[gcc(refs/vendors/riscv/heads/gcc-15-with-riscv-opts)] RISC-V: Combine vec_duplicate + vnmsac.vv to vnmsac.vx on GR2VR cost
Jeff Law
law@gcc.gnu.org
Sat Sep 13 16:28:37 GMT 2025
https://gcc.gnu.org/g:79f538e375d3e5809743ed23d354e27f442e1c53
commit 79f538e375d3e5809743ed23d354e27f442e1c53
Author: Pan Li <pan2.li@intel.com>
Date: Thu Aug 28 10:33:54 2025 +0800
RISC-V: Combine vec_duplicate + vnmsac.vv to vnmsac.vx on GR2VR cost
This patch would like to combine the vec_duplicate + vnmsac.vv to the
vnmsac.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_TERNARY_CASE_0(T, OP_1, OP_2, NAME)
\
void
\
test_vx_ternary_##NAME##_##T##_case_0 (T * restrict vd, T * restrict
vs2, \NAME T rs1, unsigned n)
\
{
\
for (unsigned i = 0; i < n; i++)
\
vd[i] = vd[i] OP_2 vs2[i] OP_1 rs1;
\
}
DEF_VX_TERNARY_CASE_0(int32_t, *, +, macc)
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 │ vnmsac.vv 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 │ vnmsac.vx v1,a2,v3
...
23 │ bne a3,zero,.L3
gcc/ChangeLog:
* config/riscv/autovec-opt.md (*vnmsac_vx_<mode>): Add new
pattern to combine to vx.
* config/riscv/vector.md (@pred_vnmsac_vx_<mode>): Add new
pattern to generate rtl.
(*pred_nmsac_<mode>_scalar_undef): Ditto.
Signed-off-by: Pan Li <pan2.li@intel.com>
(cherry picked from commit 44054e62064510d7647344e79208fb14408600dc)
Diff:
---
gcc/config/riscv/autovec-opt.md | 22 ++++++++++
gcc/config/riscv/vector.md | 96 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 118 insertions(+)
diff --git a/gcc/config/riscv/autovec-opt.md b/gcc/config/riscv/autovec-opt.md
index 1440eeaea905..c66de7d2fb93 100644
--- a/gcc/config/riscv/autovec-opt.md
+++ b/gcc/config/riscv/autovec-opt.md
@@ -1846,6 +1846,28 @@
}
[(set_attr "type" "vimuladd")])
+(define_insn_and_split "*vnmsac_vx_<mode>"
+ [(set (match_operand:V_VLSI 0 "register_operand")
+ (minus:V_VLSI
+ (match_operand:V_VLSI 3 "register_operand")
+ (mult:V_VLSI
+ (vec_duplicate:V_VLSI
+ (match_operand:<VEL> 1 "register_operand"))
+ (match_operand:V_VLSI 2 "register_operand"))))]
+ "TARGET_VECTOR && can_create_pseudo_p ()"
+ "#"
+ "&& 1"
+ [(const_int 0)]
+ {
+ insn_code icode = code_for_pred_vnmsac_vx (<MODE>mode);
+ rtx ops[] = {operands[0], operands[1], operands[2], operands[3],
+ RVV_VUNDEF(<MODE>mode)};
+ riscv_vector::emit_vlmax_insn (icode, riscv_vector::TERNARY_OP, ops);
+
+ DONE;
+ }
+ [(set_attr "type" "vimuladd")])
+
;; =============================================================================
;; Combine vec_duplicate + op.vv to op.vf
diff --git a/gcc/config/riscv/vector.md b/gcc/config/riscv/vector.md
index f8126b3a46b3..e46f415e731f 100644
--- a/gcc/config/riscv/vector.md
+++ b/gcc/config/riscv/vector.md
@@ -5539,6 +5539,52 @@
riscv_vector::prepare_ternary_operands (operands);
})
+(define_expand "@pred_vnmsac_vx_<mode>"
+ [(set (match_operand:V_VLSI_QHS 0 "register_operand")
+ (if_then_else:V_VLSI_QHS
+ (unspec:<VM>
+ [(match_operand:<VM> 1 "vector_mask_operand")
+ (match_operand 6 "vector_length_operand")
+ (match_operand 7 "const_int_operand")
+ (match_operand 8 "const_int_operand")
+ (match_operand 9 "const_int_operand")
+ (reg:SI VL_REGNUM)
+ (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
+ (minus:V_VLSI_QHS
+ (match_operand:V_VLSI_QHS 4 "register_operand")
