From: Justin Bogner <mail@justinbogner.com>
Date: Fri, 13 Jan 2017 23:46:11 +0000 (+0000)
Subject: GlobalISel: Abort in ResetMachineFunctionPass if fallback isn't enabled
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=669e297a93a12a9de7c452fd4323dd814afd5395;p=llvm

GlobalISel: Abort in ResetMachineFunctionPass if fallback isn't enabled

When GlobalISel is configured to abort rather than fallback the only
thing that resetting the machine function does is make things harder
to debug. If we ever get to this point in the abort configuration it
indicates that we've already hit a bug, so this changes the behaviour
to abort instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291977 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/CodeGen/Passes.h b/include/llvm/CodeGen/Passes.h
index a9fd301691d..2fff94c03f8 100644
--- a/include/llvm/CodeGen/Passes.h
+++ b/include/llvm/CodeGen/Passes.h
@@ -60,7 +60,9 @@ namespace llvm {
   /// as if it was just created.
   /// If EmitFallbackDiag is true, the pass will emit a
   /// DiagnosticInfoISelFallback for every MachineFunction it resets.
-  MachineFunctionPass *createResetMachineFunctionPass(bool EmitFallbackDiag);
+  /// If AbortOnFailedISel is true, abort compilation instead of resetting.
+  MachineFunctionPass *createResetMachineFunctionPass(bool EmitFallbackDiag,
+                                                      bool AbortOnFailedISel);
 
   /// createCodeGenPreparePass - Transform the code to expose more pattern
   /// matching during instruction selection.
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index cb79d3acdec..367fd66304a 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -172,7 +172,8 @@ addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
 
     // Pass to reset the MachineFunction if the ISel failed.
     PM.add(createResetMachineFunctionPass(
-        PassConfig->reportDiagnosticWhenGlobalISelFallback()));
+        PassConfig->reportDiagnosticWhenGlobalISelFallback(),
+        PassConfig->isGlobalISelAbortEnabled()));
 
     // Provide a fallback path when we do not want to abort on
     // not-yet-supported input.
diff --git a/lib/CodeGen/ResetMachineFunctionPass.cpp b/lib/CodeGen/ResetMachineFunctionPass.cpp
index 451964199ba..3e259927ac5 100644
--- a/lib/CodeGen/ResetMachineFunctionPass.cpp
+++ b/lib/CodeGen/ResetMachineFunctionPass.cpp
@@ -30,17 +30,23 @@ namespace {
     /// Tells whether or not this pass should emit a fallback
     /// diagnostic when it resets a function.
     bool EmitFallbackDiag;
+    /// Whether we should abort immediately instead of resetting the function.
+    bool AbortOnFailedISel;
 
   public:
     static char ID; // Pass identification, replacement for typeid
-    ResetMachineFunction(bool EmitFallbackDiag = false)
-        : MachineFunctionPass(ID), EmitFallbackDiag(EmitFallbackDiag) {}
+    ResetMachineFunction(bool EmitFallbackDiag = false,
+                         bool AbortOnFailedISel = false)
+        : MachineFunctionPass(ID), EmitFallbackDiag(EmitFallbackDiag),
+          AbortOnFailedISel(AbortOnFailedISel) {}
 
     StringRef getPassName() const override { return "ResetMachineFunction"; }
 
     bool runOnMachineFunction(MachineFunction &MF) override {
       if (MF.getProperties().hasProperty(
               MachineFunctionProperties::Property::FailedISel)) {
+        if (AbortOnFailedISel)
+          report_fatal_error("Instruction selection failed");
         DEBUG(dbgs() << "Reseting: " << MF.getName() << '\n');
         ++NumFunctionsReset;
         MF.reset();
@@ -62,6 +68,7 @@ INITIALIZE_PASS(ResetMachineFunction, DEBUG_TYPE,
                 "reset machine function if ISel failed", false, false)
 
 MachineFunctionPass *
-llvm::createResetMachineFunctionPass(bool EmitFallbackDiag = false) {
-  return new ResetMachineFunction(EmitFallbackDiag);
+llvm::createResetMachineFunctionPass(bool EmitFallbackDiag = false,
+                                     bool AbortOnFailedISel = false) {
+  return new ResetMachineFunction(EmitFallbackDiag, AbortOnFailedISel);
 }