Summary: Fixes crash that could occur when a divergent terminator has an unreachable parent.
Reviewers: rampitec, nhaehnle, arsenm
Subscribers: jvesely, wdng, hiraditya, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73323
markDivergent(Term);
+ // Don't propagate divergence from unreachable blocks.
+ if (!DT.isReachableFromEntry(Term.getParent()))
+ return;
+
const auto *BranchLoop = LI.getLoopFor(Term.getParent());
// whether there is a divergent loop exit from BranchLoop (if any)
--- /dev/null
+; RUN: opt %s -mtriple amdgcn-- -analyze -divergence -use-gpu-divergence-analysis | FileCheck %s
+
+; CHECK: DIVERGENT: %tmp = cmpxchg volatile
+define amdgpu_kernel void @unreachable_loop(i32 %tidx) #0 {
+entry:
+ unreachable
+
+unreachable_loop: ; preds = %do.body.i, %if.then11
+ %tmp = cmpxchg volatile i32 addrspace(1)* null, i32 0, i32 0 seq_cst seq_cst
+ %cmp.i = extractvalue { i32, i1 } %tmp, 1
+ br i1 %cmp.i, label %unreachable_loop, label %end
+
+end: ; preds = %do.body.i51, %atomicAdd_g_f.exit
+ unreachable
+}
+
+attributes #0 = { norecurse nounwind }