Index: lib/Target/AArch64/AArch64ConditionalCompares.cpp
===================================================================
--- lib/Target/AArch64/AArch64ConditionalCompares.cpp
+++ lib/Target/AArch64/AArch64ConditionalCompares.cpp
@@ -51,6 +51,12 @@
 static cl::opt<bool> Stress("aarch64-stress-ccmp", cl::Hidden,
                             cl::desc("Turn all knobs to 11"));
 
+// disable speculation of triangle when its tail is the only latch block
+// of this loop.
+static cl::opt<bool> DisableTriangleLatch(
+    "aarch64-ccmp-disable-triangle-latch", cl::init(false), cl::Hidden,
+    cl::desc("Disable when the tail block is a loop latch."));
+
 STATISTIC(NumConsidered, "Number of ccmps considered");
 STATISTIC(NumPhiRejs, "Number of ccmps rejected (PHI)");
 STATISTIC(NumPhysRejs, "Number of ccmps rejected (Physregs)");
@@ -867,6 +873,18 @@
     DEBUG(dbgs() << "Too many instructions to speculate.\n");
     return false;
   }
+
+  // Heuristic: If the tail is the only latch block for this loop then the
+  // compare conversion delays the loop backedge because we now execute ccmp
+  // instruction inside the critical path of the loop.
+  if (DisableTriangleLatch && Loops)
+    if (MachineLoop *ML = Loops->getLoopFor(CmpConv.Head))
+      if (MachineBasicBlock *LatchBB = ML->getLoopLatch())
+        if (LatchBB == CmpConv.Tail) {
+          DEBUG(dbgs() << "Won't speculate when tail block is a loop latch.\n");
+          return false;
+        }
+
   return true;
 }
 
Index: test/CodeGen/AArch64/aarch64-ccmp-heuristics.ll
===================================================================
--- /dev/null
+++ test/CodeGen/AArch64/aarch64-ccmp-heuristics.ll
@@ -0,0 +1,59 @@
+; RUN: llc < %s -mcpu=kryo -mtriple=aarch64--linux-gnu -verify-machineinstrs -aarch64-ccmp -aarch64-ccmp-disable-triangle-latch| FileCheck %s
+
+%struct.arc = type { i64, %struct.node*, %struct.node*, i32, %struct.arc*, %struct.arc*, i64, i64 }
+%struct.node = type { i64, i32, %struct.node*, %struct.node*, %struct.node*, %struct.node*, %struct.arc*, %struct.arc*, %struct.arc*, %struct.arc*, i64, i64, i32, i32 }
+%struct.basket = type { %struct.arc*, i64, i64 }
+
+; CHECK: foo
+; CHECK: %if.then34
+; CHECK: cmp x{{[0-9]+}}, #1
+; CHECK-NEXT: b.ge
+; CHECK: %if.then34.if.else.exit
+; CHECK: cmp w{{[0-9]+}}, #2
+; CHECK-NEXT: b.ne
+; Function Attrs: nounwind
+define void @foo() #0 {
+entry:
+  br label %for.body
+
+for.body:                                       ; preds = %for.inc, %entry
+  %arc = phi %struct.arc* [ %add.ptr60, %for.inc ], [ undef, %entry ]
+  %ident32 = getelementptr inbounds %struct.arc, %struct.arc* %arc, i64 0, i32 3
+  %ident32.load = load i32, i32* %ident32, align 8
+  %cmp33 = icmp sgt i32 %ident32.load, 0
+  br i1 %cmp33, label %if.then34, label %for.inc
+
+if.then34:                                        ; preds = %for.body
+  %cost35 = getelementptr inbounds %struct.arc, %struct.arc* %arc, i64 0, i32 0
+  %0 = load i64, i64* %cost35, align 8
+  %tail36 = getelementptr inbounds %struct.arc, %struct.arc* %arc, i64 0, i32 1
+  %1 = load %struct.node*, %struct.node** %tail36, align 8
+  %potential37 = getelementptr inbounds %struct.node, %struct.node* %1, i64 0, i32 0
+  %2 = load i64, i64* %potential37, align 8
+  %sub38 = sub nsw i64 %0, %2
+  %head39 = getelementptr inbounds %struct.arc, %struct.arc* %arc, i64 0, i32 2
+  %3= load %struct.node*, %struct.node** %head39, align 8
+  %potential40 = getelementptr inbounds %struct.node, %struct.node* %3, i64 0, i32 0
+  %4 = load i64, i64* %potential40, align 8
+  %add41 = add nsw i64 %4, %sub38
+  %cmp.i = icmp sgt i64 %add41, 0
+  br i1 %cmp.i, label %land.lhs.true.i, label %if.then34.if.else.exit
+
+land.lhs.true.i:                                  ; preds = %if.then34
+  %cmp1.i = icmp eq i32 %ident32.load, 1
+  br i1 %cmp1.i, label %if.then43, label %for.inc
+
+if.then34.if.else.exit:                      ; preds = %if.then34
+  %cmp2.i = icmp sgt i64 %add41, 0
+  %cmp4.i = icmp eq i32 %ident32.load, 2
+  %cmp4.i. = and i1 %cmp4.i, %cmp2.i
+  br i1 %cmp4.i., label %if.then43, label %for.inc
+
+if.then43:                                        ; preds = %if.then34
+  %abs_cost56 = getelementptr inbounds %struct.basket, %struct.basket* undef, i64 0, i32 2
+  br label %for.inc
+
+for.inc:                                        ; preds = %if.then43, %if.then34, %for.body
+  %add.ptr60 = getelementptr inbounds %struct.arc, %struct.arc* %arc, i64 undef
+  br label %for.body
+}