zero, and reject the combination
    if the GR2VR cost is greater than zero.
    
    Assume we have asm code like below, GR2VR cost is 0.
    
    Before this patch:
      11       beq a3,zero,.L8
      12       vsetvli a5,zero,e32,m1,ta,ma
      13       vmv.v.x v2,a2
      ...
      16   .L3:
      17       vsetvli a5,a3,e32,m1,ta,ma
      ...
      22       vmsleu.wv v1,v2,v3
      ...
      25       bne a3,zero,.L3
    
    After this patch:
      11       beq a3,zero,.L8
      ...
      14    .L3:
      15       vsetvli a5,a3,e32,m1,ta,ma
      ...
      20       vmsleu.wx v1,a2,v3
      ...
      23       bne a3,zero,.L3
    
    gcc/ChangeLog:
    
            * config/riscv/predicates.md: Add geu to the swappable
            cmp operator iterator.
            * config/riscv/riscv-v.cc (get_swapped_cmp_rtx_code): Take
            care of the swapped rtx code correspondly.
    
    Signed-off-by: Pan Li <pan2.li@intel.com>

Diff:
---
 gcc/config/riscv/predicates.md | 2 +-
 gcc/config/riscv/riscv-v.cc    | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/config/riscv/predicates.md b/gcc/config/riscv/predicates.md
index 3b3ae4cdcf42..33d440a3c063 100644
--- a/gcc/config/riscv/predicates.md
+++ b/gcc/config/riscv/predicates.md
@@ -612,7 +612,7 @@
   (match_code "eq,ne,le,leu,gt,gtu,lt,ltu"))
 
 (define_predicate "comparison_swappable_operator"
-  (match_code "gtu,gt"))
+  (match_code "gtu,gt,geu"))
 
 (define_predicate "ge_operator"
   (match_code "ge,geu"))
diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index d64acff8e0f8..0bf6acbea706 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -6041,6 +6041,8 @@ get_swapped_cmp_rtx_code (rtx_code code)
       return LTU;
     case GT:
       return LT;
+    case GEU:
+      return LEU;
     default:
       gcc_unreachable ();
     }