[llvm] [RISCV] Add add_like PatFrags to reduce number of required patterns [nfc] (PR #86983)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

Author: Philip Reames (preames)

<details>
<summary>Changes</summary>

This is an NFC prep patch for an upcoming change which is going to support or_is_add in a bunch more cases.  Posting separately because tblgen is not particularly my strong suit.

---
Full diff: https://github.com/llvm/llvm-project/pull/86983.diff


2 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVInstrInfo.td (+4) 
- (modified) llvm/lib/Target/RISCV/RISCVInstrInfoZb.td (+3-9) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.td b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
index 966cdc433d0fd4..fd8777fdc121c7 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
@@ -1259,6 +1259,10 @@ def or_is_add : PatFrag<(ops node:$lhs, node:$rhs), (or node:$lhs, node:$rhs),[{
 }]>;
 def : PatGprSimm12<or_is_add, ADDI>;
 
+def add_like : PatFrags<(ops node:$lhs, node:$rhs),
+                        [(or_is_add node:$lhs, node:$rhs),
+                         (add  node:$lhs, node:$rhs)]>;
+
 // negate of low bit can be done via two (compressible) shifts.  The negate
 // is never compressible since rs1 and rd can't be the same register.
 def : Pat<(XLenVT (sub 0, (and_oneuse GPR:$rs, 1))),
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoZb.td b/llvm/lib/Target/RISCV/RISCVInstrInfoZb.td
index a882b208a76889..549bc039fabbc7 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoZb.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoZb.td
@@ -255,7 +255,7 @@ class binop_with_non_imm12<SDPatternOperator binop>
   }];
 }
 def add_non_imm12       : binop_with_non_imm12<add>;
-def or_is_add_non_imm12 : binop_with_non_imm12<or_is_add>;
+def add_like_non_imm12 : binop_with_non_imm12<add_like>;
 
 def Shifted32OnesMask : IntImmLeaf<XLenVT, [{
   if (!Imm.isShiftedMask())
@@ -756,13 +756,10 @@ def : Pat<(i64 (shl (and GPR:$rs1, 0xFFFFFFFF), uimm5:$shamt)),
 def : Pat<(i64 (and GPR:$rs1, Shifted32OnesMask:$mask)),
           (SLLI_UW (XLenVT (SRLI GPR:$rs1, Shifted32OnesMask:$mask)),
                    Shifted32OnesMask:$mask)>;
-def : Pat<(i64 (add_non_imm12 (and GPR:$rs1, 0xFFFFFFFF), GPR:$rs2)),
+def : Pat<(i64 (add_like_non_imm12 (and GPR:$rs1, 0xFFFFFFFF), GPR:$rs2)),
           (ADD_UW GPR:$rs1, GPR:$rs2)>;
 def : Pat<(i64 (and GPR:$rs, 0xFFFFFFFF)), (ADD_UW GPR:$rs, (XLenVT X0))>;
 
-def : Pat<(i64 (or_is_add_non_imm12 (and GPR:$rs1, 0xFFFFFFFF), GPR:$rs2)),
-          (ADD_UW GPR:$rs1, GPR:$rs2)>;
-
 foreach i = {1,2,3} in {
   defvar shxadd_uw = !cast<Instruction>("SH"#i#"ADD_UW");
   def : Pat<(i64 (add_non_imm12 (shl (and GPR:$rs1, 0xFFFFFFFF), (i64 i)), (XLenVT GPR:$rs2))),
@@ -876,13 +873,10 @@ let Predicates = [HasStdExtZba, IsRV64] in {
 def : Pat<(shl (i64 (zext i32:$rs1)), uimm5:$shamt),
           (SLLI_UW GPR:$rs1, uimm5:$shamt)>;
 
-def : Pat<(i64 (add_non_imm12 (zext GPR:$rs1), GPR:$rs2)),
+def : Pat<(i64 (add_like_non_imm12 (zext GPR:$rs1), GPR:$rs2)),
           (ADD_UW GPR:$rs1, GPR:$rs2)>;
 def : Pat<(zext GPR:$src), (ADD_UW GPR:$src, (XLenVT X0))>;
 
-def : Pat<(i64 (or_is_add_non_imm12 (zext GPR:$rs1), GPR:$rs2)),
-          (ADD_UW GPR:$rs1, GPR:$rs2)>;
-
 foreach i = {1,2,3} in {
   defvar shxadd = !cast<Instruction>("SH"#i#"ADD");
   def : Pat<(i32 (add_non_imm12 (shl GPR:$rs1, (i64 i)), GPR:$rs2)),

``````````

</details>


https://github.com/llvm/llvm-project/pull/86983