Index: lib/Analysis/BranchProbabilityInfo.cpp =================================================================== --- lib/Analysis/BranchProbabilityInfo.cpp +++ lib/Analysis/BranchProbabilityInfo.cpp @@ -322,6 +322,9 @@ InEdges.push_back(I.getSuccessorIndex()); } + if (BackEdges.empty() && ExitingEdges.empty()) + return false; + if (uint32_t numBackEdges = BackEdges.size()) { uint32_t backWeight = LBH_TAKEN_WEIGHT / numBackEdges; if (backWeight < NORMAL_WEIGHT) Index: test/Analysis/BranchProbabilityInfo/loop.ll =================================================================== --- test/Analysis/BranchProbabilityInfo/loop.ll +++ test/Analysis/BranchProbabilityInfo/loop.ll @@ -15,7 +15,7 @@ %i.0 = phi i32 [ 0, %entry ], [ %inc3, %do.end ] call void @g1() br label %do.body1 -; CHECK: edge do.body -> do.body1 probability is 124 / 124 = 100% +; CHECK: edge do.body -> do.body1 probability is 16 / 16 = 100% do.body1: %j.0 = phi i32 [ 0, %do.body ], [ %inc, %do.body1 ] @@ -55,8 +55,8 @@ %i.010 = phi i32 [ 0, %for.body.lr.ph ], [ %inc5, %for.end ] call void @g1() br i1 %cmp27, label %for.body3, label %for.end -; CHECK: edge for.body -> for.body3 probability is 62 / 124 = 50% -; CHECK: edge for.body -> for.end probability is 62 / 124 = 50% +; CHECK: edge for.body -> for.body3 probability is 20 / 32 = 62.5% +; CHECK: edge for.body -> for.end probability is 12 / 32 = 37.5% for.body3: %j.08 = phi i32 [ %inc, %for.body3 ], [ 0, %for.body ] @@ -91,8 +91,8 @@ %0 = load i32* %c, align 4 %cmp = icmp slt i32 %0, 42 br i1 %cmp, label %do.body1, label %if.end -; CHECK: edge do.body -> do.body1 probability is 62 / 124 = 50% -; CHECK: edge do.body -> if.end probability is 62 / 124 = 50% +; CHECK: edge do.body -> do.body1 probability is 16 / 32 = 50% +; CHECK: edge do.body -> if.end probability is 16 / 32 = 50% do.body1: %j.0 = phi i32 [ %inc, %do.body1 ], [ 0, %do.body ] @@ -165,7 +165,7 @@ %i.0 = phi i32 [ 0, %entry ], [ %inc4, %do.end ] call void @g1() br label %do.body1 -; CHECK: edge do.body -> do.body1 probability is 124 / 124 = 100% +; CHECK: edge do.body -> do.body1 probability is 16 / 16 = 100% do.body1: %j.0 = phi i32 [ 0, %do.body ], [ %inc, %if.end ] @@ -209,7 +209,7 @@ %i.0 = phi i32 [ 0, %entry ], [ %inc4, %do.end ] call void @g1() br label %do.body1 -; CHECK: edge do.body -> do.body1 probability is 124 / 124 = 100% +; CHECK: edge do.body -> do.body1 probability is 16 / 16 = 100% do.body1: %j.0 = phi i32 [ 0, %do.body ], [ %inc, %do.cond ] @@ -261,14 +261,14 @@ %0 = load i32* %c, align 4 %cmp1 = icmp eq i32 %0, %i.011 br i1 %cmp1, label %for.inc5, label %if.end -; CHECK: edge for.body -> for.inc5 probability is 62 / 124 = 50% -; CHECK: edge for.body -> if.end probability is 62 / 124 = 50% +; CHECK: edge for.body -> for.inc5 probability is 16 / 32 = 50% +; CHECK: edge for.body -> if.end probability is 16 / 32 = 50% if.end: call void @g1() br i1 %cmp38, label %for.body4, label %for.end -; CHECK: edge if.end -> for.body4 probability is 62 / 124 = 50% -; CHECK: edge if.end -> for.end probability is 62 / 124 = 50% +; CHECK: edge if.end -> for.body4 probability is 20 / 32 = 62.5% +; CHECK: edge if.end -> for.end probability is 12 / 32 = 37.5% for.body4: %j.09 = phi i32 [ %inc, %for.body4 ], [ 0, %if.end ] @@ -282,7 +282,7 @@ for.end: call void @g3() br label %for.inc5 -; CHECK: edge for.end -> for.inc5 probability is 124 / 124 = 100% +; CHECK: edge for.end -> for.inc5 probability is 16 / 16 = 100% for.inc5: %inc6 = add nsw i32 %i.011, 1 @@ -314,35 +314,35 @@ %i.019 = phi i32 [ 0, %for.body.lr.ph ], [ %inc14, %for.end ] call void @g1() br i1 %cmp216, label %for.body3, label %for.end -; CHECK: edge for.body -> for.body3 probability is 62 / 124 = 50% -; CHECK: edge for.body -> for.end probability is 62 / 124 = 50% +; CHECK: edge for.body -> for.body3 probability is 20 / 32 = 62.5% +; CHECK: edge for.body -> for.end probability is 12 / 32 = 37.5% for.body3: %j.017 = phi i32 [ 0, %for.body ], [ %inc, %for.inc ] %0 = load i32* %c, align 4 %cmp4 = icmp eq i32 %0, %j.017 br i1 %cmp4, label %for.inc, label %if.end -; CHECK: edge for.body3 -> for.inc probability is 62 / 124 = 50% -; CHECK: edge for.body3 -> if.end probability is 62 / 124 = 50% +; CHECK: