llvm / llvm-project / 746e632dafbec2277c62164b3e63da4bee1d8553 / . / llvm / test / Analysis / BranchProbabilityInfo / unreachable.ll

; RUN: opt < %s -passes='print<branch-prob>' -disable-output 2>&1 | FileCheck %s | |

declare void @bar() cold | |

; Both 'l1' and 'r1' has one edge leading to 'cold' and another one to | |

; 'unreachable' blocks. Check that 'cold' paths are preferred. Also ensure both | |

; paths from 'entry' block are equal. | |

define void @test1(i32 %0) { | |

;CHECK: edge entry -> l1 probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge entry -> r1 probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge l1 -> cold probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

;CHECK: edge l1 -> unreached probability is 0x00000000 / 0x80000000 = 0.00% | |

;CHECK: edge r1 -> unreached probability is 0x00000000 / 0x80000000 = 0.00% | |

;CHECK: edge r1 -> cold probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

entry: | |

br i1 undef, label %l1, label %r1 | |

l1: | |

br i1 undef, label %cold, label %unreached | |

r1: | |

br i1 undef, label %unreached, label %cold | |

unreached: | |

unreachable | |

cold: | |

call void @bar() | |

ret void | |

} | |

; Both edges of 'l1' leads to 'cold' blocks while one edge of 'r1' leads to | |

; 'unreachable' block. Check that 'l1' has 50/50 while 'r1' has 0/100 | |

; distributuion. Also ensure both paths from 'entry' block are equal. | |

define void @test2(i32 %0) { | |

;CHECK: edge entry -> l1 probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge entry -> r1 probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge l1 -> cold probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge l1 -> cold2 probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge r1 -> unreached probability is 0x00000000 / 0x80000000 = 0.00% | |

;CHECK: edge r1 -> cold probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

entry: | |

br i1 undef, label %l1, label %r1 | |

l1: | |

br i1 undef, label %cold, label %cold2 | |

r1: | |

br i1 undef, label %unreached, label %cold | |

unreached: | |

unreachable | |

cold: | |

call void @bar() | |

ret void | |

cold2: | |

call void @bar() | |

ret void | |

} | |

; Both edges of 'r1' leads to 'unreachable' blocks while one edge of 'l1' leads to | |

; 'cold' block. Ensure that path leading to 'cold' block is preferred. | |

define void @test3(i32 %0) { | |

;CHECK: edge entry -> l1 probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

;CHECK: edge entry -> r1 probability is 0x00000000 / 0x80000000 = 0.00% | |

;CHECK: edge l1 -> cold probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

;CHECK: edge l1 -> unreached probability is 0x00000000 / 0x80000000 = 0.00% | |

;CHECK: edge r1 -> unreached probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge r1 -> unreached2 probability is 0x40000000 / 0x80000000 = 50.00% | |

entry: | |

br i1 undef, label %l1, label %r1 | |

l1: | |

br i1 undef, label %cold, label %unreached | |

r1: | |

br i1 undef, label %unreached, label %unreached2 | |

unreached: | |

unreachable | |

unreached2: | |

unreachable | |

cold: | |

call void @bar() | |

ret void | |

} | |

; Left edge of 'entry' leads to 'cold' block while right edge is 'normal' continuation. | |

; Check that we able to propagate 'cold' weight to 'entry' block. Also ensure | |

; both edges from 'l1' are equally likely. | |

define void @test4(i32 %0) { | |

;CHECK: edge entry -> l1 probability is 0x078780e3 / 0x80000000 = 5.88% | |

;CHECK: edge entry -> r1 probability is 0x78787f1d / 0x80000000 = 94.12% [HOT edge] | |

;CHECK: edge l1 -> l2 probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge l1 -> r2 probability is 0x40000000 / 0x80000000 = 50.00% | |

;CHECK: edge l2 -> to.cold probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

;CHECK: edge r2 -> to.cold probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

;CHECK: edge to.cold -> cold probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

entry: | |

br i1 undef, label %l1, label %r1 | |

l1: | |

br i1 undef, label %l2, label %r2 | |

l2: | |

br label %to.cold | |

r2: | |

br label %to.cold | |

to.cold: | |

br label %cold | |

r1: | |

ret void | |

cold: | |

call void @bar() | |

ret void | |

} | |

; Check that most likely path from 'entry' to 'l2' through 'r1' is preferred. | |

define void @test5(i32 %0) { | |

;CHECK: edge entry -> cold probability is 0x078780e3 / 0x80000000 = 5.88% | |

;CHECK: edge entry -> r1 probability is 0x78787f1d / 0x80000000 = 94.12% [HOT edge] | |

;CHECK: edge cold -> l2 probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

;CHECK: edge r1 -> l2 probability is 0x80000000 / 0x80000000 = 100.00% [HOT edge] | |

;CHECK: edge r1 -> unreached probability is 0x00000000 / 0x80000000 = 0.00% | |

entry: | |

br i1 undef, label %cold, label %r1 | |

cold: | |

call void @bar() | |

br label %l2 | |

r1: | |

br i1 undef, label %l2, label %unreached | |

l2: | |

ret void | |

unreached: | |

unreachable | |

} |