[Polly] Reject regions entered by an indirectbr/callbr.
SplitBlockPredecessors is unable to insert an additional BasicBlock
between an indirectbr/callbr terminator and the successor blocks.
This is needed by Polly to normalize the control flow before emitting
its optimzed code.
This patches rejects regions entered by an indirectbr/callbr to not fail
later at code generation.
This fixes llvm.org/PR51964
Recommit with "REQUIRES: asserts" in test that uses statistics.
GitOrigin-RevId: 027c036663322d753e2dce6ad8d568d4e046b267
diff --git a/include/polly/ScopDetectionDiagnostic.h b/include/polly/ScopDetectionDiagnostic.h
index 200fb8f..f4c2ee4 100644
--- a/include/polly/ScopDetectionDiagnostic.h
+++ b/include/polly/ScopDetectionDiagnostic.h
@@ -73,6 +73,7 @@
InvalidTerminator,
IrreducibleRegion,
UnreachableInExit,
+ IndirectPredecessor,
LastCFG,
// Non-Affinity
@@ -276,6 +277,32 @@
};
//===----------------------------------------------------------------------===//
+/// Captures regions with an IndirectBr predecessor.
+class ReportIndirectPredecessor : public ReportCFG {
+ Instruction *Inst;
+ DebugLoc DbgLoc;
+
+public:
+ ReportIndirectPredecessor(Instruction *Inst, DebugLoc DbgLoc)
+ : ReportCFG(RejectReasonKind::IndirectPredecessor), Inst(Inst),
+ DbgLoc(DbgLoc) {}
+
+ /// @name LLVM-RTTI interface
+ //@{
+ static bool classof(const RejectReason *RR);
+ //@}
+
+ /// @name RejectReason interface
+ //@{
+ std::string getRemarkName() const override;
+ const Value *getRemarkBB() const override;
+ std::string getMessage() const override;
+ std::string getEndUserMessage() const override;
+ const DebugLoc &getDebugLoc() const override;
+ //@}
+};
+
+//===----------------------------------------------------------------------===//
/// Base class for non-affine reject reasons.
///
/// Scop candidates that violate restrictions to affinity are reported under
diff --git a/lib/Analysis/ScopDetection.cpp b/lib/Analysis/ScopDetection.cpp
index bf9d7ab..aab8741 100644
--- a/lib/Analysis/ScopDetection.cpp
+++ b/lib/Analysis/ScopDetection.cpp
@@ -1757,6 +1757,13 @@
return false;
}
+ for (BasicBlock *Pred : predecessors(CurRegion.getEntry())) {
+ Instruction *PredTerm = Pred->getTerminator();
+ if (isa<IndirectBrInst>(PredTerm) || isa<CallBrInst>(PredTerm))
+ return invalid<ReportIndirectPredecessor>(
+ Context, /*Assert=*/true, PredTerm, PredTerm->getDebugLoc());
+ }
+
// SCoP cannot contain the entry block of the function, because we need
// to insert alloca instruction there when translate scalar to array.
if (!PollyAllowFullFunction &&
diff --git a/lib/Analysis/ScopDetectionDiagnostic.cpp b/lib/Analysis/ScopDetectionDiagnostic.cpp
index a324285..0bac2cf 100644
--- a/lib/Analysis/ScopDetectionDiagnostic.cpp
+++ b/lib/Analysis/ScopDetectionDiagnostic.cpp
@@ -50,8 +50,9 @@
static Statistic RejectStatistics[] = {
SCOP_STAT(CFG, ""),
SCOP_STAT(InvalidTerminator, "Unsupported terminator instruction"),
- SCOP_STAT(UnreachableInExit, "Unreachable in exit block"),
SCOP_STAT(IrreducibleRegion, "Irreducible loops"),
+ SCOP_STAT(UnreachableInExit, "Unreachable in exit block"),
+ SCOP_STAT(IndirectPredecessor, "Branch from indirect terminator"),
SCOP_STAT(LastCFG, ""),
SCOP_STAT(AffFunc, ""),
SCOP_STAT(UndefCond, "Undefined branch condition"),
@@ -240,6 +241,37 @@
}
//===----------------------------------------------------------------------===//
+// IndirectPredecessor.
+
+std::string ReportIndirectPredecessor::getRemarkName() const {
+ return "IndirectPredecessor";
+}
+
+const Value *ReportIndirectPredecessor::getRemarkBB() const {
+ if (Inst)
+ return Inst->getParent();
+ return nullptr;
+}
+
+std::string ReportIndirectPredecessor::getMessage() const {
+ if (Inst)
+ return "Branch from indirect terminator: " + *Inst;
+ return getEndUserMessage();
+}
+
+const DebugLoc &ReportIndirectPredecessor::getDebugLoc() const {
+ return DbgLoc;
+}
+
+std::string ReportIndirectPredecessor::getEndUserMessage() const {
+ return "Branch from indirect terminator.";
+}
+
+bool ReportIndirectPredecessor::classof(const RejectReason *RR) {
+ return RR->getKind() == RejectReasonKind::IndirectPredecessor;
+}
+
+//===----------------------------------------------------------------------===//
// ReportIrreducibleRegion.
std::string ReportIrreducibleRegion::getRemarkName() const {
diff --git a/test/ScopDetect/callbr.ll b/test/ScopDetect/callbr.ll
new file mode 100644
index 0000000..1981f01
--- /dev/null
+++ b/test/ScopDetect/callbr.ll
@@ -0,0 +1,39 @@
+; RUN: opt %loadPolly -polly-detect -polly-detect-track-failures -disable-output -pass-remarks-missed=polly-detect < %s 2>&1 | FileCheck %s --check-prefix=REMARK
+; RUN: opt %loadPolly -polly-detect -polly-detect-track-failures -disable-output -stats < %s 2>&1 | FileCheck %s --check-prefix=STAT
+; REQUIRES: asserts
+
+; REMARK: Branch from indirect terminator.
+
+; STAT: 1 polly-detect - Number of rejected regions: Branch from indirect terminator
+
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @func(i32 %n, double* noalias nonnull %A) {
+entry:
+ callbr void asm sideeffect "", "X,~{dirflag},~{fpsr},~{flags}"(i8* blockaddress(@func, %for)) #1
+ to label %fallthrough [label %for]
+
+fallthrough:
+ br label %for
+
+for:
+ %j = phi i32 [0, %entry], [0, %fallthrough], [%j.inc, %inc]
+ %j.cmp = icmp slt i32 %j, %n
+ br i1 %j.cmp, label %body, label %exit
+
+ body:
+ store double 42.0, double* %A
+ br label %inc
+
+inc:
+ %j.inc = add nuw nsw i32 %j, 1
+ br label %for
+
+exit:
+ br label %return
+
+return:
+ ret void
+}
