[PATCH 1/5] RISC-V: Remove float vector eqne pattern

钟居哲 juzhe.zhong@rivai.ai
Fri Mar 1 07:23:47 GMT 2024


Hello, han.  Thanks for trying to optimize the codes.


But I believe those vector-scalar patterns (eq/ne) you remove in this patch are necessary.


This is the story:
1. For commutative RTL code in GCC like plus, eq, ne, ... etc,
    we known in semantic Both (eq: (reg) (vec_duplicate ... ) and (eq: (vec_duplicate ... ) (reg)) are right.
    However, GCC prefer this order as I remembered - (eq: (vec_duplicate ... ) (reg)).


2. Before this patch, the order of the comparison as follows (take eq and lt as an example):
    
    1). (eq: (vec_duplicate ... ) (reg))  --> commutative
    2). (lt: (reg) (vec_duplicate ... )     --> non-commutative
    
   These patterns order are different.
   
   So, you see we have dedicated patterns (seems duplicate patterns) for vector-scalar eq/ne, whereas, we unify eq/ne into other comparisons for vector-vector instructions.
   If we unify eq/ne into other comparisons for vector-scalar instructions (like your patch does), we will end up have:
    
   (eq: (reg) (vec_duplicate ... ) [after this patch] instead of (eq: (vec_duplicate ... ) (reg)) [Before this patch].


So, I think this patch may not be right.
I may be wrong, Robin/Jerff/kito feel free to correct me if I am wrong.
 
 
------------------ Original ------------------
From:  "demin.han"<demin.han@starfivetech.com>;
Date:  Fri, Mar 1, 2024 02:27 PM
To:  "gcc-patches"<gcc-patches@gcc.gnu.org>; 
Cc:  "juzhe.zhong"<juzhe.zhong@rivai.ai>; "kito.cheng"<kito.cheng@gmail.com>; "Li, Pan2"<pan2.li@intel.com>; "jeffreyalaw"<jeffreyalaw@gmail.com>; 
Subject:  [PATCH 1/5] RISC-V: Remove float vector eqne pattern

 

We can unify eqne and other comparison operations.

Tested on RV32 and RV64

gcc/ChangeLog:

	* config/riscv/riscv-vector-builtins-bases.cc: Remove eqne cond
	* config/riscv/vector.md (@pred_eqne<mode>_scalar): Remove patterns
	(*pred_eqne<mode>_scalar_merge_tie_mask): Ditto
	(*pred_eqne<mode>_scalar): Ditto
	(*pred_eqne<mode>_scalar_narrow): Ditto

Signed-off-by: demin.han <demin.han@starfivetech.com>
---
 .../riscv/riscv-vector-builtins-bases.cc      |  4 -
 gcc/config/riscv/vector.md                    | 86 -------------------
 2 files changed, 90 deletions(-)

diff --git a/gcc/config/riscv/riscv-vector-builtins-bases.cc b/gcc/config/riscv/riscv-vector-builtins-bases.cc
index b6f6e4ff37e..d414721ede8 100644
--- a/gcc/config/riscv/riscv-vector-builtins-bases.cc
+++ b/gcc/config/riscv/riscv-vector-builtins-bases.cc
@@ -1420,10 +1420,6 @@ public:
     switch (e.op_info->op)
       {
 	case OP_TYPE_vf: {
-	  if (CODE == EQ || CODE == NE)
-	    return e.use_compare_insn (CODE, code_for_pred_eqne_scalar (
-					       e.vector_mode ()));
-	  else
 	    return e.use_compare_insn (CODE, code_for_pred_cmp_scalar (
 					       e.vector_mode ()));
 	}
diff --git a/gcc/config/riscv/vector.md b/gcc/config/riscv/vector.md
index ab6e099852d..9210d7c28ad 100644
--- a/gcc/config/riscv/vector.md
+++ b/gcc/config/riscv/vector.md
@@ -7520,92 +7520,6 @@ (define_insn "*pred_cmp<mode>_scalar_narrow"
    (set_attr "mode" "<MODE>")
    (set_attr "spec_restriction" "none,thv,thv,none,none")])
 
