From 45944e7cf45915eb2a0a2fae24e3396fc91dfc22 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@sifive.com>
Date: Mon, 25 Jul 2022 15:42:42 -0700
Subject: [PATCH] [RISCV] Refactor translateSetCCForBranch to prepare for
 D130508. NFC.

D130508 handles more constants than just 1 or -1. We need to extract
the constant instead of relying isOneConstant or isAllOnesConstant.
---
 llvm/lib/Target/RISCV/RISCVISelLowering.cpp | 34 +++++++++++++--------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 146605782e9a..baa19e81e436 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -1406,18 +1406,28 @@ static void translateSetCCForBranch(const SDLoc &DL, SDValue &LHS, SDValue &RHS,
     }
   }
 
-  // Convert X > -1 to X >= 0.
-  if (CC == ISD::SETGT && isAllOnesConstant(RHS)) {
-    RHS = DAG.getConstant(0, DL, RHS.getValueType());
-    CC = ISD::SETGE;
-    return;
-  }
-  // Convert X < 1 to 0 >= X.
-  if (CC == ISD::SETLT && isOneConstant(RHS)) {
-    RHS = LHS;
-    LHS = DAG.getConstant(0, DL, RHS.getValueType());
-    CC = ISD::SETGE;
-    return;
+  if (auto *RHSC = dyn_cast<ConstantSDNode>(RHS)) {
+    int64_t C = RHSC->getSExtValue();
+    switch (CC) {
+    default: break;
+    case ISD::SETGT:
+      // Convert X > -1 to X >= 0.
+      if (C == -1) {
+        RHS = DAG.getConstant(0, DL, RHS.getValueType());
+        CC = ISD::SETGE;
+        return;
+      }
+      break;
+    case ISD::SETLT:
+      // Convert X < 1 to 0 <= X.
+      if (C == 1) {
+        RHS = LHS;
+        LHS = DAG.getConstant(0, DL, RHS.getValueType());
+        CC = ISD::SETGE;
+        return;
+      }
+      break;
+    }
   }
 
   switch (CC) {