0df0906af6
In case the same src BB targets to the same dest BB in different conditions/edges, such as switch-cases, we should use prob[SrcBB->SuccIndx] instead of prob[SrcBB->DstBB] to get probability.
43 lines
1.6 KiB
LLVM
43 lines
1.6 KiB
LLVM
; RUN: opt -debug-only=branch-prob -passes=jump-threading -S %s 2>&1 | FileCheck %s
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; REQUIRES: asserts
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; Make sure that edges' probabilities would not accumulate if they are
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; the same target BB.
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; Edge L0 -> 2 and L0 -> 3 's targets are both L2, but their respective
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; probability should not be L0 -> L2, because prob[L0->L2] equls to
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; prob[L0->2] + prob[L0->3]
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; CHECK: Computing probabilities for entry
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; CHECK: eraseBlock L0
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; CHECK-NOT: set edge L0 -> 0 successor probability to 0x12492492 / 0x80000000 = 14.29%
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; CHECK-NOT: set edge L0 -> 1 successor probability to 0x24924925 / 0x80000000 = 28.57%
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; CHECK-NOT: set edge L0 -> 2 successor probability to 0x24924925 / 0x80000000 = 28.57%
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; CHECK-NOT: set edge L0 -> 3 successor probability to 0x24924925 / 0x80000000 = 28.57%
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; CHECK: set edge L0 -> 0 successor probability to 0x1999999a / 0x80000000 = 20.00%
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; CHECK: set edge L0 -> 1 successor probability to 0x33333333 / 0x80000000 = 40.00%
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; CHECK: set edge L0 -> 2 successor probability to 0x1999999a / 0x80000000 = 20.00%
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; CHECK: set edge L0 -> 3 successor probability to 0x1999999a / 0x80000000 = 20.00%
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; CHECK-NOT: !0 = !{!"branch_weights", i32 306783378, i32 613566757, i32 613566757, i32 613566757}
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; CHECK: !0 = !{!"branch_weights", i32 429496730, i32 858993459, i32 429496730, i32 429496730}
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define void @test_switch(i1 %cond, i8 %value) nounwind {
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entry:
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br i1 %cond, label %L0, label %L4
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L0:
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%expr = select i1 %cond, i8 1, i8 %value
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switch i8 %expr, label %L3 [
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i8 1, label %L1
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i8 2, label %L2
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i8 3, label %L2
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], !prof !0
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L1:
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ret void
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L2:
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ret void
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L3:
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ret void
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L4:
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br label %L0
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}
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!0 = !{!"branch_weights", i32 1, i32 7, i32 1, i32 1}
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