[llvm] [RISCV] Simplify the Zibi SFB patterns. NFC (PR #216449)

[Craig Topper via llvm-commits]

https://github.com/topperc updated https://github.com/llvm/llvm-project/pull/216449

>From b38950e687e60e28d8bd6f8d0443e834bb69c118 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Fri, 14 Aug 2026 19:57:58 -0700
Subject: [PATCH 1/3] [RISCV] Simplify the Zibi SFB patterns. NFC

Use a PatLeaf to match the valid condition codes instead of using
separate patterns for each.
---
 llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td | 23 ++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td b/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
index 409aeb4c86546..419256876f136 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
@@ -261,15 +261,18 @@ def PseudoCCLWU : SFBLoad;
 def PseudoCCLD : SFBLoad;
 }
 
+def ZibiCond : PatLeaf<(cond), [{
+  switch (N->get()) {
+  default:
+    return false;
+  case ISD::SETEQ:
+  case ISD::SETNE:
+    return true;
+  }
+}]>;
+
 // Zibi: select with immediate comparison folded into SFB.
 // imm5_zibi is defined in RISCVInstrInfoZibi.td (included before this file).
-class SelectZibiSFB<CondCode Cond>
-    : Pat<(riscv_selectcc (XLenVT GPR:$lhs), imm5_zibi:$cimm, Cond:$cc,
-                          (XLenVT GPR:$truev), GPR:$falsev),
-          (PseudoCCMOVGPR GPR:$falsev, GPR:$truev, (CCtoZibiBCC $cc), GPR:$lhs,
-                          imm5_zibi:$cimm)>;
-
-let Predicates = [HasStdExtZibi, HasShortForwardBranchImm] in {
-  def : SelectZibiSFB<SETEQ>;
-  def : SelectZibiSFB<SETNE>;
-} // Predicates = [HasStdExtZibi, HasShortForwardBranchImm]
+let Predicates = [HasStdExtZibi, HasShortForwardBranchImm] in
+def : Pat<(riscv_selectcc (XLenVT GPR:$lhs), imm5_zibi:$cimm, ZibiCond:$cc, (XLenVT GPR:$truev), GPR:$falsev),
+           (PseudoCCMOVGPR GPR:$falsev, GPR:$truev, (CCtoZibiBCC $cc), GPR:$lhs, imm5_zibi:$cimm)>;

>From a7eabe54d5b09263bc84c23e9609d5fa35a6f60a Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Fri, 14 Aug 2026 20:04:40 -0700
Subject: [PATCH 2/3] Apply suggestion from @topperc

---
 llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td b/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
index 419256876f136..79d17ace73b75 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
@@ -275,4 +275,4 @@ def ZibiCond : PatLeaf<(cond), [{
 // imm5_zibi is defined in RISCVInstrInfoZibi.td (included before this file).
 let Predicates = [HasStdExtZibi, HasShortForwardBranchImm] in
 def : Pat<(riscv_selectcc (XLenVT GPR:$lhs), imm5_zibi:$cimm, ZibiCond:$cc, (XLenVT GPR:$truev), GPR:$falsev),
-           (PseudoCCMOVGPR GPR:$falsev, GPR:$truev, (CCtoZibiBCC $cc), GPR:$lhs, imm5_zibi:$cimm)>;
+          (PseudoCCMOVGPR GPR:$falsev, GPR:$truev, (CCtoZibiBCC $cc), GPR:$lhs, imm5_zibi:$cimm)>;

>From 4275ab8acd75ab730b942b0dfaa214472ae1dfaf Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Fri, 14 Aug 2026 21:21:22 -0700
Subject: [PATCH 3/3] fixup! Update select patterns too

---
 llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td  | 15 +++-----------
 llvm/lib/Target/RISCV/RISCVInstrInfoZibi.td | 23 ++++++++++++++-------
 2 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td b/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
index 324cbbd67d110..c82e357bdc565 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoSFB.td
@@ -261,18 +261,9 @@ def PseudoCCLWU : SFBLoad;
 def PseudoCCLD : SFBLoad;
 }
 
-def ZibiCond : PatLeaf<(cond), [{
-  switch (N->get()) {
-  default:
-    return false;
-  case ISD::SETEQ:
-  case ISD::SETNE:
-    return true;
-  }
-}]>;
-
 // Zibi: select with immediate comparison folded into SFB.
-// imm5_zibi is defined in RISCVInstrInfoZibi.td (included before this file).
-let Predicates = [HasStdExtZibi, HasShortForwardBranchIALU] in {
+// imm5_zibi and ZibiCond are defined in RISCVInstrInfoZibi.td (included before
+// this file).
+let Predicates = [HasStdExtZibi, HasShortForwardBranchIALU] in
 def : Pat<(riscv_selectcc (XLenVT GPR:$lhs), imm5_zibi:$cimm, ZibiCond:$cc, (XLenVT GPR:$truev), GPR:$falsev),
           (PseudoCCMOVGPR GPR:$falsev, GPR:$truev, (CCtoZibiBCC $cc), GPR:$lhs, imm5_zibi:$cimm)>;
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoZibi.td b/llvm/lib/Target/RISCV/RISCVInstrInfoZibi.td
index e7605f5385e40..b51eb51979420 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoZibi.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoZibi.td
@@ -26,6 +26,17 @@ def imm5_zibi : RISCVOp<XLenVT>, ImmLeaf<XLenVT, [{
   let OperandType = "OPERAND_IMM5_ZIBI";
 }
 
+// The condition codes supported by BEQI/BNEI.
+def ZibiCond : PatLeaf<(cond), [{
+  switch (N->get()) {
+  default:
+    return false;
+  case ISD::SETEQ:
+  case ISD::SETNE:
+    return true;
+  }
+}]>;
+
 class Branch_imm<bits<3> funct3, string opcodestr>
     : RVInstBIMM<funct3, OPC_BRANCH, (outs),
                  (ins GPR:$rs1, imm5_zibi:$cimm, bare_simm13_lsb0:$imm12),
@@ -55,15 +66,11 @@ multiclass BccImmPat<CondCode Cond, Branch_imm Inst> {
 
 defm CC_Imm5_Zibi : SelectCC_GPR_riirr<GPR, imm5_zibi>;
 
-class SelectZibi<CondCode Cond>
-    : Pat<(riscv_selectcc (XLenVT GPR:$lhs), imm5_zibi:$cimm, Cond:$cc,
-                          (XLenVT GPR:$truev), GPR:$falsev),
-          (Select_GPR_Using_CC_Imm5_Zibi GPR:$lhs, imm5_zibi:$cimm,
-              (CCtoRISCVCC $cc), GPR:$truev, GPR:$falsev)>;
-
 let Predicates = [HasStdExtZibi] in {
-  def : SelectZibi<SETEQ>;
-  def : SelectZibi<SETNE>;
+  def : Pat<(riscv_selectcc (XLenVT GPR:$lhs), imm5_zibi:$cimm, ZibiCond:$cc,
+                            (XLenVT GPR:$truev), GPR:$falsev),
+            (Select_GPR_Using_CC_Imm5_Zibi GPR:$lhs, imm5_zibi:$cimm,
+                (CCtoRISCVCC $cc), GPR:$truev, GPR:$falsev)>;
 
   defm : BccImmPat<SETEQ, BEQI>;
   defm : BccImmPat<SETNE, BNEI>;