edge for.body3 -> for.inc probability is 16 / 32 = 50% +; CHECK: edge for.body3 -> if.end probability is 16 / 32 = 50% if.end: %1 = load i32* %arrayidx5, align 4 %cmp6 = icmp eq i32 %1, %j.017 br i1 %cmp6, label %for.inc, label %if.end8 -; CHECK: edge if.end -> for.inc probability is 62 / 124 = 50% -; CHECK: edge if.end -> if.end8 probability is 62 / 124 = 50% +; CHECK: edge if.end -> for.inc probability is 16 / 32 = 50% +; CHECK: edge if.end -> if.end8 probability is 16 / 32 = 50% if.end8: %2 = load i32* %arrayidx9, align 4 %cmp10 = icmp eq i32 %2, %j.017 br i1 %cmp10, label %for.inc, label %if.end12 -; CHECK: edge if.end8 -> for.inc probability is 62 / 124 = 50% -; CHECK: edge if.end8 -> if.end12 probability is 62 / 124 = 50% +; CHECK: edge if.end8 -> for.inc probability is 16 / 32 = 50% +; CHECK: edge if.end8 -> if.end12 probability is 16 / 32 = 50% if.end12: call void @g2() br label %for.inc -; CHECK: edge if.end12 -> for.inc probability is 124 / 124 = 100% +; CHECK: edge if.end12 -> for.inc probability is 16 / 16 = 100% for.inc: %inc = add nsw i32 %j.017, 1 Index: test/Analysis/BranchProbabilityInfo/pr18705.ll =================================================================== --- /dev/null +++ test/Analysis/BranchProbabilityInfo/pr18705.ll @@ -0,0 +1,58 @@ +; RUN: opt < %s -analyze -branch-prob | FileCheck %s + +; Since neither of while.body's out-edges is an exit or a back edge, +; calcLoopBranchHeuristics should return early without setting the weights. +; calcFloatingPointHeuristics, which is run later, sets the weights. +; +; CHECK: edge while.body -> if.then probability is 20 / 32 = 62.5% +; CHECK: edge while.body -> if.else probability is 12 / 32 = 37.5% + +define void @foo1(i32 %n, i32* nocapture %b, i32* nocapture %c, i32* nocapture %d, float* nocapture readonly %f0, float* nocapture readonly %f1) { +entry: + %tobool8 = icmp eq i32 %n, 0 + br i1 %tobool8, label %while.end, label %while.body.lr.ph + +while.body.lr.ph: + %0 = sext i32 %n to i64 + br label %while.body + +while.body: + %indvars.iv = phi i64 [ %0, %while.body.lr.ph ], [ %indvars.iv.next, %if.end ] + %b.addr.011 = phi i32* [ %b, %while.body.lr.ph ], [ %b.addr.1, %if.end ] + %d.addr.010 = phi i32* [ %d, %while.body.lr.ph ], [ %incdec.ptr4, %if.end ] + %c.addr.09 = phi i32* [ %c, %while.body.lr.ph ], [ %c.addr.1, %if.end ] + %indvars.iv.next = add nsw i64 %indvars.iv, -1 + %arrayidx = getelementptr inbounds float* %f0, i64 %indvars.iv.next + %1 = load float* %arrayidx, align 4 + %arrayidx2 = getelementptr inbounds float* %f1, i64 %indvars.iv.next + %2 = load float* %arrayidx2, align 4 + %cmp = fcmp une float %1, %2 + br i1 %cmp, label %if.then, label %if.else + +if.then: + %incdec.ptr = getelementptr inbounds i32* %b.addr.011, i64 1 + %3 = load i32* %b.addr.011, align 4 + %add = add nsw i32 %3, 12 + store i32 %add, i32* %b.addr.011, align 4 + br label %if.end + +if.else: + %incdec.ptr3 = getelementptr inbounds i32* %c.addr.09, i64 1 + %4 = load i32* %c.addr.09, align 4 + %sub = add nsw i32 %4, -13 + store i32 %sub, i32* %c.addr.09, align 4 + br label %if.end + +if.end: + %c.addr.1 = phi i32* [ %c.addr.09, %if.then ], [ %incdec.ptr3, %if.else ] + %b.addr.1 = phi i32* [ %incdec.ptr, %if.then ], [ %b.addr.011, %if.else ] + %incdec.ptr4 = getelementptr inbounds i32* %d.addr.010, i64 1 + store i32 14, i32* %d.addr.010, align 4 + %5 = trunc i64 %indvars.iv.next to i32 + %tobool = icmp eq i32 %5, 0 + br i1 %tobool, label %while.end, label %while.body + +while.end: + ret void +} + Index: test/CodeGen/ARM/ifcvt-branch-weight-bug.ll =================================================================== --- test/CodeGen/ARM/ifcvt-branch-weight-bug.ll +++ test/CodeGen/ARM/ifcvt-branch-weight-bug.ll @@ -24,7 +24,7 @@ ; CHECK: BB#1: derived from LLVM BB %for.body ; CHECK: Successors according to CFG: BB#2(130023362) BB#4(62) for.body: - br i1 undef, label %for.cond.backedge, label %lor.lhs.false.i + br i1 undef, label %for.cond.backedge, label %lor.lhs.false.i, !prof !1 for.cond.backedge: %tobool = icmp eq %classL* undef, null @@ -60,3 +60,4 @@ declare void @_Z3fn1v() !0 = metadata !{metadata !"clang version 3.5"} +!1 = metadata !{metadata !"branch_weights", i32 62, i32 62}