[gcc(refs/users/meissner/heads/work087)] Make addti3/subti3 be define_insn_and_split, instead of define_expand

[Michael Meissner]

https://gcc.gnu.org/g:b7969b56b1a3233416d40d92d99d79023fd26acc

commit b7969b56b1a3233416d40d92d99d79023fd26acc
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Thu Apr 28 16:23:32 2022 -0400

    Make addti3/subti3 be define_insn_and_split, instead of define_expand
    
    This patch makes addti3 and subti3 be define_insn_and_split instead of
    define_expand.  This patch will be a building block to support in a future
    patch PR target/103109 which wants to optimize 128-bit some integer
    multiply-add combinations to use the power9 maddld, maddhd, maddhdu
    instructions.  In order to support recognizing the multiply and add
    combination, we need to keep the addti3 and subti3 as complete insns
    through the combiner phase.
    
    2022-04-28   Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
            * config/rs6000/rs6000.md (addti3): Don't immediately expand the
            insn.  Delay expansion until the split passes.
            (subti3): Likewise.

Diff:
---
 gcc/config/rs6000/rs6000.md | 41 +++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 90a11366266..c9e5b5f10e0 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -7040,12 +7040,19 @@
 ;; allocator from allocating registers that overlap with the inputs
 ;; (for example, having an input in 7,8 and an output in 6,7).  We
 ;; also allow for the output being the same as one of the inputs.
-
-(define_expand "addti3"
-  [(set (match_operand:TI 0 "gpc_reg_operand")
-	(plus:TI (match_operand:TI 1 "gpc_reg_operand")
-		 (match_operand:TI 2 "reg_or_short_operand")))]
+;;
+;; Addti3/subti3 are define_insn_and_splits instead of define_expand, to allow
+;; for combine to make things like multiply and add with extend operations.
+
+(define_insn_and_split "addti3"
+  [(set (match_operand:TI 0 "gpc_reg_operand"               "=&r,r,r")
+	(plus:TI (match_operand:TI 1 "gpc_reg_operand"       "r, 0,r")
+		 (match_operand:TI 2 "reg_or_short_operand"  "rI,r,0")))
+   (clobber (reg:DI CA_REGNO))]
   "TARGET_64BIT"
+  "#"
+  "&& 1"
+  [(pc)]
 {
   rtx lo0 = gen_lowpart (DImode, operands[0]);
   rtx lo1 = gen_lowpart (DImode, operands[1]);
@@ -7062,13 +7069,20 @@
   emit_insn (gen_adddi3_carry (lo0, lo1, lo2));
   emit_insn (gen_adddi3_carry_in (hi0, hi1, hi2));
   DONE;
-})
-
-(define_expand "subti3"
-  [(set (match_operand:TI 0 "gpc_reg_operand")
-	(minus:TI (match_operand:TI 1 "reg_or_short_operand")
-		  (match_operand:TI 2 "gpc_reg_operand")))]
+}
+  [(set_attr "length" "8")
+   (set_attr "type"   "add")
+   (set_attr "size"   "128")])
+
+(define_insn_and_split "subti3"
+  [(set (match_operand:TI 0 "gpc_reg_operand"                "=&r,r,r")
+	(minus:TI (match_operand:TI 1 "reg_or_short_operand" "rI,0,r")
+		  (match_operand:TI 2 "gpc_reg_operand"      "r, r,0")))
+   (clobber (reg:DI CA_REGNO))]
   "TARGET_64BIT"
+  "#"
+  "&& 1"
+  [(pc)]
 {
   rtx lo0 = gen_lowpart (DImode, operands[0]);
   rtx lo1 = gen_lowpart (DImode, operands[1]);
@@ -7085,7 +7099,10 @@
   emit_insn (gen_subfdi3_carry (lo0, lo2, lo1));
   emit_insn (gen_subfdi3_carry_in (hi0, hi2, hi1));
   DONE;
-})
+}
+  [(set_attr "length" "8")
+   (set_attr "type"   "add")
+   (set_attr "size"   "128")])
 
 ;; 128-bit logical operations expanders