+ (mult:V_VLSI_QHS
+ (vec_duplicate:V_VLSI_QHS
+ (match_operand:<VEL> 2 "register_operand"))
+ (match_operand:V_VLSI_QHS 3 "register_operand")))
+ (match_operand:V_VLSI_QHS 5 "vector_merge_operand")))]
+ "TARGET_VECTOR"
+{
+ riscv_vector::prepare_ternary_operands (operands);
+})
+
+(define_expand "@pred_vnmsac_vx_<mode>"
+ [(set (match_operand:V_VLSI_D 0 "register_operand")
+ (if_then_else:V_VLSI_D
+ (unspec:<VM>
+ [(match_operand:<VM> 1 "vector_mask_operand")
+ (match_operand 6 "vector_length_operand")
+ (match_operand 7 "const_int_operand")
+ (match_operand 8 "const_int_operand")
+ (match_operand 9 "const_int_operand")
+ (reg:SI VL_REGNUM)
+ (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
+ (minus:V_VLSI_D
+ (match_operand:V_VLSI_D 4 "register_operand")
+ (mult:V_VLSI_D
+ (vec_duplicate:V_VLSI_D
+ (match_operand:<VEL> 2 "register_operand"))
+ (match_operand:V_VLSI_D 3 "register_operand")))
+ (match_operand:V_VLSI_D 5 "vector_merge_operand")))]
+ "TARGET_VECTOR && TARGET_64BIT"
+{
+ riscv_vector::prepare_ternary_operands (operands);
+})
+
(define_insn "*pred_madd<mode>_scalar"
[(set (match_operand:V_VLSI 0 "register_operand" "=vd, vr")
(if_then_else:V_VLSI
@@ -8938,6 +8984,56 @@
[(set_attr "type" "vimuladd")
(set_attr "mode" "<MODE>")])
+(define_insn "*pred_nmsac_<mode>_scalar_undef"
+ [(set (match_operand:V_VLSI_QHS 0 "register_operand" "=vd, vr")
+ (if_then_else:V_VLSI_QHS
+ (unspec:<VM>
+ [(match_operand:<VM> 1 "vector_mask_operand" " vm, Wc1")
+ (match_operand 6 "vector_length_operand" "rvl, rvl")
+ (match_operand 7 "const_int_operand" " i, i")
+ (match_operand 8 "const_int_operand" " i, i")
+ (match_operand 9 "const_int_operand" " i, i")
+ (reg:SI VL_REGNUM)
+ (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
+ (minus:V_VLSI_QHS
+ (match_operand:V_VLSI_QHS 5 "register_operand" " 0, 0")
+ (mult:V_VLSI_QHS
+ (vec_duplicate:V_VLSI_QHS
+ (match_operand:<VEL> 3 "reg_or_0_operand" " rJ, rJ"))
+ (match_operand:V_VLSI_QHS 4 "register_operand" " vr, vr")))
+ (match_operand:V_VLSI_QHS 2 "vector_undef_operand")))]
+ "TARGET_VECTOR"
+ "@
+ vnmsac.vx\t%0,%z3,%4%p1
+ vnmsac.vx\t%0,%z3,%4%p1"
+ [(set_attr "type" "vimuladd")
+ (set_attr "mode" "<MODE>")])
+
+(define_insn "*pred_nmsac_<mode>_scalar_undef"
+ [(set (match_operand:V_VLSI_D 0 "register_operand" "=vd, vr")
+ (if_then_else:V_VLSI_D
+ (unspec:<VM>
+ [(match_operand:<VM> 1 "vector_mask_operand" " vm, Wc1")
+ (match_operand 6 "vector_length_operand" "rvl, rvl")
+ (match_operand 7 "const_int_operand" " i, i")
+ (match_operand 8 "const_int_operand" " i, i")
+ (match_operand 9 "const_int_operand" " i, i")
+ (reg:SI VL_REGNUM)
+ (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
+ (minus:V_VLSI_D
+ (match_operand:V_VLSI_D 5 "register_operand" " 0, 0")
+ (mult:V_VLSI_D
+ (vec_duplicate:V_VLSI_D
+ (match_operand:<VEL> 3 "reg_or_0_operand" " rJ, rJ"))
+ (match_operand:V_VLSI_D 4 "register_operand" " vr, vr")))
+ (match_operand:V_VLSI_D 2 "vector_undef_operand")))]
+ "TARGET_VECTOR && TARGET_64BIT"
+ "@
+ vnmsac.vx\t%0,%z3,%4%p1
+ vnmsac.vx\t%0,%z3,%4%p1"
+ [(set_attr "type" "vimuladd")
+ (set_attr "mode" "<MODE>")])
+
(include "autovec.md")
(include "autovec-opt.md")
(include "sifive-vector.md")
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