From: Pan Li <pan2.li@intel.com>
Date: Mon, 9 Jun 2025 08:24:34 +0000 (+0800)
Subject: RISC-V: Combine vec_duplicate + vremu.vv to vremu.vx on GR2VR cost
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=85de2b8b58e1644f6d5f0f182426122416b19e6f;p=thirdparty%2Fgcc.git

RISC-V: Combine vec_duplicate + vremu.vv to vremu.vx on GR2VR cost

This patch would like to combine the vec_duplicate + vremu.vv to the
vremu.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 example code like below, GR2VR cost is 0.

  #define DEF_VX_BINARY(T, OP)                                        \
  void                                                                \
  test_vx_binary (T * restrict out, T * restrict in, T x, unsigned n) \
  {                                                                   \
    for (unsigned i = 0; i < n; i++)                                  \
      out[i] = in[i] OP x;                                            \
  }

  DEF_VX_BINARY(int32_t, /)

Before this patch:
  10   │ test_vx_binary_or_int32_t_case_0:
  11   │     beq a3,zero,.L8
  12   │     vsetvli a5,zero,e32,m1,ta,ma
  13   │     vmv.v.x v2,a2
  14   │     slli    a3,a3,32
  15   │     srli    a3,a3,32
  16   │ .L3:
  17   │     vsetvli a5,a3,e32,m1,ta,ma
  18   │     vle32.v v1,0(a1)
  19   │     slli    a4,a5,2
  20   │     sub a3,a3,a5
  21   │     add a1,a1,a4
  22   │     vremu.vv v1,v1,v2
  23   │     vse32.v v1,0(a0)
  24   │     add a0,a0,a4
  25   │     bne a3,zero,.L3

After this patch:
  10   │ test_vx_binary_or_int32_t_case_0:
  11   │     beq a3,zero,.L8
  12   │     slli    a3,a3,32
  13   │     srli    a3,a3,32
  14   │ .L3:
  15   │     vsetvli a5,a3,e32,m1,ta,ma
  16   │     vle32.v v1,0(a1)
  17   │     slli    a4,a5,2
  18   │     sub a3,a3,a5
  19   │     add a1,a1,a4
  20   │     vremu.vx v1,v1,a2
  21   │     vse32.v v1,0(a0)
  22   │     add a0,a0,a4
  23   │     bne a3,zero,.L3

gcc/ChangeLog:

	* config/riscv/riscv-v.cc (expand_vx_binary_vec_vec_dup): Add new
	case UMOD.
	* config/riscv/riscv.cc (riscv_rtx_costs): Ditto.
	* config/riscv/vector-iterators.md: Add new op umod.

Signed-off-by: Pan Li <pan2.li@intel.com>
---

diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index c31ec9e9b41..420baa587dc 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -5570,6 +5570,7 @@ expand_vx_binary_vec_vec_dup (rtx op_0, rtx op_1, rtx op_2,
     case DIV:
     case UDIV:
     case MOD:
+    case UMOD:
       icode = code_for_pred_scalar (code, mode);
       break;
     default:
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 14ac2f3cdbc..d5ab128f05f 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -3950,6 +3950,7 @@ riscv_rtx_costs (rtx x, machine_mode mode, int outer_code, int opno ATTRIBUTE_UN
 		    case DIV:
 		    case UDIV:
 		    case MOD:
+		    case UMOD:
 		      *total = get_vector_binary_rtx_cost (op, scalar2vr_cost);
 		      break;
 		    default:
diff --git a/gcc/config/riscv/vector-iterators.md b/gcc/config/riscv/vector-iterators.md
index b1fd607320e..42fc04c0ad3 100644
--- a/gcc/config/riscv/vector-iterators.md
+++ b/gcc/config/riscv/vector-iterators.md
@@ -4042,7 +4042,7 @@
 ])
 
 (define_code_iterator any_int_binop_no_shift_v_vdup [
-  plus minus and ior xor mult div udiv mod
+  plus minus and ior xor mult div udiv mod umod
 ])
 
 (define_code_iterator any_int_binop_no_shift_vdup_v [