diff options
Diffstat (limited to 'llvm/test/Analysis/BranchProbabilityInfo/loop.ll')
| -rw-r--r-- | llvm/test/Analysis/BranchProbabilityInfo/loop.ll | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/llvm/test/Analysis/BranchProbabilityInfo/loop.ll b/llvm/test/Analysis/BranchProbabilityInfo/loop.ll index 1a37a7a4659..3a1b01c000f 100644 --- a/llvm/test/Analysis/BranchProbabilityInfo/loop.ll +++ b/llvm/test/Analysis/BranchProbabilityInfo/loop.ll @@ -6,6 +6,7 @@ declare void @g1() declare void @g2() declare void @g3() declare void @g4() +declare i32 @g5() define void @test1(i32 %a, i32 %b) { entry: @@ -364,3 +365,39 @@ for.end15: call void @g4() ret void } + +; Test that an irreducible loop gets heavily weighted back-edges. +define void @test9(i32 %i, i32 %x, i32 %c) { +entry: + %tobool = icmp eq i32 %c, 0 + br i1 %tobool, label %if.end, label %midloop +; CHECK: edge entry -> if.end probability is 0x30000000 / 0x80000000 = 37.50% +; CHECK: edge entry -> midloop probability is 0x50000000 / 0x80000000 = 62.50% + +if.end: + br label %for.cond +; CHECK: edge if.end -> for.cond probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] + +for.cond: + %i.addr.0 = phi i32 [ %inc, %for.inc ], [ 0, %if.end ] + %cmp = icmp slt i32 %i.addr.0, %x + br i1 %cmp, label %midloop, label %end +; CHECK: edge for.cond -> midloop probability is 0x7c000000 / 0x80000000 = 96.88% [HOT edge] +; CHECK: edge for.cond -> end probability is 0x04000000 / 0x80000000 = 3.12% + +midloop: + %i.addr.1 = phi i32 [ %i, %entry ], [ %i.addr.0, %for.cond ] + %call1 = call i32 @g5() + %tobool2 = icmp eq i32 %call1, 0 + br i1 %tobool2, label %for.inc, label %end +; CHECK: edge midloop -> for.inc probability is 0x7c000000 / 0x80000000 = 96.88% [HOT edge] +; CHECK: edge midloop -> end probability is 0x04000000 / 0x80000000 = 3.12% + +for.inc: + %inc = add nsw i32 %i.addr.1, 1 + br label %for.cond +; CHECK: edge for.inc -> for.cond probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] + +end: + ret void +} |
