[PATCH v1 1/3] RISC-V: Allow RVV register overlap for vwmulsu.vv

[email protected] Wed, 5 Aug 2026 16:00:43 +0800
Newsgroups gmane.comp.gcc.patches
Message-ID <[email protected]>
From: Pan Li <[email protected]>

Like vw{add,sub,mul}[u].vv, allow the rvv register overlap for
the dual widen vv insn vwmulsu.vv.

gcc/ChangeLog:

	* config/riscv/vector.md: Leverage Wvr constraint.

Signed-off-by: Pan Li <[email protected]>
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
---
 gcc/config/riscv/vector.md | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/gcc/config/riscv/vector.md b/gcc/config/riscv/vector.md
index afaa3a51ece..4efee02fb3b 100644
--- a/gcc/config/riscv/vector.md
+++ b/gcc/config/riscv/vector.md
@@ -4303,22 +4303,22 @@ (define_insn "@pred_single_widen_sub<any_extend:su><mode>_extended_scalar"
    (set_attr "mode" "<V_DOUBLE_TRUNC>")])
 
 (define_insn "@pred_widen_mulsu<mode>"
-  [(set (match_operand:VWEXTI 0 "register_operand"                  "=&vr,&vr")
+  [(set (match_operand:VWEXTI 0 "register_operand"                 "=vr, vr, vd, vd")
 	(if_then_else:VWEXTI
 	  (unspec:<VM>
-	    [(match_operand:<VM> 1 "vector_mask_operand"           "vmWc1,vmWc1")
-	     (match_operand 5 "vector_length_operand"              "  rvl,  rvl")
-	     (match_operand 6 "const_int_operand"                  "    i,    i")
-	     (match_operand 7 "const_int_operand"                  "    i,    i")
-	     (match_operand 8 "const_int_operand"                  "    i,    i")
+	    [(match_operand:<VM> 1 "vector_mask_operand"           "Wc1,Wc1, vm, vm")
+	     (match_operand 5 "vector_length_operand"              "rvl,rvl,rvl,rvl")
+	     (match_operand 6 "const_int_operand"                  "  i,  i,  i,  i")
+	     (match_operand 7 "const_int_operand"                  "  i,  i,  i,  i")
+	     (match_operand 8 "const_int_operand"                  "  i,  i,  i,  i")
 	     (reg:SI VL_REGNUM)
 	     (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
 	  (mult:VWEXTI
 	    (sign_extend:VWEXTI
-	      (match_operand:<V_DOUBLE_TRUNC> 3 "register_operand" "   vr,   vr"))
+	      (match_operand:<V_DOUBLE_TRUNC> 3 "register_operand" "Wvr,Wvr,Wvr,Wvr"))
 	    (zero_extend:VWEXTI
-	      (match_operand:<V_DOUBLE_TRUNC> 4 "register_operand" "   vr,   vr")))
-	  (match_operand:VWEXTI 2 "vector_merge_operand"           "   vu,    0")))]
+	      (match_operand:<V_DOUBLE_TRUNC> 4 "register_operand" "Wvr,Wvr,Wvr,Wvr")))
+	  (match_operand:VWEXTI 2 "vector_merge_operand"           " vu,  0, vu,  0")))]
   "TARGET_VECTOR"
   "vwmulsu.vv\t%0,%3,%4%p1"
   [(set_attr "type" "viwmul")
-- 
2.43.0