From 5b6ba4568cf6916a61ecde702f45246db8154b9f Mon Sep 17 00:00:00 2001
From: Richard-Qin-X <richard.qin.001@gmail.com>
Date: Sat, 15 Aug 2026 20:03:59 +0800
Subject: [RISCV][GlobalISel] Legalize floating-point remainder

---
 backend/lib/CodeGen/GlobalISel/Legalizer.cpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'backend/lib/CodeGen/GlobalISel/Legalizer.cpp')

diff --git a/backend/lib/CodeGen/GlobalISel/Legalizer.cpp b/backend/lib/CodeGen/GlobalISel/Legalizer.cpp
index 877777e..8f3f06f 100644
--- a/backend/lib/CodeGen/GlobalISel/Legalizer.cpp
+++ b/backend/lib/CodeGen/GlobalISel/Legalizer.cpp
@@ -258,6 +258,12 @@ const MachinePassContract &Legalizer::contract() const noexcept {
 Expected<MachinePassResult> Legalizer::run(MachineFunction &Function,
                                            const TargetDescription &Target,
                                            MachineFunctionAnalysisManager &Analyses) {
+  if (Function.properties().has(MachineFunctionProperty::FailedISel))
+    return MachinePassResult{
+        .Changed = false,
+        .Changes = {},
+        .Preserved = PreservedAnalyses::all(),
+    };
   if (Info == nullptr)
     return std::unexpected(
         passFailure("legalizer has no target behavior interface", ErrorCode::InvalidArgument));
@@ -265,6 +271,24 @@ Expected<MachinePassResult> Legalizer::run(MachineFunction &Function,
   if (!Required)
     return std::unexpected(Required.error());
 
+  if (AbortMode != GlobalISelAbortMode::Enable) {
+    if (AbortMode != GlobalISelAbortMode::Disable &&
+        AbortMode != GlobalISelAbortMode::DisableWithDiagnostic) {
+      return std::unexpected(passFailure("legalizer has an unknown GlobalISel abort mode",
+                                         ErrorCode::InvalidArgument));
+    }
+    MachineActionReplay Actions(Analyses);
+    auto Result = runImplementation(Function, Target, Actions);
+    if (Result || Result.error().code() != ErrorCode::Unsupported)
+      return Result;
+    Function.properties().set(MachineFunctionProperty::FailedISel);
+    return MachinePassResult{
+        .Changed = true,
+        .Changes = {MachinePassChange::Instructions},
+        .Preserved = PreservedAnalyses::none(),
+    };
+  }
+
   auto Trial = cloneMachineFunction(
       Function, Target,
       MachineFunctionCloneOptions{.NewStableID = Function.stableID(), .NewName = std::nullopt});
-- 
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