-(define_expand "@pred_eqne<mode>_scalar"
-  [(set (match_operand:<VM> 0 "register_operand")
-	(if_then_else:<VM>
-	  (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")
-	     (reg:SI VL_REGNUM)
-	     (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
-	  (match_operator:<VM> 3 "equality_operator"
-	     [(vec_duplicate:V_VLSF
-	        (match_operand:<VEL> 5 "register_operand"))
-	      (match_operand:V_VLSF 4 "register_operand")])
-	  (match_operand:<VM> 2 "vector_merge_operand")))]
-  "TARGET_VECTOR"
-  {})
-
-(define_insn "*pred_eqne<mode>_scalar_merge_tie_mask"
-  [(set (match_operand:<VM> 0 "register_operand"              "=vm")
-	(if_then_else:<VM>
-	  (unspec:<VM>
-	    [(match_operand:<VM> 1 "register_operand"         "  0")
-	     (match_operand 5 "vector_length_operand"         " rK")
-	     (match_operand 6 "const_int_operand"             "  i")
-	     (match_operand 7 "const_int_operand"             "  i")
-	     (reg:SI VL_REGNUM)
-	     (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
-	  (match_operator:<VM> 2 "equality_operator"
-	     [(vec_duplicate:V_VLSF
-	        (match_operand:<VEL> 4 "register_operand"     "  f"))
-	      (match_operand:V_VLSF 3 "register_operand"      " vr")])
-	  (match_dup 1)))]
-  "TARGET_VECTOR"
-  "vmf%B2.vf\t%0,%3,%4,v0.t"
-  [(set_attr "type" "vfcmp")
-   (set_attr "mode" "<MODE>")
-   (set_attr "merge_op_idx" "1")
-   (set_attr "vl_op_idx" "5")
-   (set (attr "ma") (symbol_ref "riscv_vector::get_ma(operands[6])"))
-   (set (attr "avl_type_idx") (const_int 7))])
-
-;; We don't use early-clobber for LMUL <= 1 to get better codegen.
-(define_insn "*pred_eqne<mode>_scalar"
-  [(set (match_operand:<VM> 0 "register_operand"                "=vr,   vr,   &vr,   &vr")
-	(if_then_else:<VM>
-	  (unspec:<VM>
-	    [(match_operand:<VM> 1 "vector_mask_operand"      "vmWc1,vmWc1,vmWc1,vmWc1")
-	     (match_operand 6 "vector_length_operand"         "   rK,   rK,   rK,   rK")
-	     (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)
-	  (match_operator:<VM> 3 "equality_operator"
-	     [(vec_duplicate:V_VLSF
-	        (match_operand:<VEL> 5 "register_operand"     "    f,    f,    f,    f"))
-	      (match_operand:V_VLSF 4 "register_operand"      "   vr,   vr,   vr,   vr")])
-	  (match_operand:<VM> 2 "vector_merge_operand"        "   vu,    0,    vu,    0")))]
-  "TARGET_VECTOR && riscv_vector::cmp_lmul_le_one (<MODE>mode)"
-  "vmf%B3.vf\t%0,%4,%5%p1"
-  [(set_attr "type" "vfcmp")
-   (set_attr "mode" "<MODE>")
-   (set_attr "spec_restriction" "thv,thv,rvv,rvv")])
-
-;; We use early-clobber for source LMUL > dest LMUL.
-(define_insn "*pred_eqne<mode>_scalar_narrow"
-  [(set (match_operand:<VM> 0 "register_operand"                "=vm,   vr,   vr,  &vr,  &vr")
-	(if_then_else:<VM>
-	  (unspec:<VM>
-	    [(match_operand:<VM> 1 "vector_mask_operand"      "    0,vmWc1,vmWc1,vmWc1,vmWc1")
-	     (match_operand 6 "vector_length_operand"         "   rK,   rK,   rK,   rK,   rK")
-	     (match_operand 7 "const_int_operand"             "    i,    i,    i,    i,    i")
-	     (match_operand 8 "const_int_operand"             "    i,    i,    i,    i,    i")
-	     (reg:SI VL_REGNUM)
-	     (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
-	  (match_operator:<VM> 3 "equality_operator"
-	     [(vec_duplicate:V_VLSF
-	        (match_operand:<VEL> 5 "register_operand"     "    f,    f,    f,    f,    f"))
-	      (match_operand:V_VLSF 4 "register_operand"      "   vr,    0,    0,   vr,   vr")])
-	  (match_operand:<VM> 2 "vector_merge_operand"        "   vu,   vu,    0,   vu,    0")))]
-  "TARGET_VECTOR && riscv_vector::cmp_lmul_gt_one (<MODE>mode)"
-  "vmf%B3.vf\t%0,%4,%5%p1"
-  [(set_attr "type" "vfcmp")
-   (set_attr "mode" "<MODE>")
-   (set_attr "spec_restriction" "none,thv,thv,none,none")])
-
 ;; -------------------------------------------------------------------------------
 ;; ---- Predicated floating-point merge
 ;; -------------------------------------------------------------------------------
-- 
2.43.2
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